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Purpose: This study aimed to investigate whether vitamin K 2 (menatetrenone) suppresses bone mineral density (BMD) loss in the irradiated region after radiotherapy (RT) in uterine cancer patients., Materials and Methods: Our study included 34 patients who underwent whole pelvic irradiation for uterine cancer between 2001 and 2010. The patients were categorized in two groups: (1) Vitamin K 2 (45 mg/day) administration group (group A) with 18 cases and (2) non-administered group (group B) with 16 cases. The duration of vitamin K 2 administration was 1 year or longer. BMD was measured before and immediately, 3 months, 6 months, 1 year, 1 year or more after RT., Results: Regarding change rate in the BMD of L3-L4 which was outside the irradiated field, no significant changes were observed in BMD after radiation in either groups compared to BMD before radiotherapy. Regarding change rate in BMD of L5-S1 which was inside the irradiated field, BMD reduced significantly at 6 months after radiotherapy compared to BMD before the start of radiotherapy in Group B (P = 0.0234). However, no significant change was seen in group A. Grade 2 and 3 insufficiency fractures appeared in both groups, one in each. Regarding outside the irradiation field, one patient developed compression fracture in L2 in group B, none occurred in group A . CONCLUSION: We suggest that vitamin K 2 could suppress the decrease in BMD due to whole pelvic radiotherapy. Further studies are needed in the future to improve quality of life such as the prevention of insufficiency fractures., Competing Interests: Declarations. Conflict of interest: The authors state that there are no conflicts of interest. Ethical approval: This study has been approved by Institutional Review Board of Hiroshima University (Clinical Trial Registration number: E-1836). Patient identifiers were removed, and this study was conducted in accordance with the Declaration of Helsinki. Informed consent: Informed consent was obtained from all individual participants included in the study., (© 2025. The Author(s).)

Objective. While the biological effective dose (BED) has been used to estimate the damage to tumor cells in radiotherapy, BED does not consider intrafractional interruption (IFI) occurring during irradiation. We aim to develop a framework to evaluate the decrease in BED [ΔBED] and to create a plan compensating for the decrease by IFI. Approach. ΔBEDwas calculated using a model based on the microdosimetric kinetic model (MKM) for four brain tumor cases treated using a volumetric-modulated arc therapy. Four biologically compensated plans (BCPs) were created in the treatment planning system by a single-time optimization using a base plan consideringΔBEDcreated in in-house software and optimization objectives for the original clinically delivered plan to achieve a homogeneous BED distribution within the planning target volume (PTV). The BED-volume histogram was evaluated for non-compensated plan and BCP with different timepoint of interruption, a percentage of gantry rotation angle (GRA) before interruption in planned GRA,ηand duration of interruptionτ. Characteristics of the dose accumulation were analyzed for different collimator angle sets, Plan A (10°, 85°) and Plan B (45° and 315°), for the first case. Main Results. Hot spots in theΔBEDdistribution forη= 25%, 50%, and 75% were observed at superior-and-interior ends, central region, and peripheral region in PTV, respectively. These behaviors could be understood by characteristics of the MKM-based model producing maximumΔBEDat 50% of the dose accumulation.ΔBED50%ranged 4.5%-6.6%, 5.0%-7.3%, and 5.3%-7.7% forτ= 60, 90, and 120 min, respectively. Plan A showed fast dose accumulation at superior and inferior edges while slow on peripheries in the lateral dose profile. Plan B showed more homogeneous PD distributions than Plan A during irradiation. Significance. The developed framework successfully evaluated and compensated for the decreased BED distribution., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Objectives: To propose a radiomics-based prediction model for head and neck squamous cell carcinoma (HSNCC) recurrence after radiation therapy using a novel data imbalance correction method known as Gaussian noise upsampling (GNUS)., Materials and Methods: The dataset includes 97 HNSCC patients treated with definitive radiotherapy alone or concurrent chemoradiotherapy at two institutions. We performed radiomics analysis using nine segmentations created on pretreatment positron emission tomography and computed tomography images. Feature selection was performed by the least absolute shrinkage and selection operator analysis via five-fold cross-validation. The proposed GNUS was compared with seven conventional data-imbalance correction methods. Classification models of HNSCC recurrence were constructed on oversampled features using the machine learning algorithms of linear regression. Their predictive performance was evaluated based on accuracy, sensitivity, specificity, and the area under the curve (AUC) of the receiver operating performance characteristic curve via five-fold cross-validation using the same combinations as for feature selection., Result: The prediction model without data imbalance correction shows sensitivity, specificity, accuracy, and AUC values of 83 %, 96 %, 92 %, and 0.96, respectively. The conventional model with the best performance is the random over-sampler model, which shows sensitivity, specificity, accuracy, and AUC values of 93 %, 91 %, 92 %, 0.97, respectively, whereas the GNUS model shows values of 93 %, 94 %, 94 %, 0.98, respectively., Conclusion: Oversampling methods can reduce sensitivity and specificity bias. The proposed GNUS can improve accuracy as well as reduce sensitivity and specificity bias., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Objectives: To propose a nomogram-based survival prediction model for esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy using pretreatment computed tomography (CT), positron emission tomography (PET) radiomics and dosiomics features, and common clinical factors., Methods: Radiomics and dosiomics features were extracted from CT and PET images and dose distribution from 2 institutions. The least absolute shrinkage and selection operator (LASSO) with logistic regression was used to select radiomics and dosiomics features by calculating the radiomics and dosiomics scores (Rad-score and Dos-score), respectively, in the training model. The model was trained in 81 patients and validated in 35 patients at Center 1 using 10-fold cross validation. The model was externally tested in 26 patients at Center 2. The predictive clinical factors, Rad-score, and Dos-score were identified to develop a nomogram model., Results: Using LASSO Cox regression, 13, 11, and 19 CT, PET-based radiomics, and dosiomics features, respectively, were selected. The clinical factors T-stage, N-stage, and clinical stage were selected as significant prognostic factors by univariate Cox regression. In the external validation cohort, the C-index of the combined model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were 0.74, 0.82, and 0.92, respectively. Significant differences in overall survival (OS) in the combined model of CT-based radiomics, PET-based radiomics, and dosiomics features with clinical factors were observed between the high- and low-risk groups (P = 0.019, 0.038, and 0.014, respectively)., Conclusion: The dosiomics features have a better predicter for OS than CT- and PET-based radiomics features in ESCC treated with radiotherapy., Clinical Relevance Statement: The current study predicted the overall survival for esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy. The dosiomics features have a better predicter for overall survival than CT- and PET-based radiomics features., (Copyright © 2024 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Background/aim: This study aimed to evaluate the long-term prognosis of definitive chemoradiotherapy and clinical features of postoperative lymph node (LN) recurrence after curative resection of thoracic esophageal squamous cell cancer (ESCC)., Patients and Methods: A total of 586 patients who underwent radical resection of ESCC at the Hiroshima University Hospital from January 2000 to December 2019 were reviewed retrospectively. This study analyzed the clinical characteristics of 54 patients who developed recurrence in a solitary LN by comparing them to 182 patients who experienced total recurrence. Additionally, we analyzed the prognostic factors of 50 patients who received chemo-radiotherapy (CRT)., Results: The results revealed a tendency for a higher incidence of solitary LN recurrence in cases of early esophageal cancer and upper thoracic esophageal cancer among all recurrence cases. The 3-, 5-, and 7-year overall survival (OS) rates were 40.5%, 37.8% and 34.6%, respectively, with a median survival time of 27.9 months. Univariate analysis of OS factors, such as age, depth of the primary tumor at the initial surgery, time to LN recurrence after surgery, site of LN recurrence, and the number of the regional LNs with recurrence showed no significant impact on OS., Conclusion: Approximately 35% of patients with ESCC who experienced LN recurrence after curative resection achieved long-term survival through CRT. Despite the absence of identifiable prognostic factors, CRT proves to be a valuable initial treatment option for LN recurrence., Competing Interests: The Authors declare no conflicts of interest that may have influenced the results of this study., (Copyright 2024, International Institute of Anticancer Research.)

Objectives: Low-dose-rate brachytherapy (LDR-BT) with 198 Au grains and 192 Ir pins is an essential treatment option for oral cancer due to its high rate of local control and low invasiveness. However, the radiation exposure of medical radiation workers is concerning. Thus, we aimed to determine the radiation dose delivered to medical radiation workers during LDR-BT using 198 Au grains and 192 Ir pins for oral cancer., Methods: Thirty-two patients with oral cancer underwent 198 Au grain interstitial LDR-BT between June 2016 and May 2023, and 23 patients with tongue cancer underwent 192 Ir pin interstitial LDR-BT between March 2015 and November 2017 at our hospital. Dosimetry was performed by attaching a dosimeter to the chest pocket of the operator and assistant during 198 Au grain or 192 Ir pin LDR-BT. Since the operator also loads 198 Au grains into the implantation device, the operator's radiation dose includes the dose received during this preparation., Results: Mean radiation doses of the operators with 198 Au grain and 192 Ir pin LDR-BT were 165.8 and 211.2 μSv, respectively. Statistically significant differences between the radioactive sources of 198 Au grain and 192 Ir pin LDR-BT were observed (p = 0.0459). The mean radiation doses of the assistants with 198 Au grain and 192 Ir pin LDR-BT were 92.0 and 162.0 μSv, respectively. Statistically significant differences were observed between the radioactive sources of 198 Au grains and 192 Ir pin LDR-BT (p = 0.0003)., Conclusions: Regarding radioactive source differences, 192 Ir pin LDR-BT resulted in higher doses delivered to medical radiation workers than 198 Au grain LDR-BT., (© 2023. The Author(s) under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology.)

Background: Pathological lymph node metastasis (LNM) following multimodal therapy is an important indicator of poor prognosis in patients with esophageal cancer. However, a significant number of patients without LNM are still at high risk for recurrence., Methods: We assessed prognostic factors in 143 patients without pathological LNM who were diagnosed with locally advanced esophageal squamous cell carcinoma (ESCC) and underwent neoadjuvant chemotherapy (NAC) or chemoradiotherapy (NACRT), followed by surgery., Results: Using univariate and multivariate analyses of recurrence-free survival, carcinoembryonic antigen (CEA) levels (hazard ratio [HR]: 2.17, 95% confidence interval [CI]: 1.12-4.23, and p = 0.02) and neutrophil-to-lymphocyte ratio (NLR) (HR: 1.22, 95% CI: 1.04-1.43, and p = 0.02) were significant independent covariates. Furthermore, pretherapeutic LNM (HR: 1.94, 95% CI: 1.003-3.76, and p = 0.049), NACRT (HR: 3.29, 95% CI: 1.30-8.33, and p = 0.01), poorly differentiated tumors (HR: 2.52, 95% CI: 1.28-4.98, and p = 0.01), and lymphovascular invasion (LVI) (HR: 2.78, 95% CI: 1.27-6.09, and p = 0.01) were also significant independent covariates. The recurrence rates among patients with 0/1, 2, 3, and 4/5 poor prognostic factors were significantly different (5.0%, 25.0%, 35.7%, and 53.8%, respectively; p = 0.001); the survival rates were stratified among these prognostic groups., Conclusions: Pretherapeutic CEA and NLR levels, pretherapeutic LNM, NACRT, poorly differentiated tumors, and LVI were significantly correlated with survivals in patients without pathological LNM after neoadjuvant therapy and surgery. Postoperative therapy should be considered in patients with ESCC with several indicators of recurrence, even in those without pathological LNM who underwent surgery following neoadjuvant therapy., (© 2023 International Society of Surgery/Société Internationale de Chirurgie (ISS/SIC).)

Objectives: To develop a multi-institutional prediction model to estimate the local response to oesophageal squamous cell carcinoma (ESCC) treated with definitive radiotherapy based on radiomics and dosiomics features., Methods: The local responses were categorised into two groups (incomplete and complete). An external validation model and a hybrid model that the patients from two institutions were mixed randomly were proposed. The ESCC patients at stages I-IV who underwent chemoradiotherapy from 2012 to 2017 and had follow-up duration of more than 5 years were included. The patients who received palliative or pre-operable radiotherapy and had no FDG PET images were excluded. The segmentations included the GTV, CTV, and PTV which are used in treatment planning. In addition, shrinkage, expansion, and shell regions were created. Radiomic and dosiomic features were extracted from CT, FDG PET images, and dose distribution. Machine learning-based prediction models were developed using decision tree, support vector machine, k-nearest neighbour (kNN) algorithm, and neural network (NN) classifiers., Results: A total of 116 and 26 patients enrolled at Centre 1 and Centre 2, respectively. The external validation model exhibited the highest accuracy with 65.4% for CT-based radiomics, 77.9% for PET-based radiomics, and 72.1% for dosiomics based on the NN classifiers. The hybrid model exhibited the highest accuracy of 84.4% for CT-based radiomics based on the kNN classifier, 86.0% for PET-based radiomics, and 79.0% for dosiomics based on the NN classifiers., Conclusion: The proposed hybrid model exhibited promising predictive performance for the local response to definitive radiotherapy in ESCC patients., Clinical Relevance Statement: The prediction of the complete response for oesophageal cancer patients may contribute to improving overall survival. The hybrid model has the potential to improve prediction performance than the external validation model that was conventionally proposed., Key Points: • Radiomics and dosiomics used to predict response in patients with oesophageal cancer receiving definitive radiotherapy. • Hybrid model with neural network classifier of PET-based radiomics improved prediction accuracy by 8.1%. • The hybrid model has the potential to improve prediction performance., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Objective: This study evaluated the prognostic impact of the quality of dose distribution using dosiomics in patients with prostate cancer, stratified by pretreatment prostate-specific antigen (PSA) levels and Gleason grade (GG) group., Methods: A total of 721 patients (Japanese Foundation for Cancer Research [JFCR] cohort: N = 489 and Tokyo Radiation Oncology Clinic [TROC] cohort: N = 232) with localized prostate cancer treated by intensity-modulated radiation therapy were enrolled. Two predictive dosiomic features for biochemical recurrence (BCR) were selected and patients were divided into certain groups stratified by pretreatment PSA levels and GG. Freedom from biochemical failure (FFBF) was estimated using the Kaplan-Meier method based on each dosiomic feature and univariate discrimination was evaluated using the log-rank test. As an exploratory analysis, a dosiomics hazard (DH) score was developed and its prognostic power for BCR was examined., Results: The dosiomic feature extracted from planning target volume (PTV) significantly distinguished the high- and low-risk groups in patients with PSA levels >10 ng/mL (7-year FFBF: 86.7% vs 76.1%, P < .01), GG 4 (92.2% vs 76.9%, P < .01), and GG 5 (83.1% vs 77.8%, P = .04). The DH score showed significant association with BCR (hazard score: 2.04; 95% confidence interval: 1.38-3.01; P < .001)., Conclusion: The quality of planned dose distribution on PTV may affect the prognosis of patients with poor prognostic factors, such as PSA levels >10 ng/mL and higher GGs., Advances in Knowledge: The effects of planned dose distribution on prognosis differ depending on the patient's clinical background., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Esophageal fistula (EF) is a serious complication in patients with cT4b esophageal squamous cell carcinoma (ESCC) with adjacent organ involvement. Among EFs, aortoesophageal fistula (AEF), forming a fistula with the aorta, could be fatal. This study aimed to identify the risk factors for AEF in patients with cT4b ESCC with obvious or suspected aortic invasion who underwent definitive radiotherapy (DRT)., Methods: Forty-four patients with cT4b ESCC with obvious or suspected invasion to the aorta who underwent DRT were included. Blood tests and computed tomography (CT) findings before and after DRT were compared between the patients with and without AEF to identify the potential risk factors for AEF., Results: Nine patients (20.5%) developed AEF after DRT. Comparing between patients with and without AEF, pre-DRT white blood cell counts and post-DRT C-reactive protein (CRP) levels were significantly higher in patients with AEF. Furthermore, pre-DRT CT findings were similar between the two groups. However, post-DRT CT findings demonstrated significantly larger picus angle and lower esophageal wall thickness on the aortic side in patients with AEF. Multivariate analysis identified elevated post-DRT CRP levels [<3.3 versus ≥3.3 mg/dL; odds ratio (OR): 30.7; 95% confidence interval (CI): 2.92-323.2; P=0.004] and esophageal wall thinning on post-DRT CT scans (>6 versus ≤6 mm; OR: 13.2; 95% CI: 1.24-140.1; P=0.033) as risk factors for AEF., Conclusions: We found that post-DRT esophageal wall thinning on the aortic side, as observed on CT scans, and elevated CRP levels were predictive factors for AEF in patients with cT4b ESCC with obvious or suspected invasion to the aorta., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-23-848/coif). The authors have no conflicts of interest to declare., (2023 Journal of Thoracic Disease. All rights reserved.)

Background and Purpose: The diaphragm respiratory motion (RM) could impact the target dose robustness in the lower esophageal cancer (EC). We aimed to develop a framework evaluating the impact of different RM patterns quantitatively in one patient, by creating virtual four-dimensional computed-tomography (v4DCT) images, which could lead to tailored treatment for the breathing pattern. We validated virtual 4D radiotherapy (v4DRT) along with exploring the acceptability of free-breathing volumetric modulated arc therapy (FB-VMAT)., Methods and Materials: We assessed 10 patients with superficial EC through their real 4DCT (r4DCT) scans. v4DCT images were derived from the end-inhalation computed tomography (CT) image (reference CT) and the v4DRT dose was accumulated dose over all phases. r4DRT diaphragm shifts were applied with magnitudes derived from r4DCT scans; clinical target volume (CTV) dose of v4DRT was compared with that of r4DRT to validate v4DRT. CTV dosage modifications and planning organ at risk volume (PRV) margins of the spinal cord were examined with the diaphragm movement. The percentage dose differences (ΔDx) were determined between the v4DRT and the dose calculated on the reference CT image., Results: The CTV ΔDx between the r4DRT and v4DRT were within 1% in cases with RM ≦ 15 mm. The average ΔD 100% and ΔD mean of the CTV ranging from 5 to 15 mm of diaphragm motion was 0.3% to 1.7% and 0.1% to 0.4%, respectively. All CTV index changes were within 3% and ΔD 1cc and ΔD 2cc of Cord PRV were within 1%., Conclusion: We postulate a novel method for evaluating the CTV robustness, comparable to the conventional r4DCT method under the diaphragm RM ≦ 15 mm permitting an impact of within 3% in FB-VMAT for EC on the CTV dose distribution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Self-care demonstrated efficacy in preventing severe acute radiation dermatitis among patients with head and neck squamous cell carcinoma undergoing chemoradiotherapy (CRT). This prospective trial aimed to confirm the feasibility and safety of transcutaneous electrical sensory stimulation while examining the relationship between changes in self-care behavior through supportive care interventions and the severity of acute radiation dermatitis during CRT. Patients underwent assessments for dermatitis grading (Grades 1 to ≥3) and were interviewed regarding self-care practices. The self-care questionnaires comprised six items, and a point was deducted for each task that the patient could not perform independently. Statistical analysis was performed to determine the association between G3 radiation dermatitis and the lowest self-care behavior scores. Of the 10 patients enrolled, three experienced G3 dermatitis. During CRT, six patients maintained their initial scores and did not develop ≥G3 dermatitis. Meanwhile, three of four patients with decreased scores exhibited ≥G3 dermatitis. The group with ≥G3 dermatitis had significantly lower scores than those with ≤G2 dermatitis, suggesting that the inability of patients to perform self-care routinely may lead to severe acute radiation dermatitis. Further prospective studies are needed to confirm the potential of self-care interventions in preventing severe dermatitis.

Background/aim: With the prevalence of COVID-19, the importance of short-course radiotherapy (RT) in many cancers has been discussed. The aim of this study was to evaluate the results of hypofractionated schedule RT for localized gastric mucosa-associated lymphoid tissue (MALT) lymphoma., Patients and Methods: We assessed 45 patients with localized gastric MALT lymphoma who underwent RT between 2005 and 2019. The total RT dose ranged from 24-36 Gy in 10-18 fractions (median of 28 Gy/14 fractions). Patients were divided into three groups according to the dose fractionation: Group A, 30-36 Gy in 15-18 fractions; Group B, 26-28 Gy in 13-14 fractions; and Group C, 24-25 Gy in 10 fractions., Results: All the patients achieved complete remission without local recurrence. The 5-year overall, cause-specific, and progression-free survival rates were 97.5%, 100%, and 97.5%, respectively, with a median follow-up period of 82 months. Among the dose fractionation groups, there were no statistically significant differences in local control or incidence of grade 2 or worse adverse events., Conclusion: Results of RT for localized gastric MALT lymphoma showed excellent local control and survival with no serious adverse events, regardless of dose fractionation. In situations where short-term RT is required, a hypofractionated RT schedule of 24-25 Gy in 10 fractions could be an option for RT schedules., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Previous meta-analysis of conventional radiation therapy for painful bone metastases showed overall response (OR) rates of 72% to 75% (evaluable patients), 61% to 62% (intent-to-treat patients) for initial radiation therapy, and 68% for reirradiation (evaluable patients). However, the definition of pain response differed among the studies included. Hence, we conducted a systematic review and meta-analysis to determine the pain response rates assessed by the International Consensus Pain Response Endpoints (ICPRE) for both initial radiation therapy and reirradiation. The PubMed and Scopus databases were searched for articles published between 2002 and 2021. The inclusion criteria were (1) prospective studies or studies based on prospectively collected data and (2) studies in which pain response was assessed using ICPRE. Our primary outcomes of interest were the OR rates (sum of the complete and partial response rates) for both initial radiation therapy and reirradiation. Of the 6470 articles identified in our database search, 32 and 3 met the inclusion criteria for the analysis of initial radiation therapy and reirradiation, respectively. The OR rates of initial radiation therapy in evaluable patients (n = 4775) and intent-to-treat patients (n = 6775) were 60.4% (95% confidence interval [CI], 55.2-65.4) and 45.4% (95% CI, 38.7-52.4), respectively. The OR rates of reirradiation in evaluable patients (n = 733) and intent-to-treat patients (n = 1085) were 70.8% (95% CI, 15.7-96.9) and 62.2% (95% CI, 5.3-98.0), respectively. Subgroup analyses of initial radiation therapy including the comparison of randomized and nonrandomized studies showed no significant differences in any comparison, indicating similar response rates across different study designs. For initial radiation therapy, we determined the ICPRE-assessed response rates, which were lower than previously reported. The OR and complete response rates should be benchmarks for future randomized and nonrandomized studies. For reirradiation, the wide CIs demonstrate that the response rates based on ICPRE require further investigation., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Definitive chemoradiotherapy (DCRT) is a curative treatment option for cT1bN0M0 esophageal squamous cell carcinoma (ESCC); however, local residual disease and recurrence after complete remission may occur. We aimed to identify endoscopic findings associated with the risk of non-radical cure (local remnant or recurrence) after DCRT for cT1bN0M0 ESCC., Methods: We retrospectively analyzed 40 consecutive patients with cT1bN0M0 ESCC who had undergone DCRT between January 2007 and December 2017. We examined the endoscopic findings in patients with residual or recurrent (RR) disease (RR group) and those without RR disease [non-RR (NRR) group] after DCRT. We also evaluated outcomes after DCRT for each endoscopic finding., Results: There were 10 patients in the RR group and 30 patients in the NRR group. The RR group had a significantly larger tumor size and a higher proportion of lesions with type 0-I. The 5-year relapse-free survival rate was significantly lower in type 0-I and in the presence of B3 vessels. Endoscopic findings in 15 patients with cT1bN0M0 ESCC, type 0-I, who underwent DCRT revealed significantly more reddish lesions in the RR group compared to the NRR group., Conclusions: cT1bN0M0 ESCC large size, with B3 vessels, and type 0-I has a high risk of non-radical cure after DCRT, especially the reddish type 0-I, which may need to be considered for treatment similar to advanced cancer, including surgery with preoperative DCRT., (© 2023. The Author(s) under exclusive licence to The Japan Esophageal Society.)

Background/aim: The aim of this study was to investigate the use of spacers and their efficacy in brachytherapy with 198 Au grains for buccal mucosa cancer., Patients and Methods: Sixteen patients with squamous cell carcinoma of the buccal mucosa who were treated with 198 Au grain brachytherapy were included. The distance between 198 Au grains, distance between 198 Au grains and the maxilla or mandible, and the maximum dose/cc to the jawbone (D1cc) with and without a spacer was investigated in three out of 16 patients., Results: The median distance between 198 Au grains without and with a spacer was 7.4 and 10.7 mm, respectively; this was significantly different. The median distance between 198 Au grains and the maxilla without and with a spacer was 10.3 and 18.5 mm, respectively; again this was significantly different. The median distance between 198 Au grains and the mandible without and with a spacer was 8.6 and 17.3 mm, respectively; the difference was significant. The D1cc to the maxilla without and with a spacer were 14.9, 68.7, and 51.8 Gy and 7.5, 21.2, and 40.7 Gy in cases 1, 2, and 3, respectively. The D1cc to the mandible without and with a spacer were 27.5, 68.7, and 85.8 Gy and 11.3, 53.6, and 64.9 Gy in cases 1, 2, and 3, respectively. No osteoradionecrosis of the jaw bones was observed in any case., Conclusion: The spacer enabled maintenance of the distance between 198 Au grains, and between 198 Au grains and the jawbone. In buccal mucosa cancer, using a spacer in brachytherapy with 198 Au grains appears to reduce jawbone complications., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: We evaluated the long-term results of definitive chemoradiotherapy (CRT) with elective nodal irradiation (ENI) using a three-dimensional (3D) planning system for resectable, locally advanced esophageal squamous cell carcinoma (LA-ESCC)., Methods: This retrospective study included 65 patients with LA-ESCC who started CRT between 2006 and 2017. Patients with Stage I-IV LA-ESCC according to the Union for International Cancer Control TNM classification (eighth edition) were included. In stage IV, only supraclavicular lymph node (LN) metastasis was included. All patients received radiotherapy with ENI and concurrent chemotherapy with platinum and 5-fluorouracil., Results: The median age of the patients was 70 years (range 52-83 years). Stage I, II, III, and IV diseases were observed in 3 (5%), 28 (43%), 22 (34%), and 12 patients (18%), respectively. The median prescription dose was 66 Gy (range 50.4-66 Gy). The median follow-up period for the survivors was 71 months (range 8-175 months). The 5-year overall survival (OS) and progression-free survival rates were 54 and 43%, respectively. The 5-year OS rates for stages I-II and III-IV were 67 and 42%, respectively. Recurrence occurred in 29 patients (45%), and recurrence of regional LNs only occurred in 2 patients (3%). Grade 3 or higher late adverse events were observed in 8 patients (12%). Grade 5 heart failure occurred in two patients (3%); both had cardiovascular disease before treatment., Conclusion: The long-term results of definitive CRT with ENI for resectable LA-ESCC were favorable. ENI with a 3D planning system may reduce regional LN recurrence and late adverse events., (© 2023. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

We report on a compact two-electrode voltage clamping system composed of microfabricated electrodes and a fluidic device for Xenopus laevis oocytes. The device was fabricated by assembling Si-based electrode chips and acrylic frames to form fluidic channels. After the installation of Xenopus oocytes into the fluidic channels, the device can be separated in order to measure changes in oocyte plasma membrane potential in each channel using an external amplifier. Using fluid simulations and experiments, we investigated the success rates of Xenopus oocyte arrays and electrode insertion with respect to the flow rate. We successfully located each oocyte in the array and detected oocyte responses to chemical stimuli using our device.

This study assessed the efficacy of chemoradiotherapy for squamous cell carcinoma of the anal canal (SCCAC). Patients with T1-4N0-3M0 SCCAC received chemoradiotherapy with 5-fluorouracil (5-FU, 800 mg/m2/day, 96-h infusion) and mitomycin-C (MMC, 10 mg/m2 bolus). Patients treated with 3-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) were administered 36.0 Gy in 20 fractions or 49.5 Gy in 33 fractions for elective nodal irradiation and 59.4 Gy in 33 fractions for primary tumor and metastatic nodal irradiation. The sample size was considered sufficient to estimate 95% confidence intervals (CIs) for the true 2-year disease-free survival (DFS) within a width of +15% when the expected true 2-year DFS was 70%. The primary endpoint was 2-year DFS. The secondary endpoints were 2-year overall survival (OS), locoregional control (LC), colostomy-free survival (CFS) and adverse events. Thirty-one patients were enrolled between January 2014 and July 2019. The median follow-up was 33.3 months (range, 16.2-65.8 months). Among the 31 patients, 13%, 32%, 16% and 39% had stage I, II, IIIA and IIIB disease, respectively. Thirty patients were treated with IMRT. Complete response (CR) was achieved in 27 patients. The 2-year DFS, OS, LC and CFS rates were 77.4% (95% CI, 58.4-88.5%), 93.5% (95% CI, 76.6-98.3%), 83.9% (95% CI, 65.5-92.9%) and 80.6% (95% CI, 61.9-90.8%), respectively. One patient experienced grade 3 late adverse events; however, no grade ≥ 4 late adverse events occurred. Good DFS with a low rate of late adverse events was observed. Chemoradiotherapy with 5-FU and MMC was effective for SCCAC., (© The Author(s) 2022. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

The aim of this study was to propose optimal robust planning by comparing the robustness with setup error with the robustness of a conventional planning target volume (PTV)-based plan and to compare the robust plan to the PTV-based plan for the target and organ at risk (OAR). Data from 13 patients with intermediate-to-high-risk localized prostate cancer who did not have T3b disease were analyzed. The dose distribution under multiple setup error scenarios was assessed using a conventional PTV-based plan. The clinical target volume (CTV) and OAR dose in moving coordinates were used for the dose constraint with the robust plan. The hybrid robust plan added the dose constraint of the PTV-rectum to the static coordinate system. When the isocenter was shifted by 10 mm in the superior-inferior direction and 8 mm in the right-left and anterior directions, the doses to the CTV, bladder, and rectum of the PTV-based plan, robust plan, and hybrid robust plan were compared. For the CTV D 99% in the PTV-based plan and hybrid robust plan, over 95% of the prescribed dose was secured in all directions, except in the inferior direction. There was no significant difference between the PTV-based plan and the hybrid robust plan for rectum V 70Gy , V 60Gy , and V 40Gy . This study proposed an optimization method for patients with prostate cancer. When the setup error occurred within the PTV margin, the dose robustness of the CTV for the hybrid robust plan was higher than that of the PTV-based plan, while maintaining the equivalent OAR dose., (© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

Background: Associations between tumor metabolic and volumetric parameters determined by preoperative 18 F-fluorodeoxyglucose-positron emission tomography and survival in patients with esophageal squamous cell carcinoma who underwent trimodal therapy have not been fully investigated., Methods: We evaluated relationships between reductions in maximal standardized uptake value, metabolic tumor volume, and total lesion glycolysis in primary tumors on 18 F-fluorodeoxyglucose-positron emission tomography images between before and after neoadjuvant chemoradiotherapy and the survival of 120 patients with esophageal squamous cell carcinoma who underwent neoadjuvant chemoradiotherapy followed by surgery., Results: The optimal cutoffs of Δ maximal standardized uptake value, Δ metabolic tumor volume, and Δ total lesion glycolysis were defined to statistically yield the largest differences in recurrence-free survival for good and poor positron emission tomography responders to neoadjuvant chemoradiotherapy (cutoffs: 70%, 85%, and 90%, respectively). These cutoff values significantly stratified overall survival (Δ maximal standardized uptake value, P = .004; Δ metabolic tumor volume, P = .001; Δ total lesion glycolysis, P < .0001). Univariate analysis showed that Δ maximal standardized uptake value (hazard ratio, 0.50; 95% confidence interval, 0.32-0.79; P = .003), Δ metabolic tumor volume (hazard ratio, 0.50; 95% confidence interval, 0.31-0.81; P = .004), and Δ total lesion glycolysis (hazard ratio, 0.37; 95% confidence interval, 0.23-0.61; P < .001) were statistically significant for recurrence-free survival. Furthermore, Δ metabolic tumor volume (hazard ratio, 0.45; 95% confidence interval, 0.27-0.76; P = .003) and Δ total lesion glycolysis (hazard ratio, 0.37; 95% confidence interval, 0.22-0.63; P < .001) were independent factors for recurrence-free survival in multivariate analyses that included preoperative and pathological factors., Conclusion: Together with significant pathological prognostic factors, Δ metabolic tumor volume and Δ total lesion glycolysis were valuable for patients with esophageal squamous cell carcinoma who received trimodal therapy. Thus, preoperative 18 F-fluorodeoxyglucose-positron emission tomography is a useful and noninvasive diagnostic tool that might facilitate tailoring optimal therapies for locally advanced esophageal squamous cell carcinoma., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: JCOG1015A1 is an ancillary research study to determine the organ-specific dose constraints in head and neck carcinoma treated with intensity-modulated radiation therapy (IMRT) using data from JCOG1015., Methods: Individual patient data and dose-volume histograms of organs at risk (OAR) were collected from 74 patients with nasopharyngeal carcinoma treated with IMRT who enrolled in JCOG1015. The incidence of late toxicities was evaluated using the cumulative incidence method or prevalence proportion. ROC analysis was used to estimate the optimal DVH cut-off value that predicted toxicities., Results: The 5-year cumulative incidences of Grade (G) 1 myelitis, ≥ G1 central nervous system (CNS) necrosis, G2 optic nerve disorder, ≥ G2 dysphagia, ≥ G2 laryngeal edema, ≥ G2 hearing impaired, ≥ G2 middle ear inflammation, and ≥ G1 hypothyroidism were 10%, 5%, 2%, 11%, 5%, 26%, 34%, and 34%, respectively. Significant associations between DVH parameters and incidences of toxicities were observed in the brainstem for myelitis (D1cc ≥ 55.8 Gy), in the brain for CNS necrosis (D1cc ≥ 72.1 Gy), in the eyeball for optic nerve disorder (Dmax ≥ 36.6 Gy), and in the ipsilateral inner ear for hearing impaired (Dmean ≥ 44 Gy). The optic nerve, pharyngeal constrictor muscle (PCM), and thyroid showed tendencies between DVH parameters and toxicity incidence. The prevalence proportion of G2 xerostomia at 2 years was 17 versus 6% (contralateral parotid gland Dmean ≥ 25.8 Gy vs less)., Conclusions: The dose constraint criteria were appropriate for most OAR in this study, although more strict dose constraints might be necessary for the inner ear, PCM, and brainstem., (© 2022. The Author(s).)

Objective: We aimed to develop a predictive model for occult cervical lymph node metastasis in patients with tongue cancer using radiomics and machine learning from pretreatment contrast-enhanced computed tomography., Study Design: This study included 161 patients with tongue cancer who received local treatment. Computed tomography images were transferred to a radiomics platform. The volume of interest was the total neck node level, including levels Ia, Ib, II, III, and IVa at the ipsilateral side, and each neck node level. The dimensionality of the radiomics features was reduced using least absolute shrinkage and selection operator logistic regression analysis. We compared 5 classifiers with or without the synthetic minority oversampling technique (SMOTE)., Results: For the analysis at the total neck node level, random forest with SMOTE was the best model, with an accuracy of 0.85 and an area under the curve score of 0.92. For the analysis at each neck node level, a support vector machine with SMOTE was the best model, with an accuracy of 0.96 and an area under the curve score of 0.98., Conclusions: Predictive models using radiomics and machine learning have potential as clinical decision support tools in the management of patients with tongue cancer for prediction of occult cervical lymph node metastasis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objectives: To propose deep-learning (DL)-based predictive model for pathological complete response rate for resectable locally advanced esophageal squamous cell carcinoma (SCC) after neoadjuvant chemoradiotherapy (NCRT) with endoscopic images., Methods and Material: This retrospective study analyzed 98 patients with locally advanced esophagus cancer treated by preoperative chemoradiotherapy followed by surgery from 2004 to 2016. The patient data were split into two sets: 72 patients for the training of models and 26 patients for testing of the model. Patients was classified into two groups with the LC (Group I: responder and Group II: non-responder). The scanned images were converted into joint photographic experts group (JPEG) format and resized to 150 × 150 pixels. The input image without imaging filter (w/o filter) and with Laplacian, Sobel, and wavelet imaging filters deep-learning model to predict the pathological CR with a convolution neural network (CNN). The accuracy, sensitivity, and specificity, the area under the curve (AUC) of the receiver operating characteristic were evaluated., Results: The average of accuracy for the cross-validation was 0.64 for w/o filter, 0.69 for Laplacian filter, 0.71 for Sobel filter, and 0.81 for wavelet filter, respectively. The average of sensitivity for the cross-validation was 0.80 for w/o filter, 0.81 for Laplacian filter, 0.67 for Sobel filter, and 0.80 for wavelet filter, respectively. The average of specificity for the cross-validation was 0.37 for w/o filter, 0.55 for Laplacian filter, 0.68 for Sobel filter, and 0.81 for wavelet filter, respectively. From the ROC curve, the average AUC for the cross-validation was 0.58 for w/o filter, 0.67 for Laplacian filter, 0.73 for Sobel filter, and 0.83 for wavelet filter, respectively., Conclusions: The current study proposed the improvement the accuracy of the DL-based prediction model with the imaging filters. With the imaging filters, the accuracy was significantly improved. The model can be supported to assist clinical oncologists to have a more accurate expectations of the treatment outcome., Advances in Knowledge: The accuracy of the prediction for the local control after radiotherapy can improve with the input image with the imaging filter for deep learning.

The relationship between sensory processing and ASD-like and associated behaviors in patients with Prader-Willi Syndrome (PWS) remains relatively unexplored. Examining this relationship, 51 adults with PWS were administered the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS), Short Sensory Profile (SSP-J), Food-Related Problem Questionnaire (FRPQ), and Aberrant Behavior Checklist (ABC-J). Based on SSP-J z-scores, participants were classified into three severity groups. Analysis of variance was performed to compare the behavioral scores of these three groups. Statistically significant group differences were observed in PARS (p = .006, ηp2 = .194) and ABC-J (p = .006, ηp2 = .193) scores. Our findings suggest that the level of sensory processing may predict ASD-like and aberrant behaviors in adults with PWS, implying the importance of a proper assessment for early intervention., (©AAIDD.)

Background/aim: Surgical resection and chemoradiotherapy (CRT) can be performed as additional treatments for superficial esophageal cancer after endoscopic resection, but the selection criteria vary depending on the institution. We retrospectively evaluated the outcomes of patients with endoscopically resected superficial esophageal cancer treated with surgical resection and CRT at our institution., Patients and Methods: The outcomes of 67 cases of additional treatment after endoscopic resection of superficial esophageal cancer, excluding adenocarcinoma, performed at our hospital from January 2000 to June 2017 were compared (30 cases in the surgery group and 37 cases in the CRT group)., Results: In the surgery group, eight patients had lymph node metastasis and two had recurrence in the supraclavicular fossa lymph nodes after surgery, therefore reoperation was performed. There were no deaths from esophageal cancer, and the 5-year survival rate was 92.6%. One patient in the CRT group had a recurrence in the cervical paraoesophageal lymph node, which was resected, but no death from esophageal cancer was observed, and the 5-year survival rate was 81.0%. The 5-year survival rate was significantly better in the surgery group than in the CRT group (p=0.039). The greater number of elderly patients in the CRT group was considered to be the reason for the worse prognosis, Conclusion: Although the prognosis of esophagectomy or chemoradiotherapy (CRT) is very favorable, CRT is considered to be the preferred additional treatment after endoscopic resection of superficial esophageal cancer without lymph node metastasis from the viewpoint of organ preservation., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background and Objective: Borderline resectable pancreatic cancer (BRPC) is a tumor that infiltrates into the large blood vessels, with a high probability that the tumor will remain after surgical resection. To date, there has been no confirmed treatment strategy for BRPC. However, high-level studies, such as those using the intention-to-treat analysis, have recently been published. This review aimed to update the current status of treatment strategies for BRPC., Methods: We searched for studies, including those investigating patients with BRPC, either treated by upfront surgery or with neoadjuvant treatment and reported the R0 resection rate and overall survival using an intention-to-treat analysis., Key Content and Findings: Consequently, 22 articles were identified. Twelve were prospective studies. Six studies compared neoadjuvant therapy with upfront surgery, and both the R0 resection rate and overall survival in patients who underwent upfront surgery were significantly worse than in those who underwent neoadjuvant treatment in all studies. Six studies evaluated neoadjuvant chemotherapy, while 15 studies neoadjuvant chemoradiation. No reports showed the superiority or inferiority of the two methods, and the optimal regimen was not determined in either treatment. The high-precision radiation therapy techniques have been studied, but the optimal method and dose fractionation were unclear., Conclusions: The current standard of care for the BRPC is neoadjuvant therapy. Although the optimal regimen of neoadjuvant therapy was not determined, several prospective trials are underway to identify the optimal neoadjuvant treatment., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jgo.amegroups.com/article/view/10.21037/jgo-21-829/coif). Abdel-Wahab M reports that she is the chair of the international committee of the American society for radiation oncology. The other authors have no conflicts of interest to declare., (2022 Journal of Gastrointestinal Oncology. All rights reserved.)

Purpose: This study aimed to investigate status of displacement of gold-198 ( 198 Au) grains in patients with oral cancers as well as factors and countermeasures for the displacement of 198 Au grains., Material and Methods: The present study included 34 patients with oral cancers, who were exclusively treated with 198 Au grain brachytherapy between 2013 and 2019. Timing and duration of the 198 Au grain displacement from the oral cavity and reduction in radiation dose were estimated. Location of the displaced grain was classified as either inside or outside of gross tumor volume. Number and location of the displacement of 198 Au grains, primary lesion, and growth type were evaluated., Results: Of the 34 patients included in this study, 198 Au grains were displaced in 4 patients (11.8%) during hospitalization. A total of 5 grains (1.4%) were displaced out of an overall count of 367 grains implanted in these 34 patients. Of the four patients who experienced displacement of 198 Au grains, three had tongue cancer, and one had lip cancer. All four patients whose grains were displaced had superficial lesions., Conclusions: When performing brachytherapy with 198 Au grains for superficial lesions on the tongue or lips, care should be taken to avoid grain displacement., Competing Interests: The authors report no conflict of interest., (Copyright © 2022 Termedia.)

The purpose of this study was to extract the three-dimensional (3D) vector of the baseline drift baseline drift vector (BDV) of the specific points on the body surface and to demonstrate the importance of the 3D tracking of the body surface. Our system consisted of a near-infrared camera (NIC: Kinect V2) and software that recognized and tracked blue stickers as markers. We acquired 3D coordinates of 30 markers stuck on the body surface for 30 min for eight healthy volunteers and developed a simple technique to extract the BDV. The BDV on the sternum, rib, and abdomen was extracted from the measured data. BDV per min. was analyzed to estimate the frequency to exceed a given tolerance. Also, the correlation among BDVs for multiple body sites was analyzed. The longitudinal baseline drift was observed in the BDV of healthy volunteers. Among the eight volunteers, the maximum probability that the BDV per min. exceeded the tolerance of 1 mm and 2 mm was 30% and 15%, respectively. The correlation among BDVs of multiple body sites suggested a potential feasibility to distinguish the translational movement of the whole area and the respiratory movement. In conclusion, we constructed the 3D tracking system of multiple points on the body surface using a noninvasive NIC at a low cost and established the method to extract the BDV. The existence of the longitudinal baseline drift showed the importance of the 3D tracking in the body surface., (© 2022. Australasian College of Physical Scientists and Engineers in Medicine.)

Background/aim: We investigated treatment outcomes and complications during reirradiation of patients with oral cancers., Patients and Methods: Six patients who received definitive radiotherapy for oral cancer as the initial treatment and brachytherapy for recurrence were included. Local control and overall survival rates, soft tissue and mandibular complications, and tooth extraction were investigated., Results: The five-year local control and overall survival rates were 83.3% and 100%, respectively. The occurrence rate of grade 2 soft tissue and mandible complications was 33.3%, and the primary sites were the buccal mucosa and the floor of mouth. The positions of the extracted tooth in the two cases were adjacent to the tumor, and one case developed grade 2 complication of the mandible., Conclusion: During recurrence of the buccal mucosa and the floor of mouth cancers, reirradiation should be avoided considering mandibular complications. To avoid reirradiation-related complications, tooth extraction near the radiation field should be avoided., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Objective: This study aimed to retrospectively evaluate the radiation dose and complications in soft tissue and mandible caused by 198 Au grain brachytherapy alone or the combination with other modalities in patients with the cancer of the floor of the mouth., Materials and Methods: Twelve patients with T1 (n = 5) and T2 (n = 7) squamous cell carcinoma of the floor of the mouth, who were treated with 198 Au grain brachytherapy alone (n = 5) or the combination of external beam radiotherapy (EBRT) and/or chemotherapy and 198 Au grain brachytherapy (n = 7) from January 2005 to December 2016, were included. The relationships between the radiation dose and the complications of the soft tissue or mandible were investigated., Results: Seven of 12 patients had died. Of these 7 patients, one with T1 and 2 with T2 had died of the causes related to the cancer of the floor of the mouth. Two with T1 and 2 with T2 had died of other diseases. Two patients had grade 2 complications of the soft tissue and mandible. These patients were treated by the combination of EBRT and/or chemotherapy and 198 Au grain brachytherapy and irradiated with 123 or 139 Gy in total dose, respectively. And one of these patients was treated by the chemotherapy in addition to EBRT., Conclusion: Our study showed that the combination of EBRT and 198 Au grains brachytherapy for the floor of the mouth cancer patients might be associated with risks of developing complications of soft tissue ulcer and mandibular bone necrosis., (© 2021. The Author(s), under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd.)

Background and Purpose: Radiotherapy (RT) has recently received increasing attention as an additional treatment for organ preservation after non-curative endoscopic submucosal dissection (ESD) in patients with superficial esophageal cancer. Esophageal stenosis is an adverse event related to RT after ESD that is not widely studied. The aim of this study was to investigate esophageal stenosis related to salvage RT in superficial esophageal cancer after non-curative ESD., Materials and Methods: Fifty patients who received salvage RT after non-curative ESD at a single institution between 2011 and 2018 were included in this study. The Common Terminology Criteria for Adverse Events, version 5.0, was used to assess esophageal stenosis. Data were compared using Fisher's exact test. Statistical significance was set at P < 0.05., Results: Median follow-up time was 48 months (range, 12-95 months). Grade 2 and 3 esophageal stenosis were observed in 17 (34%), and 3 patients (6%), respectively. The frequency of grade 2 or worse esophageal stenosis decreased over time (before RT, 6 months, 1 year, and 2 years after RT: 16 (32%), 13 (26%), 10 (20%), and 6 (12%) patients, respectively). Only one patient required endoscopic balloon dilation (EBD) 1 year after RT. All grade 3 esophageal stenosis improved grade 2 or less by EBD. In univariate analysis, only tumor location was a significant risk factor for grade 3 esophageal stenosis., Conclusions: Esophageal stenosis, after salvage RT in patients with esophageal cancer who received non-curative ESD, improved naturally or after EBD; only a few cases required long-term EBD., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: The use of volumetric modulated arc therapy is gradually widespread for locally advanced non-small cell lung cancer. The purpose of this study was to identify the factors that caused ≥ grade 2 radiation pneumonitis and evaluate the impact of using volumetric modulated arc therapy on the incidence of ≥ grade 2 radiation pneumonitis by comparing three-dimensional conformal radiation therapy., Methods: We retrospectively evaluated 124 patients who underwent radical radiotherapy for locally advanced non-small cell lung cancer in our institution between 2008 and 2019. The following variables were analysed to detect the factors that affected ≥ grade 2 radiation pneumonitis; age, sex, the presence of interstitial lung disease, pulmonary emphysema, tumour location, stage, PTV/lung volume, lung V20Gy, total dose, concurrent chemoradiotherapy, adjuvant immune checkpoint inhibitor, radiotherapy method. Radiation pneumonitis was evaluated using the common terminology criteria for adverse events (version 5.0)., Results: A total of 84 patients underwent three-dimensional conformal radiation therapy (3D-CRT group) and 40 patients underwent volumetric modulated arc therapy (VMAT group). The cumulative incidence of ≥ grade 2 radiation pneumonitis at 12 months was significantly lower in the VMAT group than in the 3D-CRT group (25% vs. 49.1%). The use of volumetric modulated arc therapy was a significant factor for ≥ grade 2 radiation pneumonitis (HR:0.32, 95% CI: 0.15-0.65, P = 0.0017) in addition to lung V20Gy (≥ 24%, HR:5.72 (95% CI: 2.87-11.4), P < 0.0001) and total dose (≥ 70 Gy, HR:2.64 (95% CI: 1.39-5.03), P = 0.0031) even after adjustment by multivariate analysis., Conclusions: We identified factors associated with ≥ grade 2 radiation pneumonitis in radiotherapy for patients with locally advanced non-small cell lung cancer. Volumetric modulated arc therapy has potential benefits to reduce the risk of ≥ grade 2 radiation pneumonitis., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

It is often challenging to determine the accurate size and shape of oral lesions through computed tomography (CT) or magnetic resonance imaging (MRI) when they are very small or obscured by metallic artifacts, such as dental prostheses. Intraoral ultrasonography (IUS) has been shown to be beneficial in obtaining precise information about total tumor extension, as well as the exact location and guiding the insertion of catheters during interstitial brachytherapy. We evaluated the role of IUS in assessing the clinical outcomes of interstitial brachytherapy with 198Au grains in tongue cancer through a retrospective medical chart review. The data from 45 patients with T1 (n = 21) and T2 (n = 24) tongue cancer, who were mainly treated with 198Au grain implants between January 2005 and April 2019, were included in this study. 198Au grain implantations were carried out, and positioning of the implants was confirmed by IUS, to ensure that 198Au grains were appropriately placed for the deep border of the tongue lesion. The five-year local control rates of T1 and T2 tongue cancers were 95.2% and 95.5%, respectively. We propose that the use of IUS to identify the extent of lesions and the position of implanted grains is effective when performing brachytherapy with 198Au grains., (© The Author(s) 2021. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Objective: To propose the prediction model for degree of differentiation for locally advanced esophageal cancer patients from the planning CT image by radiomics analysis with machine learning., Methods: Data of 104 patients with esophagus cancer, who underwent chemoradiotherapy followed by surgery at the Hiroshima University hospital from 2003 to 2016 were analyzed. The treatment outcomes of these tumors were known prior to the study. The data were split into 3 sets: 57/16 tumors for the training/validation and 31 tumors for model testing. The degree of differentiation of squamous cell carcinoma was classified into two groups. The first group (Group I) was a poorly differentiated (POR) patients. The second group (Group II) was well and moderately differentiated patients. The radiomics feature was extracted in the tumor and around the tumor regions. A total number of 3480 radiomics features per patient image were extracted from radiotherapy planning CT scan. Models were built with the least absolute shrinkage and selection operator (LASSO) logistic regression and applied to the set of candidate predictors. The radiomics features were used for the input data in the machine learning. To build predictive models with radiomics features, neural network classifiers was used. The precision, accuracy, sensitivity by generating confusion matrices, the area under the curve (AUC) of receiver operating characteristic curve were evaluated., Results: By the LASSO analysis of the training data, we found 13 radiomics features from CT images for the classification. The accuracy of the prediction model was highest for using only CT radiomics features. The accuracy, specificity, and sensitivity of the predictive model were 85.4%, 88.6%, 80.0%, and the AUC was 0.92., Conclusion: The proposed predictive model showed high accuracy for the classification of the degree of the differentiation of esophagus cancer. Because of the good prediction ability of the method, the method may contribute to reducing the pathological examination by biopsy and predicting the local control., Advances in Knowledge: For esophageal cancer, the differentiation of degree is the import indexes reflecting the aggressiveness. The current study proposed the prediction model for the differentiation of degree with radiomics analysis.

Objective: This is an ancillary study of a multi-institutional randomized non-inferiority phase III trial of accelerated fractionation (AF) versus standard fractionation (SF) radiation therapy for T1-2N0M0 glottic cancer (JCOG0701). Biopsy specimens of tumors from the patients enrolled in the JCOG0701 are collected and the association between clinical outcomes and histopathologic features such as expression of epithelial cell adhesion molecule (EpCAM), p53, and p16 were investigated., Methods: Five slices of undyed slides from biopsy specimens were sent to the National Cancer Center Hospital and all the specimens were assessed for the expression of EpCAM, p53, and p16. The primary objective was to investigate the association between 3-year progression-free survival (PFS) and expression of EpCAM, p53, and p16., Results: A total of 88 out of 370 patients were enrolled in this ancillary study. The 3-year PFS for tumors with strong expression of EpCAM was 70.6% (95% CI 43.1%-86.6%), while that of tumors without strong expression of EpCAM was 77.5% (95% CI 65.9%-85.5%) with no remarkable difference between groups (P = .67). Likewise, there was no significant difference in 3-year PFS between tumors regardless of p53 or p16 status. However, in a subgroup analysis for 17 patients with a strong expression of EpCAM, AF showed better 3-year PFS than SF (100% vs 54.5%, P = .07)., Conclusions: From the current study, it could not be concluded that EpCAM, p16, and p53 were prognostic factors for early-stage glottic cancer after primary radiation therapy. AF might be an appropriate fractionation for tumors with a strong expression of EpCAM., Level of Evidence: 3 Laryngoscope, 131:1522-1527, 2021., (© 2020 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: This study aimed to propose a machine learning model to predict the local response of resectable locally advanced esophageal squamous cell carcinoma (LA-ESCC) treated by neoadjuvant chemoradiotherapy (NCRT) using pretreatment 18-fluorodeoxyglucose positron emission tomography (FDG PET) images., Methods: The local responses of 98 patients were categorized into two groups (complete response and noncomplete response). We performed a radiomics analysis using five segmentations created on FDG PET images, resulting in 4250 features per patient. To construct a machine learning model, we used the least absolute shrinkage and selection operator (LASSO) regression to extract radiomics features optimal for the prediction. Then, a prediction model was constructed by using a neural network classifier. The training model was evaluated with 5-fold cross-validation., Results: By the LASSO analysis of the training data, 22 radiomics features were extracted. In the testing data, the average accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve score of the five prediction models were 89.6%, 92.7%, 89.5%, and 0.95, respectively., Conclusions: The proposed machine learning model using radiomics showed promising predictive accuracy of the local response of LA-ESCC treated by NCRT.

Preoperative chemoradiotherapy with capecitabine or 5-fluorouracil is a standard treatment for locally advanced rectal cancer (LARC). S-1, a prodrug of 5-fluorouracil, is a candidate for this chemoradiotherapy regimen in Japan; however, treatment outcomes after S-1 treatment alone are not clear. This study aimed to assess the efficacy and tolerability of preoperative chemoradiotherapy with S-1 alone for LARC. We retrospectively evaluated 54 LARC patients who underwent preoperative chemoradiotherapy with S-1 alone in our institution between 2005 and 2017. The clinical tumor stage was cT2-3 in 31 patients and cT4 in 23 patients, and lymph node metastases were clinically evident in 31 patients. S-1, at a dose of 80 mg/m2/day, was orally administered during radiotherapy. A total dose of 45-50.4 Gy was delivered in 25-28 fractions (median: 50.4 Gy). Surgical resections were scheduled 6-10 weeks after chemoradiotherapy completion. The 3- and 5-year overall survival rates were 92.4 and 72.8%, respectively, with a median follow-up time of 51 months. The 3- and 5-year local control rates were 96.2 and 85.9%, respectively. A pathological complete response was observed in 7 patients (13.0%) at the time of surgery. Ten patients (18.5%) had grade 3 acute toxicities and 5 patients (9.3%) had grade 3 late toxicities. No grade 4 or 5 toxicities were observed. Preoperative chemoradiotherapy with S-1 alone followed by total mesorectal excision resulted in a low incidence of toxicities and comparable clinical results. Therefore, S-1 alone can be a treatment option for preoperative chemoradiotherapy in LARC patients., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Background: Although metastatic tumors in lymph nodes (LN) are potentially affected by neoadjuvant chemoradiotherapy (NCRT), the distribution of LN metastases of esophageal squamous cell carcinoma (ESCC) after trimodal therapy has never been sufficiently estimated., Patients and Methods: We evaluated the distribution of LN metastases, relationships between LN metastases and radiation fields, risk factors for LN metastasis, and the influence of LN metastasis on the survival of 184 patients with ESCC who underwent NCRT followed by esophagectomy., Results: Neoadjuvant chemoradiotherapy resulted in down-staged LN status in 74 (49.3%) patients. Pathological LN metastases were extensive in 177 LN stations in the cervical, mediastinal, and abdominal fields, and 162 (91.5%) metastases were located inside the radiation fields. Multivariate analysis showed that clinical N stage [N0 vs. 1/2/3: hazard ratio (HR), 2.69; 95% confidence interval (CI), 1.22-5.92; p = 0.01] and clinical response of primary tumor (complete vs. noncomplete: HR, 2.93; 95% CI, 1.50-5.69; p = 0.002) were statistically significant for pathological LN metastasis. Recurrence-free and overall survivals were significantly stratified according to the number of pathological LN metastases, associations between clinical and pathological LN metastases, and presence or absence of pathological LN metastases outside radiation field., Conclusions: About 50% of patients who were clinically diagnosed with LN metastasis before treatment were downstaged by NCRT, and their prognoses were relatively good. However, LN metastases were extensive at the cervical, mediastinal, and abdominal areas, even within the radiation field. Thus, systematic and adequate lymphadenectomy is required for ESCC treated by NCRT.

In this work, individual radiosensitivity was evaluated using DNA damage response and chromosomal aberrations (CAs) in peripheral blood lymphocytes (PBLs) for the prediction of acute toxicities of chemoradiotherapy (CRT) in esophageal cancer patients. Eighteen patients with esophageal cancer were enrolled in this prospective study. Prescribed doses were 60 Gy in 11 patients and 50 Gy in seven patients. Patients received 2 Gy radiotherapy five days a week. PBLs were obtained during treatment just before and 15 min after 2 Gy radiation therapy on the days when the cumulative dose reached 2, 20, 40 Gy and 50 or 60 Gy. PBLs were also obtained four weeks and six months after radiotherapy in all and 13 patients, respectively. Dicentric and ring chromosomes in PBLs were counted to evaluate the number of CAs. Gamma-H2AX foci per cell were scored to assess DNA double-strand breaks. We analyzed the association between these factors and adverse events. The number of γ-H2AX foci before radiotherapy showed no significant increase during CRT, while their increment was significantly reduced with the accumulation of radiation dose. The mean number of CAs increased during CRT up to 1.04 per metaphase, and gradually decreased to approximately 60% six months after CRT. Five patients showed grade 3 toxicities during or after CRT (overreactors: OR), while 13 had grade 2 or less toxicities (non-overreactors: NOR). The number of CAs was significantly higher in the OR group than in the NOR group at a cumulative dose of 20 Gy (mean value: 0.63 vs. 0.34, P = 0.02), 40 Gy (mean value: 0.90 vs. 0.52, P = 0.04), and the final day of radiotherapy (mean value: 1.49 vs. 0.84, P = 0.005). These findings suggest that number of CAs could be an index for predicting acute toxicities of CRT for esophageal cancer., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

Purpose: The present study aimed to evaluate the long-term results of definitive chemoradiotherapy (CRT) for unresectable locally advanced esophageal squamous cell carcinoma (LA-ESCC)., Materials and Methods: We analyzed eighty patients with unresectable LA-ESCC, who underwent definitive CRT between 2001 and 2014. The 5-year overall survival (OS), cause-specific survival (CSS), and progression-free survival (PFS) rates were calculated, and we investigated the prognostic factors and adverse events., Results: The median age was 66 years (range, 41-83 years). Histologically, all patients had squamous cell carcinoma. The most common tumor site was the middle thoracic esophagus in 43 (54%) patients. According to the eighth edition of the Union for International Cancer Control TNM classification, sixty-six patients (83%) had T4 disease, 59 (74%) had regional lymph node (LN) metastases, and 35 (44%) had distant LN metastases beyond the regional LN (M1 LYM) disease. Forty-five (56%) and 35 (44%) patients belong to clinical stages IVA and IVB, respectively. The median follow-up period for survivors was 86 months. The 5-year OS, CSS, and PFS rates were 20.2%, 25.7%, and 18.4%, respectively. On univariate analysis, only the performance status score was significantly associated with better overall survival (p = 0.026). Grade 3 or higher late adverse events were observed in 12 (15%) patients, and these included cardiopulmonary adverse events in 6 (8%) patients. Treatment-related death occurred in 3 (4%) patients., Conclusion: We showed the long-term results of definitive CRT for unresectable LA-ESCC. The survivals are still poor and new treatment strategies need to be developed., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Purpose: Lack of a reference dose distribution is one of the challenges in the treatment planning used in volumetric modulated arc therapy because numerous manual processes result from variations in the location and size of a tumor in different cases. In this study, a predicted dose distribution was generated using two independent methods. Treatment planning using the predicted distribution was compared with the clinical value, and its efficacy was evaluated., Methods: Computed tomography scans of 81 patients with oropharynx or hypopharynx tumors were acquired retrospectively. The predicted dose distributions were determined using a modified filtered back projection (mFBP) and a hierarchically densely connected U-net (HD-Unet). Optimization parameters were extracted from the predicted distribution, and the optimized dose distribution was obtained using a commercial treatment planning system., Results: In the test data from ten patients, significant differences between the mFBP and clinical plan were observed for the maximum dose of the brain stem, spinal cord, and mean dose of the larynx. A significant difference between the dose distributions from the HD-Unet dose and the clinical plan was observed for the mean dose of the left parotid gland. In both cases, the equivalent coverage and flatness of the clinical plan were observed for the tumor target., Conclusions: The predicted dose distribution was generated using two approaches. In the case of the mFBP approach, no prior learning, such as deep learning, is required; therefore, the accuracy and efficiency of treatment planning will be improved even for sites where sufficient training data are unavailable., (Copyright © 2020. Published by Elsevier Ltd.)

Background: The degree of metabolic activity in tumor cells can be determined by 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET). Associations between FDG uptake by primary tumors of locally advanced esophageal squamous cell carcinoma (ESCC) under trimodal therapy and the pathological features of such tumors have not been fully investigated., Patients and Methods: We evaluated relationships between the maximal standardized uptake (SUVmax) in primary tumors on preoperative PET images and pathological features as well as cancer recurrence in 143 patients with ESCC who underwent neoadjuvant chemoradiotherapy (NCRT) followed by surgery., Results: The post-SUVmax significantly differed after NCRT for ypT and ypN status, lymphatic invasion (LI), venous invasion (VI), and recurrence. Furthermore, the %ΔSUVmax (rate of decrease between before and after NCRT) for LI, VI, and recurrence significantly differed. Univariate and multivariate analyses selected post-SUVmax and %ΔSUVmax as independent preoperative predictors of recurrence-free survival [hazard ratio (HR) 1.46; 95% confidence interval (CI) 1.24-1.72 and HR 0.97; 95% CI 0.96-0.99, respectively; p < 0.001 for both]. Recurrence-free and overall survival were significantly stratified according to optimal SUVmax cutoffs for predicting recurrence (post- and %ΔSUVmax: 2.8 and 70, respectively)., Conclusions: The post- and %ΔSUVmax of primary tumors were significantly associated with the pathological features and recurrence of ESCC under trimodal therapy. Therefore, FDG-PET can preoperatively predict the degree of aggressive tumor behavior in ESCC under trimodal therapy.

This study aimed to clarify the motivations and timing of the decision to become radiation oncologists., Materials and Methods: We conducted an online survey for new members of the Japanese Society for Radiation Oncology (JASTRO)., Results: The response rate was 43.3%. Data of the 79 respondents who wanted to obtain a board-certification of JASTRO were analysed. We divided the respondents into two groups: Group A, those who entered a single radiation oncology department, and Group B, those who joined a radiology department in which the radiation oncology department and diagnostic radiology department were integrated. The most common period when respondents were most attracted to radiation oncology was "5th year of university" in Group A and "2nd year of junior residency" and "senior residency" in Group B. Furthermore, 79.5% of Group A and 40% of Group B chose periods before graduation from a university with a significant difference. The most common period when respondents made up their minds to become radiation oncologists was "2nd year of junior residency" in both groups. Internal medicine was the most common department to consider if they did not join the radiation oncology or radiology department., Conclusion: To increase the radiation oncologists, it is crucial to enhance clinical training in the fifth year of university for Group A and to continue an active approach to maintain interest in radiation oncology until the end of junior residency. In Group B facilities, it is desirable to provide undergraduates more opportunities to come in contact with radiation oncology., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

This study aimed to investigate whether the use of molecular-targeted agents could affect gastrointestinal (GI) toxicity in palliative radiotherapy (RT) for metastatic bone tumors in the abdominopelvic region. We collected data of patients who received palliative RT for bone metastases in the abdominopelvic region between 2013 and 2014 from six institutions. Data of 395 patients were collected and184 patients received molecularly targeted therapy, of whom 80 received vascular endothelial growth factor (VEGF)-targeted agents. For 556 lesions, 410 sessions of irradiation were undergone. GI toxicity of ≥G3 was observed in 3.8% of patients. The incidence rates of ≥G3 GI toxicity in patients without targeted agents use, in those using VEGF-targeted agents and in those using non-VEGF-targeted agents were 3.8, 7.5 and 1.0%, respectively. Regarding risk factors of the occurrence of ≥G3 GI toxicity, univariate analysis in all patients showed that a history of abdominopelvic surgery was a significant risk factor (P = 0.01), and the use of VEGF-targeted agents showed a trend of high incidence (P = 0.06). In patients using VEGF-targeted agents, both univariate and multivariate analysis showed that combined anticoagulant use (P = 0.03 and 0.01) and agent use between 1 week before and after RT (P = 0.046 and 0.03) were significant risk factors. In conclusion, the history of abdominopelvic surgery was associated with ≥G3 GI toxicity and the use of VEGF-targeted agents showed a trend for high incidence. When using VEGF-targeted agents, caution should be exercised in the combined use of anticoagulants and in the agent use between 1 week before and after RT., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.)

The present study aimed to analyze treatment outcomes after induction chemotherapy followed by chemoradiotherapy (CRT) using volumetric-modulated arc therapy (VMAT) in patients with stage IVA-B oropharyngeal cancer (OPC) or hypopharyngeal cancer (HPC), with long-term observation, including examination of larynx preservation. A total of 60 patients with stage IVA-B OPC or HPC, who underwent induction TPF chemotherapy (a combination regimen consisting of docetaxel, cisplatin, and 5-fluorouracil) followed by CRT using VMAT were analyzed. Overall survival (OS), progression-free survival (PFS), laryngoesophageal dysfunction-free survival (LEDFS), and locoregional control (LRC) were calculated and compared. Univariate and multivariate analyses were performed to determine statistical differences in OS and LEDFS. The median follow-up period at the time of evaluation was 61 months. Twenty-six (43%) patients had OPC and 34 (57%) had HPC. The 5-year OS, PFS, LEDFS, and LRC rates were 57%, 52%, 52%, and 68%, respectively. Response to TPF therapy was the only significant predictive factor of OS and LEDFS in multivariate analyses. Regarding long-term toxicities, grade ≥ 2 late toxicities accounted for 15%. No patients experienced grade ≥ 3 xerostomia, and 5% of all patients developed grade 3 dysphagia. With long-term observation, the OS, PFS, and LEDFS rates were relatively good, and the incidence of late toxicities was low. TPF followed by CRT using VMAT was feasible and more effective in those who responded to induction chemotherapy., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Background/aim: The present study aimed to analyze the treatment outcome after definitive radiotherapy (dRT) using volumetric-modulated arc therapy (VMAT) in patients with hypopharyngeal cancer (HPC), including an examination of late toxicities., Patients and Methods: A total of 62 patients with HPC, who underwent dRT using VMAT, were analyzed. Overall survival (OS), progression-free survival (PFS), laryngoesophageal dysfunction-free survival (LEDFS), and locoregional control (LRC) were calculated., Results: The median follow-up period was 49 months. The 3- and 5-year OS, PFS, LEDFS, and LRC rates were 77% and 60%, 61% and 56%, 66% and 53%, and both 79%, respectively. Regarding late toxicities, 11 (17.7%) patients developed grade ≥2 late toxicity. Grade 3 dysphagia was observed in 4 (6.5%) patients, and grade 2 xerostomia in 6 (9.7%)., Conclusion: VMAT was an effective treatment for HPC, with a low incidence of late toxicities., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: A phase II study of adaptive two-step intensity-modulated radiotherapy (IMRT) with chemotherapy for nasopharyngeal cancer (NPC) (JCOG1015) was conducted to evaluate the efficacy and safety., Methods: Patients aged 20-75 years with stages II-IVB NPC were enrolled. As adaptive two-step IMRT, computed tomography planning was performed twice before IMRT for the initial plan of 46 Gy/23 fractions and during treatment for the boost plan of 24 Gy/12 fractions with a total dose of 70 Gy. Chemotherapy (cisplatin 80 mg/m 2 /3-weeks × 3 courses) was administered concurrently with IMRT, followed by adjuvant chemotherapy (cisplatin at 70 mg/m 2 with 5-FU 700 at mg/m 2 for 5 days/4 weeks × 3 courses)., Results: Between 2011 and 2014, 75 patients were enrolled from 12 institutions. The 3-year overall survival (OS) for the 75 patients was 88%, and the upper and lower limits of the 95% CI of 78%-94% were higher than the expected 3-year OS of 75% for the target population adjusted by the actual proportion of stage II:III:IV = 21%:44%:35%. The 3-year progression-free survival (PFS) and loco-regional PFS were 71% [59-80%] and 77% [66-85%], respectively. Although no grade 4-5 late toxicities were observed, 15 patients (20%) developed grade 3 late toxicities. Grade 2 xerostomia was noted in 26%, 12%, and 9% at 1, 2, and 3 years after starting IMRT, respectively., Conclusions: Adaptive two-step IMRT for NPC demonstrated an excellent 3-year OS with acceptable toxicities. This method may be one treatment option for locally advanced NPC.

Background: Endoscopic resection is widely used as an effective treatment for superficial esophageal cancer. However, the risk of lymph node metastasis increases in cases of muscularis mucosae or deeper invasion, for which additional treatment such as radiotherapy or surgery is required. Accordingly, the current study investigated the efficacy and toxicity of salvage radiotherapy after non-curative endoscopic resection as an organ preservation strategy., Methods: We retrospectively reviewed 37 esophageal cancer patients who received salvage radiotherapy after non-curative endoscopic resection. The pathological invasion depths were the muscularis mucosae, submucosal layer, and muscularis propria in 14, 22, and one patient, respectively. All patients received external beam radiotherapy. Among them, eight received intraluminal brachytherapy following external beam radiotherapy. Elective nodal irradiation was administered to all patients. Twenty-five patients received concurrent platinum and fluorouracil-based chemotherapy., Results: The median follow-up time was 74 months (range: 3-212). The 5-year progression-free survival and overall survival rates were 64 and 78%, respectively. No local or regional lymph node recurrence was observed. The causes of death included esophageal cancer in one patient, metachronous esophageal cancer in one patient, other malignancies in eight patients, and other causes in six patients. Late cardiac toxicities ≥ grade 3 were observed in six patients, one of whom died of arrhythmia., Conclusions: Salvage radiotherapy after non-curative esophageal endoscopic resection is an effective treatment as an organ preservation strategy. Although muscularis mucosae and submucosal cancer have a high risk of lymph node metastasis, our results suggest that elective nodal irradiation contributes to reduced regional node metastases.

The aim of our study is to evaluate the metal artefact reduction techniques with the same contrast scale for different vendors' dual-energy CT (DECT): kV-CT image with metal artefact reduction method and monoenergetic CT image using Canon's DECT, and monoenergetic CT image with metal artefact reduction method using GE's DECT. The kV-CT image and DECT scans were performed with the water-based polymethyl methacrylate phantom with various metal materials (brass, aluminium, copper, stainless steel, steel, lead, and titanium). Two types of metal artefact reduction (MAR) algorithm with the monoenergetic CT images were used. Smart MAR implemented by GE and the kV-CT images with MAR algorithms. Single-energy metal artefact reduction (SEMAR), implemented by Canon, was reconstructed. The artefact index was evaluated using the converted electron density values from the kV-CT and DECT images. The artefact index with all material inserts in the monoenergetic CT images were smallest at 70-90 keV for Canon and 140 keV for GE. The artefact index without SEMAR was larger than that with SEMAR for the 80 and 135-kV CT images. In the comparison of the artefact index for the converted electron density images from the 80 and 135-kV CT images with SEMAR, as well as the monoenergetic CT images with and without MAR, the monoenergetic CT image at 140 keV with MAR showed a reduction. In the comparison of the monoenergetic CT images at 140 keV and other energy ranges without and with Smart MAR, there was no statistically significant difference (P < 0.05) for all-metal inserts at more than 100 keV for Canon's DECT and 70 keV for GE's DECT. The metal artefact could be reduced by using a monoenergetic CT image at high energy with MAR algorithm. The metal artefact for the different-contrast-scale images can be compared on the same contrast scale by the electron density conversion method.