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Health care institutions provide prevention strategies for coronavirus disease 2019 and non-infectious disease care. We investigated the characteristics of patient contamination in a radiotherapy room by examining the trajectory and number of airborne particles in the air when talking and coughing occurred and clarified the actual state of contamination in this closed space. Aerosols were visualized and evaluated in the vertical height and head-to-tail width directions when the participant was lying on the radiotherapy tabletop. Aerosol reach was significantly greater for loud voice and coughing both at vertical height and the head-to-tail width direction. The size and number of particles around the radiotherapy tabletop were also visualized and evaluated in the radiotherapy room. The radiotherapy staff who were in the presence of the participant sometimes had many particles adhering to their facial area; particle adhesion to the staff was dominated by small size particles. Particle adherence to the irradiation device surface near the ceiling had particles larger than 1 mm. Tabletop particles tended to have a wider size range, including bigger sizes and a larger count compared to the surrounding floor. The 0.7-m radius distance from the participant's mouth tended to be highly contaminated, and the smaller the particle size, the farther it reached. The capacity to estimate areas prone to contamination can be used to predict infection of other patients and medical staff in a radiotherapy room.

Anti-cancer treatments for lung cancer patients with interstitial lung disease (ILD) are challenging. The treatment options for ILD are often limited because of concerns that treatments can cause acute exacerbation (AE) of ILD. This study aimed to analyze the outcomes of carbon-ion radiotherapy (CIRT) for stage I non-small cell lung cancer (NSCLC) with ILD, using a multi-institutional registry. Patients with ILD who received CIRT for stage I NSCLC in CIRT institutions in Japan were enrolled. The indication for CIRT was determined by an institutional multidisciplinary tumor board, and CIRT was performed in accordance with institutional protocols. Thirty patients were eligible. The median follow-up duration was 30.3 months (range, 2.5–58 months), and the total dose ranged from 50 Gy (relative biological effectiveness [RBE]) to 69.6 Gy (RBE), and five different patterns of fractionation were used. The beam delivery method was passive beam in 19 patients and scanning beam in 11 patients. The 3-year overall survival (OS), cause-specific survival, disease-free survival (DFS) and local control (LC) rates were 48.2%, 62.2%, 41.2% and 88.1%, respectively. Grade > 2 radiation pneumonitis occurred in one patient (3.3%). In conclusion, CIRT is a safe treatment modality for stage I NSCLC with concomitant ILD. CIRT is a safe and feasible treatment option for early lung cancer in ILD patients.

Objective Data on the long-term outcomes of carbon-ion radiotherapy for non-squamous cell carcinomas are rare. Gunma University has been utilizing carbon-ion radiotherapy as a treatment for head and neck cancer since 2010. This study aimed to evaluate the long-term efficacy and safety of carbon-ion radiotherapy for the head and neck. Methods We prospectively evaluated 35 patients with non-squamous cell carcinoma who underwent carbon-ion radiotherapy at Gunma University Heavy Ion Medical Center between 2010 and 2014. The 5-year local control, overall survival, and progression-free survival rates were evaluated. Results The median age was 59 years (range, 31–77 years), and the median follow-up time was 65 months (range, 6.1–98.8 months). Overall, 32 and 3 patients received 64.0 Gy (relative biological effectiveness) and 57.6 Gy (relative biological effectiveness) in 16 fractions, respectively. Adenoid cystic carcinoma was the most dominant histopathological type (n = 21 patients, 60 %). The 5-year local control, progression-free survival, and overall survival rates were 74.5 %, 53.2 %, and 81.3 %, respectively. Nine patients had local recurrence, and six patients died. Adverse events included acute grade 3 radiation mucositis (Common Terminology Criteria for Adverse Events version 4.0) in 8 patients; this was improved immediately with conservative therapy. Late grade 4 adverse events were observed, including two cases of visual loss and one case of brain necrosis. No grade 5 adverse events were observed. Conclusion Carbon-ion radiotherapy achieves excellent local control and overall survival rates in non-squamous cell carcinoma patients with expected adverse events.

Carbon-ion radiotherapy is an attractive treatment option for unresectable/inoperable, nonsquamous cancers of the head and neck. Intraocular hemorrhage associated with carbon-ion radiotherapy for head and neck cancer is largely an unresearched area; hence, we investigated its incidence and predictive factors.We evaluated 79 patients (i.e., 158 eyes) with nonsquamous cancers of the head and neck treated by carbon-ion radiotherapy with a follow-up period of ≥12 months. Dosimetric parameters such as DSeven (8.9%) of 79 patients (158 eyes) developed intraocular hemorrhage with a median latent period of 24 months (range, 15-47 months). The 5-year cumulative incidence of intraocular hemorrhage was 6%. DDosimetric parameters such as V

Bone and soft-tissue sarcomas of the head and neck have very poor prognoses. This prospective study aimed to investigate the efficacy and safety of carbon-ion radiotherapy (C-ion RT) for bone and soft-tissue sarcoma of the head and neck.The present study was a prospective clinical study that included 10 consecutive patients diagnosed with bone and soft-tissue sarcoma of the head and neck who were treated with C-ion RT between 2012 and 2018 at our institution. C-Ion RT consisted of 70.4 Gy (relative biological effectiveness) in 16 fractions.The 3-year local control, overall survival, and progression-free survival rates for patients overall were 72.9%, 77.8%, and 36%, respectively.The present study demonstrated the efficacy of C-ion RT for bone and soft-tissue sarcoma of the head and neck; adverse events were within the expected range.

This retrospective study assessed the treatment planning data and clinical outcomes for 152 prostate cancer patients: 76 consecutive patients treated by carbon-ion radiation therapy and 76 consequtive patients treated by moderate hypo-fractionated intensity-modulated photon radiation therapy. These two modalities were compared using linear quadratic model equivalent doses in 2 Gy per fraction for rectal or rectal wall dose–volume histogram, 3.6 Gy per fraction-converted rectal dose–volume histogram, normal tissue complication probability model, and actual clinical outcomes. Carbon-ion radiation therapy was predicted to have a lower probability of rectal adverse events than intensity-modulated photon radiation therapy based on dose–volume histograms and normal tissue complication probability model. There was no difference in the clinical outcome of rectal adverse events between the two modalities compared in this study.

Simple Summary Lung cancer is a leading cause of cancer-related deaths worldwide. In the past few decades, radiotherapy has achieved outstanding technical advances and is widely used in the management of lung cancer. The anti-tumor effect of radiotherapy is mainly caused by DNA damage in cancer cells within the irradiated field. In addition, radiotherapy induces anti-tumor immune responses that are essential in cancer control. Recently, immune checkpoint molecules, such as cytotoxic T-lymphocyte-associated protein 4, programmed cell death-1/programmed death-ligand 1, and their inhibitors, have attracted significant attention for overcoming the immunosuppressive conditions in patients with cancer. Furthermore, some studies showed that the combination of immune checkpoint inhibitors and radiotherapy appears promising. In this review, we outlined evidence about the combination of radiotherapy, including particle therapy using protons and carbon ions, with immunotherapy in lung cancer treatment. Abstract Lung cancer is a leading cause of cancer-related deaths worldwide despite advances in treatment. In the past few decades, radiotherapy has achieved outstanding technical advances and is being widely used as a definitive, prophylactic, or palliative treatment of patients with lung cancer. The anti-tumor effects of radiotherapy are considered to result in DNA damage in cancer cells. Moreover, recent evidence has demonstrated another advantage of radiotherapy: the induction of anti-tumor immune responses, which play an essential role in cancer control. In contrast, radiotherapy induces an immunosuppressive response. These conflicting reactions after radiotherapy suggest that maximizing immune response to radiotherapy by combining immunotherapy has potential to achieve more effective anti-tumor response than using each alone. Immune checkpoint molecules, such as cytotoxic T-lymphocyte-associated protein 4, programmed cell death-1/programmed death-ligand 1, and their inhibitors, have attracted significant attention for overcoming the immunosuppressive conditions in patients with cancer. Therefore, the combination of immune checkpoint inhibitors and radiotherapy is promising. Emerging preclinical and clinical studies have demonstrated the rationale for these combination strategies. In this review, we outlined evidence suggesting that combination of radiotherapy, including particle therapy using protons and carbon ions, with immunotherapy in lung cancer treatment could be a promising treatment strategy.

Radiotherapy for angiosarcoma of the scalp has not been standardised yet. Hence, we aimed to retrospectively analyse the outcomes of patients treated with electron beam therapy or intensity-modulated radiation therapy (IMRT) for unresectable angiosarcoma of the scalp.Data from patients treated with chemoradiotherapy or radiotherapy alone for unresectable angiosarcoma of the scalp between March 2009 and March 2021 were evaluated. Survival and local control rates were analysed using the Kaplan-Meier method, and the log-rank test was used to compare groups. Adverse events were analysed using the Common Terminology Criteria for Adverse Events ver. 5.0.Sixteen patients were eligible for the study. Eight patients were treated with electron beam therapy and eight patients with IMRT. The median follow-up period was 18.0 months. The median radiation dose was 57 Gy in 19 fractions in the electron beam therapy group and 70 Gy in 35 fractions in the IMRT group. In the IMRT group, acute non-haematologic toxicity was observed in two patients with grade 3 dermatitis. The one-year overall survival rate, progression-free survival rate, and local control rate in the electron beam therapy group were 80.8%, 56.3%, and 77.4%, respectively, and the corresponding values in the IMRT group were 100%, 75%, and 100%, respectively. One-year local control was significantly better in the IMRT group compared to that in the electron beam therapy group (p=0.016).IMRT for angiosarcoma of the scalp may improve local control rates compared to electron beam therapy, but long-term follow-up studies are required to validate this finding.

Background: External auditory canal (EAC) cancer is a rare disease for which there are no adequate evidence-based treatment strategies. Radical radiotherapy is often used as the initial treatment for EAC cancer from the viewpoint of organ preservation. This study aimed to elucidate the efficacy of radiotherapy for squamous cell carcinoma (SCC) of the EAC.Methods: Fifteen consecutive patients with SCC of the EAC who were treated with radical radiotherapy were retrospectively analyzed. The fractional dose was 2.0 or 3.0, and the total dose ranged from 66 to 70 Gy. Three-dimensional conformal radiation therapy was performed on seven patients. Intensity-modulated radiation therapy was performed on eight patients. Patients with T1 disease were treated with radiotherapy alone. Patients with T2-4 disease were treated with chemoradiotherapy.Results: The median follow-up period was 30.4 months. The 3 year local control (LC) rate for all patients was 51%, the disease-free survival (DFS) rate was 44%, and the overall survival (OS) rate was 73%. For T1-3 disease, the 3 year LC rate was 74%, DFS was 62%, and OS was 89%. However, for T4 disease, the 3 year LC rate was 17%, DFS was 17%, and OS was 50%. In a univariate analysis, only the T-category was a significant factor for predicting LC and DFS (p = 0.006 and 0.02, respectively). All local recurrences were within the high-dose irradiated area.Conclusions: The results of this study suggest that chemoradiotherapy is a reasonable first-line treatment for T1-3 SCC of the EAC. However, the efficacy of chemoradiotherapy in T4 cases was inadequate. Further research is warranted to elucidate the efficacy of treatments with more intensive antitumor effects for locally advanced EAC cancers.

The feasibility and efficacy of hypofractionated salvage radiotherapy (HS-RT) for prostate cancer (PC) with biochemical recurrence (BR) after prostatectomy, and the usefulness of prostate-specific antigen (PSA) kinetics as a predictor of BR, were evaluated in 38 patients who received HS-RT without androgen deprivation therapy between May 2009 and January 2017. Their median age, PSA level and PSA doubling time (PSA-DT) at the start of HS-RT were 68 (53–74) years, 0.28 (0.20–0.79) ng/ml and 7.7 (2.3–38.5) months, respectively. A total dose of 60 Gy in 20 fractions (three times a week) was three-dimensionally delivered to the prostate bed. After a median follow-up of 62 (30–100) months, 19 (50%) patients developed a second BR after HS-RT, but only 1 patient died before the last follow-up. The 5-year overall survival and BR-free survival rates were 97.1 and 47.4%, respectively. Late grade 2 gastrointestinal and genitourinary morbidities were observed in 0 and 5 (13%) patients, respectively. The PSA level as well as pathological T-stage and surgical margin status were regarded as significant predictive factors for a second BR by multivariate analysis. BR developed within 6 months after HS-RT in 11 (85%) of 13 patients with a PSADT < 10 months compared with 1 (17%) of 6 with a PSA-DT ≥ 10 months (median time to BR: 3 vs 14 months, P < 0.05). Despite the small number of patients, our HS-RT protocol seems feasible, and PSA kinetics may be useful for predicting the risk of BR and determining the appropriate follow-up schedule.

Background & Aims: With the development of radiology, the demand for medical physicists is increasing, and the training of new medical physicists is becoming a necessity. Although a few questionnaire surveys regarding medical physicists and medical physicist training courses have been conducted, no survey reports have yet been conducted on examinees. This study is the first survey of general examinees.Methods: Gunma University has a webpage for test preparation, and we conducted a survey on examinees using this page, through a questionnaire and access analyses.Results: Approximately 80% of the users qualified as technologists. Considering the percentage of users by region, the number of medical physicists and accredited facilities were strongly correlated. The proportion of females was extremely low. Exam papers on “science and technology” and “radiation physics” were accessed more than those on “medical and biology” field. Thus, physics may be a shortcoming of many examinees; science and engineering majors were less likely to take exams and have lower pass rates.Conclusion: Recruitment and provision of learning environments for science and engineering graduates are required. To increase the number of students, while improving the quality of medical physicists, it is necessary to investigate current conditions of students in greater detail.

The purpose of this study was to clarify the opinions of radiation oncologists in Japan regarding treatment for lung cancer complicated with interstitial lung disease (ILD) by a questionnaire survey, and the risk of acute exacerbation (AE) after radiotherapy. Questionnaires were sent to all of the facilities in which radiation therapy is performed for lung cancer in Japan by using the mailing list of the Japanese Society for Radiation Oncology (JASTRO). The questionnaire survey was conducted to clarify who judges the existence of ILD, the indications for radiation therapy in cases of ILD-combined lung cancer, and the ratio of ILD-combined lung cancer in lung cancer patients treated with radiation therapy. Patients with ILD-combined lung cancer who received radiotherapy during the period from April 2014 to March 2015 were retrospectively analysed. Any cases of AE without any other obvious cause were included. ILD confirmation was performed by central radiologists using computed tomography images. A total of 47 facilities responded to the questionnaire. Radiation therapy was an option in cases of ILD-combined lung cancer in 39 (83%) of the facilities. The indication for radiation therapy was based on image findings in 35 (90%) of the 39 facilities in which radiation therapy was acceptable or was a choice in some cases of ILD. The final indication was based on the opinion of the pulmonologist in 29 (74%) of those 39 facilities. In fiscal year 2014, a total of 2128 patients in 38 facilities received chest irradiation. Seventy-eight (3.7%) of those 2128 patients had ILD-combined lung cancer. Sixty-seven patients were included in patient analysis. AE occurred in 5 patients (7.5%), and one of those 5 patients (20.0%) died from radiation-induced AE. The median period from radiotherapy to AE was 4 months (range, 2–7 months). The following four independent risk factors for AE were identified in univariate analysis: non-advanced age (

Background Nasopharyngeal cancer is endemic to Southeast Asia. However, there is limited clinical evidence of nasopharyngeal cancer in Indonesia, which has the largest population in Southeast Asia. Methods Patterns of care and treatment outcomes in 428 patients with newly-diagnosed and pathologically-confirmed nasopharyngeal cancer were retrospectively analyzed. Results Concurrent chemo-radiotherapy (CCRT) was the first-line treatment for stages I-IVB diseases. The 2-year overall survival (OS) of all patients were 100.0%, 100.0%, 93.8%, 86.2%, 82.9%, and 62.4% for stages I, II, III, IVA, IVB, and IVC, respectively. The 2-year OS of CCRT-treated patients were 100.0%, 100.0%, 92.6%, 82.4%, and 78.3% for stages I, II, III, IVA, and IVB, respectively. Conclusion The patterns of care and treatment outcomes were potentially consistent with world standards, needing future validation. This is the largest study of newly diagnosed nasopharyngeal cancer in Indonesia, a huge disease burden, providing an important basis for the clinical management of this disease.

This study aimed to explore the prognostic factors associated with acute radiation dermatitis (ARD). A normal tissue complication probability (NTCP) model for ARD in patients with head and neck cancer treated with carbon ion radiation therapy was developed.A total of 187 patients were included in the analysis, and the endpoint was ≥grade 2 ARD. The biological and physical dose-surface parameters associated with ARD were used in the logistic regression model. The mean areas under the receiver operating characteristic curve in the internal cross-validation and Akaike's corrected Information Criterion were examined for model evaluation and selection. The multivariate logistic regression NTCP models were established based on factors with weak correlation.Tumor volume, planning target volume to the skin, radiation technique and all dose-surface parameters were significantly associated with ARD (P.05). Models with high performance for grade 2 to 3 ARD were constructed. The most significant prognostic predictors were SNTCP models for ARD may provide a basis for the development of individualized treatment strategies and reduce the incidence of severe ARD in patients with head and neck cancer receiving carbon ion radiation therapy. Furthermore, biological and physical dose-surface parameter-based models are comparable. However, further validation with more evaluation parameters is warranted.

Simple Summary Colorectal cancer (CRC) screening is effective for cancer detection in average-risk adults. For prostate cancer (PCa) patients considered for carbon ion radiotherapy (CIRT), pre-treatment CRC screening is performed empirically to avoid post-treatment colonoscopic manipulation. However, the outcomes of screening remain unclear. To address this, we analyzed the outcomes of 2412 PCa patients at average risk for CRC who underwent routine pre-CIRT CRC screening and found that the estimated CRC prevalence was greater than that reported by 17 previous large-scale screening studies analyzing average-risk adults. These data indicate the possibility that the prevalence of CRC in PCa patients is greater than that in general average-risk adults, warranting further research. Abstract Colorectal cancer (CRC) screening is effective for detecting cancer in average-risk adults. For prostate cancer (PCa) patients considered for carbon ion radiotherapy (CIRT), pre-treatment CRC screening is performed empirically to avoid post-treatment colonoscopic manipulation. However, the outcomes of screening this population remain unclear. Here, we compared the outcomes of routine pre-CIRT CRC screening of 2412 PCa patients at average risk for CRC with data from two published datasets: the Japan National Cancer Registry (JNCR) and a series of 17 large-scale screening studies analyzing average-risk adults. The estimated prevalence rate was calculated using the pooled sensitivity elucidated by a previous meta-analysis. Consequently, 28 patients (1.16%) were diagnosed with CRC. CRC morbidity was significantly associated with high pre-treatment levels of prostate-specific antigen (p = 0.023). The screening positivity rate in this study cohort exceeded the annual incidence reported in the JNCR for most age brackets. Furthermore, the estimated prevalence rate in this study cohort (1.46%) exceeded that reported in all 17 large-scale studies, making the result an outlier (p = 0.005). These data indicate the possibility that the prevalence of CRC in PCa patients is greater than that in general average-risk adults, warranting further research in a prospective setting.

Interstitial lung disease (ILD) is a risk factor both for the development and treatment failure of lung cancer. In this retrospective study, we analyzed the outcome of carbon-ion radiotherapy (CIRT) in 124 patients with clinical stage I non-small cell lung cancer (NSCLC), of whom 26 (21%) had radiological signs of pre-existing ILD. ILD was diagnosed retrospectively by a pulmonologist based on critical review of CT-scans. Ninety-eight patients were assigned to the non-ILD group and 26 patients (21.0%) to the ILD group. There were significant differences in pre-treatment KL-6 values between the two groups. The three year overall survival and cause-specific survival rates were 83.2% and 90.7%, respectively, in the non-ILD group, and 59.7% and 59.7%, respectively, in the ILD group (between-group differences, p = 0.002 and p &lt, 0.001). Radiation pneumonitis worse than Grade 2 was observed in three patients (3.0%) in the non-ILD group and two patients (7.6%) in the ILD group (p = 0.29). There were no cases of acute exacerbation in the ILD group. CIRT for stage I NSCLC was as safe in the ILD group as in the non-ILD group. Coexisting ILD was a poor prognostic factor in CIRT for clinical stage I lung cancer.

The promising results of the PACIFIC study led to the approval of consolidation durvalumab for coverage by the National Health Insurance (NHI) in 2018 for patients with locally-advanced unresectable non-small cell lung carcinoma (NSCLC) treated with definitive concurrent chemoradiotherapy (CCRT). However, the effect of NHI coverage on the patterns of care for this population remains unclear. Here, we conducted a questionnaire-based survey to determine the patterns of care for patients with stage II-III NSCLC treated with definitive radiotherapy in 2017 (pre-durvalumab era) or in 2019 (post-durvalumab era). Data were obtained from 11 radiotherapy facilities in Gunma prefecture, which has a population of 1.94 million. We identified 80 and 83 patients with stage II-III NSCLC who received definitive radiotherapy in Gunma in 2017 and 2019, respectively. At a given facility, CCRT was the treatment of choice in a significantly greater proportion of patients in 2019 than in 2017 (66% ± 20% vs 51% ± 29%, P = 0.041). Intensity-modulated radiotherapy (IMRT) was more frequent in 2019 than in 2017 (24% vs 1.2%). Carboplatin plus paclitaxel was used for CCRT at higher rate in 2019 than in 2017 (73% vs 44%). Consolidation durvalumab was performed in 73% (40/55) of CCRT-treated patients in 2019, and the treatment was performed for the planned 12 months in 45% (18/40) of patients. These data indicate that NHI coverage of durvalumab might be a possible reason for choosing CCRT in patients with stage II-III NSCLC in the real-world setting.

Background: Tooth loss reduces quality of life, however, little is known about tooth loss caused by carbon ion radiotherapy (CIRT). Here, we aimed to elucidate the incidence of tooth loss post-CIRT for head and neck tumors and to identify risk-predictive dosimetric parameters. Methods: This study enrolled 14 patients (i.e., 171 teeth in total) with head and neck non-squamous cell carcinoma. All patients received CIRT comprised of 57.6 or 64.0 Gy (relative biological effectiveness, RBE) in 16 fractions. Dose–volume analysis of the teeth was performed using receiver operating characteristic (ROC) curve analysis with VX (i.e., the volume irradiated with X Gy (RBE)). Results: The median follow-up period was 69.1 months. The median time of tooth loss was 38.6 months. The 5 year cumulative incidence of tooth loss was 13.3%. The volume of irradiated teeth was significantly greater for the lost teeth than for the remaining teeth throughout the dose range. Using the cut-offs calculated from ROC curve analysis, V30–V60 showed high accuracy (i.e., &gt, 94%) for predicting tooth loss, with V50 being the most accurate (cut-off, 58.1%, accuracy, 0.95). Conclusions: This is the first report to examine the incidence of tooth loss post-CIRT and to identify risk-predictive dosimetric parameters.

A 50-year-old woman with a long history of nasopharyngeal cancer (T2N2M0, squamous cell carcinoma) underwent chemoradiotherapy and surgery. In the past, to prevent tumor recurrence or metastasis, she underwent concurrent chemoradiotherapy or neck dissection. However, during a follow-up 10 years after the surgery, intense F-18 fluorodeoxyglucose uptake was detected in the oral area (SUVmax 6.0). A biopsy of the area with F-18 fluorodeoxyglucose uptake revealed pathological inflammation. Radiography showed the presence of a wisdom tooth, located at the F-18 fluorodeoxyglucose accumulation site, and pericoronitis of this tooth was detected. Our findings indicate the importance of considering the effect of inflammatory conditions, such as periodontal disease, in using F-18 fluorodeoxyglucose positron emission tomography/computed tomography during follow-up after head and neck cancer treatment.

Little information is available on the risk factors for nasolacrimal duct obstruction after radiotherapy for head and neck tumors. We investigated the incidence and predictive dosimetric parameters for nasolacrimal duct obstruction following carbon-ion radiotherapy for head and neck tumors.Twenty-eight patients with head and neck non-squamous cell carcinoma were analyzed in this single-institution prospective study. More than half of the tumors were located in the nasal cavity and maxillary sinus. Carbon-ion radiotherapy consisting of 57.6 or 64.0 Gy(relative biological effectiveness; RBE) in 16 fractions was administered. Nasolacrimal duct obstruction was recorded according to Common Terminology Criteria for Adverse Events version 4.0. Cutoff values were determined using receiver operating characteristic (ROC) curve analysis. VX indicates the volume irradiated with X Gy(RBE).The median follow-up period was 60.3 months. Incidences of Grade 1 and 2 nasolacrimal duct obstructions were 46% (13/28) and 7% (2/28), respectively; no Grade 3 or greater toxicities were recorded. Throughout the dose range, the volumes of the irradiated nasolacrimal ducts were significantly higher in the obstruction-positive patients than in the obstruction-negative patients (p 0.001 for V10, V20, V30, V40, V50, and V60). Cutoff values determined by the ROC curve analysis classified the obstruction-positive patients with an accuracy of96% over the entire range of V10-V60.The incidence and predictive dosimetric parameters for nasolacrimal duct obstruction after carbon-ion radiotherapy were demonstrated in a prospective cohort. These data should help optimize carbon-ion radiotherapy treatments for patients with head and neck tumors.

This study aimed to evaluate the efficacy of carbon‐ion radiotherapy in combination with chemotherapy using dacarbazine, nimustine, and vincristine (DAV therapy) in mucosal melanoma. Twenty‐one patients with clinically localized mucosal melanoma of the head and neck were enrolled. The primary endpoint was 3‐year overall survival (OS). Secondary endpoints included local control, progression‐free survival (PFS), and adverse event occurrence. Carbon‐ion radiotherapy with a dose of 57.6‐64.0 Gy (relative biological effectiveness) in 16 fractions was delivered concurrently with DAV therapy, and 2 cycles of adjuvant DAV therapy were administered every 6 weeks. The median follow‐up periods were 15.5 months for all patients, and 31.2 months for 12 surviving patients. All patients had locally advanced T4a or T4b disease in the rhino‐sinus area. In 16 patients (76.2%), 3 cycles of planned DAV therapy were completed. The 3‐year OS and PFS rates were 49.2% and 37.0% respectively. The 3‐year local control rate was 92.3%. Eleven patients (52%) developed distant metastasis, which was the most frequent pattern of the first failure. Commonly presenting acute grade 2‐3 toxicities associated with radiotherapy and chemotherapy were mucositis (11 patients [53%]) and leukopenia (9 patients [43%]), which improved with conservative therapy. None of the patients developed grade 3 or greater late toxicities. Carbon‐ion radiotherapy in combination with DAV therapy led to excellent local control for advanced mucosal melanoma within acceptable toxicities. The efficacy of additional DAV therapy in improving survival was weaker than expected as distant metastases still occurred frequently. Trial registration no. UMIN000007939., It is the first prospective trial to evaluate the clinical outcomes of carbon‐ion radiotherapy combined with chemotherapy.

Cervical stump cancer, which arises in the remaining uterine cervix of a woman with a history of supravaginal hysterectomy, accounts for 1.6-4.4% of all cervical cancers. The close proximity of the rectosigmoid colon to the primary tumor, which is due to the absence of the uterine corpus, should be considered carefully in the treatment planning of brachytherapy. Although three-dimensional image-guided brachytherapy (3D-IGBT) is used widely to treat cervical cancer in those with an intact uterine corpus, the safety and efficacy of 3D-IGBT for cervical stump cancer remains unclear. Here, we report a case of cervical stump cancer (T3bN1M0) treated successfully with definitive radiotherapy, which combined external beam radiotherapy and computed tomography (CT)-based IGBT. By applying the dose prescription concept used for definitive brachytherapy of cervical cancer with an intact uterine corpus, IGBT achieved satisfactory dose conformity to the tumor while sparing the adjacent rectosigmoid colon. This led to local tumor control for three years and eight months, with no late adverse effects. This case suggests that radiotherapy using CT-based IGBT is a safe and effective treatment for cervical stump cancer.

Castration-resistant prostate cancer shows resistance to not only androgen deprivation therapy (ADT) but also X-ray therapy. On the other hand, carbon ion beams have a high biological effect and are used for various cancers showing resistance to X-ray therapy. The purposes of this study are to clarify the difference in the sensitivity of Castration-resistant prostate cancer to X-ray and carbon ion beams and to elucidate the mechanism. The androgen-insensitive prostate cancer cell line LNCaP-LA established by culturing the androgen-sensitive prostate cancer cell line LNCaP for 2 years in androgen-free medium was used for this study. First, colony formation assays were performed to investigate its sensitivity to X-ray and carbon ion beams. Next, DNA mutation analysis on 409 cancer-related genes and comprehensive transcriptome analysis (RNA-seq) were performed with a next-generation sequencer. Lethal dose 50 values of X-rays for LNCaP and LNCaP-LA were 1.4 Gy and 2.8 Gy, respectively (P

Background and purpose Osteoradionecrosis (ORN) affects the patient’s quality of life by making eating and maintaining oral hygiene painful. This study aimed to analyze carbon ion radiotherapy (C-ion RT)-induced ORN of the mandible. Materials and methods A retrospective study of 199 patients with head and neck tumors treated with C-ion RT was performed from 2010 to 2019. Only 11 patients with tumors located in the oropharynx and floor of the mouth were analyzed. C-ion RT consisted of 57.6 Gy or 64.0 Gy (relative biological effectiveness) in 16 fractions. The mandible was analyzed for magnetic resonance imaging (MRI) changes and bone exposure. The relationship between the radiation dose and ORN of the mandible was analyzed. Results Five patients (45.5%) had ORN of the mandible. The median follow-up time was 68 months. The median onset times based on MRI changes and bone exposure were 9 and 15 months, respectively. Doses of 30 Gy (relative biological effectiveness) to the mandible and teeth showed the most significant effect, causing ORN at 29.5 ± 6.7 cc and 3.9 ± 1.8 cc, respectively, with cut-off values at 16.5 cc (p = 0.002) and 1.8 cc (p = 0.0059), respectively. Conclusion This is the first study reporting the incidence, onset time, and risk-predictive dosimetry parameters of C-ion RT-induced ORN of the mandible. Our study will be useful for establishing clinical strategies for C-ion RT to the head and neck near the mandible.