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This study aimed to investigate whether ipsilateral lung doses (ILDs) could be predicted by anatomical indexes measured using diagnostic computed tomography (CT) prior to the planning stage of breast radiation therapy (RT).The thoracic diameters and the length of lines drawn manually were measured on diagnostic CT images. The parameters of interest were the skin maximum lung distance (sMLD), central lung distance (CLD), Haller index (HI), and body mass index (BMI). Lung dose-volume histograms were created with conformal planning, and the lung volumes receiving 5-40 Gy (V5-V40) were calculated. Linear regression models were used to investigate the correlations between the anatomical indexes and dose differences and to estimate the slope and 95% confidence intervals (CIs).A total of 160 patients who had undergone three-dimensional conformal RT after breast-conserving surgery were included. Univariable analysis revealed that the sMLD (p0.001), CLD (p0.001), HI (p = 0.002), and BMI (p0.001) were significantly correlated with the V20. However, multivariable analysis revealed that only the sMLD (slope: 0.147, p = 0.001, 95% CI: 0.162-0.306) and CLD (0.157, p = 0.005, 0.048-0.266) were strongly correlated with the V20. The p-value for the sMLD was the lowest among the p-values for all indexes, thereby indicating that the sMLD had the best predictive power for ILD.sMLD and CLD are anatomical markers that can be used to predict ILD in whole breast RT. An sMLD20.5 mm or a CLD24.3 mm positively correlated with a high ILD.

The purpose of this study is to evaluate the detection accuracy of a 3-dimensional (3D) body scanner, VOXELAN, in surface-guided radiotherapy (SGRT) of each part of the human body using a whole-body human phantom. We used A Resusci Anne was used as the whole-body phantom. The detection accuracy of VOXELAN in a radiotherapy treatment room with a linear accelerator (LINAC) was evaluated for two reference images: reconstruction of the planning computed tomography (CT) image (CT reference) and scanning by VOXELAN before the treatment (scan reference). The accuracy of the translational and rotational directions was verified for four treatment sites (open face shell, breast, abdomen, and arm), using the magnitude of the 6D robotic couch movement as the true value. Our results showed that the detection accuracy improved as the displacement from the reference position decreased for all the sites. Using the scan reference, the average accuracy of the translational and rotational axes was within 1.44 mm and 0.41°, respectively, for all sites except the arms. Similarly, using the CT reference, the average accuracy was within 2.45 mm and 1.35°, respectively. Additionally, it was difficult for both reference images to recognize misalignment of the arms. In conclusion we discovered that VOXELAN achieved a high detection accuracy for the head with an open face shell, chest, and abdomen, indicating that the system is useful in a clinical setting. However, it is necessary to pay attention to location matching for areas with few features, such as surface irregularities and potential errors, when the reference image is created from CT.

We aimed to evaluate the impact of systemic autoimmune diseases (SADs) on treatment outcomes and radiation toxicities following stereotactic body radiation therapy (SBRT) for stage I non-small cell lung cancer (NSCLC). We queried an institution-based database on patients with SADs treated with SBRT for lung cancer between 2001 and 2016 (SAD group). Each patient was matched to three controls without SADs. The primary outcomes of interest were the overall survival (OS) and local control rate (LCR). The secondary outcomes were radiation toxicities of grades ≥2 (≥G2). Twelve patients with SADs were matched to 36 controls. The median follow-up duration was 3.6 years. There was a significant intergroup difference in the OS (hazard ratio [HR]: 4.11, 95% confidence incidence [CI]: 1.82–9.27, p < 0.001) and LCR (HR: 15.97, 95% CI: 2.89–88.29, p < 0.001). However, there were no significant intergroup differences in the odds of acute (odds ratio [OR]: 0.38, 95% CI: 0.02–8.91, p = 0.550) and late (OR: 2.20, 95% CI: 0.32–15.10, p = 0.422) ≥G2 radiation pneumonitis. No other ≥G2 toxicities were identified. In conclusion, although radiation toxicities are not enhanced by SADs, SADs are risk factors of poor prognosis following SBRT for stage I NSCLC.

The purpose of this study was to measure the motion of the chest surface during breath-holding treatment for lung cancer using deformable image registration (DIR). Forty non-small-cell lung cancer patients treated with breath-holding stereotactic body radiation therapy were retrospectively examined. First, intensity-based DIR between 2 breath-holding computed tomography (CT) images was performed. Subsequently, deformation vector field (DVF) for all dimensions (left-right, anterior-posterior, and superior-inferior) was calculated from the result. For the analysis of chest surface, the DVF value of the only chest surface area was extracted after the chest surface was divided into 12 regions of interest (ROI) based on anatomy. Additionally, for the analysis of the correlation with the internal tumor motion, the median value of DVF for each surface ROI and the motion of the center of gravity of the tumor volume were used. It was possible to calculate the motion of chest surface without any outliers for all patients. For the average of 12 surface ROIs, the motion of 3D chest surface was within 2 mm (30 cases), 3 mm (8 cases), and 4 mm (2 cases). There was no correlation between the motion of the chest surface and that of the tumor for all 12 surface ROIs. We proposed a technique to evaluate the surface motion using DIR between multiple CT images. It could be a useful tool to calculate the motion of chest surface.

The purpose of the study was to investigate the association between tumor volume changes during stereotactic body radiation therapy (SBRT) and prognoses in stage I non-small-cell lung cancer (NSCLC). This retrospective review included stage I NSCLC patients in whom SBRT was performed at a total dose of 48.0–50.5 Gy in four or five fractions. The tumor volumes observed on computed tomography (CT) simulation and on the CT performed at the last treatment session using a CT-on-rails system were measured and compared. Then, the tumor volume changes during the SBRT period were measured and assessed for their association with prognoses (overall survival, local control, lymph node metastases and distant metastases). A total of 98 patients with a mean age of 78.6 years were enrolled in the study. The T-stage was T1a in 42%, T1b in 32% and T2a in 26% of the cases. The gross tumor volume (GTV) shrank and increased ≥10% in 23 (23.5%) and 36 (36.7%) of the cases, respectively. The 5-year local control and overall survival rates in the groups with a tumor shrinkage of ≥10% vs the group with a shrinkage of

We retrospectively reviewed the effect of stereotactic body radiation therapy (SBRT) in patients with stage I lung cancer whose lung tumor showed a nodular appearance of ground glass opacity, so-called ground glass nodule (GGN). A total of 84 patients (42 men, 42 women; mean age, 75 years) with stage I lung cancer with GGN accompanying a solid component

This study aimed to evaluate the rectal dose reduction with hydrogel spacer in 3D conformal radiotherapy (3DCRT), volumetric modulated arc therapy (VMAT), helical tomotherapy (HT), CyberKnife (CK) and proton therapy. Twenty patients who had hydrogel spacer for prostate radiotherapy were retrospectively enrolled. Computed tomography (CT) images with or without hydrogel spacer were used to evaluate rectal dose reduction. In total, 200 plans (20 patients × 2 CT images × 5 techniques) were created using the following criteria: 3DCRT, VMAT and HT [76 Gy/38 fractions (Fr), planning target volume (PTV) D50%], CK (36.25 Gy/5 Fr, PTV D95%) and proton therapy (63 GyE/21 Fr, PTV D50%). Rectal dose reduction was evaluated using low-/middle-dose (D20%, D50% and D80%) and high-dose (D2%) ranges. Rectal dose reduction of each dose index was compared for each technique. Significant rectal dose reduction (P

AIM: To evaluate the target dose coverage for lung stereotactic body radiotherapy (SBRT) using helical tomotherapy (HT) with the internal tumor volume (ITV) margin settings adjusted according to the degree of tumor motion. BACKGROUND: Lung SBRT with HT may cause a dosimetric error when the target motion is large. MATERIALS AND METHODS: Two lung SBRT plans were created using a tomotherapy planning station. Using these original plans, five plans with different ITV margins (4.0–20.0 mm for superior-inferior [SI] dimension) were generated. To evaluate the effects of respiratory motion on HT, an original dynamic motion phantom was developed. The respiratory wave of a healthy volunteer was used for dynamic motion as the typical tumor respiratory motion. Five patterns of motion amplitude that corresponded to five ITV margin sizes and three breathing cycles of 7, 14, and 28 breaths per minute were used. We evaluated the target dose change between a static delivery and a dynamic delivery with each motion pattern. RESULTS: The target dose difference increased as the tumor size decreased and as the tumor motion increased. Although a target dose difference of

The purpose of this study was to evaluate the robustness of 3-dimensional conformal technique with MLC position control into the planning target volume (PTV) in stereotactic body radiotherapy for lung cancer. Two techniques using fixed beams were compared; one technique involved setting the MLC position outside the PTV and was referred to as Plan "O." Another technique involved setting the MLC position inside the PTV and was referred to as Plan "I." Two tumor motions were simulated: (1) tumor motion on the internal target volume (ITV) boundary and (2) tumor motion on the PTV boundary. Ten-phase CT images that captured the tumor in respiratory motion were generated for 2 simulations. Then, 4-dimensional (4D) treatment planning was performed by using deformable image registration. The gross tumor volume (GTV) dose changes between the 4D accumulated dose and treatment planning dose were evaluated for Plan "O" and Plan "I," respectively. For the simulation of tumor motion on the ITV boundary, the changes in GTV D50% were -0.10 ± 0.31% and -0.22 ± 0.26% (p < 0.05) for Plan "O" and Plan "I," respectively. In the same manner, for the simulation of tumor motion on the PTV boundary, the changes in GTV D50% were -3.37 ± 2.16% and -3.68 ± 1.71% (p < 0.05). Our result suggested that the dose change would be negligible in a clinical situation where the tumor moves within the ITV margin for both techniques, while Plan "O" showed better robustness.

The present study evaluated the short-term characteristics (3 days) of a hydrogel spacer from the time of injection during stereotactic body radiation therapy (SBRT) for prostate cancer.Fifteen patients treated with SBRT via the CyberKnife system (36.25 Gy/5 fractions) were enrolled in this retrospective study. Two magnetic resonance (MR) images were obtained with a hydrogel spacer: one on a computed tomography (CT) simulation day (MR pretreatment [MRThe median period between hydrogel spacer injection and CT simulation was 1 day (range, 1-9 days). The median period between CT simulation and the last treatment was 17 days (range, 14-25 days). Regarding the volume change of the hydrogel spacer, the 2 observers observed significant differences between the volumes of the hydrogel spacer on the MRA single day is an acceptable interval between hydrogel spacer injection and treatment planning for SBRT for prostate cancer.

This study aimed to evaluate the reproducibility of deep inspiration breath-hold (DIBH) using a respiratory control device, Abches, in patients with left-sided breast cancer.Abches comprises a main body, an indicator panel, and two fulcrums, one each on the chest and abdomen. Forty left side breast cancer patients treated with DIBH using abches were enrolled in this study. For all patients, CT images were taken three times to confirm the target position inside the body and to check the breath-hold reproducibility. Three anatomical points on the nipple, sternum, and heart were selected as measurement points on CT images. After measuring the coordinates, breath-hold reproducibility was defined as the mean of the absolute difference in the coordinates between the three CT images. The maximum differences were also investigated. In addition, the dice similarity coefficient (DSC) was calculated to examine the displacement of the heart volume in detail. Moreover, digitally reconstructed radiographs (DRRs) and linac graphs (LGs) were used to measure the positional accuracy of the chest and heart.The reproducibility in all patients was within 0.75 mm for the nipple, 0.78 mm for the sternum, and 2.18 mm for the heart in each direction. Similarly, the maximum displacements for all patients were within 1.90 mm, 1.69 mm, and 4.75 mm, respectively, in each direction. For heart volume, the average DSC for all cases was 0.93 ± 0.01. The differences between the DRR and LG images were 1.70 ± 1.10 mm and 2.10 ± 1.60 mm, for the chest and heart, respectively.Our study showed that DIBH using Abches can be performed with good target reproducibility of less than 3 mm with proper breath-hold practice, whereas the heartbeat-derived reproducibility of the cardiac position is poor and needs to be monitored carefully during treatment simulation.

The present report describes a case series in which spacers with boluses were used at various sites in the oral cavity to enhance the therapeutic effect of radiation therapy in oral squamous cell carcinoma. In radiotherapy, the surface dose is reduced due to the build-up region of X-rays. In the present study, a bolus was used to complement the build-up region and increase the surface dose effect. A total of 7 patients with oral cancer from a primary care hospital underwent radiation therapy using spacers and added boluses to improve the surface dose effect. The spacer was made from a plastic splint and the bolus was connected to the splint with a quick self-curing resin. There were no complaints of pain or adverse events from the patients while wearing the intraoral splint. A total of 2 of the 7 patients were subsequently confirmed as having progressed disease, and the remaining 5 are currently being managed following a complete response to treatment. The spacers used at various sites of oral squamous cell carcinoma were safe and effective and did not cause any severe adverse effects.

BACKGROUND: 3-dimensional intra-cone beam computed tomography (intra-CBCT) could be a potentially powerful tool for use with arc irradiation such as volumetric modulated arc therapy. The aim of the study was to evaluate the image quality of intra-cone beam computed tomography (intra-CBCT) for arc irradiation with various imaging condition. MATERIALS AND METHODS: Two types of intra-CBCT imaging techniques were evaluated — intra-fractional CBCT with flattening filtered (FF) beam (intra-FF CBCT) and that with flattening filter free (FFF) beam (intra-FFF CBCT). For the intra-MV beams, four different field sizes (2 cm x 2 cm, 5 cm x 5 cm, 10 cm x 10 cm, and 20 cm x 20 cm) were used with dose rates of 500 MU/min and 1600 MU/min, for 6 MV FF and 6 MV FFF, respectively. For all image acquisitions, two rotation angles (full-arc and half-arc) were investigated. Thereafter, the linearity, contrast-to-noise ratio (CNR), and uniformity index (UI) of intra-CBCT image were compared with those of conventional CBCT image. RESULTS: All acquisition conditions had good linearity of the CT value (R 2 > 0.99). For CNR, the change rates from conventional CBCT ranged from 0.6–33.7% for a 2 cm x 2 cm beam, whereas that for a 20 cm x 20 cm beam ranged from 62.7–82.3%. Similarly, the UI increased from 1.5% to 7.0% as the field size increased. CONCLUSION: Quality of intra-CBCT image was affected by the field size and acquisition angle. Image quality of intra-CBCT was worse than that of conventional CBCT, but it was better under a smaller field and wider correction angle and would be acceptable for clinical use.

We aimed to assess the predictive value of the modified Glasgow prognostic score (mGPS) in patients with non-small cell lung cancer (NSCLC) who underwent stereotactic body radiation therapy (SBRT). We retrospectively reviewed the records of 207 patients, with a median age of 79 years. The pretreatment mGPS was calculated and categorized as high (mGPS = 1–2) or low (mGPS = 0). The median follow-up duration was 40.7 months. The five-year overall survival (OS), progression-free survival (PFS) and time to progression (TTP) rates were 44.3%, 36% and 54.4%, respectively. Multivariate analysis revealed that mGPS was independently predictive of OS (hazard ratio [HR] 1.67; 95% confidence interval 1.14–2.44: P = 0.009), PFS (HR 1.58; 1.10–2.28: P = 0.014) and TTP (HR 1.66; 1.03–2.68: P = 0.039). Patients who had high mGPS showed significantly worse OS (33.3 vs 64.5 months, P = 0.003) and worse PFS (23.8 vs 39 months, P = 0.008) than those who had low mGPS. The data showed a trend that patients with high mGPS suffered earlier progression compared to those with low mGPS (54.3 vs 88.1 months, P = 0.149). We confirmed that mGPS is independently predictive of prognosis in NSCLC patients treated with SBRT.

Background and Purpose: We aimed to validate the usefulness of prescriptions based on gross tumor volume for stereotactic body radiotherapy for small peripheral lung tumors. Materials and Methods: Radiotherapy treatment planning data of 50 patients with small peripheral lung tumors (adenocarcinoma: 24, squamous cell carcinoma: 10, other: 1, unknown: 15) receiving breath-hold computed tomography-guided stereotactic body radiotherapy at our institution during 2013–2016 were analyzed. For each case, 3 dose prescription methods were applied: one based on 95% (PTVD95%) of the planning target volume, one based on 50% of the gross tumor volume (GTVD50%), and one based on 98% (GTVD98%) of the gross tumor volume. The maximum (GTVDmax), minimum (GTVDmin), and mean gross tumor volume dose (GTVDmean) and the dose covering 98% of the gross tumor volume were calculated to evaluate variations in the gross tumor volume dose. Results: Upon switching to GTVD50%, the variations in GTVDmax and GTVDmean decreased significantly, compared with variations observed for PTVD95% (p < 0.01), but the variation in GTVDmin increased significantly (p < 0.01). Upon switching to the GTVD98%, the variation in GTVDmean decreased significantly compared with that observed for PTVD95% (p < 0.01). Conclusion: Switching from prescriptions based on 95% of the planning target volume to those based on 98% of the gross tumor volume decreased variations among cases in the overall gross tumor volume dose. Overall, prescriptions based on 98% of the gross tumor volume appear to be more suitable than those based on 95% of the planning target volume in cases of small peripheral lung tumors treated with stereotactic body radiotherapy.

Purpose: To compare the reproducibility of breath-holding and comfort between two biofeedback guidance methods (audio and visual) in a respiratory monitoring system. Method and Materials: An audio-feedback respiratory monitoring device, which was modified from a visual-feedback self-respiration monitoring system (Abches, APEX Medical Inc., Tokyo, Japan) previously developed by the authors’ group, was constructed. Twenty patients (13 men, 7 women; mean age, 68.5 years; range, 54 - 85 years) with tumors in the thorax or abdominal region were enrolled in the present study. Computed tomography images were acquired from all patients three times using the two (i.e., audio and visual) respiration monitoring devices. To evaluate the reproducibility of breath-holding, the distance between an anatomical landmark and the tumor position was measured. Furthermore, patients were asked which guidance method they preferred (visual or audio) for comfortable breath-holding. Results: The two guidance methods improved the reproducibility of breath-holding compared with free-breathing, and no significant overall differences between two methods were observed (the mean displacements of the landmark-tumor distance were 2.60 ± 1.38 mm and 2.35 ± 1.63 mm, for visual and audio guidance, respectively). In five patients, the magnitude of position displacement in the series of three computed tomography images under audio guidance was twice as large as the other under visual guidance. Audio guidance was preferred to visual guidance by 65% (13 of 20) of the patients. However, the reproducibility of breath-holding did not always correspond with patient preference. Conclusion: There were some individual differences in the reproducibility of the visual and audio guidance methods. More appropriate, individualized guidance methods for each patient would improve the reproducibility of breath-holding in respiratory motion management.

The purpose of this study was to compare the MLC error sensitivity of various measurement devices for VMAT pre‐treatment quality assurance (QA). This study used four QA devices (Scandidos Delta4, PTW 2D‐array, iRT systems IQM, and PTW Farmer chamber). Nine retrospective VMAT plans were used and nine MLC error plans were generated for all nine original VMAT plans. The IQM and Farmer chamber were evaluated using the cumulative signal difference between the baseline and error‐induced measurements. In addition, to investigate the sensitivity of the Delta4 device and the 2D‐array, global gamma analysis (1%/1, 2%/2, and 3%/3 mm), dose difference (1%, 2%, and 3%) were used between the baseline and error‐induced measurements. Some deviations of the MLC error sensitivity for the evaluation metrics and MLC error ranges were observed. For the two ionization devices, the sensitivity of the IQM was significantly better than that of the Farmer chamber (P

Purpose: To evaluate the safety and efficacy of stereotactic body radiation therapy for primary lesion of renal cell carcinoma with long-term and regular follow-up of tumor size and renal function. Methods: This prospective study included 13 patients treated with stereotactic body radiation therapy for primary lesion of stage I renal cell carcinoma between August 2007 and June 2016 in our institution. Diagnosis of renal cell carcinoma was made by 2 radiologists using computed tomography or magnetic resonance imaging. A dosage of 60 Gy in 10 fractions or 70 Gy in 10 fractions was prescribed. The higher dose was selected if dose constraints were satisfied. Tumor response on imaging examination, local progression-free rate, overall survival, and toxicity were assessed. Results: The mean follow-up period was 48.3 months (range: 11-108 months). The tumors showed very slow but continuous response during long-term follow-up. Three cases (23.1%) showed transient progression during the short follow-up. The mean duration until the day on which partial response was confirmed among the partial or complete response cases was 22.6 months (95% confidence interval, 15.3-30.0 months). Local progression-free rate was 92.3% for 3 years and overall survival rate 91.7% for 2 years and 71.3% for 3 years. Twelve cases (92.3%) had impaired renal function at baseline. Renal function decreased slowly and mildly in most of the cases, but 2 cases of solitary kidney showed grade 4 or 5 renal dysfunction. Conclusion: All renal tumors decreased in size slowly but continuously for years after stereotactic body radiation therapy. Renal cancer can be treated radically with stereotactic body radiation therapy as a radiosensitive tumor, but careful attention should be given in cases with solitary kidney.

Intrafractional setup errors during hypofractionated stereotactic radiotherapy (SRT) were investigated on the patient under voluntary breath-holding conditions with non-invasive immobilization on the CT-linac treatment table. A total of 30 patients with primary and metastatic lung tumors were treated with the hypofractionated SRT with a total dose of 48–60 Gy with four treatment fractions. The patient was placed supine and stabilized on the table with non-invasive patient fixation. Intrafractional setup errors in Right/Left (R.L.), Posterior/Anterior (P.A.), and Inferior/Superior (I.S.) dimensions were analyzed with pre- and post-irradiation CT images. The means and one standard deviation of the intrafractional errors were 0.9 ± 0.7mm (R.L.), 0.9 ± 0.7mm (P.A.) and 0.5 ± 1.0 mm (I.S.). Setup errors in each session of the treatment demonstrated no statistically significant difference in the mean value between any two sessions. The frequency within 3mm displacement was 98% in R.L., 98% in P.A. and 97% in I.S. directions. SRT under the non-invasive patient fixation immobilization system with a comparatively loose vacuum pillow demonstrated satisfactory reproducibility of minimal setup errors with voluntary breath-holding conditions that required a small internal margin.

Purpose To investigate prognostic and risk factors for recurrence after stereotactic body radiation therapy (SBRT) in patients with stage I non-small cell lung carcinoma (NSCLC), focusing on dual time point [18]F-fluorodeoxyglucose positron emission tomography (FDG PET). Materials and methods We prospectively evaluated 57 patients with stage I NSCLC (45 T1N0M0 and 12 T2N0M0) who had undergone pretreatment FDG-PET/CT and were subsequently treated with SBRT. All patients received a whole-body PET/CT scan at 60 min and a whole-lung at 120 min after the injection. The maximum standardized uptake value (SUV) and retention index (RI) of the lesions were calculated. Local recurrence, regional lymph node metastasis, distant metastasis, and the recurrence pattern were evaluated. Cox proportional hazard regression analyses were performed to evaluate prognostic factors or risk factors of recurrence. Results During the median follow-up period of 27 months, local recurrence, regional lymph node metastasis, and distant metastasis were seen in 17 (30%), 12 (21%), and 17 (30%) of the 57 patients, respectively. The 3-year overall survival rate was 63.4%. SUV max did not affect any recurrence, DFS, OS, or CSS. RI significantly predicted higher distant metastasis (HR 47.546, p = 0.026). In contrast, RI tended to predict lower local recurrence (HR 0.175, p = 0.246) and regional lymph node metastasis (HR 0.109, p = 0.115). Conclusions SUV max at staging FDG-PET does not predict any recurrence, DFS, OS or CSS. In contrast, higher RI predicts higher distant metastasis and tended to predict lower local or regional lymph node metastasis.

Stereotactic body radiotherapy (SBRT) for oligometastases represents a recent trend in radiation oncology. While abundant data are available regarding the use of SBRT for the treatment of lung or liver oligometastases from various retrospective series and prospective trials, relatively little information has been accumulated for the treatment of oligometastases at sites other than the lungs and liver, particularly for sequential oligometastases in multiple organs. Oligometastases with primary lesions controlled is called “oligo-recurrence.” We describe herein the case of a lung cancer patient who developed repeated oligo-recurrence at multiple sites that were each controlled by radical radiotherapy and achieved long-term survival and discuss the merits of locally aggressive radiotherapy for this type of disease condition with reviewing the literature. Although further investigation should be undertaken to clarify the benefits, objectives, and methods of SBRT for the treatment of oligometastases, we believe utilization of SBRT may be worthwhile for patients with remote metastases who hope for treatment to acquire better local control and possible longer survival.

A 45-year-old man complaining of cough, dyspnea, and difficulty in swallowing was referred to our hospital. Chest CT scan showed a mediastinal mass compressing the trachea. He was diagnosed with poorly differentiated lung carcinoma by percutaneous needle biopsy. Bronchoscopy and upper gastrointestinal endoscopy revealed a tracheoesophageal fistula (TEF). Long-lasting febrile neutropenia made it impossible to continue chemotherapy, but a course of radiotherapy (total 61 Gy) was completed. The next endoscopy revealed closure of the TEF. Chemoradiotherapy (CRT) has been reported to close TEF in esophageal cancer, but the risk of a CRT-induced worsening of the fistula has dissuaded physicians from using CRT to treat TEF in lung cancer patients. CRT may serve as a palliative treatment for TEF in lung cancer as well as esophageal cancer.

Pretreatment pulmonary interstitial change (PIC) has been indicated as a risk factor of severe radiation pneumonitis (RP) following stereotactic body radiation therapy (SBRT) for early-stage lung cancer, but details of its true effect remain unclear. This study aims to evaluate treatment outcomes of SBRT for stage I non-small cell lung cancer in patients with PIC. A total of 242 patients are included in this study (88% male). The median age is 77 years (range, 55&ndash, 92 years). A total dose of 40&ndash, 70 Gy is administered in 4 to 10 fractions during a 4-to-25 day period. One, two, and three-year overall survival (OS) rates are 82.1%, 57.1%, and 42.6%, respectively. Fatal RP is identified in 6.9% of all patients. The percent vital capacity &lt, 70%, mean percentage normal lung volume receiving more than 20 Gy (&gt, 10%), performance status of 2&ndash, 4, presence of squamous cell carcinoma, clinical T2 stage, regular use of steroid before SBRT, and percentage predicting forced expiratory volume in one second (&lt, 70%) are associated with worse prognoses for OS. Our results indicate that fatal RP frequently occurs after SBRT for stage I lung cancer in patients with PIC.

The aim of this study was to characterize computed tomography (CT) manifestations of local recurrence after stereotactic body radiation therapy (SBRT) for stage I non-small-cell lung cancer (NSCLC). A total of 27 stage I NSCLC patients who were treated with SBRT, including 5 patients with local recurrence, were retrospectively analyzed for serial CT examinations. A bulging margin appeared in 4 of the 5 cases (80%) with local recurrence and 1 of 22 cases (5%) without local recurrence. Air bronchograms were seen in 3 of 5 cases with local recurrence and 21 of 22 cases without local recurrence, but they subsequently disappeared in all 3 cases (100%) with local recurrence and in 4 of the 21 cases (19%) without local recurrence. Ipsilateral pleural effusion was observed in all 5 cases (100%) with local recurrence and in 5 of 22 cases (22%) without local recurrence. The opacity increased in size even after 12 months from the completion of SBRT in cases with local recurrence, whereas it decreased or did not change in size in cases without recurrence. Local recurrence should be suspected on CT when there was (1) a bulging margin, (2) disappearance of air bronchograms, (3) appearance of pleural effusion, or (4) increase in the abnormal opacity after 12 months.

The purpose of this study was to examine the characteristics and treatment plans of patients who experienced fatal radiation pneumonitis after stereotactic body radiation therapy for primary or oligometastatic lung cancer. Records of 1789 patients treated with stereotactic body radiation therapy for primary or oligometastatic lung cancer were retrospectively reviewed to identify those who developed fatal radiation pneumonitis. Twenty-three (1.3%; 18 men and 5 women) patients developed fatal radiation pneumonitis after stereotactic body radiation therapy for lung cancer; their median age was 74 years. The mean Krebs von den Lungen-6 level and percent vital capacity were 1320 U/mL and 82%, respectively. Prestereotactic body radiation therapy computed tomography revealed pulmonary interstitial change in 14 (73.7%) of 19 patients in whom computed tomography data could be reviewed. Seven (30.4%) of 23 patients had regularly used steroids. The median time duration between stereotactic body radiation therapy commencement and pneumonia symptom appearance was 75 (range: 14-204) days. Median survival time following pneumonia symptom appearance was 53 (range: 4-802) days. The 6- and 12-month overall survival rates were 34.8% and 13.0%, respectively. The 6-month overall survival rates in patients with and without heart disease were 50.0%, 16.7%, and 46.7% for heart disease existence, respectively. There were 4 patients in whom fatal radiation pneumonitis occurred within 2 months after stereotactic body radiation therapy and who died within 1 month. Three of them had no pulmonary interstitial change before stereotactic body radiation therapy, but had heart disease. In summary, the survival time in this case series was generally short but varied widely. More than half of the patients had pulmonary interstitial change before stereotactic body radiation therapy, although immediately progressive fatal radiation pneumonitis was also observed in patients without pulmonary interstitial change. True risk factors for fatal radiation pneumonitis should be examined in a prospective study with a larger cohort.

We have developed a novel irradiation technique for lung cancer that combines a linear accelerator and CT scanner with patient-controlled breath-hold and radiation beam switching. We applied this technique to stereotactic three-dimensional (3D) conformal radiotherapy for stage I non-small cell lung cancer (NSCLC) and evaluated the primary therapeutic outcomes. A total of 35 patients with stage I (15 IA, 20 IB) primary NSCLC (20 adeno, 13 squamous cell, and 2 others) were treated with this technique. Patients ranged from 65 to 92 years old (median, 78 years). Twenty-three (66%) patients were medically inoperable due to mainly chronic pulmonary disease or high age. Three-dimensional treatment plans were made using 10 different non-coplanar dynamic arcs. The total dose of 60 Gy was delivered in 10 fractions (over 5-8 days) at the minimum dose point in the planning target volume (PTV) using a 6 MV X-ray. After adjusting the isocenter of the PTV to the planned position by a unit comprising CT and linear accelerator, irradiation was performed under patient-controlled breath-hold and radiation beam switching. All patients completed the treatment course without complaint. Complete response (CR) and partial response (PR) rates were 8/35 (23%) and 25/35 (71%), respectively. Pulmonary complications of National Cancer Institute-Common Toxicity Criteria grade >2 were noted in three (9%) patients. During follow-up (range, 6-30 months; median, 13 months), two (6%) patients developed local progression and five (14%) developed distant or regional lymph node metastases. Two-year overall survival rates for total patients and medically operable patients were 58 and 83%, respectively. In conclusion, this new irradiation technique, utilizing patient-controlled radiation beam switching under self-breath-hold after precise alignment of the isocenter, allows safe high-dose stereotactic radiotherapy with sufficient margins around the CTV and reduced treatment times. Based on the initial results, excellent local control with minimal complications is expected for stage I NSCLC.

上顎洞扁平上皮癌に対して, 動注療法を同時併用した根治的放射線治療 (手術は生検か開洞腫瘍掻爬のみ) 後に1年以上局所再発の無かった症例 (A群) と, 動注療法を同時併用した術前照射後の pathological CR症例 (B群) を分析した。当科で放射線治療を行った上顎洞癌全45例中, A群は10例 (stage II 1例, stage III 5例, stagel IVA 4例), B群は9例 (stage III 3例, stage IVA 6例) であった。照射終了時のCT画像的評価は, A群でCR70%, B群で67%であった。局所再発はA群10例中1例で, B群9例中1例に認めた。5年粗生存率, 5年原病生存率は, A群10例の53%, 89%, B群で67%と, 67%であった。動注化学療法同時併用の放射線治療後に縮小効果良好なものでは, 上顎骨温存を試みるべきである。

Background Treatment of primary renal cell carcinoma using radiotherapy with curative intent is rare, because renal cell carcinoma is generally regarded as a radiation-resistant tumor. Recently, stereotactic body radiation therapy has been radically applied for cancers in various organs including renal cell carcinoma. However, there were few reports describing pathological changes of renal cell carcinoma post stereotactic body radiation therapy. This is the first report we are aware of documenting late histological effects of stereotactic body radiation therapy on renal cell carcinoma and surrounding normal tissue. Case presentation A right renal tumor was identified in a Japanese 70-year-old man on follow-up computed tomography for his chronic hepatitis. T1N0M0 renal cell carcinoma was clinically diagnosed as the tumor was 3 cm in diameter and well-enhanced with intravenously infused contrast material in the arterial phase on computed tomography. No metastases in regional lymph nodes or distant sites were evident. Stereotactic body radiation therapy was selected as an alternative therapy to surgery because of his poor liver function. A total dose of 60 Gy in 10 fractions over 12 days was delivered using a 10-megavolt X-ray. The renal tumor gradually decreased in size and partial response had been achieved at 2 years after completing stereotactic body radiation therapy. Hepatocellular carcinoma was identified during follow-up in the patient and he died of progression of hepatocellular carcinoma with hepatic failure 2.5 years after completing stereotactic body radiation therapy. Autopsy was done and it showed almost complete necrosis of tumor tissues with a small amount of viable renal carcinoma cells. These pathological findings suggested marked effects of stereotactic body radiation therapy on clear cell renal cell carcinoma. Conclusion Our case demonstrates a good pathological response with small foci of remnant viable cancer cells after stereotactic body radiation therapy of 60Gy in 10 fractions for small renal cell carcinoma. Although further experiences and longer follow-up are mandatory to conclude the optimal treatment schedule and efficacy of stereotactic body radiation therapy for renal cell carcinoma, stereotactic body radiation therapy may represent a novel less-invasive option for the treatment of primary renal cell carcinoma.

Background As stereotactic body radiotherapy (SBRT) is a highly dose-dense radiotherapy, adverse events of neighboring normal tissues are a major concern. This study thus aimed to clarify the frequency and degree of clinical symptoms in patients with rib fractures after SBRT for primary lung cancer and to reveal risk factors for rib fracture. Appropriate α/β ratios for discriminating between fracture and non-fracture groups were also investigated. Methods Between November 2001 and April 2009, 177 patients who had undergone SBRT were evaluated for clinical symptoms and underwent follow-up thin-section computed tomography (CT). The time of rib fracture appearance was also assessed. Cox proportional hazard modeling was performed to identify risk factors for rib fracture, using independent variables of age, sex, maximum tumor diameter, radiotherapeutic method and tumor-chest wall distance. Dosimetric details were analyzed for 26 patients with and 22 randomly-sampled patients without rib fracture. Biologically effective dose (BED) was calculated with a range of α/β ratios (1–10 Gy). Receiver operating characteristics analysis was used to define the most appropriate α/β ratio. Results Rib fracture was found on follow-up thin-section CT in 41 patients. The frequency of chest wall pain in patients with rib fracture was 34.1% (14/41), and was classified as Grade 1 or 2. Significant risk factors for rib fracture were smaller tumor-chest wall distance and female sex. Area under the curve was maximal for BED at an α/β ratio of 8 Gy. Conclusions Rib fracture is frequently seen on CT after SBRT for lung cancer. Small tumor-chest wall distance and female sex are risk factors for rib fracture. However, clinical symptoms are infrequent and generally mild. When using BED analysis, an α/β ratio of 8 Gy appears most effective for discriminating between fracture and non-fracture patients.