Long-term outcomes and central nervous system relapse in extranodal natural killer/T-cell lymphoma.

To elucidate the long-term outcomes of non-anthracycline-containing therapies and central nervous system (CNS) events in patients with extranodal NK/T-cell lymphoma, nasal type (ENKTL), the clinical data of 313 patients with ENKTL diagnosed between 2000 and 2013 in a nationwide retrospective study in Japan were updated and analyzed. At a median follow-up of 8.4 years, the 5-year overall survival (OS) and progression-free survival (PFS) were 71% and 64%, respectively, in 140 localized ENKTL patients who received radiotherapy-dexamethasone, etoposide, ifosfamide, and carboplatin (RT-DeVIC) in clinical practice. Nine (6.4%) patients experienced second malignancies. In 155 localized ENKTL patients treated with RT-DeVIC, 10 (6.5%) experienced CNS relapse (median, 12.8 months after diagnosis). In five of them, the events were confined to the CNS. Nine of the 10 patients who experienced CNS relapse died within 1 year after CNS relapse. Multivariate analysis identified gingival (hazard ratio [HR], 54.35; 95% confidence interval [CI], 8.60-343.35) and paranasal involvement (HR, 7.42; 95% CI, 1.78-30.89) as independent risk factors for CNS relapse. In 80 advanced ENKTL patients, 18 received steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) chemotherapy as first-line treatment. Patients who received SMILE as their first-line treatment tended to have better OS than those who did not (p = 0.071). Six (7.5%) advanced ENKTL patients experienced isolated CNS relapse (median, 2.6 months after diagnosis) and died within 4 months of relapse. No second malignancies were documented in advanced ENKTL patients. In the entire cohort, the median OS after first relapse or progression was 4.6 months. 12 patients who survived 5 years after PFS events were disease-free at the last follow-up. Of those, 11 (92%) underwent hematopoietic stem cell transplantation. Our 8-year follow-up revealed the long-term efficacy and safety of RT-DeVIC and SMILE. The risk of CNS relapse is an important consideration in advanced ENKTL.

Utility of whole brain radiation therapy for leptomeningeal carcinomatosis.

BACKGROUND: Although whole brain radiation therapy (WBRT) is commonly used as first-line treatment for leptomeningeal carcinomatosis, the prognosis is uncertain despite treatment. Moreover, the benefit of WBRT for leptomeningeal carcinomatosis has not been adequately evaluated. Therefore, this study aimed to clarify the utility of WBRT for leptomeningeal carcinomatosis. METHODS: Consecutive patients who received WBRT for leptomeningeal carcinomatosis or brain metastasis from solid tumors between January 2008 and July 2017 were retrospectively evaluated. The overall survival, symptom relief, and adverse events were compared between patients with leptomeningeal carcinomatosis and those with brain metastasis after WBRT. RESULTS: Of the 277 treated patients, 204 patients (22 with leptomeningeal carcinomatosis and 182 with brain metastasis) were included in the study. The median overall survival was 440 days (95% confidence interval [CI] 0-931 days) for patients with leptomeningeal carcinomatosis and 322 days (95% CI 196-448 days) for those with brain metastasis (p = 0.972 on the log-rank test). On evaluating the overall survival of patients with leptomeningeal carcinomatosis, the prognostic factors of performance status 0-1, no extracranial metastasis, and no symptoms at the time of WBRT showed a significant survival advantage on univariate analysis. Among patients with leptomeningeal carcinomatosis, those with headache and nausea often showed improvement while those with depressed levels of consciousness and seizures did not. On comparing all-grade adverse events, vomiting and seizures were more frequent in patients with leptomeningeal carcinomatosis than in those with brain metastasis. CONCLUSIONS: WBRT was generally well tolerated and effective for treating patients with leptomeningeal carcinomatosis.

Early disease progression in patients with localized natural killer/T-cell lymphoma treated with concurrent chemoradiotherapy.

Prognosis of patients with localized nasal extranodal natural killer/T-cell lymphoma, nasal type (ENKL) has been improved by non-anthracycline-containing treatments such as concurrent chemoradiotherapy (CCRT). However, some patients experience early disease progression. To clarify the clinical features and outcomes of these patients, data from 165 patients with localized nasal ENKL who were diagnosed between 2000 and 2013 at 31 institutes in Japan and who received radiotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin (RT-DeVIC) were retrospectively analyzed. Progression of disease within 2 years after diagnosis (POD24) was used as the definition of early progression. An independent dataset of 60 patients with localized nasal ENKL who received CCRT at Samsung Medical Center was used in the validation analysis. POD24 was documented in 23% of patients who received RT-DeVIC and in 25% of patients in the validation cohort. Overall survival (OS) from risk-defining events of the POD24 group was inferior to that of the reference group in both cohorts (P < .00001). In the RT-DeVIC cohort, pretreatment elevated levels of serum soluble interleukin-2 receptor (sIL-2R), lactate dehydrogenase, C-reactive protein, and detectable Epstein-Barr virus DNA in peripheral blood were associated with POD24. In the validation cohort, no pretreatment clinical factor associated with POD24 was identified. Our study indicates that POD24 is a strong indicator of survival in localized ENKL, despite the different CCRT regimens adopted. In the treatment of localized nasal ENKL, POD24 is useful for identifying patients who have unmet medical needs.

Stereotactic body radiotherapy for second primary lung cancer and intra-parenchymal lung metastasis in patients previously treated with surgery: evaluation of indications and predictors of decreased respiratory function.

BACKGROUND: The adaptation criteria for administration of stereotactic body radiotherapy (SBRT) to patients with lung cancer who previously underwent surgery and subsequently developed a second primary lung cancer (SPLC) or intra-parenchymal lung metastasis (IPLM) are controversial, unlike the criteria for repeat surgery. We aimed to evaluate the feasibility of SBRT for these patients. Factors associated with decreased respiratory function were also evaluated. MATERIAL AND METHODS: Sixty-nine patients with 89 lesions who underwent SBRT between 2008 and 2017 were analyzed. Of these, 29 were diagnosed with SPLC while the remaining 40 had IPLM. The distribution of histological types was as follows: squamous cell carcinoma (n = 13 lesions); adenocarcinoma (n = 25); non-small cell carcinoma (n = 1); unknown histological type (n = 49). The prescribed doses to the planning target volume (PTV) were 50 Gy in five fractions for 85 lesions and 60 Gy in 10 fractions for four lesions at PTV mean. RESULTS: Over a median follow-up period of 55 months, the 4-year overall survival and local control rates were 50.3% and 87.6%, respectively. Six patients experienced grade 2 radiation pneumonitis and one experienced grade 3. Two patients experienced grade 5 pulmonary fibrosis. Decreased respiratory function was observed in 10 patients (15.1%). On multivariate analysis, the presence of pulmonary disease before SBRT was the only statistically significant factor associated with decreased respiratory function. CONCLUSIONS: SBRT is safe and feasible in patients with SPLC or IPLM previously treated surgically. Pre-existing pulmonary disease was a predictive factor for decreased respiratory function.

[18F]Fluorodeoxyglucose uptake by positron emission tomography predicts outcomes for oropharyngeal and hypopharyngeal cancer treated with definitive radiotherapy.

This study evaluated the prognostic significance of the maximum standardized uptake value of the primary site (pSUVmax) in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans of patients with oropharyngeal or hypopharyngeal cancer who were treated using definitive radiotherapy. The study included 86 patients who were primarily treated with radiotherapy for oropharyngeal or hypopharyngeal cancer. Sixty-nine patients underwent concurrent chemotherapy. The associations between pre-treatment pSUVmax and treatment outcomes were evaluated. The most appropriate pSUVmax cut-off value for predicting disease-free survival (DFS) and local control (LC) was selected using receiver operating characteristic (ROC) curves. The median follow-up time for surviving patients was 60 months, while the median survival time in the entire patient cohort was 55 months. A pSUVmax cut-off value of 9.0 showed the best discriminative performance. Five-year OS and DFS rates were 65.9% and 60.0%, respectively. In univariate analyses, pSUVmax (p = 0.009), T-stage (p = 0.001), N-stage (p = 0.039), and clinical stage (p = 0.017) were identified as significant prognostic predictors for DFS. The multivariate analysis did not identify any statistically significant factors, but the association between pSUVmax and DFS was borderline significant (p = 0.055). Interestingly, pSUVmax was predictive of local controllability in T1-T2 disease (p = 0.024), but there was no significant association for T3-T4 disease (p = 0.735). In this study, pSUVmax was predictive of DFS and LC in patients with oropharyngeal or hypopharyngeal cancer that was treated with definitive radiotherapy. pSUVmax was strongly associated with LC in T1-T2 disease.

Quality of life and cost-utility of surgical treatment for patients with spinal metastases: prospective cohort study.

PURPOSE: Palliative surgery for patients with spinal metastasis provides good clinical outcomes. However, there have been few studies on quality of life (QOL) and cost-utility of this surgery. We aimed to elucidate QOL and cost-utility of surgical treatment for spinal metastasis. METHODS: We prospectively analyzed 47 patients with spinal metastasis from 2010 to 2014 who had a surgical indication. Thirty-one patients who desired surgery underwent spinal surgery (surgery group). Sixteen patients who did not want to undergo spinal surgery (non-surgery group). The EuroQol 5D (EQ-5D) and relevant costs were measured at one, three, six, and 12 months after study enrollment. Health state values were obtained by Japanese EQ-5D scoring and quality-adjusted life years (QALY) gained were calculated for each group. Cost-utility was expressed as the incremental cost-utility ratio (ICUR). RESULTS: Health state values improved from 0.036 at study enrollment to 0.448 at 12 months in the surgery group, but deteriorated from 0.056 to 0.019 in the non-surgery group, with a significant difference between groups (P < 0.05). The mean QALY gained at 12 months were 0.433 in the surgery group and 0.024 in the non-surgery group. The mean total cost per patient in the surgery group was $25,770 compared with $8615 in the non-surgery group. The ICUR using oneyear follow-up data was $42,003/QALY gained. CONCLUSIONS: Surgical treatment for spinal metastases is associated with significant improvement in health state value. In orthopaedic surgery, an ICUR less than $50,000/QALY gained is considered acceptable cost-effectiveness. Our results indicate that surgical treatment could be cost-effective.

Hypofractionated stereotactic radiotherapy for brain metastases from lung cancer : Evaluation of indications and predictors of local control.

AIM: To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) for brain metastases (BMs) from lung cancer, and to explore prognostic factors associated with local control (LC) and indication. PATIENTS AND METHODS: We evaluated patients who were treated with linac-based HSRT for BMs from lung cancer. Lesions treated with stereotactic radiosurgery (SRS) in the same patients during the same periods were analysed and compared with HSRT in terms of LC or toxicity. There were 53 patients with 214 lesions selected for this analysis (HSRT: 76 lesions, SRS: 138 lesions). For HSRT, the median prescribed dose was 35 Gy in 5 fractions. RESULTS: The 1­year LC rate was 83.6 % in HSRT; on multivariate analysis, a planning target volume (PTV) of <4 cm(3), biologically effective dose (BED10) of ≥51 Gy, and adenocarcinoma were significantly associated with better LC. Moreover, in PTVs ≥ 4 cm(3), there was a significant difference in LC between BED10 < 51 Gy and ≥ 51 Gy (p = 0.024). On the other hand, in PTVs < 4 cm(3), both HSRT and SRS had good LC with no significant difference (p = 0.195). Radiation necrosis emerged in 5 of 76 lesions (6.6 %) treated with HSRT and 21 of 138 (15.2 %) lesions treated with SRS (p = 0.064). CONCLUSION: Linac-based HSRT was safe and effective for BMs from lung cancer, and hence might be particularly useful in or near an eloquent area. PTV, BED10, and pathological type were significant prognostic factors. Furthermore, in BMs ≥ 4 cm(3), a dose of BED ≥ 51 Gy should be considered.

Treatment outcomes of the patients with early glottic cancer treated with initial radiotherapy and salvaged by conservative surgery.

OBJECTIVE: This retrospective study analyzed the oncological and treatment outcomes of the patients with T1-T2N0 glottic cancer, who were treated with radiotherapy as initial treatment and salvaged by conservative surgery for radiation failure. METHODS: Between May 1999 and December 2010, 115 patients with glottic laryngeal cancer were treated at Kobe University Hospital. At presentation, 54 patients had stage T1a disease, 26 had stage T1b disease and 35 had stage T2 disease. Seventy-nine patients were treated with conventional radiotherapy and 36 patients were treated with hyperfractionated radiotherapy as initial treatment. RESULTS: Median duration of follow-up was 61 months. Five-year local control rates of radiotherapy were 92% in T1a, 83% in T1b and 86% in T2. Of 12 patients who developed local recurrence, larynx was successfully preserved in 3 patients by laryngomicrosurgery, 7 patients by vertical partial laryngectomy and one patient by subtotal laryngectomy. Ultimate 5-year laryngeal preservation rate and local control rate of all cases were 99 and 100%, respectively. CONCLUSIONS: Present results suggest that initial treatment with radiotherapy salvaged by organ preservation surgery is an effective strategy for laryngeal preservation in the treatment of T1-T2N0 glottic laryngeal cancer.

The current status and future of radiotherapy for spinal bone metastases.

The management of spinal bone metastases is complex. In this review, the efficacy, methodology, and utilization of radiotherapy (RT) for spinal bone metastases are discussed. A number of randomized trials have evaluated the efficacy of 8 Gy, single-fraction RT for the palliation of painful bone metastases. However, RT for metastatic spinal cord compression has not been evaluated with respect to its optimal dose, palliative potential, or its ability to improve motor function. Two highly sophisticated RT techniques - stereotactic body RT (SBRT) and intensity-modulated RT (IMRT) - have recently been adapted for the treatment of spinal bone metastases, and both have the potential to achieve excellent control while minimizing acute and late toxicity. SBRT and IMRT are particularly well suited for the treatment of spinal bone metastases when they are localized or require re-irradiation, and may provide superior tumor control. Predicting the prognosis of patients with bone metastases and assessing spinal instability are both important when selecting the optimal RT method and deciding whether to perform surgery. The proper care of spinal bone metastases patients requires an interdisciplinary treatment approach.

Autologous Peripheral Blood Stem Cell Transplantation and Timing of Local Radiation Therapy in Patients With Malignant Lymphoma: Results of the Japanese Radiation Oncology Study Group Questionnaire Survey.

BACKGROUND/AIM: Malignant lymphoma (ML) including Hodgkin's lymphoma and non-Hodgkin's lymphoma is often treated with local radiation therapy (RT) in combination with autologous hematopoietic stem cell transplantation (ASCT) to prevent relapse; however, the efficacy and optimal timing of this approach is unclear. In this study, a national survey conducted by the Japanese Radiation Oncology Study Group reviewed ML cases from 2011 to 2019 to determine whether RT should be added to ASCT, focusing on the use of autologous peripheral blood stem cell transplantation (auto-PBSCT), a predominant form of ASCT. PATIENTS AND METHODS: The survey encompassed 92 patients from 11 institutes, and assessed histological ML types, treatment regimens, timing of RT relative to auto-PBSCT, and associated adverse events. RESULTS: The results indicated no significant differences in adverse events, including myelosuppression, based on the timing of RT in relation to auto-PBSCT. However, anemia was more prevalent when RT was administered before auto-PBSCT, and there was a higher incidence of neutropenia recovery delay in patients receiving RT after auto-PBSCT. CONCLUSION: This study provides valuable insights into the variable practices of auto-PBSCT and local RT in ML treatment, emphasizing the need for optimized timing of these therapies to improve patient outcomes and reduce complications.

Quality of palliative radiotherapy assessed using quality indicators: a multicenter survey†.

We sought to identify potential evidence-practice gaps in palliative radiotherapy using quality indicators (QIs), previously developed using a modified Delphi method. Seven QIs were used to assess the quality of radiotherapy for bone metastases (BoM) and brain metastases (BrM). Compliance rate was calculated as the percentage of patients for whom recommended medical care was conducted. Random effects models were used to estimate the pooled compliance rates. Of the 39 invited radiation oncologists, 29 (74%) from 29 centers participated in the survey; 13 (45%) were academic and 16 (55%) were non-academic hospitals. For the QIs, except for BoM-4, the pooled compliance rates were higher than 80%; however, for at least some of the centers, the compliance rate was lower than these pooled rates. For BoM-4 regarding steroid use concurrent with radiotherapy for malignant spinal cord compression, the pooled compliance rate was as low as 32%. For BoM-1 regarding the choice of radiation schedule, the compliance rate was higher in academic hospitals than in non-academic hospitals (P = 0.021). For BrM-3 regarding the initiation of radiotherapy without delay, the compliance rate was lower in academic hospitals than in non-academic hospitals (P = 0.016). In conclusion, overall, compliance rates were high; however, for many QIs, practice remains to be improved in at least some centers. Steroids are infrequently used concurrently with radiotherapy for malignant spinal cord compression.

Income and Employment of Patients at the Start of and During Follow-up After Palliative Radiation Therapy for Bone Metastasis.

Purpose: The aim of this study was to understand the income and employment status of patients at the start of and during follow-up after palliative radiation therapy for bone metastasis. Methods and Materials: From December 2020 to March 2021, a prospective multi-institutional observational study was conducted to investigate income and employment of patients at the start of administration of radiation therapy for bone metastasis and at 2 and 6 months after treatment. Of 333 patients referred to radiation therapy for bone metastasis, 101 were not registered, mainly because of their poor general condition, and another 8 were excluded from the follow-up analysis owing to ineligibility. Results: In 224 patients analyzed, 108 had retired for reasons unrelated to cancer, 43 had retired for reasons related to cancer, 31 were taking leave, and 2 had lost their jobs at the time of registration. The number of patients who were in the working group was 40 (30 with no change in income and 10 with decreased income) at registration, 35 at 2 months, and 24 at 6 months. Younger patients (P = 0), patients with better performance status (P = 0), patients who were ambulatory (P = .008), and patients with lower scores on a numerical rating scale of pain (P = 0) were significantly more likely to be in the working group at registration. There were 9 patients who experienced improvements in their working status or income at least once in the follow-up after radiation therapy. Conclusions: The majority of patients with bone metastasis were not working at the start of or after radiation therapy, but the number of patients who were working was not negligible. Radiation oncologists should be aware of the working status of patients and provide appropriate support for each patient. The benefit of radiation therapy to support patients continuing their work and returning to work should be investigated further in prospective studies.

Factors associated with quality of life in patients receiving palliative radiotherapy for bone metastases: a secondary cross-sectional analysis of data from a prospective multicenter observational study.

OBJECTIVE: To identify factors significantly associated with quality of life (QOL) and determine if these associations are strong enough to predict certain aspects of QOL without measuring them. METHODS: We conducted an exploratory secondary analysis of baseline data of 224 patients (enrolled between December 2020 and March 2021) from a previously published prospective observational study on radiotherapy for bone metastases at 26 centres. Using univariable linear regression, we assessed the association between patient/treatment factors and QOL scale scores as measured by the European Organization for Research and Treatment of Cancer (EORTC) QOL Questionnaire Core 15-Palliative (QLQ-C15-PAL) and the EORTC QOL Questionnaire Bone Metastases module (QLQ-BM22). RESULTS: Age and sex were not significantly associated with QOL. Worse performance status, higher pain scores, and opioid and single-fraction use were significantly associated with most QOL scales; these four factors were associated with worse global QOL, worse functioning status, and more severe symptoms. The coefficients of determination for most QOL scales were less than 0.2, indicating that most of the variability in QOL scores was not explained by any of the explanatory variables. CONCLUSION: Performance status, pain intensity, and opioid and single-fraction use were significantly associated with most QOL scales. However, the associations were not strong enough to estimate QOL. ADVANCES IN KNOWLEDGE: To date, the association between treatment factors and QOL in patients with bone metastases has not been fully studied. We identified the factors that were significantly associated with QOL and found that these associations were not strong enough to predict QOL.

Clinical practice guidelines for duodenal cancer 2021.

Duodenal cancer is considered to be a small intestinal carcinoma in terms of clinicopathology. In Japan, there are no established treatment guidelines based on sufficient scientific evidence; therefore, in daily clinical practice, treatment is based on the experience of individual physicians. However, with advances in diagnostic modalities, it is anticipated that opportunities for its detection will increase in future. We developed guidelines for duodenal cancer because this disease is considered to have a high medical need from both healthcare providers and patients for appropriate management. These guidelines were developed for use in actual clinical practice for patients suspected of having non-ampullary duodenal epithelial malignancy and for patients diagnosed with non-ampullary duodenal epithelial malignancy. In this study, a practice algorithm was developed in accordance with the Minds Practice Guideline Development Manual 2017, and Clinical Questions were set for each area of epidemiology and diagnosis, endoscopic treatment, surgical treatment, and chemotherapy. A draft recommendation was developed through a literature search and systematic review, followed by a vote on the recommendations. We made decisions based on actual clinical practice such that the level of evidence would not be the sole determinant of the recommendation. This guideline is the most standard guideline as of the time of preparation. It is important to decide how to handle each case in consultation with patients and their family, the treating physician, and other medical personnel, considering the actual situation at the facility (and the characteristics of the patient).

National survey on total-body irradiation prior to reduced-intensity stem cell transplantation in Japan: The Japanese Radiation Oncology Study Group.

Reduced-intensity stem cell transplantation (RIST) minimizes the adverse effects of traditional hematopoietic stem cell transplantation, and low-dose total-body irradiation (TBI) is administered over a short period prior to RIST (TBI-RIST). Different institutes adopt different approaches for the administration of TBI-RIST, and since no study had previously investigated this issue, a survey of the TBI schedules in Japan was conducted. In October 2015, the Japanese Radiation Oncology Study Group initiated a national survey of TBI-RIST procedures conducted between 2010 and 2014. Of 186 institutions performing TBI, 90 (48%) responded to the survey, 78 of which performed TBI-RIST. Of 2488 patients who underwent TBI for malignant disease at these institutions, 1412 (56.8%) patients were treated for leukemia, 477 (19.2%) for malignant lymphoma, 453 (18.2) for myelodysplastic syndrome, 44 (1.8%) for multiple myeloma, and 102 (4.1%) for other malignant diseases. Further, 206 (52.0%) of 396 patients (a high proportion of patients) who underwent TBI for benign disease had aplastic anemia. The TBI-RIST equipment and treatment methods were similar to those used for myeloablative regimens. Routinely shielded organs included the lungs (43.6%), eyes (50.0%) and kidneys (10.2%). The ovaries (14.1%), thyroid (6.4%) and testicles (16.7%) were also frequently shielded, possibly reflecting an emphasis on shielding reproductive organs in children. TBI-RIST was performed more frequently than myeloablative conditioning in patients with benign disease. Genital and thyroid shielding were applied more frequently in patients treated with TBI-RIST than in patients treated with myeloablative conditioning. In conclusion, this study indicates the status of TBI-RIST in Japan and can assist future efforts to standardize TBI-RIST treatment methods and to design a future multicenter collaborative research study.

Dental intervention against osteoradionecrosis of the jaws in irradiated patients with head and neck malignancy: a single-arm prospective study.

BACKGROUND: The purpose of this study was to investigate the effectiveness of dental intervention before and after radiation therapy (RT) for head and neck malignancy on prevention of osteoradionecrosis (ORN) of the jaws. METHODS: This is a single-arm prospective study according to intervention protocol of prophylactic dental extraction before RT and routine follow-up after RT. The primary endpoint was the occurrence of jawbone exposure during the first 2 years after RT. RESULTS: Sixty-seven patients were assessed. Before RT, 144 teeth among 39 patients (58%) were prophylactically extracted. The occurrence of transient jawbone exposure during the first 2 years after RT was 7%. Because those jawbone exposures healed with intervention after RT, no jawbone exposure was found at 2 years after RT. CONCLUSIONS: Dental intervention both before and after RT seemed to be important to prevent ORN development. Further studies in larger cohorts are necessary.

Evaluation of a Small Animal Irradiation System for Animal Experiments Using EBT3 Model GAFCHROMIC™ Film.

In cancer research, small animal models, for example, mice, rats, or rabbits, facilitate the in-depth study of biological processes and the effects of radiation treatment that can lead to breakthrough discoveries. However, the physical quality of small animal irradiation systems has not been previously evaluated. In this study, we evaluate the quality of a small animal irradiation system using GAFCHROMIC™ film and a Tough Water Phantom. The profiles and percentage depth dose curves for several irradiation conditions were measured to evaluate the quality of the irradiation system. The symmetry ratios when the table was rotated were 1.1 (no filter), 1.0 (0.5 mm Al filter), 1.0 (1.0 mm Al filter), 1.1 (2 mm Al filter), and 1.0 (filter consisting of 0.5 mm Al combined with 0.1 mm Cu). The results of measuring the percentage depth dose curve showed that the relative doses were 17.5% (10 mm depth), 12.4% (20 mm depth), 9.5% (30 mm depth), and 7.4% (40 mm filter) with no filters inserted, 78.0% (10 mm depth), 61.1% (20 mm depth), 46.9% (30 mm depth), and 35.3% (40 mm depth) when a 1.0 mm Al filter was inserted, and 94.4% (10 mm depth), 81.7% (20 mm depth), 68.1% (30 mm depth), and 54.7% (40 mm depth) when a filter consisting of 1.0 mm Al combined with 0.2 mm Cu was inserted. These physical assessments seem to be necessary especially in vivo experiments because those increase reliability of data obtained from small animal irradiation systems.

Comparison of dosimetric parameters in the treatment planning of magnetic resonance imaging-based intracavitary image-guided adaptive brachytherapy with and without optimization using the central shielding technique.

This study aimed to compare dosimetric parameters between non-optimized and optimized treatment planning (NOP and OP, respectively) of magnetic resonance imaging (MRI) -based intracavitary (IC) image-guided adaptive brachytherapy (IGABT) using the central shielding (CS) technique for cervical cancer. Fifty-three patients treated with external beam radiotherapy using CS and MRI-based IGABT with the IC approach alone were evaluated. The total high-risk clinical target volume (HR-CTV) D90 was aimed at >70 Gy equivalent dose in 2 Gy fractions (EQD2). In the small HR-CTV group (≤30 cm3), the mean D90s for NOP/OP were 98.6/80.7 Gy. In the large (30.1-40 cm3) and extensive (>40 cm3) HR-CTV groups, the mean D90s were 81.9/77.5 and 71.1/73.6 Gy, respectively. The mean D2cc values for organs at risks (OARs) in OP were acceptable in all groups, despite the high bladder D2cc in the NOP. The correlation between HR-CTV at first brachytherapy (BT) and NOP D90 was stronger than that between HR-CTV at first BT and OP D90. The targeted HR-CTV D90 and dose constraints of D2cc for OARs were both achieved in 16 NOP/47 OP patients for the bladder, 39/50 for the rectum, and 47/50 for the sigmoid colon (P < 0.001, P = 0.007, and P = 0.34, respectively). For small tumors, the role of optimization was to reduce the D2cc for OARs while maintaining the targeted D90. However, optimization was of limited value for extensive tumors. Methods of optimization in IGABT with CS for cervical cancer should be standardized while considering its effectiveness and limitations.

National survey of myeloablative total body irradiation prior to hematopoietic stem cell transplantation in Japan: survey of the Japanese Radiation Oncology Study Group (JROSG).

A myeloablative regimen that includes total-body irradiation (TBI) before hematopoietic stem cell transplantation results in higher patient survival rates than achieved with regimens without TBI. The TBI protocol, however, varies between institutions. In October 2015, the Japanese Radiation Oncology Study Group initiated a national survey of myeloablative TBI (covering 2010-2014). Among the 186 Japanese institutions performing TBI, 90 (48%) responded. The 82 institutions that had performed myeloablative TBI during this period treated 2698 patients with malignant disease [leukemia (2082 patients, 77.2%), malignant lymphoma (378, 14%)] and 37 with non-malignant disease [severe aplastic anemia (20, 54%), inborn errors of metabolism (5, 14%)]. A linear accelerator was used at all institutions. The institutions were divided into 41 large and 41 small institutions based on the median number of patients. The long source-surface distance technique was the method of choice in the 34 institutions (82.9%) and the moving-couch technique in the 7 (17.1%) in the large institutions. The schedules most routinely used by the participating institutions consisted of 12 Gy/6 fractions/3 days (26 institutions, 63.5%) in the large institutions. The dose rate varied from 5 to 26 cGy/min. The lungs and lenses were routinely shielded in 23 large institutions (56.1%), and only the lungs in 9 large institutions (21.9%). At lung-shielding institutions, the most frequent maximum acceptable total dose for the lungs was 8 Gy (19 institutions, 27.5%). Our results reveal considerable differences in the TBI methods used by Japanese institutions and thus the challenges in designing multicenter randomized trials based on TBI.