Geometric target margin strategy of proton craniospinal irradiation for pediatric medulloblastoma.

In proton craniospinal irradiation (CSI) for skeletally immature pediatric patients, a treatment plan should be developed to ensure that the dose is uniformly delivered to all vertebrae, considering the effects on bone growth balance. The technical (t) clinical target volume (CTV) is conventionally set by manually expanding the CTV from the entire intracranial space and thecal sac, based on the physician's experience. However, there are differences in contouring methods among physicians. Therefore, we aimed to propose a new geometric target margin strategy. Nine pediatric patients with medulloblastoma who underwent proton CSI were enrolled. We measured the following water equivalent lengths for each vertebra in each patient: body surface to the dorsal spinal canal, vertebral limbus, ventral spinal canal and spinous processes. A simulated tCTV (stCTV) was created by assigning geometric margins to the spinal canal using the measurement results such that the vertebral limb and dose distribution coincided with a margin assigned to account for the uncertainty of the proton beam range. The stCTV with a growth factor (correlation between body surface area and age) and tCTV were compared and evaluated. The median values of each index for cervical, thoracic and lumber spine were: the Hausdorff distance, 9.14, 9.84 and 9.77 mm; mean distance-to-agreement, 3.26, 2.65 and 2.64 mm; Dice coefficient, 0.84, 0.81 and 0.82 and Jaccard coefficient, 0.50, 0.60 and 0.62, respectively. The geometric target margin setting method used in this study was useful for creating an stCTV to ensure consistent and uniform planning.

Clinical application of real-time tumor-tracking for stereotactic volumetric modulated arc therapy for liver tumors.

Real-time tumor-tracking volumetric modulated arc therapy (RT-VMAT) enabling beam-gating based on continuous X-ray tracking of the three-dimensional position of internal markers is relevant for moving tumors. Dose-volume characteristics and treatment time were evaluated in ten consecutive patients who underwent liver stereotactic body radiation therapy with RT-VMAT. Target dose conformity and sparing of the stomach and the intestine were improved comparing RT-VMAT with RT-3D conformal radiotherapy. The mean treatment time for each fraction was less than 10 min. RT-VMAT could be effective, especially for targets located adjacent to organs at risk.

Application of motion prediction based on a long short-term memory network for imaging dose reduction in real-time tumor-tracking radiation therapy.

PURPOSE: To demonstrate the possibility of using a lower imaging rate while maintaining acceptable accuracy by applying motion prediction to minimize the imaging dose in real-time image-guided radiation therapy. METHODS: Time-series of three-dimensional internal marker positions obtained from 98 patients in liver stereotactic body radiation therapy were used to train and test the long-short-term memory (LSTM) network. For real-time imaging, the root mean squared error (RMSE) of the prediction on three-dimensional marker position made by LSTM, the residual motion of the target under respiratory-gated irradiation, and irradiation efficiency were evaluated. In the evaluation of the residual motion, the system-specific latency was assumed to be 100 ms. RESULTS: Except for outliers in the superior-inferior (SI) direction, the median/maximum values of the RMSE for imaging rates of 7.5, 5.0, and 2.5 frames per second (fps) were 0.8/1.3, 0.9/1.6, and 1.2/2.4 mm, respectively. The median/maximum residual motion in the SI direction at an imaging rate of 15.0 fps without prediction of the marker position, which is a typical clinical setting, was 2.3/3.6 mm. For rates of 7.5, 5.0, and 2.5 fps with prediction, the corresponding values were 2.0/2.6, 2.2/3.3, and 2.4/3.9 mm, respectively. There was no significant difference between the irradiation efficiency with and that without prediction of the marker position. The geometrical accuracy at lower frame rates with prediction applied was superior or comparable to that at 15 fps without prediction. In comparison with the current clinical setting for real-time image-guided radiation therapy, which uses an imaging rate of 15.0 fps without prediction, it may be possible to reduce the imaging dose by half or more. CONCLUSIONS: Motion prediction can effectively lower the frame rate and minimize the imaging dose in real-time image-guided radiation therapy.

Clinical outcome, radiological findings, and genetic features of IDH-mutant brainstem glioma in adults.

BACKGROUND: With the recent advent of genetic testing, IDH-mutant glioma has been found among adult brainstem gliomas. However, the clinical outcome and prognosis of IDH-mutant brainstem gliomas in adults have not been elucidated. This study aimed to investigate the clinical outcome, radiological findings, and genetic features of adult patients with IDH-mutant diffuse brainstem gliomas. METHODS: Data from adult patients with brainstem glioma at Hokkaido University Hospital between 2006 and 2022 were retrospectively analyzed. Patient characteristics, treatment methods, genetic features, and prognosis were evaluated. RESULTS: Of 12 patients with brainstem glioma with proven histopathology, 4 were identified with IDH mutation. All patients underwent local radiotherapy with 54 Gray in 27 fractions combined with chemotherapy with temozolomide. Three patients had IDH1 R132H mutation and one had IDH2 R172G mutation. The median progression-free survival and overall survival were 68.4 months and 85.2 months, respectively, longer than that for IDH-wildtype gliomas (5.6 months and 12.0 months, respectively). At the time of initial onset, contrast-enhanced lesions were observed in two of the four cases in magnetic resonance imaging. CONCLUSION: As some adult brainstem gliomas have IDH mutations, and a clearly different prognosis from those with IDH-wildtype, biopsies are proactively considered to confirm the genotype.

Clinical outcomes for olfactory neuroblastoma.

Background: Olfactory neuroblastoma (ONB) is a rare malignant tumor arising from the olfactory neuroepithelium. The standard of care for ONB is surgical resection; however, detailed treatment protocols vary by institution. Our treatment protocol consists of endoscopic skull base surgery (ESBS) for endoscopically resectable cases and induction chemotherapy followed by craniotomy combined with ESBS for locally advanced cases, with postoperative radiotherapy performed for all cases. Chemoradiotherapy (CRT) is performed in unresectable cases. In this study, we evaluate our treatment protocol and outcomes for ONB. Methods: A retrospective review of patients with ONB was conducted. Outcomes included survival outcomes and perioperative data. Results: Fifteen patients (53.6%) underwent ESBS, 12 (42.9%) underwent craniotomy combined with ESBS, and 1 (3.6%) received CRT. The 5- and 10-year overall survival rates for all patients were 92.9% and 82.5%, respectively, with a median follow-up period of 81 months. The 5- and 10-year disease-free survival rates were 77.3% and 70.3%, respectively, and the 5- and 10-year local control rates were 88.2% and 80.2%, respectively. Patients undergoing ESBS demonstrated a significantly shorter operating time, period from operation to ambulation, hospitalization period, and less blood loss than those undergoing craniotomy combined with ESBS. Conclusion: Our treatment protocol was found to afford favorable outcomes. Patients who underwent endoscopic resection showed lower complication rates and better perioperative data than those who underwent craniotomy combined with ESBS. With appropriate case selection, ESBS is considered a useful approach for ONB.

A Single-Institution Prospective Study To Evaluate the Safety and Efficacy of Real- Time Image-Gated Spot-Scanning Proton Therapy (RGPT) for Prostate Cancer.

Purpose: In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer. Methods and Materials: Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the required number of cases was calculated to be 43 using the one-sample binomial test by the Southwest Oncology Group statistical tools with the one-sided significance level of 2.5% and the power 80%. Patients with localized prostate cancer were enrolled and 3 to 4 pure gold fiducial markers of 1.5-mm diameter were inserted in the prostate. The prescribed dose was 70 Gy(relative biologic effectiveness) in 30 fractions, and treatment was performed with 3 fields from the left, right, and the back, or 4 fields from either side of slightly anterior and posterior oblique fields. The primary endpoint was the frequency of early AE (≥grade 2) and the secondary endpoint was the biochemical relapse-free survival rate and the frequency of late AE. Results: Forty-five cases were enrolled between 2015 and 2017, and all patients completed the treatment protocol. The median follow-up period was 63.0 months. The frequency of early AE (≥grade 2) was observed in 4 cases (8.9%), therefore the noninferiority was verified. The overall 5-year biochemical relapse-free survival rate was 88.9%. As late AE, grade 2 rectal bleeding was observed in 8 cases (17.8%). Conclusions: The RGPT for prostate cancer with 1.5-mm markers and 3- or 4- fields was as safe as conventional proton therapy in early AE, and its efficacy was comparable with previous studies.

Probability of normal tissue complications for hematologic and gastrointestinal toxicity in postoperative whole pelvic radiotherapy for gynecologic malignancies using intensity-modulated proton therapy with robust optimization.

This retrospective treatment-planning study was conducted to determine whether intensity-modulated proton therapy with robust optimization (ro-IMPT) reduces the risk of acute hematologic toxicity (H-T) and acute and late gastrointestinal toxicity (GI-T) in postoperative whole pelvic radiotherapy for gynecologic malignancies when compared with three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated X-ray (IMXT) and single-field optimization proton beam (SFO-PBT) therapies. All plans were created for 13 gynecologic-malignancy patients. The prescribed dose was 45 GyE in 25 fractions for 95% planning target volume in 3D-CRT, IMXT and SFO-PBT plans and for 99% clinical target volume (CTV) in ro-IMPT plans. The normal tissue complication probability (NTCP) of each toxicity was used as an in silico surrogate marker. Median estimated NTCP values for acute H-T and acute and late GI-T were 0.20, 0.94 and 0.58 × 10-1 in 3D-CRT; 0.19, 0.65 and 0.24 × 10-1 in IMXT; 0.04, 0.74 and 0.19 × 10-1 in SFO-PBT; and 0.06, 0.66 and 0.15 × 10-1 in ro-IMPT, respectively. Compared with 3D-CRT and IMXT plans, the ro-IMPT plan demonstrated significant reduction in acute H-T and late GI-T. The risk of acute GI-T in ro-IMPT plan is equivalent with IMXT plan. The ro-IMPT plan demonstrated potential clinical benefits for reducing the risk of acute H-T and late GI-T in the treatment of gynecologic malignances by reducing the dose to the bone marrow and bowel bag while maintaining adequate dose coverage to the CTV. Our results indicated that ro-IMPT may reduce acute H-T and late GI-T risk with potentially improving outcomes for postoperative gynecologic-malignancy patients with concurrent chemotherapy.

Impact of adaptive radiotherapy on survival in locally advanced nasopharyngeal carcinoma treated with concurrent chemoradiotherapy.

PURPOSE: To investigate the clinical significance of adaptive radiotherapy (ART) in locally advanced nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS: Eligible patients were treated with concurrent chemoradiotherapy using IMRT. Planning computed tomography in ART was performed during radiotherapy, and replanning was performed. Since ART was started in May 2011 (ART group), patients who were treated without ART up to April 2011 (non-ART group) were used as the historical control. The Kaplan-Meier method was used to calculate overall survival (OS), locoregional recurrence-free survival (LRFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). LRFS for the primary tumor (LRFS_P) and regional lymph node (LRFS_LN) were also studied for more detailed analysis. Statistical significance was evaluated using the log-rank test for survival. RESULTS: The ART group tended to have higher radiation doses. The median follow-up period was 127 months (range, 10 to 211 months) in the non-ART group and 61.5 months (range, 5 to 129 months) in the ART group. Compared to the non-ART group, the ART group showed significantly higher 5-year PFS (53.8% vs. 81.3%, p = 0.015) and LRFS (61.2% vs. 85.3%, p = 0.024), but not OS (80.7% vs. 80.8%, p = 0.941) and DMFS (84.6% vs. 92.7%, p = 0.255). Five-year LRFS_P was higher in the ART group (61.3% vs. 90.6%, p = 0.005), but LRFS_LN did not show a significant difference (91.9% vs. 96.2%, p = 0.541). CONCLUSION: Although there were differences in the patient backgrounds between the two groups, this study suggests the potential effectiveness of ART in improving locoregional control, especially in the primary tumor.

Real-time tumor-tracking radiotherapy with SyncTraX for primary liver tumors requiring isocenter shift†.

The SyncTraX series enables real-time tumor-tracking radiotherapy through the real-time recognition of a fiducial marker using fluoroscopic images. In this system, the isocenter should be located within approximately 5-7.5 cm from the marker, depending on the version, owing to the limited field of view. If the marker is placed away from the tumor, the isocenter should be shifted toward the marker. This study aimed to investigate stereotactic body radiotherapy (SBRT) outcomes of primary liver tumors treated with SyncTraX in cases where the isocenter was shifted marginally or outside the planning target volume (PTV). Twelve patients with 13 liver tumors were included in the analysis. Their isocenter was shifted toward the marker and was placed marginally or outside the PTV. The prescribed doses were generally 40 Gy in four fractions or 48 Gy in eight fractions. The overall survival (OS) and local control (LC) rates were calculated using the Kaplan-Meier method. All patients completed the scheduled SBRT. The median distance between the fiducial marker and PTV centroid was 56.0 (interquartile range [IQR]: 52.7-66.7) mm. By shifting the isocenter toward the marker, the median distance between the marker and isocenter decreased to 34.0 (IQR: 33.4-39.7) mm. With a median follow-up period of 25.3 (range: 6.9-70.0) months, the 2-year OS and LC rates were 100.0% (95% confidence interval: 100-100). An isocenter shift makes SBRT with SyncTraX feasible in cases where the fiducial marker is distant from the tumor.

Daily fraction dose-adjusted radiotherapy policy to avoid prolonging the overall treatment time for early glottic squamous cell carcinoma: a single-institutional retrospective study.

The objective of this study was to determine the outcomes of radical radiotherapy for early glottic squamous cell carcinoma (EGSCC) with the policy of increasing the fraction size during radiotherapy when the overall treatment time (OTT) was expected to be prolonged. Patients diagnosed with clinical T1-2N0M0 EGSCC, who were treated with radical radiotherapy between 2008 and 2019 at Hokkaido University Hospital, were included. Patients received 66 Gy in 33 fractions for T1 disease and 70 Gy in 35 fractions for T2 disease as our standard regimen (usual group [UG]). If the OTT was expected to extend for >1 week, the dose fraction size was increased from 2.0 to 2.5 Gy from the beginning or during radiotherapy (adjusted group [AG]). At this time, we performed a statistical analysis between UG and AG. In total, 116 patients were identified, and the treatment schedules of 29 patients were adjusted. The median follow-up was 60.9 months. In the T1 group, the cumulative 5-year local failure rate was 12.0% in the AG and 15.4% in the UG, and in the T2 group, the rate was 40.7% in the AG and 25.3% in the UG. There were no significant differences between the AG and UG. Similarly, no significant differences were observed for overall survival and progression-free survival rates. Our single-institutional retrospective analysis of EGSCC patients suggested that a method of adjusting the radiotherapy schedule to increase fraction size from the beginning or during the course may be effective in maintaining treatment outcomes.

Radiotherapy with or without chemotherapy for locally advanced head and neck cancer in elderly patients: analysis of the Head and Neck Cancer Registry of Japan.

BACKGROUND: Whether concurrent chemotherapy with radiotherapy (CRT) is effective for elderly patients with head and neck cancer is a controversial topic. This study aimed to analyze the effectiveness of CRT vs. radiation therapy (RT) among elderly patients in Japan. METHODS: Data from the Head and Neck Cancer Registry of Japan were extracted and analyzed. Patients with locally advanced squamous cell carcinoma of the oropharynx, hypopharynx, or larynx who received definitive CRT or RT between 2011 and 2014 were included. RESULTS: CRT was administered to 78% of the 1057 patients aged ≥ 70 years and 67% of the 555 patients aged ≥ 75 years. For the patients aged ≥ 75 years, the overall survival (OS) rate was significantly better in the CRT group than in the RT group (P < 0.05), while the progression-free survival (PFS) rate was not significantly different (P > 0.05). The add-on effect of CRT was significantly poor in elderly patients (P < 0.05), and it was not a significant factor in the multivariate analysis for patients aged ≥ 75 years. After propensity score matching, there were no significant differences in the OS and PFS rates between the patients aged ≥ 70 years and those aged ≥ 75 years (all, P > 0.05). CONCLUSION: Although aggressive CRT is administered to elderly patients in Japan, its effectiveness is uncertain. Further prospective randomized trials are needed to verify whether CRT is superior to RT alone for elderly patients.

A new predictive parameter for dose-volume metrics in intensity-modulated radiation therapy planning for prostate cancer: Initial phantom study.

BACKGROUND: Organ-at-risk (OAR) sparing is often assessed using an overlap volume-based parameter, defined as the ratio of the volume of OAR that overlaps the planning target volume (PTV) to the whole OAR volume. However, this conventional overlap-based predictive parameter (COPP) does not consider the volume relationship between the PTV and OAR. PURPOSE: We propose a new overlap-based predictive parameter that consider the PTV volume. The effectiveness of proposed overlap-based predictive parameter (POPP) is evaluated compared with COPP. METHODS: We defined as POPP = (overlap volume between OAR and PTV/OAR volume) × (PTV volume/OAR volume). We generated intensity modulated radiation therapy (IMRT) based on step and shoot technique, and volumetric modulated arc therapy (VMAT) plans with the Auto-Planning module of Pinnacle3 treatment planning system (v14.0, Philips Medical Systems, Fitchburg, WI) using the American Association of Physicists in Medicine Task Group (TG119) prostate phantom. The relationship between the position and size of the prostate phantom was systematically modified to simulate various geometric arrangements. The correlation between overlap-based predictive parameters (COPP and POPP) and dose-volume metrics (mean dose, V70Gy, V60Gy, and V37.5 Gy for rectum and bladder) was investigated using linear regression analysis. RESULTS: Our results indicated POPP was better than COPP in predicting intermediate-dose metrics. The bladder results showed a trend similar to that of the rectum. The correlation coefficient of POPP was significantly greater than that of COPP in < 62 Gy (82% of the prescribed dose) region for IMRT and in < 55 Gy (73% of the prescribed dose) region for VMAT regarding the rectum (p < 0.05). CONCLUSIONS: POPP is superior to COPP for creating predictive models at an intermediate-dose level. Because rectal bleeding and bladder toxicity can be associated with intermediate-doses as well as high-doses, it is important to predict dose-volume metrics for various dose levels. POPP is a useful parameter for predicting dose-volume metrics and assisting the generation of treatment plans.

Treatment outcomes of radiotherapy with concurrent weekly cisplatin in older patients with locally advanced head and neck squamous cell carcinoma.

BACKGROUND: Tri-weekly cisplatin and radiotherapy (CDDP + RT) is a standard of care for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) but is sometimes challenging to complete in older patients. Weekly CDDP + RT has shown mild toxicity compared to tri-weekly CDDP + RT for LA-HNSCC and is a promising option for older adults. We aimed to report the treatment outcomes and prognostic factors in patients with LA-HNSCC treated with weekly CDDP + RT. METHODS: We analyzed patients aged ≥ 70 years who started weekly CDDP + RT for LA-HNSCC between July 2006 and October 2022. LA-HNSCC includes cancer in the oropharynx, hypopharynx, or larynx with a clinical stage of 3 or 4 without distant metastases based on the Union for International Cancer Control staging system 8th edition. The radiation dose of 70 Gy was delivered in 35 fractions by 3-dimensional conformal radiotherapy, intensity-modulated radiotherapy, or proton beam therapy. The primary endpoint was the 3-year overall survival (OS), and the secondary endpoints were the 3-year progression-free survival (PFS) and 3-year cause-specific survival (CSS). The Kaplan-Meier method was used to calculate survival rates, and the log-rank test was used to evaluate statistical significance. A Cox proportional hazards model was used for the multivariate analysis of prognostic factors. RESULTS: The median age of the 49 patients was 72 (range: 70-78) years. The median CDDP dose was 200 (40-280) mg/ m2, and 47 patients completed scheduled radiotherapy. Forty-eight patients (98.0%) had a performance status of ≥ 1 at the initial visit. The 3-year OS, PFS, and CSS were 80.9% (95% confidence interval [CI]: 64.8-90.7), 68.3% (95% CI 51.8-81.2), and 85.0% (95% CI 68.7-93.4), respectively. In the multivariate analysis, the cumulative CDDP dose (< 200 or ≥ 200 mg/m2) was a significant factor for OS (hazard ratio: 0.29 [95% CI 0.08-0.97], p = 0.044). There was one case of early mortality. Grade 3 or higher late adverse events were observed in four patients (8.2%). CONCLUSIONS: Weekly CDDP + RT in older patients led to good survival outcomes with an acceptable rate of adverse events. CDDP should be administered at a dose of at least 200 mg/m2 in older patients. Trial registration Retrospectively registered.

Predicting the daily gastrointestinal doses of stereotactic body radiation therapy for pancreatic cancer based on the shortest distance between the tumor and the gastrointestinal tract using daily computed tomography images.

Objectives: We aimed to investigate whether daily computed tomography (CT) images could predict the daily gastroduodenal, small intestine, and large intestine doses of stereotactic body radiation therapy (SBRT) for pancreatic cancer based on the shortest distance between the gross tumor volume (GTV) and gastrointestinal (GI) tract. Methods: Twelve patients with pancreatic cancer received SBRT of 40 Gy in five fractions. We recalculated the reference clinical SBRT plan (PLANref) using daily CT images and calculated the shortest distance from the GTV to each GI tract. The maximum dose delivered to 0.5 cc (D0.5cc) was evaluated for each planning at-risk volume of the GI tract. Spearman's correlation test was used to determine the association between the daily change in the shortest distance (Δshortest distance) and the ratio of ΔD0.5cc dose to D0.5cc dose in PLANref (ΔD0.5cc/PLANref) for quantitative analysis. Results: The median shortest distance in PLANref was 0 mm in the gastroduodenum (interquartile range, 0-2.7), 16.7 mm in the small intestine (10.0-23.7), and 16.7 mm in the large intestine (8.3-28.1 mm). The D0.5cc of PLANref in the gastroduodenum was >30 Gy in all patients, with 10 (83.3%) having the highest dose. A significant association was found between the Δshortest distance and ΔD0.5cc/ PLANref in the small or large intestine (p < 0.001) but not in the gastroduodenum (p = 0.404). Conclusions: The gastroduodenum had a higher D0.5cc and predicting the daily dose was difficult. Daily dose calculations of the GI tract are recommended for safe SBRT. Advances in knowledge: This study aimed to predict the daily doses in SBRT for pancreatic cancer from the shortest distance between the GTV and the gastrointestinal tract.Daily changes in the shortest distance can predict the daily dose to the small or large intestines, but not to the gastroduodenum.

Challenges and Opportunities With the Use of Hypofractionated Radiation Therapy in Cancer Care: Regional Perspectives From South Korea, Japan, Singapore, and Australia.

Hypofractionated radiotherapy schedules provide higher per-fraction radiation doses delivered in fewer fractions than conventional schedules. This novel delivery method is supported by a large body of clinical trial evidence across various cancer sites in both curative and palliative settings. Hypofractionation is associated with benefits such as lower costs, improved patient access and increased treatment precision, which has led to its inclusion in various treatment guidelines. Despite this, utilization is not uniform across cancer sites and geographic regions due to reasons such as reimbursement models, nuances in healthcare systems, and professional culture. Key factors to ensure patients benefit from access to high quality radiotherapy include publishing clinical evidence, cross-country collaboration to fill knowledge gaps, reviewing reimbursement models, and improving patient advocacy in treatment decision-making.

Treatment outcomes of the patient with sinonasal mucosal melanoma: the role of endoscopic resection and postoperative radiotherapy.

BACKGROUND: The standard of care for sinonasal mucosal melanoma is surgery and postoperative radiotherapy (PORT). Our treatment strategy comprises endoscopic resection and PORT. We performed combined endoscopic and open resection or applied an external approach alone when sufficient resection was difficult to achieve endoscopically. The objective of this study was to evaluate the validity of our treatment strategy. METHODS: We assessed 30 patients with sinonasal mucosal melanoma who underwent definitive therapy between January 2002 and April 2021, and conducted a retrospective analysis. The median follow-up period was 2.2 years. The primary endpoint was overall survival. The Kaplan-Meier method was used for the calculation of survival rates, the cumulative incidence of distant metastasis, and local recurrence. RESULTS: Twenty-eight patients underwent surgery. The other two patients were treated by definitive proton beam therapy. Twenty-one of 28 (75%) patients underwent resection by endoscopic approach alone. Postoperative radiotherapy was performed for all 28 patients who underwent surgery. Twenty-one patients (70%) experienced recurrence during the observation period. Overall, distant metastasis was observed in 19 patients. Twelve patients died during the observation period, with 10 of the 12 patients (83%) dying of distant metastasis. The overall survival rate at 2 and 5 years was 70% and 46%, respectively. The cumulative incidence rate of distant metastasis at 2 years was 63%, while the 2-year cumulative incidence rate of local recurrence was 6.7%. CONCLUSION: The local disease was controlled by our treatment strategy. To improve treatment outcomes, control of the distant metastasis is needed.

Radiation Oncology Research in Asia: Current Status and a Peep Into the Future From the Federation of Asian Organizations for Radiation Oncology.

PURPOSE: This survey was conducted to assess the current research practices among the 14 members of the Federation of Asian Organizations for Radiation Oncology (FARO) committee, to inform measures for research capacity building in these nations. MATERIALS AND METHODS: A 19-item electronic survey was sent to two research committee members from the 14 representative national radiation oncology organizations (N = 28) that are a part of FARO. RESULTS: Thirteen of the 14 member organizations (93%) and 20 of 28 members (71.5%) responded to the questionnaire. Only 50% of the members stated that an active research environment existed in their country. Retrospective audits (80%) and observational studies (75%) were the most common type of research conducted in these centers. Lack of time (80%), lack of funding (75%), and limited training in research methodology (40%) were cited as the most common hindrances in conducting research. To promote research initiatives in the collaborative setting, 95% of the members agreed to the creation of site-specific groups, with head and neck (45%) and gynecological cancers (25%) being the most preferred disease sites. Projects focused on advanced external beam radiotherapy implementation (40%), and cost-effectiveness studies (35%) were cited as some of the potential areas for future collaboration. On the basis of the survey results, after result discussion and the FARO officers meeting, an action plan for the research committee has been created. CONCLUSION: The results from the survey and the initial policy structure may allow facilitation of radiation oncology research in the collaborative setting. Centralization of research activities, funding support, and research-directed training are underway to help foster a successful research environment in the FARO region.

The superselective intra-arterial infusion of cisplatin and concomitant radiotherapy (RADPLAT) is effective for metastatic lymph nodes in head and neck squamous cell carcinoma.

BACKGROUND: Superselective intra-arterial infusion of cisplatin and concomitant radiotherapy (RADPLAT) is a very promising treatment modality for locally advanced head and neck squamous cell carcinoma. However, there are some concerns regarding its potential for the control of neck lymph node metastasis. The objective of this study was to investigate whether RADPLAT provided inferior regional control compared to intravenous chemoradiotherapy (IV-CRT). METHODS: A total of 172 patients with neck lymph node metastases, 66 of whom underwent RADPLAT and 106 IV-CRT, were enrolled in this study. We retrospectively compared regional control rates between RADPLAT and IV-CRT. Furthermore, to adjust for differences in factors related to patient background between the groups, we conducted inverse probability weighting (IPW) analysis using the propensity score. RESULTS: A comparison between the two groups revealed that the regional control rates were almost equal under unadjusted conditions; however, after adjustment by IPW analysis, the RADPLAT group had a relatively better regional control rate than did the IV-CRT group (1 year regional control rate: 86.6% vs. 79.4%). In addition, the analysis of relative risk factors for regional control in the RADPLAT group showed that the absence of intra-arterial cisplatin infusion into metastatic lymph nodes was the only independent risk factor (Hazard ratio: 4.23, p = 0.04). CONCLUSION: This study showed that the regional control rate in patients treated with RADPLAT was noninferior to that for IV-CRT. Locally advanced head and neck cancers is a good indication for RADPLAT, even if the patients have neck lymph node metastases.

Proton beam therapy for muscle-invasive bladder cancer: A systematic review and analysis with Proton-Net, a multicenter prospective patient registry database.

To assess the safety and efficacy of proton beam therapy (PBT) for muscle-invasive bladder cancer (MIBC), we examined the outcomes of 36 patients with MIBC (cT2-4aN0M0) who were enrolled in the Proton-Net prospective registry study and received PBT with concurrent chemotherapy from May 2016 to June 2018. PBT was also compared with X-ray chemoradiotherapy in a systematic review (X-ray (photon) radiotherapy). The radiotherapy consisted of 40-41.4 Gy (relative biological effectiveness (RBE) delivered in 20-23 fractions to the pelvic cavity or the entire bladder using X-rays or proton beams, followed by a boost of 19.8-36.3 Gy (RBE) delivered in 10-14 fractions to all tumor sites in the bladder. Concurrently, radiotherapy was given with intra-arterial or systemic chemotherapy of cisplatin alone or in combination with methotrexate or gemcitabine. Overall survival (OS), progression-free survival (PFS) and local control (LC) rates were 90.8, 71.4 and 84.6%, respectively, after 3 years. Only one case (2.8%) experienced a treatment-related late adverse event of Grade 3 urinary tract obstruction, and no severe gastrointestinal adverse events occurred. According to the findings of the systematic review, the 3-year outcomes of XRT were 57-84.8% in OS, 39-78% in PFS and 51-68% in LC. The weighted mean frequency of adverse events of Grade 3 or higher in the gastrointestinal and genitourinary systems was 6.2 and 2.2%, respectively. More data from long-term follow-up will provide us with the appropriate use of PBT and validate its efficacy for MIBC.