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This study investigates the influence of calculation accuracy in peripheral low-dose regions on the gamma pass rate (GPR), utilizing the Acuros XB (AXB) algorithm and ArcCHECK™ measurement. The effects of varying small field sizes, dose grid sizes, and split-arc techniques on GPR were analyzed. Various small field sizes were employed. Thirty-two single-arc plans with dose grid sizes of 2 mm and 1 mm and prescribed doses of 2, 5, 10, and 20 Gy were calculated using the AXB algorithm. In total, 128 GPR plans were examined. These plans were categorized into three sub-fields (3SF), four sub-fields (4SF), and six sub-fields (6SF). The GPR results deteriorated with smaller target sizes and a 2 mm dose grid size in a single arc. A similar degradation in GPR was observed with smaller target sizes and a 1 mm dose grid size. However, the 1 mm dose grid size generally resulted in better GPR compared with the 2 mm dose grid size for the same target sizes. The GPR improved with finer split angles and a 2 mm dose grid size in the split-arc method. However, no statistically significant improvement was observed with finer split angles and a 1 mm dose grid size. This study demonstrates that coarser dose grid sizes result in lower GPRs in peripheral low-dose regions as calculated by AXB with ArcCHECK™ measurement. To enhance GPR, employing split-arc methods and finer dose grid sizes could be beneficial. [ABSTRACT FROM AUTHOR]

Purpose: Fixed bulky nodal disease in patients with head and neck cancer of unknown primary (HNCUP) remains difficult to treat. This retrospective study evaluated the therapeutic efficacy of selective intra-arterial chemoradiotherapy with docetaxel and nedaplatin for fixed bulky nodal disease in HNCUP. Methods: Data from seven consecutive patients with fixed bulky nodal disease in HNCUP who had undergone selective intra-arterial chemoradiotherapy were analyzed. Whole pharyngeal mucosa and all bilateral nodal areas were irradiated (total dose 50 Gy), and bulky nodal lesions were provided an additional 20 Gy. Intra-arterial chemotherapy used a combination of nedaplatin (80 mg/m2) and docetaxel (60 mg/m2). Outcome measures were local control, disease-free survival, overall survival, and adverse events. Statistical analyses were performed using the Kaplan–Meier method. Results: Median follow-up period was 24 months (range 9–64). All patients had extracapsular extension (N3b) on imaging and clinical findings. Symptoms due to bulky disease were neck discomfort (100%), tumor bleeding (43%), tracheal obstruction (14%), and carotid sinus syndrome (28%). Median value for maximum diameter of cervical disease was 84 mm (range 70–107), and 3-year local control, disease-free survival, and overall survival rates were 100, 54, and 64%, respectively. Symptoms due to bulky disease disappeared in all patients after intra-arterial chemoradiotherapy. Grade 4 leukopenia occurred in two patients (28%) as an acute adverse event. No other serious acute adverse events were observed. Conclusion: Selective intra-arterial chemoradiotherapy with docetaxel and nedaplatin can potentially achieve both favorable local control and survival in in HNCUP with fixed bulky nodal disease. [ABSTRACT FROM AUTHOR]

Background: Postoperative chemoradiotherapy is recommended for patients with head and neck squamous cell carcinoma with positive margins or extracapsular extension at high risk of recurrence. However, high-dose radiotherapy in the head and neck region often causes severe acute and late radiation-related adversities. In our institution, the radiation dose has been relatively lower than that used in Western countries to reduce radiation-related toxicities. Therefore, in this study, we examined the treatment outcomes of low-dose postoperative chemoradiotherapy. Methods: The outcomes of 90 consecutive head and neck squamous cell carcinoma patients who received postoperative radiotherapy between June 2009 and December 2016 were retrospectively analyzed. All patients received postoperative three-dimensional conformal radiotherapy with or without concurrent systemic chemotherapy. The median patient age was 65 years. Concurrent chemoradiotherapy was administered at a total dose of 50.4 Gy in 28 fractions (daily fraction, 1.8 Gy). High-risk patients received 10.8 Gy of boost irradiation in six fractions. For radiotherapy alone, the irradiation dose was up to 54 Gy in 30 fractions and 64.8 Gy in 36 fractions for high-risk patients to increase the treatment intensity. Results: The median follow-up period was 40.5 months. The 3-year locoregional control and overall survival rates were 67.5% and 82.7%, respectively. A significantly higher proportion of patients with oral cavity carcinoma experienced locoregional failure (p = 0.004). The acute adverse events were mild, and the only late adverse event was grade 3 dysphagia (n = 3). Conclusion: This study suggests that de-escalation of the postoperative radiation dose can potentially reduce the severe adverse events of irradiation in patients while ensuring its effectiveness. In patients with oral cavity carcinoma, it might be necessary to increase the radiation dose. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of chemoembolization for inoperable metastatic epidural spinal cord compression (MESCC) refractory to re-radiotherapy. Methods: Nineteen consecutive patients with recurrent MESCC after re-radiotherapy who had undergone chemoembolization were retrospectively analyzed. Outcome measures were pain relief rate, neurological improvement rate, objective response rate, and adverse events. MESCC degree classification was assessed using Bilsky grades. Pain assessment was performed using Numerical Rating Scale, and neurological function was evaluated using the Frankel classification. Results: The median follow-up period was 7 (range 2–44) months. All participants had MESCC grade 2 or higher and had severe pain. Fifteen patients (79%) had neurological deficits, and ten had Frankel classification C and five had D. Symptoms were relieved in almost all patients the day following chemoembolization. Pain relief was achieved in 18 of 19 (95%) patients; the median decrease in Numerical Rating Scale score was 8 (range 0–10; p < 0.001). Neurological improvement was achieved in 11 of 15 patients (73%); the median increase in Frankel classification was 1 (range 0–2; p = 0.006). Ten of 19 (53%) patients showed a reduction in MESCC; the median decrease in Bilsky grade was 1 (range 0–2; p = 0.005). There was no correlation between the change in Bilsky grade and pain relief (p = 0.421). However, the decrease in Bilsky grade significantly improved neurological symptoms (p = 0.01). No serious adverse events occurred. Conclusion: Chemoembolization may be a useful palliative treatment modality for MESCC refractory to re-radiotherapy. Level of Evidence: Level 3b, Follow up Study. [ABSTRACT FROM AUTHOR]

Purpose: Fractures are known to shorten life expectancy and worsen the quality of life. The risk of fractures after radiation therapy in cervical cancer patients is known to be multifactorial. In this study, we examined risk factors for fractures in cervical cancer patients, especially by evaluating bone densities and DVH parameters for fractured bones. Materials and Methods: For 42 patients, clinical characteristics, pretreatment CT bone densities, and radiation dose were compared between patients with and without fractures. Results: Posttreatment fractures occurred in 25 bones among ten patients. Pretreatment CT bone densities were significantly lower in patients with fractures (P < 0.05–0.01 across sites, except for the ilium and the ischium). Although DVH parameters were also significantly associated with fractures in univariate analysis, only CT densities were significantly associated with fractures in multivariate analysis. Conclusion: Pretreatment CT densities of spinal and pelvic bones, which may reflect osteoporosis, have a significant impact on the risk for posttreatment fractures. [ABSTRACT FROM AUTHOR]

Background: This prospective study investigated the feasibility, toxicity, and oncologic outcomes of definitive radiotherapy (RT) consisting of whole pelvic radiotherapy with no central shielding (noCS-WPRT) and CT-based intracavitary brachytherapy (ICBT) in Japanese patients with cervical cancer. Methods: Patients with cervical cancer of FIGO stages IB1–IVA were eligible. The treatment protocol consisted of noCS-WPRT of 45 Gy in 25 fractions and CT-based high dose-rate ICBT of 15 or 20 Gy in 3 or 4 fractions prescribed at point A. The prescribed ICBT dose was decreased if the manual dwell time/position optimization failed to meet organs-at-risk constraints. Graphical optimization and additional interstitial needles were not applied. Results: We enrolled 40 patients. FIGO stages were IB1: 11, IB2: 13, IIA2: 1, IIB: 11, IIIB: 3, and IVA: 1. Median (range) pretreatment tumor diameter was 47 (14–81) mm. Point A doses were decreased in 19 of 153 ICBT sessions (12%). The median follow-up duration was 33 months. The 2-year rates of pelvic control, local control (LC), and progression-free survival were 83%, 85%, and 75%, respectively. Pre-ICBT tumor diameter, high-risk clinical target volume (HR-CTV), total HR-CTV D90, and overall treatment time (OTT) significantly affected LC. Late adverse events (grade ≥ 3) were observed in 3 patients (2 in the bladder, 1 in the rectum). Conclusions: Definitive RT consisting of noCS-WPRT and CT-based ICBT was feasible for Japanese patients with cervical cancer. To further improve LC, additional interstitial needles for patients with a large HR-CTV and shorter OTT should be considered. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to compare the efficacy of radiotherapy (RT) combined with transcatheter arterial chemoembolization (TACE) with RT alone for the treatment of bone metastases from renal cell carcinoma (RCC).Methods: We included in this retrospective study 25 RCC patients (28 bone metastases), who were treated with RT at our institution. Patients were divided into two groups: patients treated with RT alone (monotherapy group; n = 17) and those treated with RT combined with TACE (combined therapy group; n = 11). The administered median RT dose was 30 Gy in 10 fractions. Anti-cancer agents used in TACE were cisplatin (median dose, 50 mg) and carboplatin (median dose, 240 mg) for patients with reduced renal function. We evaluated the objective response, post-RT-skeletal-related event (PR-SRE)-free rate, and adverse events associated with treatment for each group.Results: The objective response rates for bone metastases in the monotherapy and combined therapy groups were 33% and 82%, respectively (p = 0.009). The 2-year PR-SRE-free rate in the monotherapy and combined therapy groups was 41.8% and 100%, respectively (p = 0.009). The objective response and PR-SRE-free rates were significantly superior in the combined therapy than in the monotherapy group. There were no significant differences in adverse events or survival between the two groups.Conclusion: RT combined with TACE is a promising treatment for bone metastases from RCC, as it results in higher objective response, and PR-SRE-free rates compared with RT alone.Key Points: • Skeletal-related events (SREs) are common in patients with bone metastases from renal cell carcinoma (RCC). • Radiotherapy (RT) provides pain relief in patients with bone metastases from RCC, but rarely achieves objective response. • Combination of RT with transcatheter arterial chemoembolization results in higher objective response and post-RT-SRE-free rates compared with RT alone and is a promising treatment for bone metastases from RCC, as it. [ABSTRACT FROM AUTHOR]

Background: To determine the current practice of stereotactic irradiation (STI) for brain metastases in Japan by a questionnaire survey.Methods: A questionnaire was distributed to 313 institutions performing STI with one of the following machines: Gamma Knife (GK), CyberKnife (CK), Novalis (Nov), or other linear accelerator (LINAC)-based systems (OLS). The participation was voluntary.Results: There were 163 responding institutions. The total number of STI treatments between April 2013 and March 2014 was 10,684. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) were performed in 8624 (80.7%) and 2060 (19.3%) cases, respectively. Whole-brain radiation therapy (WBRT) was performed for a total of 3515 cases. For a case model of a 1.5-cm solitary brain metastasis in a non-eloquent area, the most common GTV-PTV margin was 2 mm (22 of 114 institutions), and an institutional standard fraction was 1 (75 of 114 institutions). The doses for the model case also varied from 13.0 to 26.0 Gy (Median 20 Gy) when converted to SRS (α/β = 10). A prescription point was at the PTV margin the most. The median dose constraints which were converted to SRS (α/β = 3) to organs at risk were 12.2, 12.7, and 13.7 Gy for optic nerves, cavernous sinus, and brainstem, respectively.Conclusions: STI for brain metastases in current practice varied significantly among institutions. These different strategies relied mostly on the type of treatment machine used. It is thus necessary to establish a common guideline to express dose prescriptions and plan qualities for different STI machines. [ABSTRACT FROM AUTHOR]

Purpose: Our aim was to assess the patterns of practice and treatment outcomes of definitive radiotherapy (RT) for vaginal cancer in Japan.Materials and methods: RT methods and outcomes of patients with vaginal cancer treated with definitive RT or chemoradiotherapy at 10 institutes of the Japanese Radiation Oncology Study Group between January 2000 and March 2010 were retrospectively evaluated.Results: A total of 90 patients were enrolled in the study. The clinical stages were I, II, III, and IVA in 34, 36, 16, and 4 patients, respectively. Seventy patients were treated with three-dimensional conformal RT (3DCRT) and brachytherapy (BT), 12 with BT alone, and 8 with 3DCRT alone. Chemotherapy was administered to 29 patients. The 5-year overall survival and local control rates were 77 and 83% with a median follow-up period of 94 months for surviving or lost patients. The 5-year overall survival rates according to stage were 94, 71, 56, and 75% for stages I, II, III, and IVA, respectively. The 5-year local control rates according to stage were 94, 77, 74, and 75% for stages I, II, III, and IVA, respectively. Twenty-nine percent (6 of 21 patients) of local recurrences occurred between 5 and 10 years after RT. The 10-year local control rate of all patients was 71%. Significant prognostic factors for overall survival by univariate and multi-variate analyses were performance status, tumor size, and pelvic lymph node metastasis. Grade 3 late radiation morbidity of the rectum, pelvic bone, urinary bladder, and skin developed in 9% (8 of 90 patients).Conclusions: Good outcomes similar to those of cervical cancer can be achieved with definitive RT delivered by 3DCRT and/or BT for vaginal cancer. Long follow-up is necessary for a continuing risk of local recurrence after 5 years. [ABSTRACT FROM AUTHOR]

Background: This second questionnaire-based survey was performed to determine the clinical results of definitive esophageal cancer treatment with radiotherapy (RT) or chemoradiotherapy (CRT) between 2004 and 2008. Materials/methods: Clinical results of definitive RT for patients were collected from major Japanese institutions. Patients were classified into three groups: (A) stage I, (B) resectable stages II-III, (C) unresectable stages III-IVA. For group A, all patients treated with RT alone or CRT were included. For groups B and C, only those treated with CRT were included. Results: In total, 990 patients (group A 259, group B 333, group C 398 patients) were included from 11 institutions. In group A, 199 patients (78 %) were treated with CRT, and 60 patients (23 %) received RT alone. In groups B and C, 420 patients (57 %) were treated with full-dose cisplatin/5-FU, and 181 patients (25 %) with low-dose protracted-infusion cisplatin/5-FU. The median and range of the 5-year overall survival rate were 73 % (40-94 %) for group A, 40 % (0-57 %) for group B, and 18 % (6-26 %) for group C, respectively. The 5-year overall survival rates were consistently good for five high-volume centers where more than 20 patients/year with esophageal cancer were treated definitively as compared with the remaining six medium-volume centers (5-15 patients/year). The median and range of the incidence of grade ≥3 late toxicities were 10 % and 6-22 %, respectively. Conclusions: A wide disparity in 5-year overall survival rates among the institutions was still apparent in the second survey for groups A and B. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to consider the safety and efficacy of concurrent use of strontium-89 (Sr-89) with external beam radiotherapy (EBRT) for multiple bone metastases, including lesions that require urgent therapy.Methods: A retrospective review was performed of a consecutive series of patients who received Sr-89 for multiple bone metastases. Forty-five patients with multiple bone metastases received Sr-89 injection. Since 17 of the 45 patients had osteolytic bone lesions requiring emergent EBRT, they underwent concurrent use of Sr-89 with EBRT (concurrent group). The remaining 28 patients, none of whom had osteolytic lesions requiring urgent EBRT, were given Sr-89 injection only (singularity group). The injection of Sr-89 was to be given during EBRT, or on the day before the first day of EBRT. The dose of EBRT was 30 Gy in 10 fractions or 40 Gy in 20 fractions. Adverse events were evaluated according to hematological toxicity as measured by the Common Terminology Criteria for Adverse Events (V4.0). To assess efficacy, we checked changes in the pain scale and analgesic drug dosages, and the presence or absence of serious complications from bone metastases.Results: Fifteen of 17 patients (88.2%) in the concurrent group and 17 of 28 patients (60.7%) in the singularity group reported bone pain relief. A statistically significant difference was found between the two groups, and severe complications (spinal cord compression and pathological fracture) from bone metastases could be prevented in all patients in the concurrent group. Severe hematological toxicity (grade 3 or higher) was not observed in the two groups. There was no statistical difference between the two groups. No one required additional intervention. The adverse events were tolerable.Conclusions: The results of our study suggest that concurrent use of Sr-89 with EBRT for multiple bone metastases can be performed safely if it is carried out with care, and that it may be an effective therapy in cases requiring emergency treatment. [ABSTRACT FROM AUTHOR]