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Purpose: To evaluate treatment results and investigate predictors of local control., Methods and Materials: In this retrospective study of 236 patients with cervical cancer, we administered CT-based adaptive brachytherapy (BT) in combination with whole- pelvic (WP)- and central shielding (CS)- external beam radiotherapy (EBRT) with or without chemotherapy. The study cohort comprised patients with cervical cancer treated with definitive radiotherapy (RT) or concurrent chemoradiotherapy between June 2013 and March 2019. Local control (LC), overall survival (OS), and late toxicity were evaluated. Predictive factors for LC were analyzed by univariate and multivariate analyses., Results: Median doses of WP- and CS-EBRT and BT were 30.6 Gy EQD2 , 19.8 Gy EQD2 , and 40.3 Gy EQD2 , respectively. The 3-year LC rates for T1b2, T2a, T2b, T3b, and T4 were 100%, 100%, 97.3%, 86.9%, and 91.7%, respectively (p = 0.346). The 3-year OS for Stages IB, IIB, IIIB, IIIC, and IVA were 100%, 94.8%, 82.5%, 81.7%, and 74.6%, respectively (p = 0.037). Rates of Grade 3-4 gastrointestinal and genitourinary toxicities were 3.8% and 1.7%, respectively. Multivariate analysis showed that T3-4, nonsquamous cell histology, and high-risk clinical target volume (CTV HR ) D90 of BT < 36Gy EQD2 were independently associated with significantly poorer LC., Conclusions: The combination of WP- and CS-EBRT and CT-based IGBT with or without concurrent chemotherapy produced favorable LC outcomes with low rates of late toxicities for patients with small or medium-sized tumors. However, LC was less favorable for patients who had large T3 disease, and the use of CS requires caution in these patients., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To analyze the dose-volume histogram of the central shielding technique for cervical cancer radiotherapy by computing the composite three-dimensional EQD2 dose distributions of external-beam radiotherapy plus intracavitary brachytherapy., Methods and Materials: On a phantom, three patterns of high-risk clinical target volume (HR-CTV) with right-left diameters of 3, 4, and 5 cm were created using clinical data. Four patterns of combinations of whole-pelvis irradiation plus "pelvis irradiation using the central shielding technique" (CS) (shielding width, 3 or 4 cm) were created: 20 Gy/10 fractions + 30 Gy/15 fractions, 30 Gy/15 fractions + 20 Gy/10 fractions, 40 Gy/20 fractions + 10 Gy/5 fractions, and 50 Gy/25 fractions + 0 Gy. The intracavitary brachytherapy plan was set as 24 Gy/4 fractions prescribed to the Point A. The HR-CTV D90/D98 and modeled bladder/rectum D2cc were computed using the composite EQD2 dose distributions of all the treatment combinations., Results: If appropriate combinations of the treatment plans were selected on the basis of the CS doses and the HR-CTV sizes, the D90/D98 of HR-CTV 3 cm, HR-CTV 4 cm, and HR-CTV 5 cm were 89.7 Gy/80.6 Gy, 77.3 Gy/72.0 Gy, and 73.0 Gy/69.2 Gy in the case of CS width 3 cm, respectively; and 86.2 Gy/76.0 Gy, 73.3 Gy/67.6 Gy, and 70.9 Gy/67.1 Gy in the case of CS width 4 cm, respectively. The contributions of CS to the HR-CTV D90/bladder D2cc/rectum D2cc values were 24-56%/28-32%/9% of the CS plan doses for shielding width of 3 cm and were 13-35%/11-16%/5-6% for shielding width of 4 cm., Conclusion: The dose contributions of CS were variable but not negligible when analyzing the total doses delivered to the HR-CTV., (Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the efficacy and the incidence of complications of high-dose-rate (HDR) and low-dose-rate (LDR) intraluminal brachytherapy (IBT) boost after external beam radiation therapy in patients with superficial esophageal cancer., Methods and Materials: Fifty-four consecutive patients with Stage I thoracic esophageal squamous cell carcinoma who were treated with definitive radiotherapy using IBT between 1991 and 2007 were studied retrospectively. LDR-IBT and HDR-IBT were performed for 19 and 35 patients, respectively. After external beam radiation therapy of 56-60 Gy with a conventional fractionation, LDR-IBT (5 Gy × 2) or HDR-IBT (3 Gy × 3) was given within 2 weeks. The median follow-up was 47 months (7-151 months)., Results: Overall, the 5-year overall survival, cause-specific survival (CSS), and locoregional control (LRC) rates were 61%, 86%, and 79%, respectively. The 5-year overall survival, CCS, and LRC rates did not differ significantly between the LDR-IBT and HDR-IBT groups (68% vs. 58% (p=0.50), 83% vs. 85% (p=0.63), and 84% vs. 75% (p=0.42), respectively). Salvage treatment was given in 8 locally recurrent patients, and 6 patients were rescued. The Grade ≥2 late morbidities of esophagus and heart/lung were observed in 5 patients (4 in the LDR-IBT group and 1 in the HDR-IBT group) and 2 patients (one from each group), respectively., Conclusions: In view of the safety profile and effectiveness, our results encourage the continued adoption of HDR-IBT as radiation boost in medically inoperable or elderly superficial esophageal cancer patients undergoing definitive radiotherapy., (Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)