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Purpose: To determine the significance of dose-volume histogram parameters for predicting late rectal toxicity (LRT) after single-fraction high-dose-rate brachytherapy (HDRBT) boost and external beam radiotherapy (EBRT) in prostate cancer., Materials and Methods: Three hundred patients with intermediate- or high-risk prostate cancer were included between August 2010 and March 2015. Treatment comprised a single-fraction HDRBT boost of 15.0 Gy plus EBRT (46.0 Gy delivered in 23 fractions) or an HDRBT boost of 9.5 Gy plus EBRT (60.0 Gy delivered in 30 fractions) if the seminal vesicles were infiltrated using real-time transrectal ultrasound-based planning. LRT was evaluated every 3 months after the end of the combined treatment using the Common Terminology Criteria for Adverse Events, version 4.0. The minimum dose received by the most exposed 0.1 and 2.0 cm 3 volume of the rectum (D0.1 cc/D2cc) was analyzed by estimating the biologically equivalent rectal dose according to the recommendations of the Groupe Européen de Curiethérapie/European Society for Radiotherapy and Oncology and an ordinal regression analysis was performed., Results: LRT was observed in 62 patients (20.7%) at a median followup of 33 (range, 2-68) months. Twenty patients (6.7%) developed grade 2 and 3 patients (1%) developed grade 3 LRT. A significant association was observed between D2cc and the probability of developing grade 1-3 LRT (p = 0.04)., Conclusions: D2cc is associated with the occurrence of LRT in HDRBT-treated prostate cancer patients. The dose constraints proposed and recommended by experienced HDRBT centers must be investigated to determine the threshold dose through long-term and prospective studies., (Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.)

Purpose: The purpose of the study was to analyze patients with vaginal-involving recurrences of gynecological tumors and primary vaginal tumors, treated with transperineal interstitial brachytherapy (P-ISBT). Dosimetric, clinical, and toxicity analysis of these patients was conducted, incorporating MRI in volume definition and dose-volume dosimetry. Material and methods: Forty-two patients were retrospectively analyzed. They were treated with radical or adjuvant intent (in hysterectomized patients with high-risk of relapse). P-ISBT was performed with MUPIT (CT-based planning) in 18 patients (42.9%) and with Template Benidorm (TB) (MRI-based planning) in 24 patients (57.1%). Results: Median age was 59 years (range, 39-78 years). Median clinical target volume (CTV) was 81.4 cc (range, 33.8-286.2 cc) in MUPIT, and 47.5 cc (range, 10-156.4 cc) in TB-treated patients (p = 0.01). Median EQD2 for EBRT and brachytherapy D90 CTV was 69.2 Gy (range, 27.9-88.8 Gy) in MUPIT, and 77.2 Gy (range, 31-84.3 Gy) in TB. Median rectal D2cc was 69.2 Gy (range, 23.5-82.6 Gy) in MUPIT, and 66.3 Gy (range, 16.4-75 Gy) in TB. Median bladder D2cc was 71.5 Gy (range, 23.6-90.8 Gy) in MUPIT, and 66.9 Gy (range, 18.2-78.3 Gy) in TB. Median follow-up was 36.5 months (range, 4-188 months). Local control was 95% at 3 and 5 years. Overall survival was 77% at 3 years, and 66% at 5 years. Disease-specific survival was 81% at 3 years, and 75% at 5 years. Chronic grade 1-2 proctitis presented in 10 patients (24%; 8 treated with MUPIT and 2 treated with TB; p = 0.01). Grade 3 toxicity was documented in 4 patients (9.6%). Conclusions: MRI-based planning is superior to CT-based planning in P-ISBT. It allows for better definition of CTV, resulting in smaller and more selective treatment volumes. Our results show a tendency towards higher D90 CTV dose and lower rectal/bladder D2cc dose, leading to less events of late rectal toxicity. [ABSTRACT FROM AUTHOR]

Purpose: Esteya and Valencia surface applicators are designed to treat skin tumors using brachytherapy. In clinical practice, in order to avoid errors that may affect the treatment outcome, there are two issues that need to be carefully addressed. First, the selected applicator for the treatment should provide adequate margin for the target, and second, the applicator has to be precisely positioned before each treatment fraction. In this work, we describe the development and use of a new acrylic templates named Template La Fe-ITIC. They have been designed specifically to help the clinical user in the selection of the correct applicator, and to assist the medical staff in reproducing the positioning of the applicator. These templates are freely available upon request. Material and methods: Templates that were developed by University and Polytechnic Hospital La Fe (La Fe) and Hospital Clínica Benidorm (ITIC) in cooperation with Elekta, consist of a thin sheet made of transparent acrylic. For each applicator, a crosshair and two different circles are drawn on these templates: the inner one corresponds to the useful beam, while the outer one represents the external perimeter of the applicator. The outer circle contains slits that facilitate to draw a circle on the skin of the patient for exact positioning of the applicator. In addition, there are two perpendicular rulers to define the adequate margin. For each applicator size, a specific template was developed. Results: The templates have been used successfully in our institutions for more than 50 patients' brachytherapy treatments. They are currently being used for Esteya and Valencia applicators. Conclusions: The template La Fe-ITIC is simple and practical. It improves both the set-up time and reproducibility. It helps to establish the adequate margins, an essential point in the clinical outcome. [ABSTRACT FROM AUTHOR]