ORIGINAL RESEARCH article
Front. Oncol.
Sec. Radiation Oncology
Long-Term Outcomes of External Beam Radiotherapy Combined with High-Dose-Rate Brachytherapy Boost in Intermediate-and High-Risk Prostate Cancer
Provisionally accepted
Ahmed Gawish1,2*
Kerem Tuna Tas1,2Tristan Spartmann1Edgar Smalec1,2Phillip Lishewski1,2Fatima Frosan Sheikhzadeh1,2Martin Böttcher2
Klemens Zink1,2Ioanna Fragkandrea-Nixon3Johannes Huber1,2,4Sebastian Adeberg1,2- 1University of Marburg, Marburg, Germany
- 2Universitatsklinikum Giessen und Marburg - Standort Marburg, Marburg, Germany
- 3NHS Scotland, Glasgow, United Kingdom
- 4UniversitatsKlinikum Heidelberg, Heidelberg, Germany
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Abstract Background: For intermediate-and high-risk prostate cancer, dose escalation is essential to optimize oncological control. While external beam radiotherapy (EBRT) alone can be limited by dose constraints to adjacent organs-at-risk, high-dose-rate (HDR) brachytherapy provides a highly conformal boost option. Methods: This retrospective single-institution study analyzed 250 patients with localized intermediate-and high-risk prostate cancer treated between 06/2004 and 03/2024 with EBRT plus HDR brachytherapy boost. The EBRT dose averaged 50.4 Gy (range: 45–64 Gy), followed by HDR boost in nearly all patients (98.8%) with two fractions of 9 Gy. Androgen deprivation therapy (ADT) was administered to 39.2 % of patients (98/250). Primary outcomes included local control (LC), progression-free survival (PFS), and overall survival (OS). Results: After a median follow-up of 63.5 months (mean 70.4, range 3–231), oncological outcomes were excellent. LC rates were 99.6% at 3 years, 98.8% at 5 years, and 98.4% at 10 years. PFS was 98%, 96.8%, and 96% at 3, 5, and 10 years, respectively. OS reached 98.4% at 5 years and 96% at 10 years. During the 231-month follow-up, 8.4% of patients developed biochemical recurrence, whereas in-field progression was observed in only 1.6%. Patients receiving ADT achieved 100% LC across all timepoints. Patterns of failure were predominantly distant (lymph nodes and bone). Acute and late toxicity was predominantly mild. No acute Grade ≥3 genitourinary (GU) or gastrointestinal (GI) toxicity was observed. Late Grade ≥3 toxicity was rare (0.8%, limited to GU events), and no late Grade ≥3 GI toxicity occurred. Conclusions: The combination of EBRT and HDR brachytherapy boost yields outstanding long-term LC, PFS, and OS for intermediate-and high-risk prostate cancer, confirming this regimen as a highly effective treatment strategy. The dominant pattern of failure was distant, underscoring the need for optimized systemic therapy integration in high-risk patients.
Keywords: androgen deprivation therapy, Dose Escalation, external beam radiotherapy, High-dose-rate brachytherapy, local control, Progression-free survival, prostate cancer
Received: 10 Dec 2025; Accepted: 12 Feb 2026.
Copyright: © 2026 Gawish, Tas, Spartmann, Smalec, Lishewski, Sheikhzadeh, Böttcher, Zink, Fragkandrea-Nixon, Huber and Adeberg. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Ahmed Gawish
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.