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Published on: February 6, 2019
Two-fraction Ultrahypofractionated Radiotherapy with focal BOost for intermediate-risk, localized prostate cancer
T A Lalmahomed1, E M Monninkhof2, M J van Rijssel3
1Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands. t.a.lalmahomed-2@umcutrecht.nl.
Background:
Hypofractionation in prostate cancer radiotherapy (RT) has drastically reduced fractionation schemes from 35 to 5 fractions for patients with intermediate-risk prostate cancer, providing good oncological outcomes and well-tolerated treatment toxicity. With an ageing population and a subsequently higher volume of patients with localized prostate cancer, optimizing treatment options is essential to maintain a sustainable healthcare system. Magnetic resonance (MR)-guided RT, allows for the delivery of higher doses of radiation with more accuracy, while limiting genitourinary (GU) and gastrointestinal (GI) toxicity. These advantages facilitate the development of ultrahypofractionation schedules in which the number of treatment fractions can be decreased whilst delivering a sufficient dose for oncological control. The objective of the Two-fraction Ultrahypofractionated Radiotherapy with focal BOost (TURBO) trial is to assess if a radiotherapy schedule of 24 Gy to the prostate in two fractions with a boost to the intraprostatic tumor of up to 27 Gy, is safe and tolerable in terms of treatment toxicity, quality of life, and oncological outcomes.
Methods:
TURBO is a single-center, open-label, randomized controlled trial, designed to assess non-inferiority over standard treatment. Data are collected within the longitudinal Multi-OutcoMe EvaluatioN of radiation Therapy Using the Unity MR-Linac Study (MOMENTUM). We will include 160 patients with intermediate risk, localized prostate cancer, who are treated on a 1.5 T MR-linear accelerator (MR-Linac) and randomized (1:1). Participants in the control arm (n = 80) will receive standard of care (36.25 Gy in five fractions, delivered in 16-18 days). Participants in the experimental arm (n = 80) are treated with two fractions of 12 Gy to the prostate, with a boost of up to 13.5 Gy to the gross tumor volume (GTV) in 8 days. The main endpoint is Common Terminology Criteria for Adverse Events (CTCAE) grade ≥ 2 GU acute toxicity (up to 90 days after treatment). Secondary outcomes are acute GI toxicity and late GU and GI toxicity 1, 2, and 5 years after treatment, as well as QoL through assessment of patient-reported outcome measures (EORTC-QLQ-C30, EORTC-QLQ-PR15, EQ-5D-5L) and biochemical recurrence and overall survival up to 5 years.
Discussion:
TURBO compares a 2-fraction radiotherapy course of 12 Gy per fraction to the clinical target volume (CTV) with a simultaneously integrated boost to the GTV of up to 13.5 Gy to a standard 5-fraction course of 7.25 Gy per fraction. The objective is to assess non-inferiority in terms of treatment toxicity and to compare oncological outcomes.
Trial Registration:
ClinicalTrials.gov Identifier NCT06518226. Registered on 24 July 2024. First participant included on March 28th 2024.
