Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Nov 26:S0360-3016(25)06502-2.
doi: 10.1016/j.ijrobp.2025.11.028. Online ahead of print.

Primary endpoint analysis of the phase II DESTINATION-MRL trial for patients with intermediate-risk prostate cancer

Mathijs G Dassen  1 , Alison C Tree  2 , Lisa Wiersema  3 , Ben Neijndorff  3 , Peter de Ruiter  3 , Joeke van der Linden  3 , Adam Mitchell  2 , Alex Dunlop  2 , Sophie Alexander  2 , Dylan Y Breitkreutz  4 , Sian Cooper  2 , Tomas Janssen  3 , Floris Pos  3 , Danny Vesprini  4 , Uulke A van der Heide  5
Affiliations
Free article

Primary endpoint analysis of the phase II DESTINATION-MRL trial for patients with intermediate-risk prostate cancer

Mathijs G Dassen et al. Int J Radiat Oncol Biol Phys. .
Free article

Abstract

Purpose: Escalating dose to the gross tumor volume (GTV) whilst de-escalating dose to the prostate clinical target volume (CTV) and using a 0 mm PTV margin can potentially minimize toxicity without compromising biochemical control in patients with intermediate-risk prostate cancer (PCa). We evaluated the technical feasibility of this approach in online adaptive MRI-guided stereotactic body radiation therapy (SBRT).

Materials and methods: The XXXXX trial ran as 3 parallel single-center phase II non-randomized trials in 3 different institutes. Each institute enrolled 20 patients who were all treated on a 1.5T Unity MR-Linac. The GTV was defined as tumor(s) visible on multi-parametric MRI. The CTV was defined as the whole prostate. The proximal 1-2 cm of seminal vesicles were included in the CTV at the clinician's discretion. An intra-prostatic margin of 4 mm was applied to the GTV to account for delineation and pathological uncertainty (GTV4mm) and no PTV margin was applied to the CTV. All patients were treated with 30 Gy in 5 fractions to the CTV and an isotoxic boost of 45 Gy to the GTV4mm. The primary endpoint was technical feasibility defined as accumulated GTV D90% of >42Gy on the post-treatment MRI in ≥90% of the patients.

Results: Between May 2023 and September 2024, 60 patients were treated of which 54 were included for analysis. An accumulated GTV D90% of >42 Gy was reached in 46 patients (85%). Analysis per institute showed that this criterion was reached in 10 of 14 patients (71%) in institute 1 and in 18 of 20 patients (90%) in both institute 2 and 3.

Conclusion: While toxicity-minimizing radiotherapy in online adaptive MRI-guided SBRT for PCa was feasible in 2 of the 3 institutes, robust coverage of the GTV and CTV could not be assured in the absence of a gating strategy.

Keywords: Dose accumulation; Dose de-escalation; GU toxicity; MRI-guided online adaptive radiotherapy; Prostate cancer.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest UH and TJ: The department of radiation oncology of the Netherlands Cancer Institute receives research funding from Elekta AB and Philips Healthcare. SC declares funding by the Royal Marsden NHS Foundation Trust whose research fellow program receives funds from Elekta AB. AT declares that The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research are part of the MR-linac consortium and receive funding from Elekta for related activities.

LinkOut - more resources