Magnetic resonance imaging-guided versus computed tomography-guided stereotactic body radiotherapy for prostate cancer (MIRAGE): Interim analysis of a phase III randomized trial.

• DOI: 10.1200/jco.2022.40.6_suppl.255
• Publication Date: 2022-02-16T21:35:25Z
• Authors: Amar Upadhyaya Ki...; James Lamb; Maria Casado; Xiaoyan Wang; Ting Martin Ma; Daniel Low; Ke Sheng; Yingli Yang; Yu Gao; Vincent Basehart; Minsong Cao; Michael L. Steinberg
• Keywords: Clinical endpoint; Interim analysis

255 Background: Magnetic resonance imaging (MRI) guidance offers several theoretical advantages over computed tomography (CT) in the context of stereotactic body radiotherapy (SBRT) for intact prostate cancer. Here we report results an interim analysis phase III MIRAGE trial, which directly compared MRI- and CT-guidance with a pragmatic primary endpoint acute grade ≥2 genitourinary (GU) toxicity. Methods: is single center, randomized 3 trial. Men undergoing SBRT localized cancer were randomly assigned to either or MRI-guidance. Planning margins 4 mm (CT-arm) 2 (MRI-arm) placed around proximal seminal vesicles, this volume received 40 Gy five fractions. Elective nodal rectal spacers allowed per physician discretion. The outcome was incidence (i.e., within 90 days SBRT) GU physician-reported toxicity (by CTCAE version 4.03). Secondary outcomes interest included toxicity, changes IPSS scores at 1 months, EPIC-26 bowel domain summary months. A pre-specified efficacy planned once 100 th patient eligible evaluation endpoint. Results: On 9/1/2021, patients became (51 CT arm, 49 MRI arm). Acute significantly reduced men receiving MRI-guided (incidence 24 (47.1%) vs. 11 (22.4%), p = 0.01). GI also 7 (13.7%) 0 (0%), 0.01.). increase from baseline higher CT-guided month post-SBRT (median change 10 6, 0.03), but not months 2, 0.3). decrement greater -8.3 0, -2.3 0.4). Given large signal seen, our protocol amended reduce projected sample size 154 while still maintaining 89% power detect difference. Conclusions: This demonstrates statistically significant reduction MRI-guidance versus SBRT. Patient-reported urinary function metrics are better preserved time point MRI-guidance, though difference dissipates (potentially due side-effect management) point. Accrual has been completed as October 2021 final anticipated early 2022. Clinical trial information: NCT04384770.