MR-guided radiotherapy for prostate cancer: an inevitable transition?

The rising global incidence of prostate cancer has intensified both clinical and economic pressures to optimize radiotherapy (RT) delivery. Advances in imaging and fractionation - particularly magnetic resonance imaging (MR)-guided workflows and stereotactic body RT (SBRT) - aim to reduce treatment duration and minimize toxicity. This review explores these innovations and their potential inclusion into routine clinical practice.

MR-guided RT (MRgRT) planning and delivery offer superior soft tissue contrast and real-time motion tracking, enabling reduced target margins and improved sparing of adjacent normal tissues. Hypofractionated regimens (e.g., 60 Gy in 20 fractions) have become standard, while ultra-hypofractionated SBRT (up to 12 Gy per fraction over 2-5 sessions) is gaining traction due to MRgRT capabilities. Adaptive RT allows for daily modification of treatment plans, based on real-time imaging. Several trials, including MIRAGE and SCIMITAR, have demonstrated reductions in acute genitourinary and gastrointestinal toxicity with MR-guided SBRT. Ongoing clinical trials and the MOMENTUM registry aim to clarify long-term outcomes and contribute to the standardization of MRgRT workflows.

Based on available, preliminary evidence, MRgRT and adaptive SBRT are associated with a promising toxicity profiles. Nonetheless, further multicenter studies with extended follow-up are needed to validate outcomes and establish practice guidelines.