Magnetic Resonance Imaging-Directed Stereotactic Body Radiation Therapy Microboost in Concert With Pelvic Nodal Irradiation for Prostate Cancer in the Higher-Risk Spectrum: Toxicity

In the early follow-up period, we observed no significant difference in GI or GU toxicity between those who underwent MIB and those who did not. These results suggest that MRI-directed SBRT MIB did not increase GI toxicity and may even reduce GU toxicity compared with standard treatment. Future research should explore long-term side effects, with attention to the Expanded Prostate Cancer Index Composite (EPIC) scores and oncologic outcomes of this novel method of dose escalation.