ViewRay announces publication on MRIdian MRI-Guidance in SBRT

ViewRay announced that findings from the phase III randomized controlled MIRAGE trial were published on January 12 in JAMA Oncology. The MIRAGE trial compared MRI-guided and CT-guided stereotactic body radiation therapy for localized prostate cancer and found MRI-guided radiation therapy – delivered with MRIdian – to be superior in substantially reducing acute genitourinary and gastrointestinal toxicity. MRI-guided radiation was also associated with significantly better patient-reported quality of life metrics. The MIRAGE trial was led by Amar Kishan, M.D. and Michael L. Steinberg, M.D. at the University of California, Los Angeles, The study was independently designed, conducted, and analyzed exclusively by UCLA. In this trial, the investigator team randomized 156 patients to receive either MRI-guided SBRT or CT-guided SBRT. Acute grade greater than or equal to2 GU toxicity rates were significantly lower with MRI guidance vs. CT guidance. Acute grade greater than or equal to2 GI toxicity rates were also significantly lower with MRI guidance. On multivariate analysis, which controls for differences in the use of a rectal spacer, prostate size, and baseline urinary symptoms, the MRI-guided arm was associated with a 60% reduction in odds of grade greater than or equal to2 GU toxicity. More notably, there were improvements in multiple patient-reported outcomes. Significantly more patients receiving CT-guided SBRT experienced large increases in urinary symptoms, as measured by a greater than15 points increase in International Prostate Symptom Score. Similarly, a significantly greater percentage of patients experienced a clinically notable decrease in bowel-related quality of life with CT-guided, as measured by the Expanded Prostate Cancer Index Composite-26 survey. Finally, though it is too early to conclude, as more than 2/3rds of men on the trial received hormonal therapy, exploratory analysis in men who did not receive hormonal therapy showed that patient-reported sexual-function scores decreased more in men receiving CT-guided SBRT.