(HealthDay News) — Magnetic resonance imaging (MRI)-guided radiation therapy offers significant benefit over computed tomography (CT)-guided therapy for treatment of prostate cancer, according to a study published online in JAMA Oncology.

Amar U. Kishan, MD, from University of California in Los Angeles, and colleagues assessed whether aggressive margin reduction with MRI guidance significantly reduces acute grade 2 or greater genitourinary toxic effects after prostate stereotactic body radiotherapy (SBRT) versus CT guidance (79 vs 77 patients). A prespecified interim futility analysis was conducted after 100 patients reached ≥90 days after SBRT.

The researchers found that the incidence of acute grade 2 or greater genitourinary toxic effects was significantly lower with MRI versus CT guidance (24.4 vs 43.4%), as was the incidence of acute grade 2 or greater gastrointestinal toxic effects (0.0 vs 10.5%). At one month, MRI guidance was associated with a significantly smaller percentage of patients with a ≥15-point increase in the International Prostate Symptom Score (6.8 vs 19.4%) and a significantly reduced percentage of patients with a clinically significant (≥12-point) decrease in Expanded Prostate Cancer Index Composite-26 bowel scores (25 vs 50%).

Continue Reading

“In this randomized clinical trial, compared with CT-guidance, MRI-guided SBRT significantly reduced both moderate acute physician-scored toxic effects and decrements in patient-reported quality of life,” the authors write. “Longer-term follow-up will confirm whether these notable benefits persist.”

Several authors disclosed financial ties to ViewRay, maker of the MRI-guided radiation therapy system used in the study.

Abstract/Full Text

Editorial (subscription or payment may be required)