Speakers and panel during a news briefing at ASTRO 2024
A phase III clinical trial comparing proton beam therapy and intensity modulated radiation therapy (IMRT) for localized prostate cancer found that the treatments provide equally effective tumor control and maintain high quality of life for patients.
Results from the PARTIQoL trial, presented at the 2024 ASTRO Annual Meeting, revealed no significant differences between the two therapies in patient-reported outcomes or disease progression.
Led by Dr. Jason Efstathiou from Massachusetts General Hospital, the trial enrolled 450 patients with low- or intermediate-risk prostate cancer from 29 centers between June 2012 and November 2021. Patients were randomly assigned to receive either proton therapy or IMRT, with median follow-up lasting over five years.
Self-reported quality of life data, including bowel, urinary, and sexual function, were collected at multiple time points. According to Dr. Efstathiou, “Both are very safe, effective treatments that give patients excellent outcomes in terms of quality of life and cancer control.”
No differences were observed between the treatment groups across any quality of life domains. For example, average bowel function scores dropped slightly from baseline, with both IMRT and proton therapy showing a roughly 2% decline after two years. Progression-free survival was also comparable, with 93.7% of IMRT patients and 93.4% of proton therapy patients showing no tumor progression after five years.
Proton therapy offers more precise targeting of radiation by releasing energy directly at the tumor site, reducing potential harm to surrounding tissue. However, this precision comes at a significantly higher cost, as proton therapy requires specialized equipment and facilities. IMRT, a photon-based therapy, uses modulated beams that shape radiation to the tumor, offering similar efficacy.
“There have been so many advances in the delivery of contemporary radiation that the potential gaps between these technologies have narrowed over time,” said Dr. Efstathiou.
Further analysis is ongoing to explore whether certain subgroups may benefit more from one therapy than the other, though no such differences have been identified yet.