Patients who underwent proton beam therapy for prostate cancer reported higher quality of life in early follow-up and similar scores at two years, compared with 3D conformal therapy and intensity-modulated radiation therapy, according to research presented at the American Society for Radiation Oncology (ASTRO) annual meeting in Boston.

Limited data are available to compare treatment options for prostate cancer, specifically 3D conformal (3-D CRT), proton beam (PBT) and intensity-modulated radiation therapy (IMRT). With high survival rates among various modalities for most patients, other measures, such as quality of life (QOL) may help differentiate treatment options.  

Phillip J. Gray, MD, resident in radiation oncology at Harvard Medical School in Boston, and colleagues evaluated QOL for patients treated with these modalities. The study population included 94 patients treated with PBT, 123 treated with 3-D CRT and 153 treated with IMRT.

During the initial follow-up at two to three months after treatment, the PBT cohort reported minimal bowel problems. Patients in the 3-D CRT and IMRT groups reported modest yet significant problems with bowel function. “IMRT patients reported modest yet significant urinary problems at their first follow-up, while patients treated with PBT did not report similar problems until 12 months after treatment.”

At two years after treatment, patients in all three groups reported no significant problems with urination and similar problems with bowel function. However, patients in all three groups reported steadily worsening sexual function over the two-year study period.

“Our study provides a unique addition to existing research in this field and suggests that patients undergoing proton beam therapy for prostate cancer may experience fewer immediate side effects,” said Gray in a release. “Given the inherent limitations of any retrospective study, a prospective randomized controlled trial to investigate these differences will provide the most rigorous and valid comparison of these advanced technologies.”

Massachusetts General Hospital and University of Pennsylvania have opened a randomized comparison of PBT and IMRT for patients with localized prostate cancer.

For more about prostate cancer, read “Prostate Cancer: In the Eye of the Storm,” in Health Imaging.