Dr. Henderson on Proton Therapy Versus IMRT in Prostate Cancer

Randal H. Henderson, MD, MBA, professor, Department of Radiation Oncology and associate medical director at the University of Florida Health Proton Therapy Institute, discusses the potential benefits of proton therapy versus intensity-modulated radiation therapy (IMRT) in prostate cancer.

Proton therapy and IMRT damage cancer cells differently, says Henderson. Single-stranded DNA breaks typically result from IMRT, while double-stranded DNA breaks occur more frequently with proton therapy, as protons are heavy charged particles. These complex, double-stranded breaks are more difficult for cancer cells to repair, he adds. As such, dose-for-dose, proton therapy may yield a greater amount of cancer cell death than IMRT.

In Henderson’s experience, the control rates seen in patients with intermediate- and high-risk disease who were treated with proton therapy are better than rates observed in patients treated with IMRT in trials conducted at Memorial Sloan Kettering Cancer Center.

A trial funded by the Patient-Centered Outcomes Research Institute is now open and will accumulate 3,000 patients and allow investigators to compare the 2 therapies. Nearly all the proton facilities in the country—and many academic centers that do not have protons—will participate.