Maximizing target tumor dose while minimizing healthy tissue damage continues to be a challenge in radiation therapy. Because of its appealing dosimetric characteristics, proton beam therapy (PBT) has held the clinical promise of allowing for higher doses of radiation to be delivered more safely, especially for ocular, skull base, and spinal tumors that require exceptional precision. But the role of protons is less clear for more common tumors, like prostate, where their dosimetric advantages may be diminished and for which intensity-modulated radiation therapy (IMRT) can now safely deliver optimally high radiation doses.
To help consider the increased number of offers from University Affiliates to provide contracted off-site proton irradiation therapy, the VA Radiation Oncology Program requested that the Evidence-based Synthesis Program Coordinating Center (ESP CC) synthesize the most recent literature on the comparative effectiveness of PBT in various cancers.
Key Question 1: How does PBT compare with conventional X-ray-based external beam treatments and state-of-the-art therapies with regard to benefits and harms for both new patients and those who have locally recurrent tumors after irradiation?
Key Question 2:
How do the comparative effects of proton and photon beam therapies differ according to variation in tumor motion?