Study demonstrates proton therapy to be an established and effective treatment for patients with prostate cancer.
The Particle Therapy Co-Operative Group (PTCOG) Genitourinary Subcommittee, comprising highly experienced international oncologists, have published a “Consensus Statement on Proton Therapy for Prostate Cancer”, published in the International Journal of Particle Therapy, Fall 2021.
The paper highlights high-level evidence showing the relative benefits of proton therapy in improving patient quality of life (QOL), reducing toxicity, and improving cure rates among patients treated with radiation therapy.
The consensus statement explores several prospective clinical trials and retrospective outcome reviews that have been published documenting the effectiveness of proton therapy in patients with prostate cancer. For instance three clinical trials at the University of Florida that demonstrated excellent 5-year biochemical control rates of 99% for low-risk, and 99% for intermediate-risk prostate cancer, with very low rates of side effects (<1% and 2.9% respectively).
The authors explored research demonstrating that proton therapy has been shown to reduce the radiation dose to organs at risk surrounding the prostate, including the bladder, bowel, and rectum.
Various studies have shown that conventional radiotherapy generates a much higher integral dose than proton therapy, leading researchers to predict that conventional radiotherapy was 5 times more likely to lead to secondary cancer development than proton therapy when treating prostate cancer.
They also concluded that “outcomes appear to be consistent across multiple proton medical centres that span various regions, countries, decades, and patient ethnicities.”
Shortened schedule proton therapy (also known as ‘hypofractionation’) was also investigated, and the authors concluded that the use of shortened schedule proton therapy treatment regimes appear at least equivalent to hypofractionated conventional radiotherapy treatments.
The authors highlighted the importance of further research and several ongoing clinical trials aimed at clarifying the role of proton therapy in treating prostate cancer. However, the authors, based on the research currently available, conclude that proton therapy is an established and effective treatment for patients with prostate cancer, which reduces the excess radiation delivered to healthy tissues surrounding the prostate when compared with conventional radiation therapy. Several prospective and retrospective studies have been published documenting the safety and effectiveness of proton therapy in the management of prostate cancer and long-term follow-up data are available and are accumulating.
Consequently, proton therapy should not be considered experimental in the management of prostate cancer. “Because the costs associated with proton therapy continue to decrease, further evidence of proton therapy as an effective platform for hypofractionation may prove it to be a cost-effective treatment modality in the management of prostate cancer.”