Proton beam therapy is a highly advanced form of radiation that precisely targets tumors, significantly reducing the radiation dose to surrounding healthy tissue and organs. Patients treated with proton therapy experience fewer side effects and better quality of life during and after treatment, and up to a 40% reduced risk of secondary cancers compared to conventional radiation.
Unfortunately, proton therapy has received some negative press from the media and even from other radiation oncologists recently. One of the reasons is that the published data and clinical trials on proton therapy were often a blended group of patients who were treated with both x-ray (photon) treatments combined with proton therapy, which was used as boost. There were very few trials and data that used proton beam therapy exclusively as the sole treatment modality to understand how good or bad it is when used for treatment. That is why a recent study published in the Journal of Radiation Oncology, which reviewed clinical toxicity and patient-reported outcomes for men treated with proton beam therapy for prostate cancer, is so crucial to give us a clear picture on the toxicities of proton beam therapy when used as the only definitive treatment.
The final analysis included outcomes for 192 patients with more than one year of follow-up after treatment. Grade 3 toxicity was only seen in 5 of the 192 patients, and there were no reports of grade 4 or 5 toxicity (which include life-threatening or disabling events, or death). Patient reported quality of life was excellent, with no change in urinary function post-treatment, and minor declines in erectile and bowel function at one-year post treatment. Bowel toxicity was mostly in the form of rectal bleeding and linked to anticoagulation use. You can read the full study here.
Some prior studies have shown there was increased bowel toxicity with proton beam therapy compared to standard radiation therapy. This current analysis helps to confirm the suspicions that most proton beam centers are seeing that toxicities are less with proton beam therapy. I know of no studies that show delivering less dose to normal tissue translates into more toxicity either acutely or long term.
This is one of few contemporary studies that evaluates outcomes and toxicity of proton beam thearpy for localized prostate cancer with prospectively collected data, including patient reported outcomes. More studies like this are needed to fully understand all of the benefits of proton therapy for prostate cancer. Additionally, some of the greatest benefits will be seen including decreased risk of second malignancies when we continue to collect data in much longer follow up.
At Ackerman Cancer Center, we are proud to be one of 28 centers in the United States to offer proton therapy to our patients. You can learn more about prostate cancer treatment at Ackerman Cancer Center here.
If you have questions about proton therapy for prostate cancer, please email me at firstname.lastname@example.org.