Stereotactic Body Radiation Therapy Results in Almost 100% Cure Rate For Patients With Prostate Cancer
A recent study showed a 98.6% cure rate at 5 years with stereotactic body radiation therapy (SBRT) in patients with low- or intermediate-risk prostate cancer.
Current forms of radiation for prostate cancer are prolonged regimens of 44 treatments administered over 9 weeks. SBRT, which uses highly focused radiation beams, only requires 5 treatments, but the long terms effects of its use have not been clearly defined.
Investigators led by Raquil Hannan, MD, PhD, University of Texas Southwest Medical Center (Dallas, TX), conducted a clinical trial evaluating the safety and efficacy of SBRT over a period of 5 years to see if it could produce better results than conventional methods without causing significant harm later in life. They published their findings in the European Journal of Cancer.
Patients were eligible for inclusion in the trial if they presented with prostate cancer that was low risk (Gleason score of 6 with prostate specific antigen ≤ 20) or intermediate risk (Gleason score of 7 with prostate specific antigen ≤ 15).
A total of 91 patients were included for analysis, 63.7% of whom were classified as intermediate risk and 36.3% of whom were low risk. At a median follow-up of 54 months, the actuarial freedom from biomedical failure rate was 100% and 98.6% at 3 and 5 years, respectively. In addition, overall survival was 94% at 3 years and 89.7% at 5 years, with no deaths attributed to prostate cancer.
While SBRT was not compared directly with other methods in the trial, these results were far superior to what has been reported in past studies of conventional radiation therapies.
Toxicity was found to be highly tolerable. At 3 years, there were no acute or late grade 3 or higher toxicity events, and, at 5 years, events occurred in only 5.5% of patients. High-grade (3, 4 or 5) gastrointestinal acute and late toxicity events occurred in 2% and 7% of patients at 3 and 5 years, respectively. Only 4 men in total experience grade 4 toxicity.
From these results, investigators concluded that treatment with SBRT treatment produced an exceptional cure rate for patients with low- and intermediate-risk prostate cancer.