Radiation oncology firm Accuray is touting the results of a prospective study in which stereotactic body radiation therapy (SBRT) performed with its CyberKnife system provided excellent disease control at the five-year mark for men with locally recurrent prostate cancer.
Most importantly, 69% of the male subjects required no androgen deprivation therapy (ADT) treatment within the first five years following CyberKnife prostate SBRT. There also were overall low rates of toxicity among the patients, all of whom had undergone radiation therapy treatment.
"Most men, if treated, receive only ADT, which has the potential for long-lasting whole-body side effects while rarely eradicating the tumor completely," said lead investigator Dr. Donald Fuller of Genesis Healthcare Partners in San Diego, CA, in a statement.
Other findings from the study, published online October 6, 2019 in the International Journal of Radiation Oncology, Biology, Physics, include the following:
- At five years, the disease-free survival rate was 60%, indicating patients experienced no signs or symptoms of their cancer during that time.
- The median prostate-specific antigen decreased to 0.16 ng/mL at five years, similar to initial treatment with brachytherapy and lower than typical conventional fractionation, based on results from other studies.
- No grade two or higher gastrointestinal events were reported. Genitourinary toxicity also was lower than reported rates for salvage radical prostatectomy and seems less frequent after prior standard external radiation treatment.
