Ultrahypofractionated Radiotherapy for Intermediate-Risk Prostate Cancer
Posted: Tuesday, August 18, 2020
For patients with intermediate-risk prostate cancer, stereotactic body radiation treatment may be an effective alternative therapy, according to a phase II study published in the American Journal of Clinical Oncology. This treatment regimen should be “delivered with flattening filter-free volumetric modulated arc therapy and gated by electromagnetic transponders,” according to Marta Scorsetti, MD, of the Humanitas Clinical and Research Center, Italy, and colleagues. However, better patient selection criteria are necessary to maximize the safety and efficacy of this treatment.
A total of 36 patients with intermediate-risk prostate cancer (as defined by the National Comprehensive Cancer Network) were enrolled in the study. All patients had a World Health Organization performance score less than or equal to 2, a Gleason score of 7, and prostate-specific antigen (PSA) level up to 20 ng/mL. Between 7 and 10 days before simulation CT, all patients received transrectal beacon responders within the prostate parenchyma. Patients were administered 38 Gy of radiotherapy in 4 fractions every other day.
Analysis revealed a 7.0 ng/mL value for the median initial PSA level. Following stereotactic body radiation treatment, the median PSA level was reduced to 0.2 ng/mL. In addition, the 3-year biochemical recurrence free survival rate was 89.8%.
Furthermore, 21 patients had acute genitourinary toxicity (dysuria grade 1 = 41.7%, grade 2 = 16.7%), and 9 patients had acute gastrointestinal toxicity (proctitis, 19.4% vs. 5.6%). A total of three biochemical recurrences were revealed at a median follow-up of 41 months.
The authors concluded: “This study proves that higher doses of stereotactic body radiation therapy are required to control the intermediate-risk prostate cancer, and that dose escalation is safely achievable with real-time tracking….”
Disclosure: For full disclosures of the study authors, visit journals.lww.com.
