Stereotactic Body Radiotherapy Using Cyberknife for Localized Prostate Cancer

Stereotactic body radiation therapy (SBRT) using Cyberknife delivers high-dose fraction of radiation without increasing toxicity.
We present the follow-up outcomes and toxicities of patients with localized prostate cancer treated by use of Cyberknife as a monotherapy.
Patients and This study was based on a retrospective analysis of the 34 patients treated with SBRT using Cyberknife for localized prostate cancer (26.5% low risk, 67.6% intermediate risk, and 5.9% high risk). Total dose of 36.25 Gy in 5 fractions of 7.25Gy were administered without use of androgen deprivation therapy (ADT). The acute and late toxicities were recorded using the radiation therapy oncology group scale. Prostate-specific antigen (PSA) response was monitored.
Thirty-four patients with a median 52 months (range 12 - 71 month) follow-up were analyzed. The biochemical relapse-free survival was 93.3%. PSA fell to a median of 0.39 ng/mL at 4 years and PSA bounce occurred in 28.1% of patients. Acute side effects resolved within 1 - 2 months of treatment completion. There was no grade 3 and 4 late toxicity observed.
In this study, SBRT using Cyberknife without ADT has provided promising outcomes in localized prostate cancer with good PSA response and minimal toxicity. Hypofractionated SBRT using Cyberknife leads to long-term favorable 5-year biochemical relapse-free survival and minimal toxicity in localized prostate cancer as a monotherapy.