Stereotactic body radiotherapy with or without external beam radiation as treatment for organ confined high-risk prostate carcinoma: a six year study
1 Long Island Radiation Therapy, 6 Ohio Drive, New Hyde Park, NY, USA
2 Flushing Radiation Oncology Services, 40-20 Main Street, Flushing, NY, USA
3 New York University School of Medicine, 550 1st Ave, New York, NY 10016, USA
Radiation Oncology 2014, 9:1 doi:10.1186/1748-717X-9-1Published: 1 January 2014
Stereotactic Body Radiotherapy (SBRT) has excellent control rates for low- and intermediate-risk prostate carcinoma.The role of SBRT for high-risk disease remains less studied. We present long-term results on a cohort of patients with NCCN-defined high-risk disease treated with SBRT.
We retrospectively studied 97 patients treated as part of prospective trial from 2006–2010 with SBRT alone (n = 52) to dose of 35–36.25 Gy in 5 fractions, or pelvic radiation to 45 Gy followed by SBRT boost of 19–21 Gy in 3 fractions (n = 45). 46 patients received Androgen Deprivation Therapy. Quality of life and bladder/bowel toxicity was assessed using the Expanded Prostate Index Composite (EPIC) and RTOG toxicity scale.
Median followup was 60 months. 6-year biochemical disease-free survival (bDFS) was 69%. On multivariate analysis, only PSA remained significant (P < 0.01) for bDFS. Overall toxicity was mild, with 5% Grade 2–3 urinary and 7% Grade 2 bowel toxicity. Use of pelvic radiotherapy was associated with significantly higher bowel toxicity (P = .001). EPIC scores declined for the first six months and then returned towards baseline.
SBRT appears to be a safe and effective treatment for high-risk prostate carcinoma. Our data suggests that SBRT alone may be the optimal approach. Further followup and additional studies is required to corroborate our results.