Abstract
Purpose: We studied the treatment outcomes of CT-guided 3-dimensional conformal radiotherapy (3DCRT) for localized prostate cancer using doses of 74–76 Gy.
Materials and Methods: In total, 139 patients with T1c to T3bN0M0 prostate cancer were enrolled between October 2007 and May 2014 in this retrospective study. The median patient age was 74 years (range, 56–81 years). There were 13 low-risk, 30 intermediate-risk, and 96 high-risk patients according to National Comprehensive Cancer Network definitions. Androgen deprivation therapy (ADT) was used in 123 patients (88%), with a median treatment period of 25 months (range, 1–128 months). Biochemical relapse was evaluated according to the Phoenix definition, while adverse events were evaluated according to Common Terminology Criteria for Adverse Events (version 4.0). Median follow-up was 42 months (range, 13–94 months).
Results: Three-year biochemical relapse-free survival (bRFS) rates were 100%, 100%, and 92%, respectively, for low-risk, intermediate-risk, and high-risk groups, while 3-year overall survival was 100%, 96%, and 95%, respectively. Meanwhile, 3-year distant metastasis-free survival was 100%, 100%, and 96%, and 3-year cause-specific survival was 100%, 100%, and 98%. Multivariate analysis showed that long-term ADT (24 months or longer) was a factor influencing bRFS in the high-risk group (hazard ratio 0.23, p = 0.044). Rates of grade 2 late rectal and urinary toxicities were 3.6% and 0.7% respectively, while no grade 3 or higher toxicities were observed.
Conclusion: These results demonstrate the safety of high-dose CT-guided 3DCRT performed at our hospital.
