Room: Track 3
Purpose: Two main techniques in radiation therapy (RT) for low-risk and intermediate-risk prostate cancer (CaP) patients are intensity modulated radiation therapy (IMRT) and brachytherapy (BT). In this study, the efficacy of IMRT and BT has been evaluated in terms of overall survival (OS) using National Cancer Database (NCDB).
Methods: Analyzed a very large data set from NCDB for stage T1-2c prostate cancer patients treated from 2004 to 2015. Patients were stratified according to the National Comprehensive Cancer Network (NCCN) guidelines: low-risk (clinical stage T1–T2a, Gleason Score (GS) of 6, and PSA < 10), intermediate-risk (clinical stageT2b or T2c, GS of 7, or PSA of 10–20). Based on RT techniques used, we considered two groups of patients: (1) IMRT group (n=32,462; 23%), who received initial/primary as well as the boost treatment with IMRT modality, and (2) BT group (n=108,508; 77%), who were treated with either low-dose-rate (LDR) or high-dose-rate (HDR) or any other unspecified brachytherapy only. Considered total dose was 70-81Gy for IMRT; monotherapy was considered for LDR and HDR or unspecified brachytherapy. OS probability was determined using Kaplan-Meier estimator. IBM SPSS software (version 24) was used for statistical analysis; p-value <0.05 was considered statistically significant.
Results: Median age of the patients was 67.0yrs (range: 29-90yrs). Median follow-up was 78.2months (range: 0-157.7months). Observed mean OS about 8.0% and 9.8% higher for low-risk (135.9 vs. 125.8months) and intermediate-risk patients (127.4 vs. 116.0months), respectively, in brachytherapy (BT) group. 10-year survivals were also higher in BT group by 2.4% and 8.1% for low-risk and intermediate-risk patients, respectively. All these differences in survival were statistically significant (p<0.05).
Conclusion: This study indicates that for low-risk and intermediate-risk CaP, brachytherapy is preferred over IMRT (77% vs. 23%). Overall survival and 10-year survival in brachytherapy group are better as compared to IMRT group.