Brachytherapy Improves Biochemical Failure-Free Survival in Low- and Intermediate-Risk XXXX Compared With Conventionally Fractionated External Beam Radiation Therapy: A Propensity Score Matched Analysis.

@entity1 @entity263 @entity5 @entity1349
PURPOSE: To compare, in a retrospective study, biochemical failure-free survival (bFFS) and @entity1349 ( @entity1349 ) in low-risk and intermediate-risk @entity263 @entity1 who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. METHODS AND MATERIALS: @entity1 data were obtained from the ProCaRS database, which contains 7974 @entity263 @entity1 treated with primary radiation therapy at four Canadian @entity5 institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2) intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and @entity1349 in the 3 matched groups. RESULTS: Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in @entity1349 was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). CONCLUSIONS: Propensity score matched analysis showed that BT options led to statistically significant improvements in bFFS in low- and intermediate-risk @entity263 @entity1 populations.
