br The study served as a pilot for the
The study served as a pilot for the elaboration and conduct of the large ongoing Canadian Cancer Trials Group PR-19.
The primary endpoint of the large-scale trial is biochemical control; HRQOL is a secondary endpoint. The pilot trial was already enrolling when the decision was made to make local control the primary endpoint for the large-scale study.
Independent 2-sample t tests were performed for comparison of continuous variables (EPIC and IPSS) between the 2 treatment arms. The effects of treatment on repeated measurements of these Vaborbactam continuous variables were assessed using mixed effects modeling. Estimator functions of time to IPSS resolution, defined as return to baseline score 5, points was calculated using the Kaplan-Meier method and compared between covariate subgroups using the log-rank test. A multiple-comparison (FDR) adjusted P value of .05 was considered signifi-cant. Treatment characteristics were also assessed using 2-sample t tests as appropriate. The associations between toxicities and treatment characteristics were evaluated using logistic regressions. CTCAE grade 0 or 1 was considered no toxicity, and toxicity was considered as grade 2. R version 3.3.2 2016 was used for the analyses.
Between December 2015 and December 2016, 31 patients met the eligibility criteria and were randomized across 3 centers. The pilot study was deemed successful because all the specific pilot study goals (accrual, follow-up, major dose-volume histogram deviations, and compliance in filling out questionnaires) were met.
The patients’ characteristics are described in Table 1. Median age at treatment was 64 years. LDRB was delivered to 15 patients and HDRB to 16 patients. The median baseline scores of IPSS and mean baseline scores of EPIC urinary incontinence, EPIC urinary irritative, EPIC bowel habits, and EPIC sexual function were not significantly different between groups. The prostate vol-ume was significantly higher for the HDRB group compared to the LDRB group (median, 54.3 vs 40.7 mL; P Z .016), whereas the number of needles was signifi-cantly lower (median, 17 vs 21; P Z .0002). The treat-ment characteristics for LDRB and HDRB are detailed in Tables 2 and 3, respectively. TRUS-based treatment planning was exclusively used in all LDRB cases. In HDRB cases, TRUS-based treatment planning was used in 8 patients, and CT-based treatment planning was used in the remaining 8 patients as per institutional standard.
At 3 months, patients treated with LDRB had a higher IPSS score (median, 14 vs 5 respectively; adjusted P Z .001) and lower EPIC urinary irritative score (mean, 69.2 vs 85.3 respectively; adjusted P Z .037) compared with patients hypertension received HDRB. On repeated measures at 1, 3, 6, and 12 months, the IPSS (P Z .003) and EPIC urinary irritative scores (P Z .011) were significantly better in the HDR arm, translating into a lower urinary toxicity profile, as shown in Figure 1. There were no significant differences in the EPIC urinary incontinence, sexual function, or bowel habits scores between the 2
HDR vs LDR brachytherapy for prostate cancer 5
Table 1 Patient characteristics
Characteristics LDRB group, n (%) HDRB Entire cohort, n (%) P value
ECOG performance status
Pretreatment EPIC urinary incontinence, mean (range) 93.6
Pretreatment EPIC urinary 89.3
Irritative, mean (range)
Pretreatment EPIC sexual, mean (range) 70.4
Pretreatment EPIC bowel, median (IQR) 97.2
Abbreviations: ECOG Z Eastern Cooperative Oncology Group; EPIC Z Expanded Prostate Cancer Index Composite; HDRB Z high-dose-rate brachytherapy; IQR Z interquartile range; LDRB Z low-dose-rate brachytherapy; PSA Z prostate specific antigen.