Étude randomisée d'un régime de dutasteride et de bicalutamide pour la cytoréduction prostatique avant une curiethérapie par implants permanents d'iode-125

Authors: Gaudet, Marc
Advisor: Meyer, FrançoisMartin, André-Guy
Abstract: OBJECTIVE: To determine if a regimen of Bicalutamide and Dutasteride is of similar efficacy compared to a standard regimen for prostate cytoreduction prior to permanent implant prostate brachytherapy and to compare toxicity for both of these regimens MATERIALS AND METHODS Patients with an adenocarcinoma of the prostate treated with permanent implant brachytherapy having an initial total prostate volume of 50 cc or more were randomized to either Bicalutamide 50 mg daily, Dutasteride 0.5 mg daily and Tamoxifen 10 mg daily (Experimental group = EG) or an LHRH agonist (3 month dose) and Bicalutamide 50 mg daily for one month (Control Group = CG). Total prostate volume (TPV) was evaluated at time of randomization (t1) and approximately 2.5 months after the start of cytoreductive therapy (t2). Permanent implant I-125 brachytherapy was completed 3 months after randomization. Relative TPV change in % and absolute TPV change in cc were compared between groups. Expanded Prostate Index Composite questionnaires were completed by patients at t1, t2, as well as at 6 weeks (t3), 3 months (t4), and 6 months (t5). Profile changes in EPIC sexual and hormonal domains were evaluated qualitatively. RESULTS The first 11 patients registered for the study were analyzed (EG n=5; CG n=6) Baseline parameters were similar between groups. All patients had low risk characteristics (PSA < 10, Clinical stage ≤T2a and Gleason score ≤6). Median baseline TPV was 51.00 cc in EG and 55.56 in CG. Median reduction in absolute TPV was 18.46 cc in EG and 24.61 in CG (Wilcoxon exact test p=0.03). As for median relative change in TPV, this was 36.44 % in EG and 24.61 cc in CG (p=0.25). All 11 patients were able to undergo brachytherapy without pubic arch interference and with acceptable dosimetric parameters. Median EPIC of both sexual and hormonal domains of the EPIC questionnaire seemed to favor the EG over time. DISCUSSION This early exploratory analysis does not have sufficient power to reject or accept the hypothesis of non-inferiority the experimental regimen for prostate volume reduction. Nonetheless, this regimen allowed brachytherapy without pubic arch interference and with acceptable dosimetric parameters. The experimental regimen of Bicalutamide and Dutasteride also seemed to show a favorable toxicity profile. The results of this early analysis thus justify continued randomization for the study but do not allow definitive conclusions due to small sample size.
Document Type: Mémoire de maîtrise
Issue Date: 2011
Open Access Date: 17 April 2018
Permalink: http://hdl.handle.net/20.500.11794/22506
Grantor: Université Laval
Collection:Thèses et mémoires

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