Low Dose Rate Brachytherapy versus Cryotherapy in Low and Intermediate Risk Prostate Cancer
Menée à partir de données portant sur 359 patients atteints d'un cancer de la prostate à risque faible ou intermédiaire de récidive et traités entre 1990 et 2012, cette étude compare, du point de vue de la survie sans progression biochimique à 5 ans, l'efficacité d'une curiethérapie à faible débit de dose et d'une cryothérapie
Purpose : Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single institutional retrospective studies. Currently, no published evidence has compared low-dose rate brachytherapy versus cryotherapy. Materials : Institutional Review Board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990-2012. For inclusion, patients must have carried prostate cancer diagnoses and have been considered low- to intermediate-risk according to the National Comprehensive Cancer Network criterion. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2ng/mL. Results : A total of 359 patients were analyzed. Groups were comprised of 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. Median prostate-specific antigen follow-up was 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression free survival (bPFS) between the two total groups was 57.9% in cryotherapy versus 89.6% in the brachytherapy group (P<0.0001). The 5-year bPFS was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB) and 89.7% (IRB). The bPFS was significantly different between brachytherapy and cryotherapy for low and intermediate risk groups (p<0.05). The mean nadir temperature reached for cryotherapy patients was -35 (range: -6 to -96) degrees Celsius. Cryotherapy utilized a median of 2 (range: 2-4) freeze thaw cycles. Conclusions : Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with low- to intermediate-risk prostate cancer. Patient selection criterion for consideration of cryotherapy and brachytherapy is similar in terms of anesthesia candidacy. Therefore, cryotherapy would not be recommended as a first-line local therapy for this particular patient subset.