Does location of prostate cancer by sextant biopsies predict for relapse after I-125 seed implant brachytherapy?

作者：Hill Jesse^*; Hackett Cian; Sloboda Ron; Menon Geetha; Singhal Sandeep; Pervez Nadeem; Pedersen John; Yee Don; Murtha Albert; Amanie John; Usmani Nawaid

来源：Brachytherapy, 2015, 14(6): 788-794.

DOI：10.1016/j.brachy.2015.07.002

• Prostate cancer
• Prostate brachytherapy
• PSA failure
• LDR
• Sector analysis

PURPOSE: To report on the importance of cancer location from diagnostic prostate biopsies in predicting biochemical relapse for patients treated with I-125 seed implant brachytherapy as monotherapy for favorable risk disease; specifically, to assess the clinical significance of potentially underdosing the base region of the prostate gland.
METHODS AND MATERIALS: Of 1145 consecutive patients, 846 had pretreatment biopsies allowing for sextant analysis and consequent evaluation of biochemical failure tendencies. Biochemical failure was defined as a posttreatment rise in the nadir prostate-specific antigen (PSA) by at least 2 ng/mL. Patient and tumor characteristics, dosimetry, the use of hormone therapy, source strength, and postimplant PSA kinetics were analyzed between sextant subgroups.
RESULTS: Sixty-two patients (7.3%) with sextant pathology had biochemical failure. There was no significant difference between the failure locations. There were 528 patients (62.4%) with some element of base involvement (BD, and 318 patients (37.6%) with no evidence of BI. Of the 62 patients with biochemical failure, 42 (67.7%) showed BI on biopsy and 20 (32.3%) had no BI. The 10-year relapse-free survival, rate is 88.2% (95% confidence interval: 84.3%, 92.2%) and 92.0% (95% confidence interval: 88.4%, 95.8%) for the BI and no BI groups, respectively (p = 0.17). The mean D90 delivered to the base, midgland, and apex was 140.8 (+/-21.8) Gy, 170.8 (+/-22.5) Gy, and 177.9 (+/-29.5) Gy, respectively, for all patients.
CONCLUSIONS: There are no significantly worse outcomes for patients treated with an I-125 seed implant for favorable risk prostate cancer with some element of BI, despite lower doses of radiation delivered to the base region.

• 出版日期2015-12