Jesse Hill1, Cian Hackett2, Ron Sloboda3, Geetha Menon3, Sandeep Singhal4, Nadeem Pervez5, John Pedersen2, Don Yee2, Albert Murtha2, John Amanie2, Nawaid Usmani2. 1. Department of Oncology, Faculty of Medicine and Dentistry, Division of Radiation Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada; Department of Oncology, University of Alberta, Edmonton, Alberta, Canada. Electronic address: jlh1@ualberta.ca. 2. Department of Oncology, Faculty of Medicine and Dentistry, Division of Radiation Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada; Department of Oncology, University of Alberta, Edmonton, Alberta, Canada. 3. Department of Oncology, University of Alberta, Edmonton, Alberta, Canada; Department of Oncology, Faculty of Medicine and Dentistry, Division of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada. 4. Department of Oncology, University of Alberta, Edmonton, Alberta, Canada. 5. Radiotherapy Department, Tawam Hospital In Affiliation With John Hopkins Medicine, Al Ain, Abu Dhabi, UAE.
Abstract
PURPOSE: To report on the importance of cancer location from diagnostic prostate biopsies in predicting biochemical relapse for patients treated with (125)I 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 (BI), 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 (125)I seed implant for favorable risk prostate cancer with some element of BI, despite lower doses of radiation delivered to the base region.
PURPOSE: To report on the importance of cancer location from diagnostic prostate biopsies in predicting biochemical relapse for patients treated with (125)I 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 (BI), 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 (125)I seed implant for favorable risk prostate cancer with some element of BI, despite lower doses of radiation delivered to the base region.
Authors: Kevin Martell; Soumyajit Roy; Tyler Meyer; Jordan Stosky; Will Jiang; Kundan Thind; Michael Roumeliotis; John Bosch; Steve Angyalfi; Harvey Quon; Siraj Husain Journal: Heliyon Date: 2020-06-07