Analysis of outcomes after non-contour-based dose painting of dominant intra-epithelial lesion in intra-operative low-dose rate brachytherapy. Issue 6 (June 2020)

• Record Type: Journal Article
• Authors: Martell, Kevin; Roy, Soumyajit; Meyer, Tyler; Stosky, Jordan; Jiang, Will; Thind, Kundan; Roumeliotis, Michael; Bosch, John; Angyalfi, Steve; Quon, Harvey; Husain, Siraj
• Is Part Of: Heliyon. Volume 6:Issue 6(2020)
• Publication Date: 2020-06
• Subjects: Radiation physics -- Surgery -- Cancer surgery -- Urology -- Oncology -- Prostate cancer -- Brachytherapy -- Low-dose-rate; Research -- Periodicals; Medical sciences -- Periodicals; Natural history -- Periodicals; Social sciences -- Periodicals; Earth sciences -- Periodicals; Physical sciences -- Periodicals; 507.2
• DOI: 10.1016/j.heliyon.2020.e04092
• Languages: English
• ISSNs: 2405-8440

Abstract

Abstract: Purpose: To compare the outcomes of patients with intermediate risk prostate cancer (IR-PCa) treated with low-dose rate I-125 seed brachytherapy (LDR-BT) and targeted dose painting of a histologic dominant intra-epithelial lesion (DIL) to those without a DIL. Methods: 455 patients with IR-PCa were treated at a single center with intra-operatively planned LDR-BT, each following the same in-house dose constraints. Patients with a DIL on pathology had hot spots localized to that region but no specific contouring during the procedure. Results: 396 (87%) patients had a DIL. Baseline tumor characteristics and overall prostate dosimetry were similar between patients with and without DIL except the median number of biopsy cores taken: 10 (10–12) vs 12 (10–12) (p = 0.002). 19 (5%) and 18 (5%) of patients with and 1 (2%) and 0 (0%) of those without DIL experienced CTCAE grade 2 and 3 toxicity respectively. Overall, toxicity grade did not significantly correlate with presence of DIL (p = 0.10). Estimated 7-year freedom from biochemical failure (FFBF) was 84% (95% confidence interval: 79–89) and 70% (54–89) in patients with and without a DIL (log-rank p = 0.315). In DIL patients, cox regression revealed location of DIL ("Base" vs "Apex" HR: 1.03; 1.00–1.06; p = 0.03) and older age (70 vs 60 HR: 1.62; 1.06–2.49; p = 0.03) was associated with poor FFBF. Conclusions: Targeting DIL through dose painting during intraoperatively planned LDR-BT provided no statistically significant change in FFBF. Patients with DILs in the prostate base had slightly lower FFBF despite DIL boost. Abstract : Radiation physics; Surgery; Cancer surgery; Urology; Oncology; Prostate cancer; Brachytherapy; Low-dose-rate.