Propensity score-matched analysis comparing dose-escalated intensity-modulated radiation therapy versus external beam radiation therapy plus high-dose-rate brachytherapy for localized prostate cancer

Abstract

Purpose Dose-escalated external beam radiation therapy (EBRT) and EBRT + high-dose-rate brachytherapy (HDR-BT) boost are guideline-recommended treatment options for localized prostate cancer. The purpose of this study was to compare long-term outcome and toxicity of dose-escalated EBRT versus EBRT + HDR-BT boost. Methods From 2002 to 2019, 744 consecutive patients received either EBRT or EBRT + HDR-BT boost, of whom 516 patients were propensity score matched. Median follow-up was 95.3 months. Cone beam CT image-guided EBRT consisted of 33 fractions of intensity-modulated radiation therapy with simultaneous integrated boost up to 76.23 Gy (DMean). Combined treatment was delivered as 46 Gy (DMean) EBRT, followed by two fractions HDR-BT boost with 9 Gy (D90%). Propensity score matching was applied before analysis of the primary endpoint, estimated 10-year biochemical relapse-free survival (bRFS), and the secondary endpoints metastasis-free survival (MFS) and overall survival (OS). Prognostic parameters were analyzed by Cox proportional hazard modelling. Genitourinary (GU)/gastrointestinal (GI) toxicity evaluation used the Common Toxicity Criteria for Adverse Events (v5.0). Results The estimated 10-year bRFS was 82.0% vs. 76.4% (p = 0.075) for EBRT alone versus combined treatment, respectively. The estimated 10-year MFS was 82.9% vs. 87.0% (p = 0.195) and the 10-year OS was 65.7% vs. 68.9% (p = 0.303), respectively. Cumulative 5‑year late GU ≥ grade 2 toxicities were seen in 23.6% vs. 19.2% (p = 0.086) and 5‑year late GI ≥ grade 2 toxicities in 11.1% vs. 5.0% of the patients (p = 0.002); cumulative 5‑year late grade 3 GU toxicity occurred in 4.2% vs. 3.6% (p = 0.401) and GI toxicity in 1.0% vs. 0.3% (p = 0.249), respectively. Conclusion Both treatment groups showed excellent long-term outcomes with low rates of severe toxicity.

Biochemical control in intermediate- and high-risk prostate cancer after EBRT with and without brachytherapy boost

“…In their retrospective study, Kishan et al also found improvements in disease-specific survival when comparing BTB with ADT and EBRT with ADT, but many patients with EBRT and ADT received insufficient K EBRT doses [23]. A propensity score-matched analysis by Tamiharda et al showed no significant difference between EBRT and BTB, although many patients did not receive ADT or pelvic irradiation in that study, and the BTB dose was only 100 Gy EQD2Gy [24]. In considering toxicity, most [7,25] but not all [2] studies showed increased toxicity with BTB.…”

Comparison of chronic gastrointestinal and genitourinary toxicities between brachytherapy and external beam radiotherapy for patients with prostate cancer: A systematic review and meta-analysis

“…In a previous study, BT with hormonotherapy increases the progression-free survival rates for men with localized prostate cancer [47]; however, the study did not evaluate GU toxicity. In one study evaluating EBRT for men with localized prostate cancer, HT increased the risk of grade 2 acute GU toxicities significantly [48,49]. A meta-analysis reported that HT combined with RT could decrease micro-metastases and delay biochemical relapse; however, both RT and HT S368 X. Li et al / Comparison of chronic GI and GU toxicities between BT and external beam RT have a greater toxicity than RP [50].…”

Interactions between circRNAs and miR-141 in Cancer: From Pathogenesis to Diagnosis and Therapy

“…Dose-escalated external beam radiation therapy (EBRT) and EBRT plus high-dose rate brachytherapy (HDR-BT) are well-established recommended treatment options for localized PC [141]. It was discovered that circRNAs can improve the effectiveness of radiation therapy in PC through miR-141-3p sponging and the regulation of TR4/QKI/circZEB1/miR-141-3p/ZEB1 axis [100].…”