Late toxicity and biochemical recurrence after external‐beam radiotherapy combined with permanent‐source prostate brachytherapy

Abstract

BACKGROUND The combination of external‐beam radiotherapy and brachytherapy is used commonly to treat men with prostate cancer. In this analysis, the authors examined the rate of biochemical recurrence (BR) and late grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity after treatment with external‐beam radiotherapy and brachytherapy in a multiinstitutional, cooperative group setting. METHODS All eligible patients received external‐beam radiotherapy (45 Gray [Gy] in 25 fractions) followed 2 to 6 weeks later by an interstitial implant using iodine‐125 to deliver an additional 108 Gy. BR was defined in 2 ways: according to the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus Definition (ACD) and according to the Phoenix definition (PD) (prostate‐specific antigen nadir +2 ng/mL). The Radiation Therapy Oncology Group(RTOG)/European Organization for Research and Treatment of Cancer late radiation morbidity scoring system was used to grade all toxicity. RESULTS One hundred thirty‐eight patients were enrolled, and 130 were eligible for the current analysis. The median follow‐up for surviving patients was 49 months (range, 20–60 months). The 48‐month estimate of late grade ≥3 GU/GI toxicity was 15% (95% confidence interval [95% CI], 8–21%), and the 48‐month estimate of BR was 19% (95% CI, 12–26%) and 14% (95% CI, 8–20%) according to the ACD and PD, respectively. CONCLUSIONS The morbidity observed in this multiinstitutional, cooperative group study was slightly higher than that reported in recent RTOG studies using brachytherapy alone or high‐dose external‐beam radiotherapy. The BR rate observed in this report was similar to that observed with high‐dose external‐beam radiotherapy alone in similar patients. Cancer 2007. © 2007 American Cancer Society.

Phase II Trial of Combined High Dose Rate Brachytherapy and External Beam Radiotherapy for Adenocarcinoma of the Prostate: Preliminary Results of RTOG 0321

“…It is reassuring the overall frequency and severity of the reported AE was low, and it are comparable to other prospective brachytherapy studies. (6,(21)(22)(23) This is also comparable to other prospective HDR brachytherapy studies. Borghede et al reported on the results of 50 patients treated with 50 Gy of external beam radiotherapy combined with 2 HDR brachytherapy implants delivering a total dose of 20 Gy (2 fractions).…”

Recent advances in the management of radiation colitis

“…Notably, three-dimensional conformal radiotherapy techniques, including intensity-modulated radiotherapy, may not reduce late intestinal toxicity because margins around the cancer may not be able to be safely reduced and because of the prescription of higher radiation doses [97,98] . Brachytherapy, alone or as a supplement to external beam radiotherapy, is now increasingly being utilized to decrease normal tissue toxicity, without compromising treatment efficacy, in the management of prostate carcinoma [99,100] . Brachytherapy is a kind of radiotherapy whereby the source of radiation is located either within the malignant tissue (interstitial brachytherapy) or within a cavity in its immediate vicinity (intracavitary brachytherapy), rather than at a distance (typically 100 cm) from the center of the neoplasm target, as it is the case with external beam radiotherapy.…”

Late rectal toxicity after prostate brachytherapy: Influence of supplemental external beam radiation on dose–volume histogram analysis

“…For intermediate-and highrisk prostate cancer, brachytherapy is often combined with external beam radiation therapy (EBRT) to supplement dose to other tissues at risk, including the seminal vesicles. However, supplemental EBRT has not been uniformly supported as a means to improve disease control (3,4) and may also increase the risk of late toxicity compared with brachytherapy as monotherapy (5).…”