Does supplemental external beam radiation therapy impact urinary, bowel, and erectile function following permanent prostate brachytherapy?: results of two prospective randomized trials

Inverse planning in high-dose rate brachytherapy improves quality of life of prostate cancer patients compared with forward planning

OBJECTIVES

To understand differences in quality of life outcomes between cases with forward planning and cases with inverse planning, we examine patients undergoing high-dose rate brachytherapy combined with external beam radiotherapy for localized prostate cancer.

METHODS

We prospectively identified 283 patients with localized prostate cancer and divided them into forward planning and inverse planning groups. We extracted data on doses to the prostate, rectum and urethra that could potentially affect quality of life. We also evaluated quality of life using the Japanese version of Medical Outcome Study 8-Items Short Form Health Survey and Expanded Prostate Cancer Index Composite at pre-treatment and at 3, 6, 12 and 24 months after treatment. Wilcoxon signed rank test and Bonferroni correction were used to analyze the irradiation dose and any change in quality of life.

RESULTS

Doses to the prostate and rectum were not significantly different between the two groups. Notably, however, doses to the urethra were significantly lower in the inverse planning group than in the forward planning group. Patients in the forward planning group had significantly poorer physical component summary scores at 3 months according to survey results. In Expanded Prostate Cancer Index Composite, patients in the forward planning group had statistically significant poorer urinary, bowel and sexual scores than those in the inverse planning group. Quality of life related to decline in sexual function was significantly reduced in the inverse planning group.

CONCLUSIONS

Inverse planning in high-dose rate brachytherapy could significantly improve quality of life of patients with prostate cancer.

Interventional therapy in malignant conditions of the prostate

Interventional therapies are emerging modalities for the treatment of localized prostate cancer. Their aim is to reduce the morbidity associated with radical therapies (rT) by minimizing damage to non-cancerous tissue, with priority given to sparing key structures such as the neurovascular bundles, external sphincter, bladder neck, and rectum, while maintaining local cancer control. Interventional ablative technologies deliver energy in different ways to destroy cancer cells. The most widely investigated techniques are brachytherapy, external beam radiotherapy, cryotherapy, and high-intensity focused ultrasound. Although functional outcomes of focal therapies have been encouraging, with generally low rates of urinary incontinence and erectile dysfunction, robust medium- and long-term oncological outcomes are not available for all techniques. To date, major controversies in focal therapy concern appropriate patient selection, efficacy of focal therapies, as well as treatment paradigms based on the dominant index lesion hypothesis. This review articles discusses the current status of interventional therapies and the oncological and functional outcomes.

The current state of randomized clinical trial evidence for prostate brachytherapy

Interstitial brachytherapy is one of several curative therapeutic options for the treatment of localized prostate cancer. In this review, we summarize all available randomized data to support the optimal use of prostate brachytherapy. Evidence from completed randomized controlled trials is the focus of this review with a presentation also of important ongoing trials. Gaps in knowledge are identified where future investigation may be fruitful with intent to inspire well-designed prospective studies with standardized treatment that focuses on improving oncological outcomes, reducing morbidity, or maintaining quality of life.

Brachytherapy for localized prostate cancer in the modern era: a comparison of patient-reported quality of life outcomes among different techniques

Purpose

To report our institutional quality of life (QOL) data for low-dose-rate (LDR) monotherapy (LDR mono), high-dose-rate (HDR) monotherapy (HDR mono), and EBRT with an HDR brachytherapy boost (HDR boost).

Material and methods

The charts of 165 patients with localized adenocarcinoma of the prostate treated with LDR monotherapy (LDR mono), HDR monotherapy (HDR mono), and EBRT with an HDR brachytherapy boost (HDR boost) at a single institution between 2012 and 2015 were reviewed. All patients completed the American Urological Association symptom score (AUASS) and Expanded Prostate Index for Prostate Cancer - Clinical Practice (EPIC-CP) quality of life assessments prior to treatment and at least one follow-up survey. Time points included baseline, ≤ 2 months, 2-≤ 6 months, 6-≤ 12 months, 12-≤ 18 months, 18-≤ 24 months, 24-≤ 30 months, and > 30 months. Linear mixed models were performed to test for significant changes and differences in each outcome over time.

Results

Mean follow-up was 19.5 months. All major functional QOL domains were affected after treatment with brachytherapy for localized prostate cancer. All domains improved over time, with the exception of sexual function scores for all groups and urinary incontinence scores for the HDR mono group. Patients treated with LDR did have higher AUA, irritability/obstructive symptoms, incontinence, bowel, and QOL scores acutely compared to the HDR and HDR + boost groups. Vitality scores were significantly worse in the HDR boost group both acutely and at the > 30-month time point.

Conclusions

Patients receiving HDR brachytherapy had lower acute urinary and rectal toxicity compared to the patients receiving LDR, even when combined with EBRT. However, long-term toxicity was similar.