Predictors of urinary morbidity in Cs-131 prostate brachytherapy implants.
ABSTRACT Cesium-131 is a newer radioisotope being used in prostate brachytherapy (PB). This study was conducted to determine the predictors of urinary morbidity with Cs-131 PB.
A cohort of 159 patients underwent PB with Cs-131 at our institution and were followed by using Expanded Prostate Cancer Index Composite (EPIC) surveys to determine urinary morbidity over time. EPIC scores were obtained preoperatively and postoperatively at 2 and 4 weeks, and 3 and 6 months. Different factors were evaluated to determine their individual effect on urinary morbidity, including patient characteristics, disease characteristics, treatment, and dosimetry. Multivariate analysis of covariance was carried out to identify baseline determinants affecting urinary morbidity. Factors contributing to the need for postoperative catheterization were also studied and reported.
At 2 weeks, patient age, dose to 90% of the organ (D90), bladder neck maximum dose (D(max)), and external beam radiation therapy (EBRT) predicted for worse function. At 4 weeks, age and EBRT continued to predict for worse function. At the 3-month mark, better preoperative urinary function, preoperative alpha blockers, bladder neck D(max), and EBRT predicted for worse urinary morbidity. At 6 months, better preoperative urinary function, preoperative alpha blockers, bladder neck D(max), and EBRT were predictive of increased urinary problems. High bladder neck D(max) and poor preoperative urinary function predicted for the need for catheterization.
The use of EBRT plus Cs-131 PB predicts for worse urinary toxicity at all time points studied. Patients should be cautioned about this. Age was a consistent predictor of worsened morbidity immediately following Cs-131 PB, while bladder D(max) was the only consistent dosimetric predictor. Paradoxically, patients with better preoperative urinary function had worse urinary morbidity at 3 and 6 months, consistent with recently published literature.
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ABSTRACT: To investigate possible relationships between the dose to the sub-segments of the lower urinary tract and lower urinary tract symptoms (LUTS) after brachytherapy of the prostate. This study involved 225 patients treated for prostate cancer with I-125 seeds. Post-implant dose-volume histograms of the prostate, urethra, bladder wall, bladder neck and external sphincter were determined. Endpoints were the mean and the maximum International Prostate Symptom Score (IPSS) during the first 3months after the treatment. For binary analysis the patients were stratified in a group with enhanced LUTS and a group with non-enhanced LUTS. The dose to 0.5cm(3) of the bladder neck 'D0.5cc-blne' (p=0.002 and p=0.005), the prostate volume prior to treatment 'Vpr-0' (p=0.005 and p=0.024) and the pre-treatment IPSS (both p<0.001) were independently correlated with mean and maximum IPSS, respectively. Of the patients with a D0.5cc-blne⩾175Gy and a Vpr-0⩾42cm(3), 68% suffered from enhanced LUTS, against just 30% of the other patients (p<0.0001). Pre-treatment IPSS, prostate volume and dose to the bladder neck are correlated with post-implant IPSS. A combination of a large prostate and a high dose to the bladder neck is highly predictive for enhanced early LUTS.Radiotherapy and Oncology 09/2013; · 4.86 Impact Factor
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ABSTRACT: Over the past two decades, brachytherapy has played an ever expanding role in the definitive radiotherapy of prostate cancer. Brachytherapy surpasses external beam radiotherapy in its ability to deliver intense intraprostatic dose escalation. Although initially low dose rate permanent seed brachytherapy was favored for favorable risk prostate cancers, and high dose rate temporary brachytherapy for intermediate and advanced disease, both types of brachytherapy now have a place across all the risk groups of localized prostate cancer. This article will review indications and patient selection, planning and technical aspects, toxicity and efficacy for both low and high dose rate prostate brachytherapy.Cancer/Radiothérapie 06/2011; 15(3):230-7. · 1.11 Impact Factor