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PubMed2005

Erectile function after prostate brachytherapy.

PURPOSE: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. METHODS AND MATERIALS: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of > or =13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V(100/150/200)); the dose delivered to 90% of the prostate gland (D(90)); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. RESULTS: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal erections, and dose to the proximal penis predicted for postimplant erectile function. However, in multivariate analysis, only the preimplant IIEF score and the D(50) to the proximal crura were statistically significant predictors of brachytherapy-related erectile function. CONCLUSIONS: Using a patient-administered validated quality-of-life instrument, brachytherapy-induced ED occurred in 50% of patients at 3 years. On multivariate analysis, preimplant erectile function and the D(50) to the proximal crura were the best predictors of brachytherapy-related erectile function. Because the proximal penis is the most significant treatment-related predictor of brachytherapy-related ED, techniques to minimize the radiation dose to the proximal penis may result in improved rates of potency preservation.

Age Factors↗

PubMed2002

Permanent prostate brachytherapy-induced morbidity in patients with grade II and III obesity.

OBJECTIVES: To determine the influence of obesity on the development of urinary, bowel, and sexual dysfunction after brachytherapy by means of patient-administered questionnaires. The effect of obesity on dosimetric quality and biochemical outcome was also evaluated. METHODS: Thirty-two patients with grade II and III obesity underwent brachytherapy from June 1997 through April 2001. Grade II and III obesity was defined as a body mass index of 35.0 to 39.9 and 40.0 kg/m2 or greater, respectively. Serial International Prostate Symptom Score (IPSS) evaluations were obtained at predetermined intervals. Bowel and sexual function were assessed by a rectal function assessment score (R-FAS) and the specific erectile questions of the International Index of Erectile Function (IIEF). The median follow-up was 26.4 months. An alpha-blocker was initiated before implantation and continued at least until the IPSS normalized. Catheter dependency, alpha-blocker dependency, and the incidence of urethral strictures were also evaluated. The efficacy of sildenafil in brachytherapy-induced erectile dysfunction was also evaluated. Dosimetric parameters evaluated included the percentage of the prostate receiving 100%, 150%, and 200% of the prescribed dose (V100, V150, and V200), the minimal dose received by 90% of the prostate (D90), urethral doses, and rectal doses. Biochemical outcome was determined by the ASTRO consensus conference definition. RESULTS: Of the 32 patients, 31 (97%) had the urinary catheter permanently removed on day 0, and no patient required a urinary catheter for longer than 1 day. One patient developed a urethral stricture. No patient required a transurethral resection or developed urinary incontinence. On average, the IPSS peaked 2 weeks after implantation and returned to baseline at a median of 8 weeks (mean 16). The post-treatment R-FAS was 3.6. No patient developed a rectal ulcer or fistula. Of the 22 patients who were potent before implantation, 7 (31.8%) maintained potency. With pharmacologic support, 59.1% maintained erections sufficient for vaginal penetration. Day 0 dosimetry demonstrated a median V100 and D90 of 96.5% and 113.5%. At last follow-up, all patients remained free of biochemical failure, with a median prostate-specific antigen level of 0.1 ng/mL. CONCLUSIONS: No difference in quality-of-life parameters was discerned in patients with grade II and III obesity. In addition, the dosimetric quality of the implants was outstanding, and the short-term biochemical outcome was encouraging.

Adenocarcinoma↗