Erectile function durability following permanent prostate brachytherapy.
OBJECTIVE
To evaluate long-term changes in erectile function following prostate brachytherapy.


METHODS
This study included 226 patients with prostate cancer and preimplant erectile function assessed by the International Index of Erectile Function-6 (IIEF-6) who underwent brachytherapy in two prospective randomized trials between February 2001 and January 2003. Median follow-up was 6.4 years. Pre- and postbrachytherapy potency was defined as IIEF-6 > or = 13 without pharmacologic or mechanical support. The relationship among clinical, treatment, and dosimetric parameters and erectile function was examined.


RESULTS
The 7-year actuarial rate of potency preservation was 55.6% with median postimplant IIEF of 22 in potent patients. Potent patients were statistically younger (p = 0.014), had a higher preimplant IIEF (p < 0.001), were less likely to be diabetic (p = 0.002), and were more likely to report nocturnal erections (p = 0.008). Potency preservation in men with baseline IIEF scores of 29-30, 24-28, 18-23, and 13-17 were 75.5% vs. 73.6%, 51.7% vs. 44.8%, 48.0% vs. 40.0%, and 23.5% vs. 23.5% in 2004 vs. 2008. In multivariate Cox regression analysis, preimplant IIEF, hypertension, diabetes, prostate size, and brachytherapy dose to proximal penis strongly predicted for potency preservation. Impact of proximal penile dose was most pronounced for men with IIEF of 18-23 and aged 60-69. A significant minority of men who developed postimplant impotence ultimately regained erectile function.


CONCLUSIONS
Potency preservation and median IIEF scores following brachytherapy are durable. Thoughtful dose sparing of proximal penile structures and early penile rehabilitation may further improve these results.
Taira
Al V
AV
Department of Radiation Oncology, University of Washington, Seattle, WA.
Merrick
Gregory S
GS
Galbreath
Robert W
RW
Butler
Wayne M
WM
Wallner
Kent E
KE
Kurko
Brian S
BS
Anderson
Richard
R
Lief
Jonathan H
JH
D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D001918:Brachytherapy / Q000009:adverse effects*; D016009:Chi-Square Distribution; D007172:Erectile Dysfunction / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010410:Penile Erection / Q000502:physiology* / Q000528:radiation effects; D010413:Penis / Q000503:physiopathology / Q000528:radiation effects; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D020127:Recovery of Function; D011795:Surveys and Questionnaires; D013997:Time Factors