Dose-volume parameters of the corpora cavernosa do not correlate with erectile dysfunction after external beam radiotherapy for prostate cancer: results from a dose-escalation trial.
OBJECTIVE
To analyze the correlation between dose-volume parameters of the corpora cavernosa and erectile dysfunction (ED) after external beam radiotherapy (EBRT) for prostate cancer.


METHODS
Between June 1997 and February 2003, a randomized dose-escalation trial comparing 68 Gy and 78 Gy was conducted. Patients at our institute were asked to participate in an additional part of the trial evaluating sexual function. After exclusion of patients with less than 2 years of follow-up, ED at baseline, or treatment with hormonal therapy, 96 patients were eligible. The proximal corpora cavernosa (crura), the superiormost 1-cm segment of the crura, and the penile bulb were contoured on the planning computed tomography scan and dose-volume parameters were calculated.


RESULTS
Two years after EBRT, 35 of the 96 patients had developed ED. No statistically significant correlations between ED 2 years after EBRT and dose-volume parameters of the crura, the superiormost 1-cm segment of the crura, or the penile bulb were found. The few patients using potency aids typically indicated to have ED.


CONCLUSIONS
No correlation was found between ED after EBRT for prostate cancer and radiation dose to the crura or penile bulb. The present study is the largest study evaluating the correlation between ED and radiation dose to the corpora cavernosa after EBRT for prostate cancer. Until there is clear evidence that sparing the penile bulb or crura will reduce ED after EBRT, we advise to be careful in sparing these structures, especially when this involves reducing treatment margins.
van der Wielen
Gerard J
GJ
Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam, The Netherlands. g.vanderwielen@erasmusmc.nl
Hoogeman
Mischa S
MS
Dohle
Gert R
GR
van Putten
Wim L J
WL
Incrocci
Luca
L
D000368:Aged; D004307:Dose-Response Relationship, Radiation; D007172:Erectile Dysfunction / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008297:Male; D010413:Penis / Q000528:radiation effects*; D011471:Prostatic Neoplasms / Q000150:complications / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology*; D018570:Risk Assessment; D013223:Statistics as Topic; D016896:Treatment Outcome