SAN FRANCISCOSildenafil (Viagra) is highly effective in improving
erectile function in prostate cancer patients following three-dimensional (3D)
conformal external radiotherapy, according to a study presented at the 43rd
Annual Meeting of the American Society for Therapeutic Radiology and Oncology
(ASTRO abstract 248).
"Sildenafil is well tolerated, and it works well in reversing sexual
dysfunction," said lead author Luca Incrocci, MD, PhD, of the Department
of Radiation Oncology, University Hospital Rotterdam-Daniel den Hoed Cancer
Center, Rotterdam, the Netherlands. "It should be the first line of
treatment in men with prostate cancer who sustain sexual dysfunction after
In this double-blind, placebo-controlled crossover study, 60 patients
received either 50 mg of sildenafil or a placebo for the first 2 weeks of the
study. The medications were taken 1 hour before sexual intercourse on demand
but not more than once a day. After 2 weeks, the dose could be increased to 100
mg in case of unsatisfactory erectile response. At week 6, patients crossed
over to placebo or sildenafil with the same study design as the first period.
Sexual data were collected using the International Index of Erectile
Dysfunction (IIEF), a validated self-administered questionnaire, at baseline (4
weeks prior to treatment) and after 2 and 6 weeks of treatment. At the same
time intervals, all patients completed a side effects questionnaire. Responses
to the IIEF were graded on a scale of 1 (almost never or never) to 5 (almost
always or always).
Patients who had treatment for prostate cancer from 1996 to 1998 were
selected from medical records. The mean age of the patients was 68. All
patients had complaints of erectile dysfunction, no evidence of metastases,
were not on hormonal therapy or nitrates, and did not have a history of
Half of the patients had T1c-2a carcinoma and the other half had a T2b-3b
tumors, with the majority having well or moderately differentiated disease.
All patients had completed radiation at least 6 months prior to the study,
with a mean radiation dose of 66 Gy and a mean energy of 23 MV (range, 6 to