PHOENIX—A self-administered questionnaire that measures patients’ sexual problems after radiation therapy for prostate cancer has now been validated and could provide a means of standardizing reports of sexual dysfunction after prostate cancer treatment.

“The degree of sexual dysfunction after prostate cancer therapy varies widely in the literature,” Deborah Watkins Bruner, RN, said at the American Society of Therapeutic Radiology and Oncology (ASTRO) annual meeting. “This may be because we are all using very different scales or ways to measure sexual function.”

When the Radiation Therapy Oncology Group (RTOG) began to examine available instruments a decade ago, it found that “some were ridiculously long, with 150 or 200 items on sexual adjustment, and some were ridiculously expensive,” Ms. Bruner said. RTOG found the Sexual Adjustment Questionnaire (SAQ), developed by Metcalfe and Waterhouse in 1986, to be the most “user-friendly,” and began using it in some of its trials.

Ms. Bruner reported results of a validation study in 471 patients of a modified 16-item version of the SAQ, measuring five factors: sexual dysfunction, satisfaction, activity, desire, and fatigue (see table for sample questions). Patients were given the SAQ pretreatment and at follow-up.

 “The RTOG-modified SAQ proved to be a valid and reliable measure of sexual function,” Ms. Bruner said. She pointed out that this patient self-assessment, which asked about degrees of erectile function (never, sometimes, always), was more reliable than physician assessment, which asked a yes or no question about erectile dysfunction, in the same study.

“Physicians are right only about 50% of the time in assessing erectile function,” she said. “An erection is not an all or nothing phenomenon, and we are not very good at assessing patients’ capabilities in areas of quality of life.”

She noted that the modified SAQ will be used in RTOG trials of prostate cancer, including an upcoming Viagra study. The SAQ is both sensitive and specific, she said, “meaning that we can delineate patients on different treatments by their SAQ scores.”