Potency following conformal neutron/photon irradiation for localized prostate cancer

To assess the effect of conformal neutron/photon irradiation with or without neoadjuvant hormonal therapy on posttreatment potency.

Seventy-six patients with localized adenocarcinoma of the prostate, State T1 or T2 N0 M0, Gleason score < or = 7, were enrolled on a prospective Phase II study. Each patient received 9-10 Neutron + 38 Photon Gy. Twenty-eight patients received neoadjuvant hormonal therapy in conjunction with radiation therapy. Potency was assessed prior to starting treatment and was assessed at each subsequent follow-up visit.

Fifty-two of patients (70%) were potent at the start of therapy. Thirty-eight of 52 (73%) had functional erections and 14 of 52 (27%) had erections termed nonfunctional, which were of insufficient strength for intercourse. After treatment, 35 of 52 (67%) retained potency. Twenty-nine of 38 (76%) with functional erections pretreatment maintained this ability. Only 6 of 14 patients (43%) with nonfunctional erection pretreatment maintained their level of potency. Neoadjuvant hormonal therapy did not impact on the ability to maintain erections. Sixty-five percent of those patients receiving hormones retained erectile function, while 69% of those who did not receive hormones maintained erectile function. Age was not a significant factor in posttreatment potency, although a trend towards potency in younger patients was observed. (p = 0.74).

The majority (67%) of patients maintained their level of erectile function following conformal sequential neutron photon irradiation. This is comparable to that achieved with photon irradiation alone. No significant change in potency was seen with neoadjuvant hormonal therapy or with increasing patient age.