The role of radiation therapy for the extramammary paget's disease of the vulva ; experience of 3 cases.

We have experienced three cases of extramammary Paget's disease (EMPD) of the vulva that received radiation therapy (RT). Here, we analyze the efficacy of RT and include a literature survey.Three patients with EMPD of the vulva were treated with curative RT between 1993 and 1998. One of the patients had associated underlying adenocarcinoma of the vulva. The total doses of radiation administered were 54~78 Gy/6~8 weeks. Radiation fields encompassed 2 to 3 cm outer margins free from all visible disease including or not including the inguinal area using a 9 MeV electron or a 6 MV photon beam. Follow-up durations after radiotherapy were 0.6~11 years. Complete response was obtained in all three patients. Marginal failure occurred in one patient, and another patient with underlying adenocarcinoma treated by vulvectomy with bilateral inguinal lymph node dissection followed by external RT showed no relapse. Radiation induced side effects were transient acute confluent wet desquamation in the treated area resulting in mild late atrophic skin changes.Although surgery is currently considered the preferred primary treatment for EMPD, it has a high relapse rate due to the multifocal nature of the disease. We conclude that RT is of benefit in some selected cases of EMPD.