Soft-X-ray therapy in Bowen's disease and erythroplasia of Queyrat.

The therapeutic results obtained with soft-X-ray irradiation on 77 lesions in 52 patients are reported. 35 males (67.3%) and 17 females (32.7%) were treated. Clinical and histological features revealed Bowen's disease in 73 cases (94.8%) and erythroplasia of Queyrat in 4 cases (5.2%). The primary healing was rated as 100% in all cases up to 6 months after a cumulative dosage of 3,200-5,000 R. 2 cases with a genital localization (2.6% of all sites and 11.1% of anogenital localizations) relapsed after 8 and 16 months, respectively. The follow-up period ranged from 1 to 11 years with a mean of 3 years. In order not to miss the late recurrences, the oncologic follow-up is taken care of by the Dermatology Department of the Zurich University Hospital during 10 years, or longer in some cases. Association with a malignant internal tumour (larynx, bronchi, anus) was found in 3 patients (5.8%).