Interstitial radiotherapy combined with interstitial hyperthermia in the management of recurrent tumors.

During a 2-year period 31 sites in 27 patients with recurrent, previously treated tumors received a combination of interstitial 192Ir radiation (RT) with microwave hyperthermia (HT). Head and neck sites were treated most frequently (48%), with breast and vagina each representing about 20% of sites. Complete response (CR) with no local recurrence was obtained in 61%, partial response (PR) in 11 (36%), and one (3%) had less than 50% tumor regression. Of these patients, nine had no evidence of tumor following HT-RT therapy, 8/18 in the CR group and 1/11 in the PR group. Significant factors influencing CR were: radiation dose, tumor volume and duration of tumor control following the initial therapy (p less than 0.02). Treated site, histology and thermal dose were not significant factors influencing tumor regression. Complications of significance developed in one patient who had local skin necrosis. Interstitial HT-RT combination provides an effective palliative therapy for recurrent and/or persistent tumors. Randomized trials are necessary to assess the effectiveness of this combination as a component part of primary management of selected tumors.