Hyperthermia and radiation in the treatment of superficial malignancy: an analysis of treatment parameters, response and toxicity

A total of 41 superficial tumours have been treated with radiation alone (21 lesions) or in combination with hyperthermia (20 lesions) in a non-randomized study on 16 patients. A minimum tumour heat dose in excess of 30 min equivalent at 43 degrees C was achieved in 46 of the 80 (57 per cent) hyperthermia treatments. Small lesions received better quality heat treatments and were more likely to achieve a complete response. There is a significant increase in the response of lesions treated with the combined modality compared with radiation alone (P less than 0.01). Similar results were obtained when matched lesions with internal controls were analysed separately. There was an increased incidence of severe skin reactions in the hyperthermia-treated group with the reaction tending to develop more quickly. There were three instances of late fibrosis in the hyperthermia group. There is a significant correlation between the severity of the skin reaction and the average maximum skin heat dose per treatment.