Irradiation alone or combined with hyperthermia in the treatment of recurrent carcinoma of the breast in the chest wall: a nonrandomized comparison.

Tumour response and control (freedom from local relapse) were compared in two non-randomized groups of patients with recurrences from carcinoma of the breast (95 per cent in the chest wall and 5 per cent in the axillary or supraclavicular lymph nodes) receiving treatment at the Mallinckrodt Institute of Radiology. One group, comprising 48 patients treated between March 1978 and December 1984, received varying doses of irradiation (2000-4000 cGy in fractions of 400 cGy every 72 h) followed by local microwave hyperthermia (41-43 degrees C, 30-60 min). Irradiation was usually delivered with electrons ranging from 9 to 16 MeV. Hyperthermia was administered with 915 MHz external microwaves. The second group of 116 patients, with lesions similar to those treated with hyperthermia and irradiation, were treated with irradiation alone between January 1964 and December 1984. Doses of irradiation ranged from 2000 to 6000 cGy, usually delivered in daily fractions of 200-300 cGy TD. Irradiation was administered with Cobalt-60, 4 MeV photons or electrons (9-13 MeV) and occasionally with superficial X-rays. Patients with lesions 1-3 cm in diameter treated with irradiation and hyperthermia exhibited a complete tumour response rate of 80 per cent (12/15) while patients receiving irradiation alone had a complete response rate of 33 per cent (P = 0.04, Fisher exact test, two tail). The complete response rate for tumours larger than 3 cm treated with irradiation and heat was 65 per cent (13/20) compared to 42 per cent (18/43) for lesions receiving irradiation alone (P = 0.1, Fisher exact test, two tail).(ABSTRACT TRUNCATED AT 250 WORDS)