Hyperthermia in combination with radiotherapy: a review of five years experience in the treatment of superficial tumors.

Facilities for regional tumor hyperthermia has been in use at RPMI since 1976, and have been routinely used to treat patients according to protocol since 1977. Hyperthermia delivery has been exclusively by microwave using 434 MHz, 915 MHz and 2450 MHz. Greatest success at reaching tumor temperatures of 43-44 degrees C with minimal skin heating was obtained using 915 MHz. The majority of the patients were treated with this frequency. Approximately 125 patients have been treated and 70 have achieved completion of therapy and follow-up. Follow-up has been at least one month and several patients have been followed for one to two years. Initially, for entry into the hyperthermia protocol, patients were required to have three or more lesions. One lesion on each patient was treated with 800 rad fractions repeated three times on a 72 hour schedule. The second lesion was treated with 700 rad fractions and the third with 500 rad plus hyperthermia on the same schedule. Twelve patients with multiple melanoma lesions completed this study. One of 12 patients showed no response to the combination of hyperthermia plus radiotherapy, while four showed no response to radiotherapy alone. Of eight patients who survived three months, all lesions treated by hyperthermia plus radiotherapy responded completely, while only five lesions treated by radiotherapy alone so responded. In a second study, 58 patients with superficial tumors were treated by a protocol where hyperthermia was added to optimal conventional radiotherapy. Of the total, 43 patients had complete tumor response at follow-up varying from one month to 18 months. A subgroup of 24 of these patients had two lesions, one of which was treated with hyperthermia in addition to radiotherapy while the other served as control, receiving radiotherapy only. Nineteen lesions demonstrated complete response to hyperthermia plus radiotherapy, while only 14 of the controls had complete response. None of the lesions treated with hyperthermia responded less well than those treated by radiotherapy alone. Morbidity, as measured by skin reaction, was rarely increased in the heated field.

Technical management of a pregnant patient undergoing radiation therapy to the head and neck.

The fetal dose in a pregnant patient undergoing radiation therapy to the head and neck region was investigated. Implicit in this study was the design and evaluation of a shield used to minimize the fetal dose. To evaluate the fetal dose, a phantom was irradiated with the fields designed for this patient's therapy. The peripheral dose was measured for each field individually, both without and with a custom shield designed to be placed about the patient's abdominal and pelvic regions. The total dose at the location of the fetus over the course of this patient's radiation therapy was then estimated from peripheral dose rate measurements made at several points within the simulated uterus. With no shielding, the total dose within the uterus of the patient would have ranged from 13.3 cGy at the cervix to 28 cGy at the fundus. With the shield applied, the uterine dose was significantly less: 3.3 cGy at the cervix to 8.6 cGy at the fundus. In fact, at every measurement point, the peripheral dose with the shield in place was 30% to 50% of the dose without the shield. Some data suggest that the rate of significant abnormalities induced by irradiation in utero increases with increasing dose within the range of total peripheral doses incurred during most radiation treatment courses. It is therefore prudent to make reasonable attempts at minimizing the dose to the lower abdominal and pelvic regions of any pregnant patient. The shield designed in this work accomplished this goal for this patient and is flexible enough to be used in the treatment of almost all tumor volumes.