Single-Dose Radiation Therapy in the Palliation of Metastatic Disease

Abstract

A LARGE SEGMENT of the practice of radiotherapy today concerns itself with the palliative care of incurable cancer patients. Since it is unrealistic to consider that these patients can be cured by any means whatsoever, effective palliation is concerned with improving the quality of the remaining period of life. In the treatment of metastatic disease in which only one of a number of metastases is being considered for irradiation because it alone is giving rise to pain, the sole object of therapy is to remove this distressing symptom. The therapy will have no influence upon the ultimate course of the disease. Therefore, treatment is predicated upon achieving maximum relief of signs and symptoms with the minimum morbidity and in the least time necessary to achieve these ends. It has been the practice of the Radio-therapy Center at Mount Sinai Hospital in New York to treat selected patients in a single session to effect palliation. The purpose of this report is to present the results of such treatment in 204 instances in 116 patients seen during the last decade on whom follow-up studies were available. Material And Methods Of the total of 204 treatments, 119 utilized cobalt-60 irradiation. Six patients were treated with betatron photons and 5 with betatron electrons. The remainder (73 patients) were treated with conventional kV x rays. Generally speaking, a single field was employed; parallel opposed fields and arc and rotational therapy were used on a few occasions. The size of the field varied widely from a circle 1.5 cm in diameter up to as much as 250 cm2. All of the doses stated herein are the calculated dose in the metastases. The doses varied widely from 400 to 1,800 rads (Fig. 1), with the smaller volumes receiving higher doses; but account was also taken of the probable radiosensitivity of the tumor. The governing factor was the rule that the entrance dose did not exceed the tolerance for the selected site and volume. This fact is the one most responsible for the wide variation of the stated tumor dose. The most important indication for single-session therapy was pain, primarily from bone metastases. Hemoptysis was seen in a few instances, edema associated with the superior vena cava in 5 instances, and spinal cord compression with neurological symptoms in another 5. Adjuvant hormone and/or chemotherapy, either prior to or after irradiation, was recorded in 22 cases. Skin reactions were seen in only 12 patients. Ten of the 12 received treatment with conventional x ray and 1 with cobalt. The dose with cobalt was 2,000 rads to the skin with a field of 10 X 7 cm. With the twelfth patient, treatment by means of betatron-generated 15 MeV electrons for a skin dose of 1,500 rads was given through a circle 6 cm in diameter. Systemic reactions were noticeably absent.