Radiatio herapy of malignant bone tumors.

Abstract

Although radiation therapy has been used in the management of malignant bone tumors for many years (1), its precise role remains uncertain. Preoperative irradiation in osteogenic sarcoma, as proposed by Ferguson (5), is still of controversial value. Furthermore, the ability of radiation therapy alone to control the primary lesion in Ewing's sarcoma has been questioned (17). The problem of differentiation between Ewing's sarcoma and reticulum-cell sarcoma has led to some skepticism in respect to cures of the former. To provide insight into the proper place of radiation therapy in the management of these lesions, we reviewed their treatment at this institution. Material The records of all 87 patients treated for osteogenic sarcoma, Ewing's sarcoma, and reticulum-cell sarcoma at the University of California San Francisco Medical Center between 1945 and 1965 were studied. The 70 records of patients given primary treatment at this Center were analyzed in detail. In addition, two osteogenic sarcomas treated elsewhere were evaluated as to radiation dose versus viable tumor. Records of the other 15 given primary therapy elsewhere and referred here because of recurrence or metastasis were reviewed, and because of incomplete data these were discarded from the study. The histologic classification of Dahlin (1) was used. In cases of apparent cure, the histologic material was re-evaluated and the diagnosis was confirmed in all instances. Of the 70 patients given primary treatment at this hospital, 36 had osteogenic sarcoma, 21 Ewing's sarcoma, and 13 reticulum-cell sarcoma. All with either osteogenic or Ewing's sarcoma treated less than five years ago are already dead. Thus, complete five-year results are available for these two groups. The roentgenograms of those with osteogenic sarcoma were compared with the operative and histologic findings to determine how far tumor had extended within the marrow space of the involved bone. In only a limited number of cases were the histologic sections at various locations in the bone adequate for this purpose. Most osteogenic sarcomas treated between 1945 and 1965 were irradiated preoperatively. As suggested by Ferguson, this form of treatment would delay amputation and, it was hoped, would improve results. It would also allow preservation of the extremity in patients in whom early metastasis was to develop. Because some orthopedists did not agree with the use of preoperative irradiation, however, 11 patients were managed by surgery alone. In the earlier years of the period under study, two courses of radiation therapy were given. Each course consisted of a tumor dose of 5,000 rads delivered in about seven weeks and separated by an interval of about three months. Such a split course was given to 5 patients. The other 18 received a single course of irradiation with doses of 5,000 to 9,700 rads in five to seventeen weeks.