Radiotherapy of Sarcoma of the Soft Parts

NO OTHER group of tumors includes tissues as widely divergent in their radiosensitivity as the sarcoma group. With the highly radiosensitive lymphosarcoma at one extreme and the radioresistant sclerosing osteosarcoma at the other, one may arrange on the basis of degree of radiosensitivity a scale of the sarcomas which would be nearly as extensive as the scale of radiosensitivity of neoplastic tissues as a whole. This behavior is a natural sequence of the morphologic and especially histogenic characteristics. For, although the general term of “sarcoma” implies pathologically a malignant tumor composed of cells of the connective tissue type and thus in appearance a rather uniform group of tumors, when further elucidation of the nature or origin of the cells is attempted, the variation is found to be exceedingly great. Since the effect of radiation, in a general way, depends on the susceptibility of the cells or tissues irradiated, and since this function, in turn, is the result of many criteria intimately associated with morphologic and histogenic characteristics, obviously the wide difference in type and origin of the cells leads, with some exceptions, to a like difference of radiosensitivity. The great radiobiologic and pathologic variation has induced not a few of the investigators to suggest the elimination of the term of “sarcoma,” and the separation of the tumors included under its heading into distinct entities of their own. Although such a position cannot be claimed to contribute, for the present, very considerably to the clarification of the problem as a whole, nevertheless it clearly indicates the necessity of dividing the sarcomas into subgroups which would permit a better insight into the more or less specific characteristics by paying due regard to the clinical course at the same time. For this reason, it is proposed that in the following the subject of radiation therapy in sarcoma be treated along identical lines, that is, by discussing the various types of sarcomas, which might constitute a subgroup, individually. There are especially two practical advantages which result from such a procedure: first, the technic of irradiation (method, dose, fractionation, etc.) can be considered on the basis of radiosensitivity of each particular type of tumor, and secondly, the extent of irradiation can be determined by the known clinical course (extension, metastases) of that specific lesion. Although the title of the paper suggests that every form of sarcoma, except sarcoma originating from the bone, is considered in the discussion, the subgroups of lymphosarcoma, melanosarcoma, and gliosarcoma were likewise omitted, for they represent such distinct processes that they may best be dealt with separately (7, 13). Statistics A review of the literature concerning the five-year cure of sarcoma in general reveals the not altogether surprising fact that the problem of radiation therapy still forms a rather favored subject of speculative argumentation.