Purpose. Relatively few results are available in the
literature about the radiation response of unresectable sarcomas
in relation to their histology. Therefore, an attempt was made to
summarize the present situation. Materials and methods.
This report is based on a review of the literature and the
author's own experience. Adult-type soft tissue sarcomas,
chondrosarcomas, and chordomas were analyzed. Radioresponse was
mainly associated with the degree of tumor shrinkage, that is,
objective responses. Histopathologic responses, that is, the degree of
necrosis, are only discussed in relation to radiation treatment
reports of soft tissue sarcomas as a group. Results.
Radiation therapy alone leads to major responses in about 50% of
lipo-, fibro-, leiomyo-, or chondrosarcomas. The response rate is
less than 50% in malignant fibrous histiocytomas, synovial,
neurogenic, and other rare soft tissue sarcomas. The response
rates may increase up to 75% through the addition of
radiosensitizers such as halogenated pyrimidines or razoxane, or
by the use of high-LET irradiation. Angiosarcomas become clearly
more responsive if biologicals, angiomodulating, and/or tubulin
affinic substances are given together with radiation therapy.
Razoxane is able to increase the duration and quality of responses
even in difficult-to-treat tumors like chondrosarcomas or
chordomas. Conclusions. The available data demonstrate
that the radioresponsiveness of sarcomas is very variable and
dependent on histology, kind of radiation, and various
concomitantly given drugs. The rate of complete sustained
remissions by radiation therapy alone or in combination with drugs
is still far from satisfactory although progress has been made
through the use of sensitizing agents.