[Alternative chemotherapy of malignant bone neoplasms in children]

The authors propose alternative chemotherapy of osteosarcoma and Ewing's sarcoma in children. The aim of this proposal was elaboration of effective and, at the same time, less expensive and less toxic therapeutic regimens. The authors recommend open surgical biopsy with doxorubicin for 3 consecutive days as a protection against the released circulating neoplastic cells. After completion of histopathologic examination, one of two types of chemotherapy is chosen randomly. In osteosarcoma, there was induction chemotherapy for 4 or 9 weeks (according to the type of operation--conservative amputation or limb salvage surgery). In the I type of induction chemotherapy, high doses of methotrexate with vincristine and citrovorum factor rescue are administrated weekly, in the II type--the combination of BCD (bleomycin, cytoxan, actinomycin D) and CDDP (cisplatin). On the regimen of intensification chemotherapy decides the degree of tumour response to induction chemotherapy assessed as tumour necrosis in histopathologic examination. Maintenance chemotherapy is the same in two types of regimen and is continued for the period up to 2 years. The authors elaborated concomitantly the regimen of high methotrexate doses administration with rescue procedure in the case of elevated serum methotrexate levels, and regimen of cisplatin administration aiming at maximal patients protecting against the toxic effects of both drugs. In Ewing's sarcoma the randomisation differentiates between T-9 Rosen's regimen of chemotherapy and own modification of Memphis group regimen. The primary tumour is treated by radiotherapy with lower doses adjusted to the tumor response to induction chemotherapy (30-50 Gy or 50 Gy) and the irradiation port limited to the residual bone lesion plus a 2-3 centimeter margin. Surgical excision of bone with tumor depends on special tumor localisation as the clavicula, rib or fibula. The results of discussed treatment regimens will be subsequently published.