[Osteosarcoma - Clinical, Radiological and Histologic Evaluation of Preoperative Chemotherapy in Correlation with Long-term Survival.].

This paper evaluates the clinical, radiological and histomorphologic effect of neoadjuvant chemotherapy in 37 patients with II B osteosarcomas. The results are compared according to the type of surgery, local recurrence and lung metastasis at a minimal follow up of five years in patients who underwent surgery at the orthopedic clinic in Prague Bulovka in 1982 - 1992. All patients continued with adjuvant chemotherapy after surgery. Bad clinical response (increase of circumference, decrease in range of motion and increase of pain) correlated with the bad histologic response evaluated according to the COSS criteria. Accurate evaluation of a complete radiological documentation (tumor calcification on plain radiographs and CT scans, decrease of tumor volume on plain radiographs and CT scans or MRI and the disappearance of pathologic vascularisation) can quite precisely estimate a good response to preoperative chemotherapy and indicate limb sparing surgery. The radiological evaluation, especially of an incomplete record, does not always fully correlate with the histomorphologic response. Good prognosis for long term survival was observed in patients with a more then 80% tumor cell necrosis. CT scans or MRI performed immediately before the beginning and at the end of preoperative chemotherapy are necessary for a reliable evaluation of tumor calcification and intramedullar tumor spread. The persistence or disappearance of pathologic vascularisation seems to be the most significant marker to evaluate residual vital tumor cells. A good radiological response enables a safe indication for a limb sparing procedure as an alternative to amputation. The radiological evaluation must be correlated with different histomorphologic osteosarcoma subtypes as well as with possible changes, especially in vascularisation, due to an incorrect biopsy or pathologic fracture. Key words: osteosarcoma, neoadjuvant chemotherapy, long term survival, indication for limb salvage.