EXTREMITY OSTEOSARCOMA IN CHILDHOOD - PROGNOSTIC VALUE OF RADIOLOGIC IMAGING

PURPOSE: To evaluate previously described radiologic prognostic factor s in extremity osteosarcoma. MATERIALS AND METHODS: In 47 pediatric pa tients, available images were evaluated for seven prognostic factors a t diagnosis and seven additional factors after preoperative chemothera py. These factors were correlated with histopathologic response and cl inical outcome. The association of histopathologic response and outcom e was also evaluated. RESULTS: Metastases at presentation and a >20-cm -diameter soft-tissue mass were predictive of a poor outcome but occur red in few patients. Factors most predictive of <90% tumor necrosis af ter chemotherapy included an increase or no change in soft-tissue mass size and increased bone destruction. Although a significant relations hip (P < .05) was found between histopathologic response and outcome, no factors predictive of histopathologic response were also predictive of outcome. The accuracy of pathologic response in predicting outcome was 66%. CONCLUSION: Radiologic studies are of only limited use in pr edicting which patients with extremity osteosarcoma will have a poor r esponse to chemotherapy or a poor outcome, and are not useful in predi cting a good response or outcome.