Diagnosis and tumor response in osteosarcoma and Ewing's sarcoma, accordmgto treatment protocols SSG II, SSG VIII, ISG SSG I, SSG IV and SSG IX

114 patients with osteosarcoma in the extremities had been reported to the SSG II trial, 132 to the SSG VIII trial and, until October 1998, 99 to the ISG/SSG trial. The SSG IV trial included 53 patients and the SSG IX trial 1 04 patients until October 1998. In the SSG II trial, 19% were good responders (grades III and IV) as compar ed to 51% in the SSG VIII trial. On reevaluation was the response changed i n one forth of the cases in both the SSG II and SSG VIII trials. In 9 and 1 0 cases (8%), respectively, the reevaluation resulted in a change from "goo d responder" to "bad responder". In the ISG/SSG I trial, the preliminary re sults showed a good response in 22% of the cases. In the SSC IV trial, 44% were good responders (grades III and IV), as compared to 54% in the SSG IX trial.