Objective: To determine the effectiveness of radiation therapy for local control of nonmetastatic osteosarcoma of the extremities after induction chemotherapy.
Patients and methods: Of 187 patients with nonmetastatic osteosarcoma of the extremities treated with induction chemotherapy since 1986, 31 refused surgery and underwent standard, fractionated external beam radiotherapy for local control. The median radiation dose to the limb was 60 Gy (range 40-68 Gy). Records were reviewed through April 2002, and outcomes including radiologic and biochemical response, local control, limb function, and survival were analyzed. The end points were local progression-free survival, metastases-free survival, and overall survival.
Results: Overall survival, local progression-free survival, and metastases-free survival at 5 years were a mean +/- SD of 61%+/-11%, 56%+/-12%, and 62%+/-10%, respectively. The outcome correlated significantly with patients' imaging and biochemical response. In patients who had a pronounced response, overall survival and metastases-free survival at 5 years were 90%+/-9% and 91%+/-9%, respectively, but it was only 35%+/-15% and 42%+/-13% in the nonresponders (P=.005 and P=.005, respectively). Local control was also related to response after induction chemotherapy. None of the 11 patients with both a good imaging and a good biochemical response had local relapse; median follow-up was 67 months. The estimated local progression-free survival among nonresponders was 31%+/-16% at 3 years and 0% at 5 years. Of 22 patients surviving without local disease progression, 19 (86%) had excellent limb function (Enneking score between 90% and 100%) at the time of most recent evaluation.
Conclusion: When used after effective induction chemotherapy for osteosarcoma of the extremities, radiation therapy can be a reliable modality to control local disease and preserve limb function.