Indications for epiphyseal preservation in metaphyseal malignant bone tumors of children: relationship between image methods and histological findings.

We compared several image methods in the evaluation of the possible physeal effect in 47 osteosarcomas and 18 Ewing's sarcomas in children. The minimal follow-up was 3 years (range, 3-17). In the histological study, the physis was affected in 53% of the cases. We correlated the histological findings and the findings from the different image methods. There were more false-positive than false-negative results, and in the computed tomography and magnetic resonance imaging (MRI) studies, there were no false negatives. The accuracy of MRI (predictive positive value plus predictive negative value) was the best (90.3%), and it is the technique that we prefer. According to these findings, we can safely preserve the epiphysis in cases of metaphyseal tumors showing no contact between the tumor and the growth plate in the MRI images. If the tumor shows contact with part of the physis, it is also possible to preserve the epiphysis.