Skeletal imaging effects of pamidronate therapy in osteosarcoma patients

Background: After observing metaphyseal changes in pediatric and young adult patients with osteosarcoma who were treated with pamidronate, we initiated a retrospective study to identify bone findings on computed radiography of the chest and extremities, chest CT, extremity MRI, and radionuclide bone scans in this population. Objective: To review the generalized skeletal imaging findings on computed radiography, CT, and MR examinations in patients with osteosarcoma (OS) receiving pamidronate. Materials and methods: A retrospective review of 40 patients with newly diagnosed OS (mean age, 16.5 years) receiving pamidronate with chemotherapy were identified at one institution. Computed radiography, CT, MR, and bone scans on 36 patients were reviewed for osseous changes. Results: Dense metaphyseal bands at the growth plates in long bones, epiphyseal ossification centers, anterior rib ends, sternum and spine were observed. Osseous changes occurred on CT in 69% of patients, and on computed chest radiography in 53%. Bone-within-bone appearance in the spine and ossification centers was identified on computed radiography in 36%. Conclusion: OS patients treated with pamidronate can develop metaphyseal sclerotic bands as well as epiphyseal and vertebral endplate sclerosis progressing to a bone-within-bone appearance. Findings occur more frequently in younger patients with open epiphyses.