Classification of osteosarcoma by 85-Sr scintimetry

The histologic type of a classical osteosarcoma may be difficult to determine because of insufficient biopsy material and polymorphism of the tumour. Since osteoformation is directly related to the differentiation and functional capacity of the tumour cells, 85-Sr scintimetry was used to evaluate osteoid formation in 90 patients with classical osteosarcoma. Measurements over an 8-day period from isotope injection revealed a separation of the lesions into three groups, with high, medium and low activity. Compared to histologic classification into osteoblastic, chondroblastic/fibroblastic, the 41 tumours classified as osteoblastic had a high 85-Sr uptake. The anaplastic lesions belonged to the group with low 85-Sr uptake. Scintimetric determination of the functional differentiation of tumoral cells may possibly be of prognostic value in osteosarcoma.