Digital picture analysis for studying the development of experimentally induced osteosarcoma.

We used the method of digital picture analysis to make a quantitative characterization, of stages of development of experimental osteosarcomas in rabbits. DMBA in gelatine pellets placed intraosteally served as a carcinogen to induce bone sarcomas. Of 25 animals treated, eight developed osteosarcomas classified as either osteoblastic, fibroblastic, or chondroblastic. We studied the process of bone neoplasia using radiographic, scintigraphic, and histological methods. To define the progress of neoplastic growth in each tumor we processed sequential radiographs of them by digital picture analysis. For this purpose, we developed a method for quantifying radiological changes using parameters independent of the rotation of the bone. In defining the histologic type of bone sarcomas, besides microscopic features we relied on quantitative criteria such as ratios of the newly formed bone and cartilage to the sarcomatous stroma. Our results, presented in this paper, indicate that digital picture analysis may be useful in characterizing experimental osteosarcomas as a model for therapeutic studies.