What is the main reason for performing a bone scan on a suspected osteosarcoma?

Performing a bone scan on a suspected osteosarcoma primarily serves the purpose of identifying possible additional bone lesions. Osteosarcoma often has a propensity to metastasize within the bone, and a bone scan allows for the detection of abnormal metabolic activity that may indicate the presence of other lesions that are not immediately apparent on conventional imaging studies.

The bone scan is particularly useful because it assesses the entire skeleton and highlights areas of increased osteoblastic activity, which is characteristic of osteosarcoma and other bone conditions. This is crucial for staging the disease and planning appropriate treatment, as the presence of additional lesions can significantly affect the prognosis and therapeutic approach.

Other imaging techniques, like X-rays or MRI, are typically used to visualize the specifics of a known lesion but may not be as comprehensive in detecting multi-focal disease spread throughout the skeleton. Therefore, the bone scan is integral in the process of evaluating the overall extent of osteosarcoma in the bone, making the identification of any additional lesions a key focus.