What is the main purpose of performing a bone scan prior to surgery on a dog suspected of having osteosarcoma?

The main purpose of performing a bone scan prior to surgery on a dog suspected of having osteosarcoma is to identify possible additional bone lesions that may represent metastases. Osteosarcoma is an aggressive tumor known to spread, often to the lungs and other bones. A bone scan, which utilizes radiopharmaceuticals to detect areas of increased bone metabolism, can reveal the presence of other lesions in different locations within the skeleton. These lesions may signify metastatic disease, which is critical information for treatment planning. Detecting additional lesions can impact the surgical approach and overall management of the disease, ensuring that all affected areas are appropriately addressed.

While obtaining greater anatomic detail and confirming a diagnosis are important considerations in the diagnostics of osteosarcoma, these may rely on different imaging modalities such as advanced radiography or MRI rather than a bone scan. Additionally, while bone scans can provide some insight into pulmonary metastases, typically, chest imaging is more effectively used for evaluating the lungs. Therefore, the primary focus of a bone scan is to assess the entire skeletal system for other potential sites of metastasis.