Accurate response assessment of breast cancer bone metastasis using computed tomography and new response criteria

568 Background: The lack of accurate criteria for assessing the response of bone metastases from breast cancer has led to bone disease being considered unmeasurable. Criteria from the UICC and the WHO based on radiography (XR) and skeletal scintigraphy (SS) are not satisfactory for clinical use. Criteria for computed tomography (CT) and magnetic resonance imaging (MR) have yet to be validated. We recently proposed a set of CT- and MR-inclusive criteria (MDA) to assess bone response (JCO 22:2942, 2004). Here we retrospectively reviewed image sets to evaluate the accuracy of MDA criteria (vs UICC, WHO) and the accuracy of each imaging modality for assessing bone response. Methods: XR, SS, CT, and MR images from patients with breast cancer and bone-only metastases were reviewed by musculoskeletal radiologists at baseline and after treatment (early: 2–6 mo, late: 11–13 mo). Responses were characterized as complete or partial, or stable or progressive disease (CR, PR, SD or PD) according to the 3 sets of crite...