Computer-aided bone scan lesion area quantitation: Inter-reader measurement variability.

e16019 Background: Bone scan is essential for response assessment in subjects with metastatic prostate cancer. However, visual assessment is subjective and prone to inter-reader variability. A commercial computer-aided (CAD) system for bone scan lesion area (BSLA) calculation has been developed (MedQIA, LLC). BSLA provides an objective and sensitive measure for response assessment. New VEGF treatments showing promising results in reducing lesion burden on bone scan present an urgent need for validated systems capable of accurately assessing treatment response. Measurement of inter reader variability is fundamental to such a validation. In this work we measure inter-reader variability in quantitation of BSLA change using the CAD system. Methods: In a multi-center clinical trial of cabozantinib (Exelixis, Inc), bone scans were acquired according to a standardized imaging protocol. Scans at baseline and Week 12 were available for 113 subjects for this analysis. Automated CAD lesion detection was performed fo...