Quantitative bone scan lesion area as an early surrogate outcome measure indicative of overall survival in metastatic prostate cancer

A clinical validation of the bone scan lesion area (BSLA) as a quantitative imaging biomarker was performed in metastatic castration-resistant prostate cancer (mCRPC). BSLA was computed from whole-body bone scintigraphy at baseline and week 12 posttreatment in a cohort of 198 mCRPC subjects (127 treated and 71 placebo) from a clinical trial involving a different drug from the initial biomarker development. BSLA computation involved automated image normalization, lesion segmentation, and summation of the total area of segmented lesions on bone scan AP and PA views as a measure of tumor burden. As a predictive biomarker, treated subjects with baseline BSLA [Formula: see text] had longer survival than those with higher BSLA ([Formula: see text] and [Formula: see text]). As a surrogate outcome biomarker, subjects were categorized as progressive disease (PD) if the BSLA increased by a prespecified 30% or more from baseline to week 12 and non-PD otherwise. Overall survival rates between PD and non-PD groups were statistically different ([Formula: see text] and [Formula: see text]). Subjects without PD at week 12 had longer survival than subjects with PD: median 398 days versus 280 days. BSLA has now been demonstrated to be an early surrogate outcome for overall survival in different prostate cancer drug treatments.

Journal of medical imaging (Bellingham, Wash.). 2018 Jan 11 [Epub]

Matthew S Brown, Grace Hyun J Kim, Gregory H Chu, Bharath Ramakrishna, Martin Allen-Auerbach, Cheryce P Fischer, Benjamin Levine, Pawan K Gupta, Christiaan W Schiepers, Jonathan G Goldin

University of California Los Angeles, Center for Computer Vision and Imaging Biomarkers, Los Angeles, California, United States., University of California Los Angeles, Department of Nuclear Medicine, Los Angeles, California, United States., University of California Los Angeles, Department of Radiological Sciences, Los Angeles, California, United States.