Decline in MTV. Percentage decline in MTV after pembrolizumab monotherapy in the 28 patients with quantifiable disease was calculated with an automatic software tool applying a local SUV maximum threshold of 41% (SyngoVia software, multifoci segmentation tool; Siemens).¹⁷  Each bar corresponds to an individual patient. The decline in MTV could not be measured in 2 of 30 cases; 1 patient had uptake that could not be distinguished from PET-avid myocardium, because of the close approximation, and another had a computer-generated decline in MTV of 100% that was inconsistent with clinical and qualitative assessment demonstrating a small focus of residual disease and a Deauville score of 4.