The aim of this work was to quantify the uptake of
18F-BMS-986192, a programmed cell death
ligand 1 (PD-L1) adnectin PET tracer, in patients with
non-small cell lung cancer. To this end, plasma input kinetic modeling of dynamic
tumor uptake data with online arterial blood sampling was performed. In addition, the accuracy of simplified uptake metrics such as SUV was investigated. Methods: Data from a study with
18F-BMS-986192 in patients with advanced-stage
non-small cell lung cancer eligible for
nivolumab treatment were used if a dynamic scan was available and lesions were present in the field of view of the dynamic scan. After injection of
18F-BMS-986192, a 60-min dynamic PET/CT scan was started, followed by a 30-min whole-body PET/CT scan. Continuous arterial and discrete arterial and venous blood sampling were performed to determine a plasma input function.
Tumor time-activity curves were fitted by several plasma input kinetic models. Simplified uptake parameters included
tumor-to-blood ratio as well as several SUV measures. Results: Twenty-two
tumors in 9 patients were analyzed. The arterial plasma input single-tissue reversible compartment model with fitted blood volume fraction seems to be the most preferred model as it best fitted 11 of 18
tumor time-activity curves. The distribution volume (VT ) ranged from 0.4 to 4.8 mL⋅cm-3 Similar values were obtained with an image-derived input function. From the simplified measures, SUV normalized for
body weight at 50 and 67 min after injection correlated best with VT , with an R2 of more than 0.9. Conclusion: A single-tissue reversible model can be used to quantify
tumor uptake of the PD-L1 PET tracer
18F-BMS-986192. SUV at 60 min after injection, normalized for
body weight, is an accurate simplified parameter for uptake assessment of baseline studies. To assess its predictive value for response evaluation during
programmed cell death protein 1 or PD-L1
immune checkpoint inhibition, further validation of SUV against VT based on an image-derived input function is recommended.