Interreader agreement and variability of FDG PET volumetric parameters in human solid tumors.

OBJECTIVE. The purpose of this article is to evaluate the interreader agreement and variability of two 18F-FDG PET parameters, metabolic tumor volume and total lesion glycolysis, in human solid tumors. MATERIALS AND METHODS. One hundred eleven patients (mean [± SD] age, 61.9 ± 12.5 years) with baseline staging FDG PET/CT scans were included. Two readers independently read the scans and segmented metabolic tumor volume and total lesion glycolysis using two fixed thresholds, 40% and 50% of the lesion's maximum standardized uptake value (SUVmax). The impact of the lesion's FDG avidity and location on reader agreement and variability was established. Intraclass correlation coefficient (ICC), precision, and Bland-Altman analysis were used to evaluate agreement and variability. RESULTS. The ICCs for 40% and 50% SUVmax segmentations of metabolic tumor volume between the readers were 0.987 and 0.995, and the corresponding values for 40% and 50% SUVmax segmentations of total lesion glycolysis were 0.987 and 0.986,...