Partial volume correction methods based on measured lesion-to-background ratio in PET-CT oncological studies

This study evaluates Operator-Dependent (OD) and Operator-Independent (OI) methods for Partial Volume effect Correction (PVC) in PET-CT oncological studies. The proposed PVC methods are based on curves of Recovery Coefficients (RC) versus Measured Lesion-to-Background ratios (M-L/B). NEMA IQ phantom PET-CT measurements were performed for RC curves estimation, for M-L/B from 2 to 30. Validation of the PVC methods was performed by ¹⁸F-FDG PET-CT studies of a Breast Oncological Phantom, miming from 1cm to 1.56 cm lesions in breasts, for prepared L/B from 14 to 54. An OI PVC method based on a threshold-technique for the estimation of lesion uptake was found the most accurate method (accuracy >80%). PVC methods were applied to the SUV quantification of 11 ¹⁸F-FDG PET-CT oncological studies. Results prove PV strongly affects lesion quantification and needs to be corrected. When a decrement in the PET lesion volume is observed, PVC-SUV always decreased well fitting the clinical assessment, as from diagnostic report. When an increment in the PET lesion volume is observed, results suggest PVC-SUV should be used together with the PET lesion volume for a better characterization or therapy response of oncological lesions.