Targeting Imaging Brain Lesions with PET/CT: F18-CH and F-18-FLT

Passing to the era of molecular imaging and precision oncology, the radiopharmaceuticals may play an incremental role in further revealing the nature of the evaluated lesion. FLT, a radiolabeled thymidine analogue, and FCH, a radiolabeled substance of the cell membrane phospholipids, have been more or less investigated in the imaging, identification, and evaluation of brain tumor lesions. In our study, using a Siemens Biograph LSO PET/CT 16 slices device, a Siemens multimodality workplace (MMWP) system for brain analysis, and qualitative and semiquantitative analysis (SUVmax, SUVpeak, T/B ratio), we investigated the role of these two radiopharmaceuticals in primary and metastatic brain lesions, lymphomas as well as in investigating neurological symptoms with inconclusive/indefinite evidence in the conducted MRI. Using F-18-CH for PET/CT imaging, we found that there was FCH uptake by active tumor sites, with no statistical significance in SUVmax, SUVpeak and T/B ratio for the discrimination of the lesions between primary, metastatic and lymphomas, (p gt; 0.05). However, recurrent primary lesions exhibited lower T/B and SUVmax compared to the respective mean values of the metastatic ones. With the utilization of F-18-FLT we concluded that it could discriminate between active from non-active foci, while mean values of T/B and SUVmax were statistically significantly higher for NHL compared to primary and metastatic tumors (p lt;0,001). There was a tendency for significance for SUVmax and T/B between low and high-grade recurrent primary tumors (p=0.08 and p=0.06, respectively) when excluding the outliers. However, further investigation is required for definite conclusions.