18F-fluoromethylcholine or 18F-fluoroethylcholine pet for prostate cancer imaging: Which is better? A literature revision

Introduction: The present review was conceived for describing the differences in biodistribution and diagnostic performance of two types of 18 F-radiolabeled choline for positron emission tomography (PET) imaging in pros- tate cancer (PCa), such as fluoromethylcholine (FCH) and fluoroethylcholine (FEC). Materials and methods: A collection of published data about two radiopharmaceutical agents was made by using PubMed, Web of Knowledge databases and Trip Database, and then a critical revision was discussed. Results: FCH was injected in 338 and 1164 patients, while FEC was injected in 20 and 139 patients, respectively for basal staging and re-staging. The diagnostic performances of FCH and FEC for the detection of lymph node metas- tasis before the surgical approach are typically around 50% or less and between 0% and 39%, respectively. Con- versely, both the tracers appear useful for the detection of recurrent PCa in case of increase in absolute PSA value or in case of high levels of PSA velocity and PSA doubling time (sensitivity ranged between 42.9% and 96% for FCH and between 62% and 85.7% for FEC). Conclusions: In according with the available information, FCH appears to be a more appropriate radiocompound as compared to FEC, although more comparative data are mandatory. A well designed and prospective trial for the evaluation of biokinetic data and diagnostic performance of both radiopharmaceutical agents seems essential. Advances in knowledge and implication for patient care: FCH seems to be an appropriate radiopharmaceutical agent as compared to FEC. Anyway both the radiocompounds are useful in the evaluation of recurrent disease in case of a serial increase in PSA value and their performance improves when a correct preparation and acquisition protocol is employed.