Effective dose estimation for oncological and neurological PET/CT procedures.

Effective dose estimation for oncological and neurological PET/CT procedures.:

EJNMMI Res. 2017 Dec;7(1):37

Authors: Martí-Climent JM, Prieto E, Morán V, Sancho L, Rodríguez-Fraile M, Arbizu J, García-Velloso MJ, Richter JA

Abstract

BACKGROUND: The aim of this study was to retrospectively evaluate the patient effective dose (ED) for different PET/CT procedures performed with a variety of PET radiopharmaceutical compounds. PET/CT studies of 210 patients were reviewed including Torso (n = 123), Whole body (WB) (n = 36), Head and Neck Tumor (HNT) (n = 10), and Brain (n = 41) protocols with (18)FDG (n = 170), (11)C-CHOL (n = 10), (18)FDOPA (n = 10), (11)C-MET (n = 10), and (18)F-florbetapir (n = 10). ED was calculated using conversion factors applied to the radiotracer activity and to the CT dose-length product.

RESULTS: Total ED (mean ± SD) for Torso-(11)C-CHOL, Torso-(18)FDG, WB-(18)FDG, and HNT-(18)FDG protocols were 13.5 ± 2.2, 16.5 ± 4.5, 20.0 ± 5.6, and 15.4 ± 2.8 mSv, respectively, where CT represented 77, 62, 69, and 63% of the protocol ED, respectively. For (18)FDG, (18)FDOPA, (11)C-MET, and (18)F-florbetapir brain PET/CT studies, ED values (mean ± SD) were 6.4 ± 0.6, 4.6 ± 0.4, 5.2 ± 0.5, and 9.1 ± 0.4 mSv, respectively, and the corresponding CT contributions were 11, 14, 23, and 26%, respectively. In (18)FDG PET/CT, variations in scan length and arm position produced significant differences in CT ED (p < 0.01). For dual-time-point imaging, the CT ED (mean ± SD) for the delayed scan was 3.8 ± 1.5 mSv.

CONCLUSIONS: The mean ED for body and brain PET/CT protocols with different radiopharmaceuticals ranged between 4.6 and 20.0 mSv. The major contributor to total ED for body protocols is CT, whereas for brain studies, it is the PET radiopharmaceutical.

PMID: 28439843 [PubMed - in process]



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