68Ga-DOTATATE PET: temporal variation of maximum standardized uptake value in normal tissues and neuroendocrine tumours. Issue 9 (September 2019)

• Record Type: Journal Article
• Authors: Coura-Filho, George Barberio; Hoff, Ana A.F.O.; Duarte, Paulo S.; Buchpiguel, Carlos A.; Josefsson, Anders; Hobbs, Robert F; Sgouros, George; Sapienza, Marcelo T.
• Is Part Of: Nuclear medicine communications. Volume 40:Issue 9(2019:Sep.)
• Publication Date: 2019-09
• Subjects: biokinetics -- gallium-68-DOTA -- neuroendocrine tumours -- PET/computed tomography; Nuclear medicine -- Periodicals; 616.07575
• DOI: 10.1097/MNM.0000000000001048
• Languages: English
• ISSNs: 0143-3636

Abstract

Abstract : Objectives: Higher affinity of 68 Ga compounds to somatostatin receptors (SSTRs) and PET better image resolution increased interest in 68 Ga-labelled somatostatin analogs in the management of neuroendocrine tumours (NETs). This study aimed to evaluate the maximum standardized uptake value (SUVmax) variation in sequential somatostatin analogs-PET in NET patients and identify optimal tumour detection and characterization imaging time. Methods: Patients with histological or biochemical NET diagnosis performed two to three PET/computed tomography (CT) scans after intravenous injection of 68 Ga-DOTATATE: Early PET [EarlyPET: <15 minutes postinjection (p.i.)], diagnostic PET (DiagPET: 45–90 minutes p.i.) and delayed PET (DelayPE: 90–240 minutes p.i.). Up to five tumour sites and normal tissues had SUVmax determined. Time-SUVmax curves were created for the target lesions and normal organs. Ratios between tumour and liver SUVmax (SUVTU/Liver) and tumour/blood pool (SUVTU/BP) were also calculated. Results: Twenty-nine patients were included, 16 female, mean age of 46.5 ± 14.3 years. Average administered activity was 129.5 ± 29.6 MBq. Kidneys SUVmax was higher in EarlyPET compared with DiagPET ( P = 0.04) and DelayPET showed higher SUVmax compared with DiagPET for normal liver, pancreas and kidneys ( P = 0.02). No differences were noted between EarlyPET, DiagPET and DelayPET in tumour SUVmax ( P > 0.05). SUVTU/Liver and SUVTU/BP did not change between EarlyPET and DiagPET, with a slight decrease in DelayPET. Conclusion: Stability in tumour SUVmax values measured at different intervals independently of tumour location, as also in normal tissues as kidneys and liver suggest that a more flexible imaging protocol may be adopted.