1. Optimization of parathyroid C-11-choline PET protocol for localization of parathyroid adenomas in patients with primary hyperparathyroidism
- Author
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Schelto Kruijff, Rudi Dierckx, Mostafa El Moumni, Gert Luurtsema, David Vállez García, Walter Noordzij, Milou E Noltes, Malgorzata Trofimiuk-Muldner, Marta Opalińska, Alicja Hubalewska-Dydejczyk, Ronald Boellaard, Adrienne H. Brouwers, Eef D. Telenga, Guided Treatment in Optimal Selected Cancer Patients (GUTS), Molecular Neuroscience and Ageing Research (MOLAR), Basic and Translational Research and Imaging Methodology Development in Groningen (BRIDGE), and ACS - Heart failure & arrhythmias
- Subjects
lcsh:Medical physics. Medical radiology. Nuclear medicine ,Adenoma ,lcsh:R895-920 ,Primary hyperparathyroidism ,11C-Choline PET ,GUIDELINES ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Radiology, Nuclear Medicine and imaging ,In patient ,Cardiac imaging ,ULTRASOUND ,Parathyroid adenoma ,medicine.diagnostic_test ,business.industry ,Ultrasound ,Scan protocol ,medicine.disease ,FDG PET/CT ,Inter-observer agreement ,Positron emission tomography ,030220 oncology & carcinogenesis ,C-11-Choline PET ,business ,Nuclear medicine ,Kappa - Abstract
PURPOSE: To evaluate the optimal tracer uptake time, the minimal amount of radioactivity and the inter-observer agreement for 11C-choline positron emission tomography/computed tomography (PET/CT) in patients with primary hyperparathyroidism (pHPT).METHODS: Twenty-one patients with biochemically proven pHPT were retrospectively studied after injection of 6.3 ± 1.2 MBq/kg 11C-choline. PET data of the first nine patients, scanned for up to 60 min, were reconstructed in 10-min frames from 10- to 60-min postinjection (p.i.), mimicking varying 11C-choline uptake times. Parathyroid adenoma to background contrast ratios were calculated and compared, using standardized uptake values (SUVs). Data was reconstructed with varying scan durations (1, 2.5, 5, and 10 min) at 20-30-min p.i. (established optimal uptake time), mimicking less administered radioactivity. To establish the minimal required radioactivity, the SUVs in the shorter scan durations (1, 2.5, and 5 min) were compared to the 10-min scan duration to determine whether increased variability and/or statistical differences were observed. Four observers analyzed the 11C-choline PET/CT in four randomized rounds for all patients.RESULTS: SUVpeak of the adenoma decreased from 30 to 40 p.i. onwards. All adenoma/background contrast ratios did not differ from 20- to 30-min p.i. onwards. The SUVs of adenoma in the scan duration of 1, 2.5, and 5 min all differed significantly from the same SUV in the 10-min scan duration (all p = 0.012). However, the difference in absolute SUV adenoma values was well below 10% and therefore not considered clinically significant. The inter-observer analysis showed that the Fleiss' kappa of the 1-min scan were classified as "moderate," while these values were classified as "good" in the 2.5-, 5-, and 10-min scan duration. Observers scored lower certainty scores in the 1- and 2.5-min scans compared to the 5- and 10-min scan durations.CONCLUSION: The optimal time to start PET/CT scanning in patients with pHPT is 20 min after mean injection of 6.3 MBq/kg 11C-choline, with a recommended scan duration of at least 5 min. Alternatively, the radioactivity dose can be lowered by 50% while keeping a 10-min scan duration without losing the accuracy of 11C-choline PET/CT interpretation.
- Published
- 2019