18F-fluorocholine PET/CT Imaging in Hyperparathyroidism

Diagnostic Value of 18F-fluorocholine PET/CT Imaging in Localization of Hyperfunctioning Parathyroid Tissue in Hyperparathyroidism

To assess the efficiency of 18F-fluorocholine PET/CT in localization of hyperfunctioning parathyroid tissue in hyperparathyroidism, thereby enabling minimally invasive surgical approaches with fewer complications and comparable success rates

Primary hyperparathyroidism is a common endocrine disorder for which the diagnosis is biochemical and therapy surgical in the vast majority of cases; in secondary and tertiary hyperparathyroidism, surgical treatment is usually chosen when conservative measures fail to control the condition. The previously used surgical approach of bilateral neck exploration is being replaced by minimally invasive procedures, whose advantage is shorter duration of operation and general anesthesia, lower morbidity and fewer complications with comparable success rates. A prerequisite for minimally invasive surgery is successful localization of the offending parathyroid tissue. Most commonly used imaging modality for this purpose is parathyroid scintigraphy with 99mTc-sestaMIBI, usually supplemented by ultrasound of the neck. Overall, parathyroid scintigraphy is a sensitive method for localization of hyperfunctioning parathyroid tissue; however, its diagnostic performance is significantly lower in patients with multiple parathyroid lesions. In comparison to conventional nuclear medicine imaging approaches for localization of the offending parathyroid tissue, positron emission tomography with computed tomography (PET/CT) offers superior image resolution with an additional advantage of attenuation correction and co-registration of functional and anatomical information. 18F-fluorocholine is a PET tracer which is commonly used for prostate cancer imaging. In contrast to 18F-fluorodeoxyglucose (18F-FDG), it is also taken up by well-differentiated neoplasms in which 18F-FDG uptake is unreliable. The investigators hypothesize that 18F-fluorocholine might be efficiently taken up by parathyroid adenomata and/or hyperplasia. The aim of this study is to investigate the efficiency of localization of hyperfunctioning parathyroid tissue with 18F-fluorocholine PET/CT in patients with primary hyperparathyroidism and to compare its efficiency to conventional scintigraphic imaging methods for this purpose.

Choline PET/CT imaging added to conventional imaging assessment in hyperparathyroidism (parathyroid scintigraphy, ultrasound, CT or MRI if indicated)

Normalization of biochemical abnormalities related to hyperfunctioning parathyroid tissue (iPTH levels [pg/mL])

Normalization of biochemical abnormalities related to hyperfunctioning parathyroid tissue (Ca2+ levels [mmol/L])

Inclusion Criteria: Age over 18 years Biochemically proven hyperparathyroidism (elevated iPTH, elevated on normal Ca2+) or elevated Ca2+ and inadequately supressed iPTH Exclusion Criteria: Age under 18 years Pregnancy Clinical history of oncological, inflammatory/infectious disease of the head and neck

Lezaic L, Rep S, Sever MJ, Kocjan T, Hocevar M, Fettich J. (1)(8)F-Fluorocholine PET/CT for localization of hyperfunctioning parathyroid tissue in primary hyperparathyroidism: a pilot study. Eur J Nucl Med Mol Imaging. 2014 Nov;41(11):2083-9. doi: 10.1007/s00259-014-2837-0. Epub 2014 Jul 26.

Rep S, Lezaic L, Kocjan T, Pfeifer M, Sever MJ, Simoncic U, Tomse P, Hocevar M. Optimal scan time for evaluation of parathyroid adenoma with [(18)F]-fluorocholine PET/CT. Radiol Oncol. 2015 Nov 27;49(4):327-33. doi: 10.1515/raon-2015-0016. eCollection 2015 Dec.

Hocevar M, Lezaic L, Rep S, Zaletel K, Kocjan T, Sever MJ, Zgajnar J, Peric B. Focused parathyroidectomy without intraoperative parathormone testing is safe after pre-operative localization with 18F-Fluorocholine PET/CT. Eur J Surg Oncol. 2017 Jan;43(1):133-137. doi: 10.1016/j.ejso.2016.09.016. Epub 2016 Oct 21.