Role of 18 Fluorocholine Positron Emission Tomography/Computed Tomography in the Localization of Culprit Lesions in Patients of Persistent/Recurrent Primary Hyperparathyroidism: A Prospective Study in COVID Times.

INTRODUCTION: Recurrent/persistent primary hyperparathyroidism in patients who have undergone previous parathyroidectomy is a challenging condition. Imaging is important for localizing the parathyroid adenoma for re-exploration and 18 F-Fluorocholine (18 F-FCH) positron emission tomography/computed tomography (PET/CT) seems ideal for this purpose.

AIM: This prospective study attempted to ascertain the utility of 18 F-FCH PET/CT as an investigation in preoperative localization of abnormal parathyroid tissue in recurrent/persistent primary hyperparathyroidism while comparing it with 99m Tc-Sestamibi dual-phase scintigraphy with early single-photon emission CT (SPECT)/CT and neck ultrasonography (USG).

METHODS: Twenty patients with biochemical features of recurrent/persistent primary hyperparathyroidism were enrolled into this study. They underwent neck USG, 99m Tc-Sestamibi dual-phase scintigraphy with early SPECT/CT and 18 F-FCH PET/CT for localization of parathyroid lesions. Six patients underwent surgical resection of the detected lesions, 3 were awaiting surgery, and 11 were managed conservatively. One patient died due to COVID.

RESULTS: The calculated positive predictive values on a per-lesion basis of neck USG, 99m Tc-sestamibi scintigraphy and early SPECT/CT and 18 F-FCH PET/CT in the cohort of the 5 operated patients were 75% (3/4), 71.4% (5/7), and 71.4% (5/7), respectively. On a per-patient basis, the lesion detection rate was 100% for 99m Tc-sestamibi scan and FCH PET (5/5) and 80% on neck USG (4/5).

CONCLUSION: 18 F-FCH PET/CT is a highly accurate imaging modality for the detection of parathyroid lesions in patients with recurrent/persistent primary hyperparathyroidism.