[18F]Fluorocholine-PET-CT reduces operation time and improves cure rate over ultrasonography and [99mTc]Tc-MIBI-scintigraphy for primary hyperparathyroidism, a randomized trial

Background Ultrasonography and [99mTc]Tc-MIBI-scintigraphy have long been the standard imaging modalities in parathyroid surgery, but recent studies indicate that [18F]Fluorocholine-PET-CT is more accurate. This randomized study compared [18F]Fluorocholine-PET-CT to ultrasonography and [99mTc]Tc-MIBI-scintigraphy for first-line localization in patients with sporadic primary hyperparathyroidism. Methods In this non-blinded, single-centre trial, adult patients with pHPT were randomized to either [18F]Fluorocholine-PET-CT or ultrasonography and [99mTc] Tc-MIBI-scintigraphy. Patients with previous thyroid or parathyroid surgery, planned concurrent thyroid surgery, lithium therapy, hereditary disease or severe renal insufficiency were not eligible. If the allocated localization investigations failed, 4D-CT was performed. The primary outcome was operation time in minutes. Secondary outcomes were biochemical cure; recurrent laryngeal nerve paresis; hypocalcaemia; persistent disease; sensitivity, specificity, PPV and NPV per-lesion and per-patient; total irradiation; total imaging and procedure cost. Results In all, 126 patients were included, of which 66 were randomized to [18F]Fluorocholine-PET-CT and 60 to conventional imaging (controls). 11 patients withdrew and 8 were excluded, after which, 59 patients remained in the PET group and 48 among the controls. 4D-CT was performed in 2 patients in the PET group, and in 19 among the controls. Median operation time was shorter and cure rate higher in the PET group compared to the conventional group, 26 (IQR 19–36) vs. 34.5 (20–48) minutes, p=0.042, and 100% vs. 91%, p=0.036. There were no adverse events. Conclusions [18F]Fluorocholine-PET-CT provides better preoperative localization in primary hyperparathyroidism, reducing operation time and improving cure rate compared to standard imaging with ultrasonography and [99mTc]Tc-MIBI-scintigraphy.