PT - JOURNAL ARTICLE AU - Yu Xue TI - <sup>18</sup>F-FCH PET/CT for patients with uremic hyperparathyroidism DP - 2019 May 01 TA - Journal of Nuclear Medicine PG - 513--513 VI - 60 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/60/supplement_1/513.short 4100 - http://jnm.snmjournals.org/content/60/supplement_1/513.full SO - J Nucl Med2019 May 01; 60 AB - 513Introduction: Uremic hyperparathyroidism (uHPT) is a common complication at the end stage of chronic kidney disease (CKD), including secondary hyperparathyroidism (SHPT) and tertiary hyperparathyroidism (THPT). 2017 Kidney Disease Improving Global Outcomes (KDIGO) guideline has suggested that persistent parathyroid hormone (PTH) elevations over nine times the upper limit of normal should be considered an indication for surgical management. The method of preoperative localization for uPHT remains a source of ongoing controversy. Ultrasonography (US) and 99mTc-MIBI SPECT/CT were routinely used to locate abnormal glands. Many reports have demonstrated that 18F-fluorocholine (FCH) has high diagnostic value for primary hyperparathyroidism (PHPT); however, there is no analysis on the preoperative diagnostic value of 18F-FCH PET for uHPT. In our study, the diagnostic efficacy of 18F-FCH PET in uHPT was compared with 99mTc-MIBI SPECT/CT. Methods: 16 uHPT patients caused by CKD stage-5 were prospectively enrolled, consisting of nine man and seven women with a median age of 50 years (range,38-66 years). Median preoperative levels of PTH level were 2152.9 Pg/ml (range, 224.2-3347.1 Pg/ml, with a reference range of 12.0-88.0 Pg/ml). All patients underwent ultrasound, 99mTc-MIBI SPECT/CT and 18F-FCH at the same period, and received surgical treatment shortly. After administration of 111-185 MBq (3-5mCi) of FCH, PET imaging in the same area was performed, followed by CT imaging at 10 minutes and 60 minutes respectively. Visual and quantitative methods were used for the image analysis, intraoperative localization and postoperative histological results were the reference standard, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)of the three methods were calculated and compared, and the localization diagnostic efficacy of 18F-FCH PET/CT in uHPT was evaluated. This study was approved by the institutional review board. Results: A total of 60 parathyroid hyperplasia were resected in 16 uHPT patients, 47 lesions were detected by FCH PET/CT with no false positive results. The sensitivity, specificity, PPV and NPV were 78.33%, 100%, 100%, 45.83%, respectively. In comparison, the above values of MIBI and US were 65%, 90.91%, 97.5%, 32.26% (Figure 1)and 67.24%, 81.82%, 95.12% , 32.14%, respectively. US mistook parathyroid hyperplasia located in the thyroid for the thyroid nodules (TI-RADS classification :4A) in 3 patients, while FCH PET could correctly judge the nature (Figure 2). Conclusion: The results of this study showed that 18F-FCH PET/CT was superior to US and MIBI in the preoperative diagnosis of uHPT, especially for lesions diagnosed as the thyroid nodule by US. Nevertheless, larger trials are needed in future to confirm the superiority of FCH PET/CT. Fig 1: Images in a 62-year-old woman with three parathyroid hyperplasia, the later 90 minute planar 99mTc-MIBI SPECT/CT image(a),the axial CT image (not shown) and fusion image(c) cannot present all three lesions clearly because of Hashimoto's thyroiditis. Although the planar 18F-FCH PET image (b) is a little messy because of renal osteopathy, the lesion is visible on the image(arrows). 18F-FCH PET/CT fusion image (d) show the homogeneous tracer uptake behind the left lobe of the thyroid gland(arrow).Fig 2: Images in a 61-year-old woman with multiple parathyroid hyperplasia, one with slightly ectopic (in the middle portion of the right thyroid gland) localization. US mistook it for a thyroid nodule (dotted circle) (b). The lesion is well delineated on the planar 18F-fluorocholine PET image (a) , the axial CT image (c) and PET/CT fusion image (d)(arrow).