Semi-quantitative Analysis of99mTc-MIBI SPECT/CT in Distinguishing Between Renal Secondary Hyperparathyroidism and Tertiary Hyperparathyroidism

1295 Purpose: Renal hyperparathyroidism (rHPT) includes secondary hyperparathyroidism (sHPT) and tertiary hyperparathyroidism (tHPT). Medication is usually an effectively treatment for sHPT, while resistant to medical treatment occurs in cases with tHPT and parathyroidectomy may be the best choice.In this study, we aim to investigate the value of semi-quantitative analysis of 99mTc-MIBI SPECT/CT in distinguishing between sHPT and tHPT, trying to provide helpful information in selecting most appropriate therapy for the individual rHPT patients. Methods: The study group comprised 96 patients (51 males, 45 females, age range: 25-79 years). According to the serum calcium levels and the result of calcium load experiment or the response to medication, the 96 patients were divided into a sHPT group (n=39) and a tHPT group (n=57). L/B (L, lesion; B, background) ratio was calculated as the ratio of lesion radioactivity count to background radioactivity count. The volume is calculated by multiplying the long diameter, short diameter and height of each parathyroid gland. In addition, the number of MIBI-avid glands was recorded. The patients with serum calcium range of 2.1-2.5mmol/L from the two groups were divided into sHPT subgroup (n=32) and tHPT (n=25) subgroup. The SPECT/CT parameter and laboratory test were compared between two subgroups and ROC analysis were also performed for them. Results: Compared with the sHPT group, L/B ratio [7.26 (6.40-12.61) vs 3.93 (1.92-7.42)], volume of parathyroid glands[3060mm3 (1310-4786 mm3) vs 780mm3 (0-1368 mm3)], number of MIBI-avid glands [4 (3-4) vs 2(0-3)], PTH (224±105.52 pmol/L vs 115.81±58.87 pmol/L) and Ca [2.15 mmol/L (2.36-2.73 mmol/L) vs 2.27 mmol/L (2.15-2.39 mmol/L)] of the tHPT group were higher significantly (P