RT Journal Article SR Electronic T1 Semi-quantitative Analysis of99mTc-MIBI SPECT/CT in Distinguishing Between Renal Secondary Hyperparathyroidism and Tertiary Hyperparathyroidism JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1295 OP 1295 VO 61 IS supplement 1 A1 Junjun Cheng YR 2020 UL http://jnm.snmjournals.org/content/61/supplement_1/1295.abstract AB 1295Purpose: 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<0.001). Multivariate analysis revealed that the volume of parathyroid glands and the number of MIBI-avid glands were the impact factor of L/B ratio; and the L/B ratio, PTH and Ca were the impact factor of volume of parathyroid glands. The AUC values for volume of parathyroid glands, L/B ratio, the number of MIBI-avid glands, serum Ca and PTH were 0.850, 0.847, 0.818, 0.825 and 0.798, respectively. The most efficient value for differential diagnosis is volume of parathyroid glands. The accuracy, sensitivity and negative predictive value of L/B ratio were the highest (79.2%,86.0%,77.1%), while serum Ca had the highest specificity and positive predictive value (94.9%, 92.1%). There were still differences in the L/B ratio, volume of parathyroid glands, the number of MIBI-avid glands and PTH between the sHPT subgroup and the tHPT subgroup (P<0.001). The sensitivity and negative predictive value of the L/B value were still the highest (96.0%,95.2%), followed by volume of parathyroid glands (92%, 90.5%), whereas PTH had the highest accuracy, specificity and positive predictive value (86.0%,93.7%,90.5%).Conclusion: Semi-quantitative analysis of 99mTc-MIBI SPECT/CT showed that L/B ratio, volume of parathyroid glands, the number of MIBI-avid glands were higher in tHPT patients than in sHPT patients. Among them, the volume of parathyroid glands is related to laboratory indexes such as PTH and calcium. When the serum calcium of rHPT patients is in the normal range, L/B ratio, volume of parathyroid glands, the number of MIBI-avid glands can be helpful for identifying whether a patient has progressed to tHPT and can be used as an effective reference index in addition to serum PTH, calcium, phosphate.