Semi-quantitative method for the assessment of focal lesions in parathyroid scintigraphy with relation to histopathology: a prospective study

Abstract

BBACKGROUND:The aim of this paper was to analyse our own semi-quantitative method of assessing focal lesions localised in pre-operative diagnostic scintigraphy of primary hyperparathyroidism (PHPT) using 99m Tc-MIBI with washout and comparing these data with the result of the histopathological examination (HP). MATERIAL AND METHODS:A total of 40 (37 female, 3 male, average age 58.7 years) patients with a suspicion of PHPT were enrolled for prospective analysis. Dual phase planar and SPECT/CT examination with 99m Tc-MIBI were performed. The tumour to background ratios in the 10 th and 120 th minute were calculated (TBR10 and TBR120) on the basis of the planar acquisition.PTH, ionised calcium and phosphate levels were measured.Parathyroid surgery alone or combined with subtotal/total thyreoidectomy was conducted in 23 (57.5%) and 17 (42.5%) patients, respectively. A HP was performed in all patients. RESULTS:Average concentration of PTH in the whole group was 243.95 pg/ml. There was a statistically significant correlation between medians of PTH concentration and parathyroid histopathological results (p = 0.01). A total of 45 lesions of increased uptake were found in 32 (80.0%) and 34 (85%) patients in the early phase and the delayed phase, respectively.The post-operative material contained 20 (44.5%) parathyroid adenomas, 11 (24.5%) cases of hyperplasia, 2 (4.4%) cancers, 4 (8.9%) cases of normal parathyroid tissue, 2 (4.4%) lymph nodes and 6 (13.3%) cases of thyroid gland tissue.The medians of TBR10 and TBR120 for lesions examined in the HP were respectively: 3.64 and 2.59 for adenoma; 3.08 and 2.18 for hyperplasia; 7.7 and 5.5 for parathyroid cancer, 4.89 and 3.16 for normal tissue and 5.26 and 2.95 for lymph nodes or thyroid gland tissue.A high correlation coefficient of TBR10 to TBR120 in the parathyroid adenoma and parathyroid hyperplasia groups was observed with r = 0.867 and r = 0.964, respectively. The ρr correlation coefficient of TBR10 to TBR120 for normal parathyroid was 0.4.There was a statistically significant association between the HP and TBR10 medians (p = 0.047), but not between histopathology and TBR120 medians (p = 0.840

The role of 99mTc-MIBI SPECT/CT in patients with secondary hyperparathyroidism: comparison with 99mTc-MIBI planar scintigraphy and ultrasonography

“…We included the LBR, maximum diameter, volume, CT mean and location of the 157 lesions. Previous studies have suggested that parathyroid lesions with lower LBRs or smaller parathyroid lesions tend to be missed [11,13,17,18]. In addition, the adjacent tissues varied in different locations, and we suspected that the adjacent tissues with similar parathyroid density may lead to missed diagnoses.…”

“…Regions of interest (ROIs) in the lesion and background (adjacent muscles) were manually delineated on SPECT/ CT axial images slice by slice. The maximum of radioactivity counts was selected to represent MIBI uptakes of lesion and background, and the LBR was calculated [17,18]. The length, height, width and CT mean of the lesions were measured on CT images.…”

“…This means that some lesions may be missed during the imaging diagnosis. Several previous studies have mentioned some possible causes of missed diagnosis [11,13,17,18], such as low uptake and small size of lesions.…”

Ectopic and Eutopic Located Parathyroid Lesions: Do They Behave Differently? How Can We Monitorize Them? What Can We Look for?

“…Therefore, the rate of the PT/T obtained from interested areas including adenoma and neighboring normal tissue will reveal the amount of absorption of radiopharmaceutics by the lesion. Common consensus in the nuclear medicine literature is that the rate of the PT/T increases with time after the MIBI injection (15). In compliance with this consensus, we determined that there was a significant difference between the values of early PT/T and late PT/T in both the eutopic and ectopic groups, whereas the enhancement in the PT/T values was more remarkable in the late period.…”

Semiquantitative Assessment of 99mTc-MIBI Uptake in Parathyroids of Secondary Hyperparathyroidism Patients from Chronic Renal Failure

“…In the MIBI scintigraph with slight MIBI uptake, ROIs covered most of the upper or lower one thirds of thyroid background image [3], because the majority of parathyroid glands distributed among the four usual anatomical positions [4,13] and located immediately posterior to the thyroid gland [14,15]. In the MIBI scintigraph loaded into ImageJ 1.46r (National Institute of Health, USA), the average value of the gray value mean of bilateral neck ROIs was utilized as background, and the calculation of target (the gray value mean of speci ed parathyroid ROI) to background ratio (TBR) for dual phases was used as the indicator for semiquantitatively [16] manifesting the MIBI uptake strength. So the bigger the TBR, the less MIBI uptake level; if some indices were negatively related to the gray value of MIBI uptake, these indices were positively related to MIBI uptake intensiveness; and vice versa.…”