Preoperative parathyroid gland localization with technetium-99m sestamibi in secondary hyperparathyroidism

Abstract

Technetium-99m sestamibi scintigraphy has become a valuable tool in locating parathyroid glands in patients with primary hyperparathyroidism. The aim of this study was to evaluate its usefulness in secondary hyperparathyroidism. Twenty patients were injected intravenously with 740 MBq of 99mTc-sestamibi and images were obtained at 15 min and 2 h post injection. All patients underwent parathyroid ultrasonography (US) as well as bilateral surgical neck exploration and 64 parathyroid glands were removed. US revealed at least one enlarged gland in 15/20 patients (75%), while 99mTc-sestamibi scintigraphy showed focal areas of increased uptake in at least one gland in 17/20 patients (85%). When imaging results for all glands were evaluated according to surgical results, sensitivity was 54% for parathyroid scintigraphy and 41% for US, and specificity was 89% for both imaging techniques. There was a discrepancy between the two imaging modalities in 28 glands (35%). The mean surgical weight of US-positive glands (1492+/-1436 mg) was significantly higher than that of US-negative glands (775+/-703 mg) (P<0.05). However, there were no significant differences in weight between sestamibi-positive and sestamibi-negative glands. When only sestamibi-positive glands were considered, a positive correlation between uptake and weight was found (r=0.4, P<0.05). In conclusion, parathyroid US and 99mTc-sestamibi scintigraphy are complementary imaging techniques in the preoperative localization of abnormal parathyroid glands in patients with secondary hyperparathyroidism. The limited sensitivity of the techniques means that patients will still require bilateral neck exploration; therefore routine preoperative parathyroid scanning in renal patients is not justified.

Value of 123I-Subtraction and Single-Photon Emission Computed Tomography in Addition to Planar 99mTc-MIBI Scintigraphy Before Parathyroid Surgery

“…According to previous studies, dual-phase scintigraphy yielded a low sensitivity for hyperplastic glands. 4,6,7,33 However, SPECT did not improve the sensitivity and delayed SPECT even reduced the sensitivity (54% vs. 44%), which may be attributed to the spatial resolution limits of SPECT and the low signal in some glands against background noise. Gallowitsch et al 22 reported lower sensitivity (38%) with dual-phase scintigraphy, but higher sensitivity with SPECT (62%).…”

“…3 In multiglandular disease, which is present in about 12% of patients with pHPT and is also found in some patients with secondary (sHPT) or tertiary hyperparathyroidism (tHPT), the sensitivity for both adenomas and hyperplastic glands tends to be much lower (44%-54%). [4][5][6][7] To improve the diagnostic performance of 99m Tc-MIBI, single photon emission computed tomography (SPECT) is sometimes added to routine planar scans. SPECT improves contrast and provides a 3-dimensional visualization.…”

Dual-phase 99mTc-MIBI scintigraphy to assess calcimimetic effect in patients on haemodialysis with secondary hyperparathyroidism

“…The sensitivity of imaging procedures in secondary hyperparathyroidism patients has been reported to be lower than in primary hyperparathyroidism because of multiglandular hyperplastic disease rather than solitary adenomas [24]. However, there are also series published showing high sensitivities for 99m Tc-MIBI when compared with other imaging procedures, at least to localize one pathological gland [9][10][11][12]25].…”

“…Imaging of the parathyroid glands using 99m Tc-MIBI has been widely used in the identification of solitary parathyroid adenomas, which is the most common finding in patients with primary hyperparathyroidism [7,8]. Some groups indicate that 99m Tc-MIBI imaging can also be used initially to localize abnormal glands in haemodialysis patients with secondary hyperparathyroidism, before ultrasound, magnetic resonance and computed tomography in preoperative parathyroidectomy patients [9][10][11][12][13]. However, the need for imaging in such patients is still debatable because of the low sensitivity in the detection of hyperplastic multiglandular disease.…”

L'imagerie préopératoire des hyperparathyroïdies des insuffisants rénaux a-t-elle un intérêt en pratique clinique ?

“…Notre étude confirme cette corrélation puisque le diamètre maximal moyen des glandes parathyroïdes était significativement plus élevé dans le groupe des glandes positives en scintigraphie ou en échographie. Certains auteurs ont établi une corrélation entre le volume de la glande et sa détection isotopique sans pouvoir montrer une corrélation similaire avec le poids [15,16]. Dans notre expérience, une telle corrélation a pu être mise en évidence, pour l'échographie comme pour la scintigraphie, probablement du fait de la plus grande taille de notre échantillon.…”