Contribution of early SPECT/CT to 99mTc-MIBI double phase scintigraphy in primary hyperparathyroidism: Diagnostic value and correlation between uptake and biological parameters

Quantitative application of dual-phase 99mTc-sestamibi SPECT/CT imaging of parathyroid lesions: identification of optimal timing in secondary hyperparathyroidism

PURPOSE

In this retrospective study, we compared the maximum standardized uptake values (SUVmax) of parathyroid lesions and the target-to-background ratio (TBR) of parathyroid lesions to thyroid tissue in early-phase single-photon emission computed tomography/computed tomography (SPECT/CT) versus delayed-phase SPECT/CT in patients with secondary hyperparathyroidism (SHPT) in order to determine the optimal timing of 99mTc- methoxyisobutylisonitrile (99mTc-MIBI) SPECT/CT imaging.

METHODS

Seventeen patients with a history of chronic kidney failure stage 5 on hemodialysis, underwent pre-operative parathyroid scintigraphy for detection and localization of parathyroid lesions. Retrospective analysis was conducted for lesions with focal accumulation of 99mTc-MIBI. All patients underwent dual-phase 99mTc-MIBI parathyroid scintigraphy and dual-phase SPECT/CT. SUVmax of parathyroid lesions and thyroid tissues was measured.

RESULTS

Mean SUVmax of parathyroid lesions was 4.86 on early-phase and 2.58 on delayed-phase SPECT/CT, respectively. Mean TBR was 1.14 on early phase and 1.48 on delayed-phase SPECT/CT, respectively. Statistically significant differences in SUVmax and TBR between dual-phase SPECT/CT were observed (P < 0.001).

CONCLUSIONS

Delayed-phase SPECT/CT in SHPT is required because of the better image contrast.

Primary hyperparathyroidism presenting as a brown tumor in the mandible: a case report

BACKGROUND

Primary hyperparathyroidism is characterized by hypercalcemia and elevated or inappropriately normal serum levels of parathyroid hormone. Brown tumor of bone is a rare non-neoplastic lesion resulted from abnormal bone metabolism in hyperparathyroidism. However, nowadays, skeletal disease caused by primary hyperparathyroidism is uncommon. We report a case of brown tumor in the mandible as the initial exhibition of primary hyperparathyroidism associated with an atypical parathyroid adenoma.

CASE PRESENTATION

The patient was a 49-year-old female, she had a pain mass on the right mandible a year ago and was treated with root canal therapy and marginal resection. After seven months, the mass recurred and enlarged. Enhanced CT scan, laboratory examination, Ultrasonography, ^99mTc-MIBI SPECT-CT scintiscan and pathological examination were used to confirm the diagnosis of brown tumor. The patient's symptom improved after parathyroidectomy.

CONCLUSIONS

^99mTc-MIBI SPECT/CT scintigraphy is a highly sensitive examination of the localization diagnosis of hyperparathyroidism. Brown tumors should be considered in the differential diagnosis of osteolytic lesions to avoid unnecessary and harmful interventions.

Advantages of the 99mTc-sestamibi Single-Photon Emission Computed Tomography/Computed Tomography in Occult Parathyroid Adenoma and Concomitant Thyroid Papillary Carcinoma

Hyperparathyroidism and concurrent thyroid nodular disease are prominent. In contrast, concomitant papillary thyroid cancer and hyperparathyroidism are uncommon (1%–2%). Parathyroid adenomas in unusual locations are difficult to detect by conventional diagnostic imaging. ^99mTc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) has increased the localizing success rate of these lesions since it provides specific functional and anatomical information, improving exploratory parathyroid surgery planning and decreasing operative time, unnecessary dissections, complications, and morbidity. We confirmed its usefulness in a patient with an occult parathyroid adenoma that was clearly identified by ^99mTc-sestamibi SPECT/CT 2 weeks after a thyroidectomy for papillary carcinoma. The SPECT/CT results allowed us to successfully perform efficient reexploration of the thyroid bed, in a retroesophageal parathyroid adenoma by minimally invasive surgery.

Single Photon Emission Computed Tomography/Computed Tomography Detects a Second Ignored Intrathyroidal Parathyroid Adenoma

The primary hyperparathyroidism (PHPT) is a result of high levels of parathyroid hormone and serum calcium, the most frequent cause is a solitary parathyroid adenoma. Double parathyroid adenoma is <5% of the PHPT. Intrathyroidal parathyroid adenoma (IPA) occurs< 3.2%. We present a case of 58-year-old female with persistent primary hyperparathyroidism due to a second undetected IPA, suspected by ultrasound and confirmed by ^99mTc sestamibi single-photon emission computed tomography/computed tomography.

Low-radiation of technetium-99m-sestamibi and single-photon emission computed tomography/computed tomography to diagnose parathyroid lesions

We compared preoperative regular activity and low-activity radiology-based predictions with real surgical and pathological findings for parathyroidectomy surgery. The study retrospectively analyzed 54 consecutive cases (2009–2016) for benign tumor removal. Technetium-99m (Tc-99m)-sestamibi was used as a diagnostic radiopharmaceutical for diagnostic dual-phase parathyroid scintigraphy and single-photon emission computed tomography/computed tomography. We assessed images obtained with the radiation activity of 925 megabecquerel (MBq) and images obtained with the activity of 185 MBq. The study compared preoperative evaluation of tumor presence, multiplicity, location, and the type of pathology with actual data that were revealed during the operation and pathological investigation. The agreement between preoperative radiological prediction and actual location, number, and type of the parathyroid lesions was achieved in 98.4% (n = 61/62 lesions). The agreement between 925 MBq-based and 185-MBq based investigations was 100%. The agreement between radiological and pathological findings was 100% for both investigations. Our data suggest that the radioactivity of 185 MBq applied in the evaluation of the parathyroid glands provides results similar to the currently used 925–1110 MBq if used for diagnostic dual-phase parathyroid scintigraphy with Tc-99m-sestamibi. Such radioactivity may reduce the exposure to radiation of the patients and the staff without compromising results of the investigation.

Comparison between technetium-99m methoxyisobutylisonitrile scintigraphy and ultrasound in the diagnosis of parathyroid adenoma and parathyroid hyperplasia

Objective

The aim of this study was to evaluate the value of technetium-99m methoxyisobutylisonitrile (^99mTc-MIBI) imaging and ultrasound in preoperative localization of parathyroid adenoma (PA) and parathyroid hyperplasia (PH).

Participants and methods

A retrospective study of ^99mTc-MIBI double-phase scintigraphy (DPS) was performed in 187 hyperparathyroidism cases with pathologically diagnosed PA or PH. Of these patients, 167 cases underwent ultrasound, and 146 cases underwent ^99mTc-MIBI single-photon emission computed tomography/computed tomography (SPECT/CT). The sensitivity and diagnostic accuracy of ultrasound, ^99mTc-MIBI DPS, and SPECT/CT were compared between PA and PH. Differences in ^99mTc-MIBI DPS, serum parathyroid hormone (PTH), serum calcium and phosphorus, as well as the weight and longest diameter of lesion between PA and PH were also compared.

Results

As per patient-based analysis, the sensitivity of ultrasound, ^99mTc-MIBI DPS, and SPECT/CT was 90.70% (39/43), 95.56% (43/45), and 100.00% (30/30), respectively, for PA, and 93.55% (116/124), 90.85% (129/142), and 93.10% (108/116), respectively, for PH. There were no significant differences in sensitivity of these three imaging methods between PA and PH. However, per lesion-based analysis, the accuracy of ultrasound, ^99mTc-MIBI DPS, and SPECT/CT in detecting PA was 78.43% (40/51), 86.79% (46/53) and 96.88% (31/32), respectively, and the accuracy of ^99mTc-MIBI DPS was higher than that of ultrasound (χ²=6.507, P=0.011), and for PH, it was 49.69% (160/322), 40.71% (171/420), and 43.80% (152/347), respectively. The accuracy of ultrasound was higher than that of ^99mTc-MIBI DPS (χ²=5.940, P=0.015). The accuracy of a combination of all three examinations of ultrasound+^99mTc-MIBI DPS, ultrasound+^99mTc-MIBI SPECT/CT, ^99mTc-MIBI DPS+SPECT/CT, and ultrasound+^99mTc-MIBI DPS+^99mTc-MIBI SPECT/CT was 51.51% (154/299), 53.85% (161/299), 50.17% (150/299), and 54.18% (162/299), respectively, which was higher than that of ultrasound (χ²=5.273, P=0.022; χ²=8.226, P=0.004; χ²=3.880, P=0.049; χ²=8.702, P=0.003, respectively). Serum levels of PTH and phosphorus were lower in patients with PA than in patients with PH (P<0.001), and serum calcium level, the weight, and the longest diameter of lesion and early uptake rate of ^99mTc-MIBI DPS were higher in patients with PA than in patients with PH (P<0.01). Serum PTH level is often less than 1000 pg/ml in PA, but usually more than 1000 pg/ml in PH.

Conclusion

Ultrasound, ^99mTc-MIBI DPS, and SPECT/CT all have a higher value in the diagnosis of PA than PH. ^99mTc-MIBI SPECT/CT should be optimal for detecting PA, and early SPECT/CT scan might be better than delayed scan. Compared with ^99mTc-MIBI DPS and SPECT/CT, ultrasound has a slight advantage in localization of PH lesions. The combination of ultrasound and ^99mTc-MIBI DPS or SPECT/CT imaging could improve the accuracy in localization of PH lesions and should be considered as the first-line method for detecting PH.

Localization of parathyroid adenomas using 11C-methionine pet after prior inconclusive imaging

PURPOSE

Minimally invasive parathyroidectomy (MIP) is the recommended treatment in primary hyperparathyroidism (pHPT) for which accurate preoperative localization is essential. The current imaging standard consists of cervical ultrasonography (cUS) and MIBI-SPECT/CT. 11C-MET PET/CT has a higher resolution than MIBI-SPECT/CT. The aim of this study was to determine the diagnostic performance of 11C-MET PET/CT after initial inconclusive or negative localization.

METHODS

We performed a retrospective single center cohort study of patients with pHPT undergoing parathyroid surgery after prior negative imaging and later localization by means of 11C-MET PET/CT between 2006 and 2014. Preoperative localization by 11C-MET PET/CT was compared with later surgical localization, intraoperative quick PTH (IOPTH), duration of surgery, histopathology, and follow-up data. Also, differences in duration of surgery between the groups with and without correct preoperative localization were analyzed.

RESULTS

In 18/28 included patients a positive 11C-MET-PET/CT result corresponded to the surgical localized adenoma (64%). In 3/28 patients imaging was false positive and no adenoma was found. In 7/28 patients imaging was false negative at the side of the surgically identified adenoma. Sensitivity of 11C-MET PET/CT was 72% (18/25). Duration of surgery of correctly localized patients was significantly shorter compared to falsely negative localized patients (p = 0.045).

CONCLUSION

In an intention to treat 11C-MET-PET/CT correctly localized the parathyroid adenoma in 18/28 (64%) patients, after previous negative imaging. A preoperatively correct localized adenoma leads to a more focused surgical approach (MIP) potentially reducing duration of surgery and potentially healthcare costs.

THE VOLUME OF SOLITARY PARATHYROID ADENOMA IS RELATED TO PREOPERATIVE PTH AND 25OH-D3, BUT NOT TO CALCIUM LEVELS

Purpose

To correlate the volume of parathyroid adenomas with the hormonal and metabolic profile at patients diagnosed with primary hyperparathyroidism (pHPTH).

Patients and Methods

Cross-sectional multicentric study, enrolling 52 patients with pHPTH from two medical institutions. Serum calcium and PTH were evaluated in all patients before surgery, whereas 25OHD3 was measured only in the 33 patients recruited form one medical unit. The volume of parathyroid adenoma was measured by using the formula of a rotating ellipsoid.

Results

We observed a significant correlation of the volume of parathyroid adenomas with PTH at patients from the two units and in the whole group (p < 0.0001), but not with serum calcium (p = 0.494). Twenty-five out of the 33 patients at whom 25OHD3 was measured had levels in the range of deficiency. 25OHD3 was not correlated with PTH or calcium levels, but was negatively correlated to the adenoma volume and positively to the PTH/volume ratio (p = 0.041 and p = 0.048, respectively).

Conclusions

The volume of parathyroid adenoma seems to be related to preoperative PTH and 25OHD3, but not to calcium level. Vitamin D deficiency is frequently found at patients with pHPTH and may contribute to particular disease profiles, including larger parathyroid adenomas.