Preoperative Localization Of Parathyroid Adenomas Research Articles

Utility of 99mTc-Sestamibi Single-Photon Emission Computed Tomography (SPECT)/CT Single Imaging Strategy in the Preoperative Localization of Parathyroid Adenoma.

Background Primary hyperparathyroidism is an endocrinopathy associated with dysregulated calcium homeostasis. The most common etiology is a parathyroid adenoma most definitely managed via a parathyroidectomy. The two main surgical approaches include a minimally invasive parathyroidectomy (MIP) and open four-gland exploration (4-GE). MIP is the preferred operative strategy since it is associated with less postoperative complications. Accurate preoperative imaging is essential in informing the optimal approach to surgery. MIP is only considered if adenoma is able to be localized precisely. The most commonly used imaging modality includes ultrasound and sestamibi single-photon emission computed tomography (SPECT)/CT, either as a singleor combination strategy. Other options include MRI, PET, and 4D CT. There is no universally accepted preoperative imaging strategy. The literature is discordant and recommendations proposed by existing guidelines are incongruous. Objectives This study aimed to evaluate currently utilized preoperative parathyroid imaging modalities at our institution and correlate them with surgical and histological findings to determine the most efficient imaging strategy to detect adenomas for our patient cohort. This will ultimately guide the best surgical approach for patients receiving parathyroidectomies. Methods This is a retrospective observational study of all patients undergoing first-time surgery for biochemically proven primary hyperparathyroidism at our institution over the past five years. Multiple data points were collected including modality of preoperative disease localization, operation type, final histopathology, biochemical investigations, and cure rate. Patients were categorized into one of three groups based on the method of disease localization. Results A total of 244 patients had parathyroidectomies performed at our institution in the past five years from January 2018 to December 2022. Ninety-six percent (n=235) of all patients received dual imaging preoperatively with SPECT/CT and ultrasound performed on the same day and therefore included in this study. A total of 64.3% (n=151) underwent MIP. Eighty percent (n=188) of all histopathology revealed adenomas and 26.8% (n=63) of patients had adenoma localized on SPECT/CT only (sensitivity: 58.1%, specificity: 71%, and positive predictive value {PPV}: 85.7%). A total of 9.8% (n=23) had adenoma localized on ultrasound only (sensitivity: 15.6%, specificity: 73.3%, and PPV: 65.2%). A total of 45.1% (n=106) were dual localized on both SPECT/CT and ultrasound (sensitivity: 75.6%, specificity: 46.6%, and PPV: 84.9%). The cure rate was 91.5% in the dual-localized group, 86% in the dual-unlocalized group, and 96.5% when localized with SPECT/CT alone. Conclusion A dual-imaging modality with SPECT/CT and ultrasound should remain the first-line imaging strategy. This approach has higher sensitivity rates and poses no inherent patient or surgical-related risks. Patients with disease unlocalized on SPECT/CT alone had a positive predictive value, specificity, and likelihood ratio for adenoma detection comparable to dual-localized patients. Therefore, SPECT/CT alone is sufficient for directing MIP in the presence of a negative ultrasound.

Abstract #1561754: Correlation of Preoperative Localization of Parathyroid Adenoma With Imaging Findings and Surgical Outcome

Abstract #1561754: Correlation of Preoperative Localization of Parathyroid Adenoma With Imaging Findings and Surgical Outcome

FRI689 First-line F18-choline PET/CT Versus Tc99m-sestaMIBI SPECT/CT In The Surgical Management Of Primary Hyperparathyroidism: The Multicentre APACH2 Phase III Trial

Abstract Disclosure: E. Quak: None. A. Lasne-cardon: None. M. Cavarec: None. B. Lireux: None. V. Bastit: None. N. Roudaut: None. P. Salaun: None. N. Keromnes: None. G. Potard: None. P. Vaduva: None. A. Esvant: None. F. Jegoux: None. O. Crouy-chanel: None. A. Devillers: None. C. Guery: None. C. Lasnon: None. R. Ciappuccini: None. M. Sali dauda: None. B. Legrand: None. A. Estienne: None. J. Grellard: None. S. Bardet: None. B. Clarisse: None. Introduction: Whether F18-choline PET/CT (FCH PET/CT) should replace Tc99m-sestaMIBI SPECT/CT (MIBI SPECT/CT) as a first-line imaging technique for preoperative localisation of parathyroid adenomas in primary hyperparathyroidism (pHPT) is unclear. Methods: We conducted a multicentre randomized open diagnostic intervention phase III trial in adults with primary hyperparathyroidism and indication for surgical treatment. Patients were assigned in a 1:1 ratio to receive first-line FCH PET/CT (FCH1) or MIBI SPECT/CT (MIBI1). In case of negative or inconclusive first-line imaging, patients received second-line FCH PET/CT (FCH2) after MIBI1 or MIBI SPECT/CT (MIBI2) after FCH1. The main aim of the trial was to compare the proportions of patients in whom the first-line imaging method resulted in successful mini-invasive parathyroidectomy (MIP) and cure, defined as the normalisation of serum calcium and parathyroid hormone levels at 1 month. We hypothesized a 30% superiority of FCH1 over MIBI1 for sample size determination (Quak et al, BMC Endocr Disord. 2021, PMID: 33413316). Results: From 11/2019 to 05/2022, 58 patients were assigned to receive FCH1 (n=30) or MIBI1 (n=28). Baseline patient characteristics were similar between groups. FCH1 was positive in 23/29 patients and led to successful MIP and cure in 22/23 patients. MIBI1 was positive in 18/28 and led to MIP in 16/17 operated patients, and video-assisted thoracoscopy (VATS) in 1/17 patient. Cure was obtained in 15/17 patients. The proportion of patients in whom the first-line imaging exam led to successful MIP and cure was 22 (76%) for FCH1 and 13 (50%) for MIBI1 (p=0.047). Diagnostic performances were superior for FCH1 than for MIBI1: sensitivity (92% vs 68%), specificity (100% vs 75%), positive predictive value (100% vs 94%), negative predictive value (67% vs 30%), and area under the ROC curve (96% vs 71%, p=0.022), respectively. Ten patients received FCH2 and 6 patients received MIBI2. FCH2 was positive in 8/10 patients, leading to 7/9 MIP and 2/9 bilateral cervical explorations (surgery recused in 1 patient), and cure in 9/9 patients. MIBI2 was positive in 2/6 patients, leading to 1 MIP and 1 VATS; all 6 patients were cured. No adverse events related to imaging and 4 adverse events related to surgery were reported. Conclusions: The proportion of patients who underwent correct imaging-guided MIP leading to cure was higher for FCH1 than for MIBI1, 76% vs 50% respectively. Diagnostic performances were better for FCH1 than for MIBI1. Cost-benefit analyses should elucidate whether first-line FCH PET/CT in pHPT management is justified. Presentation: Friday, June 16, 2023

Feasibility and Performance of Free-Hand Single-Photon Computed Tomography/Ultrasonography for Preoperative Parathyroid Adenoma Localization: A Pilot Study.

The aim of this prospective pilot study was to evaluate the feasibility of a new hybrid imaging modality, free-hand single-photon computed tomography/ultrasonography (fhSPECT/US), for preoperative localization of parathyroid adenomas and to compare its performance with conventional ultrasonography and SPECT/CT. Twelve patients diagnosed with primary hyperparathyroidism underwent sequentially US and parathyroid scintigraphy, including SPECT/CT, followed by fhSPECT/US, allowing for real-time fusion between US and freehand-generated gamma-camera images. The fhSPECT/US detection rates were correlated with histopathology, when available, or with the imaging modality showing the most lesions. Based on a per patient analysis, the detection rate was significantly different when comparing SPECT/CT to fhSPECT/US (p = 0.03), and not significantly different when comparing SPECT/CT to US (p = 0.16) and US to fhSPECT/US (p = 0.08). Based on a per-lesion analysis, the detection rate of SPECT/CT was significantly higher than that of US (p = 0.01) and fhSEPCT/US (p = 0.003), and there was no significant difference in detection rate when comparing US to fhSPECT/US (p = 0.08). The main perceived limitations of fhSPECT/US in lesion detection were: (i) lesions localized at a depth ≥4.5 cm; (ii) imperfect image fusion due to tissue compression; (iii) limited spatial manipulation ability of the SPECT mobile camera handheld probe; and (iv) a wide spread of detected activity. In conclusion, clinical use of fhSPECT/US for localization of parathyroid adenomas is feasible, but shows lower sensitivity than conventional modalities and requires technical improvements.

Clinical, Biochemical, and Sonographic Factors Influencing Performance of Parathormone Washout Measurement vs. 99mTc-MIBI Scintigraphy in the Preoperative Diagnostics of Parathyroid Adenomas.

The purpose of the study was to assess the clinical, biochemical, and sonographic factors influencing the performance of parathormone washout measurement (PTHw) vs. MIBI in the preoperative localization of parathyroid adenoma (PA). The studied group consisted of 39 patients with primary or tertiary hyperparathyroidism. The measurement of PTH concentrations was performed using an electro-chemiluminescence immunoassay. Scintigraphic localization of PA was carried out using dual-tracer planar neck scintigraphy, using 74 MBq 99mTc-pertechnetate and 740 MBq of 99mTc-MIBI. MIBI was unambiguously positive in 74% of patients. Among patients with negative or inconclusive MIBI, 90% had a positive PTHw result. Among patients with negative PTHw, two out of three had a positive MIBI result. The PTHw of lesions <10 mm in their largest diameter yielded positive results in 95%, compared to 75% for MIBI. For lesions ≥10 mm in largest diameter, 88% were visualised using MIBI. In conclusion, PTHw is a highly effective, easy, quick, safe, and relatively cheap procedure which might be considered for PA localisation, especially in patients with lesions presenting typical ultrasound features and a size below 10 mm. MIBI remains a useful procedure in specialized centres, particularly for patients in whom PTHw failed, larger lesions, and in cases of the ectopic location of PA.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

Preoperative Localization of Parathyroid Adenomas with Diffusion MR Imaging: Readout-segmented versus Single-shot Echo-planar Imaging.

To evaluate whether readout-segmented echo-planar imaging (RS-EPI) diffusion-weighted imaging (DWI) can reduce image distortion and improve the lesion identification in parathyroid adenomas (PTAs) compared to single-shot EPI (SS-EPI) DWI, and to determine whether PTAs can be differentiated from other soft tissue structures of the head and neck region by using the apparent diffusion coefficient (ADC) value. We retrospectively analyzed the preoperative MR images including DWI of 24 patients with surgically confirmed PTA. RS-EPI and SS-EPI DWI were evaluated by two independent readers for the identification of the lesions and distortion. The ADC values of the PTAs were compared with those of thyroid glands and cervical lymph nodes. RS-EPI provided significantly less distortion compared to SS-EPI. RS-EPI tended to have better lesion identification compared with SS-EPI without a statistically significant difference. On SS-EPI, the PTAs had significantly higher ADC values compared with the cervical lymph nodes. On RS-EPI, the PTAs had significantly higher ADC values compared with the thyroid glands and cervical lymph nodes. RS-EPI reduces the DWI distortion in PTAs. The ADC value obtained using RS-EPI enables the differentiation of PTAs from nearby structures, such as thyroid glands and cervical lymph nodes.

A giant parathyroid adenoma mimicking a thyroid swelling: A case report

Giant parathyroid adenomas are uncommon. Its clinical management is challenging. Our study’s goal is to share our experience with pre-operative localization of parathyroid adenomas while emphasizing the importance of intraoperative parathyroid hormone (IOPTH) assays in such situations. Here, we present the case of a 46-year-old woman who was diagnosed with parathyroid adenoma. The clinical aspects, pre-operative management, and surgical procedure have all been examined. Parathyroid hormone levels were reduced by 90% following surgical removal of the tumor and an IOPTH assay. IOPTH significantly improves surgical success rates in patients with only one positive imaging test result and adds significant value to surgical decision-making.

Efficacy of surgeon performed ultrasound scan in localization of parathyroid adenomas in patients with primary hyperparathyroidism

Abstract Introduction The success of minimally invasive parathyroid surgery is largely based on accurate preoperative localization of parathyroid adenomas. In the U.K, NICE guidance recommends either ultrasound scanning alone or combined with sestamibi scintigraphy to help guide surgery. In the recent past, surgeon performed ultrasound (SUS) has been adopted in North America and Australia for preoperative localization with a sensitivity of 63–91%. This was equivalent or superior to radiology performed ultrasound (RUS). In comparison, data from the U.K for surgeon performed imaging is sparse. In this study, we investigate the efficacy of surgeon performed ultrasound in localization of parathyroid disease and discuss its cost benefits. Methods This is a prospective study with data collected from November 2019 to June 2021. All patients had primary hyperparathyroidism and underwent either MIBI, radiology performed ultrasound or both. A single experienced surgeon performed ultrasound on all patients under general anaesthesia. The intraoperative findings were used to determine the accuracy of all imaging techniques. Results A total of 46 patients underwent surgery and were found to have single gland disease. The categories were: Double imaging (n=17), MIBI (n=34), RUS (n=22), SUS(n=46), no imaging (n=9). MIBI, radiology performed ultrasound and surgeon performed ultrasound had sensitivities of 58%, 55% and 81% respectively. 8 patients had ectopic glands and were not included in the sensitivity analysis of ultrasound scans. Conclusion Surgeon performed ultrasound by an experienced provider is effective in localizing parathyroid adenomas and guides minimally invasive surgery. It could significantly reduce costs associated with outpatient radiology performed ultrasound scanning

Utility of Contrast-Enhanced Ultrasound and 4-Dimensional Computed Tomography for Preoperative Detection and Localization of Parathyroid Adenomas Compared With Surgical Results.

To investigate the accuracy, sensitivity, and specificity of contrast-enhanced ultrasound (CEUS) for detection of parathyroid adenomas and compare it to those of 4-dimensional computed tomography (4DCT), which has been established as a reliable, effective tool for preoperative localization of parathyroid adenomas. About 27 patients with suspected parathyroid pathology underwent imaging evaluations with 4DCT and CEUS and 22 patients subsequently underwent surgical resection of parathyroid lesions. 4DCT and CEUS were performed and interpreted by consensus of two expert radiologists with extensive experience in each modality. Assessment for the side, z-axis (craniocaudal axis), and quadrant of the pathologically proven lesion was performed based on the surgical report. For single-gland disease, the accuracy for CEUS localization to the correct quadrant and side were 81.0 and 90.1% respectively. For single-gland disease, the accuracy for 4DCT localization to the correct quadrant and side were 81.0 and 90.5% respectively. 4DCT localization sensitivity and specificity were comparable to those for CEUS. 4DCT allowed for accurate diagnosis in multigland disease in contradistinction to CEUS. CEUS is a noninvasive, real-time imaging technique that has relatively high diagnostic confidence and accuracy of localization which are comparable to the accuracy of 4DCT for preoperative parathyroid adenoma detection, characterization, and localization. This technique should be considered for primary preoperative diagnosis, especially in younger patients.

Detectability of 18F-choline PET/MR in primary hyperparathyroidism.

We aimed to evaluate the power of 18F-fluorocholine (FCH) positron emission tomography/magnetic resonance (PET/MR) imaging in unlocalized primary hyperparathyroidism. Thirty-four patients were included. In 17/34 patients, PET/MR was performed immediately after a negative 18F-FCH PET/CT. Sensitivity, specificity, positive and negative predictive values were calculated for MR only (blinded to PET data) and PET only (blinded to MR data) findings. 18F-FCH PET/MR was positive in 26/34 (76%) patients. PET/MR was also positive in 12/17 (71%) patients with a negative PET/CT. Among 11/34 (32%) patients where 18F-FCH PET-only and MR-only results were discordant, MR was false positive in 7/11 patients (3/7 of the lesions were not 18F-FCH avid and in 4/7 of them PET and MRI pointed different locations. Postoperative histopathology revealed that 18F-FCH-positive ones were true positives). Sensitivity, specificity, PPV, NPV and accuracy of neck MR evaluated blinded to PET data were 80%, 50%, 70%, 64% and 68%, respectively, and all were calculated as 100% for PET/MR. 18F-FCH PET/MR is very effective in preoperative localization of parathyroid adenomas even if 18F-FCH PET/CT is negative. Neck MR alone is insufficient in detecting parathyroid adenomas but PET/MR combination helps in precise localisation.

Value of [11C]-Methionine PET/CT in Preoperative Localization of Parathyroid Adenomas.

There are multiple imaging modalities in primary hyperparathyroidism. Ultrasound examination and subtraction scintigraphy are usually the first-line imaging techniques. When these results are negative or inconsistent, additional [11C]-methionine PET/CT (MET-PET/CT) or 4-dimensional computed tomography can be performed. ​This study aims to evaluate MET-PET/CT in comparison with other imaging techniques in primary hyperparathyroidism. This is a retrospective cohort study. Eighty-four patients with primary hyperparathyroidism, who underwent parathyroid surgery, were included. ​Imaging results have been correlated to the perioperative drop in parathyroid hormone level and to the pathological analysis. ​Descriptive statistics are used, supplemented with 95% Clopper-Pearson confidence intervals for sensitivity and specificity and a sub-analysis with the McNemar test on paired data only. The per-lesion sensitivity of MET-PET/CT seems higher than that of [99mTc]-sestamibi or [99mTc]-tetrofosmin and [99mTc]-pertechnetate subtraction scintigraphy. The McNemar test, on paired data only, shows significantly higher sensitivity of MET-PET/CT compared to ultrasound (p=0.039) and significantly higher specificity of ultrasound compared to subtraction scintigraphy (p=0.035).​ MET-PET/CT after inconclusive or negative ultrasound and/or subtraction scintigraphy has an additional value in 70% of the cases.​ Preoperative parathyroid hormone levels were higher in patients in whom MET-PET/CT correctly predicted the pathological parathyroid glands, compared to those where MET-PET/CT missed at least one adenoma. The same trend was seen for 4-dimensional computed tomography. In conclusion, MET-PET/CT seems a valuable imaging modality in primary hyperparathyroidism, at least as second line imaging approach, with a higher per-lesion sensitivity than ultrasound in such setting. Especially when ultrasound and/or subtraction scintigraphy are inconclusive or negative, MET-PET/CT directs the surgeon to the correct localization of the parathyroid adenoma.

The preoperative localisation of small parathyroid adenomas improves when adding Tc-99m-Sestamibi SPECT to multiphase contrast-enhanced CT

ObjectivesTo investigate the incremental value of Sestamibi SPECT combined with a non-enhanced and contrast-enhanced CT, using SPECT/CT, for the preoperative localisation of small parathyroid adenomas (PTA).MethodsRetrospectively, 147 patients surgically cured from primary hyperparathyroidism, as verified by biochemistry 6 months postoperatively, were included. All patients had preoperatively undergone a dual time 99mTechnetium-Sestamibi SPECT (S) with multiphase CT including native (N), arterial (A) and venous (V) phases. Independently, two radiologists blinded from both the surgical and the preoperative imaging reports, sequentially performed PTA localisation starting with either [A] or [V], thereafter [A + N] or [V + N] and finally with the complete [A + N + S] or [V + N + S]. PTA localisation was reported for each image-set. The readers results were combined and the diagnostic performance for each image set was determined. Sensitivity was also calculated for the different quartiles of PTA weight distribution.ResultsThe median adenoma weight was 315 mg. No statistically significant differences in diagnostic performance between arterial and venous based image sets were found. The net effect of adding [N] was to increase specificity. Sestamibi SPECT significantly increased the overall diagnostic accuracy for arterial- and venous-based image sets, p = 0.0008 and p = 0.001, respectively. [A + N + S] was found to have the highest diagnostic performance with 86.5% sensitivity and 94.9% overall accuracy. [A + N + S] was particularly advantageous for locating PTA in the lower weight quartiles.ConclusionsNative CT-phase and dual time point Sestamibi SPECT increase specificity and sensitivity, respectively. These, in combination with a single contrast-enhanced CT-phase is the most optimal examination protocol for preoperative localisation of PTA using SPECT/CT.

Efficacy of ultrasonography and Tc-99m MIBI SPECT/CT in preoperative localization of parathyroid adenomas causing primary hyperthyroidism

BackgroundPrimary hyperparathyroidism (PHPT) results from an excess of parathyroid hormone (PTH) produced from an overactive parathyroid gland. The study aimed to explore the sonographic features of parathyroid adenomas and assess the diagnostic performance of ultrasonography (US) and Tc-99m MIBI SPECT/CT for preoperative localization of parathyroid adenomas.MethodsA total of 107 patients were enrolled in this retrospective study who had PHPT and underwent parathyroidectomy. Of the 107 patients, 97 performed US and Tc-99m MIBI SPECT/CT examinations for preoperative localization of parathyroid nodules. The sensitivity and accuracy of each modality were calculated.ResultsIn this study, residual parathyroid sign and polar vascular sign were identified as characteristic US features of parathyroid adenomas. These manifestations were closely related to the size of the abnormal parathyroid lesions. Among the 108 parathyroid nodules from 97 patients with PHPT, the sensitivity and accuracy of US for locating the parathyroid nodules were significantly higher than those of Tc-99m MIBI SPECT/CT (93.0% vs. 63.0% and 88.0% vs. 63.0% respectively; χ2 = 26.224, 18.227 respectively, P < 0.001). The differences between US + Tc-99m MIBI SPECT/CT and Tc-99m MIBI SPECT/CT-alone were statistically significant (χ2 = 33.410, 21.587 respectively, P < 0.001), yet there were no significant differences in the sensitivity or accuracy between US + Tc-99m MIBI SPECT/CT and US-alone (χ2 = 0.866, 0.187 respectively, P = 0.352 and 0.665).ConclusionsUS shows significantly better sensitivity and accuracy for localization of parathyroid adenomas than Tc-99m MIBI SPECT/CT. However, US combined with Tc-99m MIBI SPECT/CT is of great clinical value in the preoperative localization of parathyroid nodules in patients with PHPT.

Cushing’s Disease (CD) Due to ACTH-Secreting Pituitary Microadenoma Incidentally Discovered on a Sestamibi Scan for Primary Hyperparathyroidism

Introduction: MIBI scintigraphy is commonly being used for the preoperative localization of parathyroid adenomas. Multiple studies showed MIBI uptake in pituitary adenomas are likely due to higher metabolic activity. When hyperfunctioning pituitary adenomas were reported, both had CD [1,2]. We present the third case of increased pituitary uptake on a MIBI scan later confirmed as CD. CaseA 64-year-old Caucasian female s/p renal transplantation for RPGN who presented for evaluation of hypercalcemia. Evaluation confirmed primary hyperparathyroidism with persistently elevated PTH levels 74-108 pg/ml (11-68), serum calcium levels 10.0-10.4 mg/dl (8.4-10.3), albumin 4.1-4.3 g/dl (3.6-5.1), phosphorus 3.0-3.2 mg/dl (2.5-4.5), creatinine 0.94-1.07 mg/dl. 24-hour urine calcium 60 mg/day (35-250). Vitamin D-25 OH level was 37 ng/dL (30-100). A sestamibi scan showed uptake in the right lower parathyroid, the midsternal chest region and the pituitary gland. MRI of the pituitary revealed a 7mm cystic pituitary microadenoma in the right posterior pituitary. CD was confirmed by the findings of persistently elevated 8 AM serum cortisol levels of 28.4 and 24.2 mcg/dl (4-22), ACTH levels of 59 and 39 pg/ml (10-48), and an elevated plasma free cortisol of 1.43 mcg/dl (0.07-0.93). CT of the abdomen showed L adrenal thickening suggesting adrenal hyperplasia from CD. Plasma cortisol suppressed to 1.2 mg/dl following 1 mg of dexamethasone. 24 urine for free cortisol 26.7 mcg/day (4-50). The patient had no proximal muscle weakness, striae or Cushingoid facial features. She had no hyperglycemia or hypertension. Patient was diagnosed with an ACTH secreting pituitary microadenoma with mild CD and adrenal hyperplasia. Her DXA scan showed osteoporosis. Genetic testing for MEN1 mutation was negative. Patient did not wish surgery for either her hyperparathyroidism or her CD and is being evaluated for medical treatment of hypercortisolism. Conclusion: There are two prior case reports of an incidentally discovered pituitary adenoma on sestamibi scan later diagnosed as CD [1,2]. Corticotrophs may have a strong affinity for sestamibi. Our case is the first, to our knowledge, of pituitary MRI confirmation of the ACTH secreting pituitary incidentaloma initially suspected by pituitary uptake on a sestamibi scan in a patient with hyperparathyroidism. Reference1. Kuhadiya ND et al. Incidentally Discovered ACTH-Secreting Pituitary Adenoma on a Sestamibi Scan in a Patient With Hyperparathyroidism. AACE Clinical Case Reports. 2015;1(3):e152-5. 2. Gierach M et al. The case of Cushing’s disease imaging by SPECT examination without manifestation of pituitary adenoma in MRI examination. Nuclear Medicine Review. 2005;8(2):137-9.

The Added Value of Technetium-99mSestamibi Scan in Patients with Primary Hyperparathyroidism and Positive Ultrasound.

Neckultrasound (US) and Technetium-99mSestamibi (MIBI) scan are the most commonly used imaging studies for preoperative localization of parathyroid adenomas. The aim of this study was to determine the added value of MIBI scan and its effect on the operative plan via a hypothetical model where a stepwise approach is conducted and MIBI is considered only after the ultrasound is evaluated. Patients who underwent parathyroidectomy for primary hyperparathyroidism (PHPT) between 2012 and 2019 at two tertiary centers were included. Data collected included demographic data, preoperative workup, operative findings and follow-up. The added value of MIBI scans was determined for patients with positive ultrasound. A total of 513 patients with positive US result and a MIBI scan were included. If a stepwise approach was conducted then MIBI scan would not change the operative plan in 492 (95.9%). Among the remaining 21 patients, MIBI scan would correctly change the ultrasound-based operative plan in only 12 (2.3%) patients, while incorrectly change the plan in 9 (1.8%), resulting in unnecessary exploration of the contralateral side. In patients with sonographic appearance of a parathyroid gland larger than 1.2cm, MIBI scan would correctly change the operative plan in only 1 of the 287 (0.35%) patients. Our study suggests that the routine use of MIBI scans may have limited added value in patients with PHPT and a positive neck ultrasound, especially in those with adenoma size larger than 1.2cm. Positive ultrasound alone may be sufficient for the preoperative localization of parathyroid disease.

RARE AND DEMANDING: PARATHYROID ADENOMA LOCALIZATION, SURGERY AND OUTCOME.

Objectives: To assess the methods of preoperative parathyroid adenoma localization and to compare it with operative findings. Patients and methods: Between June 2017 and June 2019, we had operated 8 cases of parathyroid adenomas. Three patients were males and 5 patients were females. Age ranged from 26 year old to 72 year old with average of 42 year old. Seven cases were sporadic while one case was part of MEN2a. All patients had ultrasonography for preoperative localization, all had CT scan and 4 patients had Sestamibi scan. In all patients, intraoperative measurements of parathyroid hormone was done before and 10 minutes after surgical excision. Results: Ultrasonography was successful in localizing only one case with certainty. CT scan located the adenoma in another 2 patients. In 4 patients who performed Sestamibi scan, the adenomas were located precisely in all of them including one case of ectopic parathyroid adenoma behind the sternum. In one patient, all the modalities failed in localization which was achieved easily intraoperatively. Single adenoma was found in 6 patients and two adenomas in two patients. The adenomas were located in the neck in 7 patients and in the anterior mediastinum in one patient .Surgical removal was done through neck incision in 7 cases while midline sternotomy in one case. All the patients had resolution of symptoms within the follow up period. Conclusion: Sestamibi scan is the best investigation in preoperative localization of parathyroid adenoma. Ultrasonography and CT scan can aid in the diagnosis with less sensitivity. Intraoperative localization is possible even in cases of negative investigations.

Upfront F18-choline PET/CT versus Tc99m-sestaMIBI SPECT/CT guided surgery in primary hyperparathyroidism: the randomized phase III diagnostic trial APACH2

BackgroundThe common endocrine disorder primary hyperparathyroidism (PHPT) can be cured by surgery. Preoperative localization of parathyroid adenoma (PTA) by imaging is a prerequisite for outpatient minimally invasive parathyroidectomy (MIP). Compared to inpatient bilateral cervical exploration (BCE) which is performed if imaging is inconclusive, MIP is superior in terms of cure and complication rates and less costly. The imaging procedure F18-choline (FCH) PET/CT outperforms Tc99m-sestaMIBI (MIBI) SPECT/CT for PTA localization, but it is much costlier. The aim of this study is to identify the most efficient first-line imaging modality for optimal patient care in PHPT without added cost to society.MethodsWe will conduct a multicenter open diagnostic intervention randomized phase III trial comparing two diagnostic strategies in patients with PHPT: upfront FCH PET/CT versus MIBI SPECT/CT. The primary endpoint is the proportion of patients in whom the first-line imaging method results in successful MIP and cure. Follow-up including biological tests will be performed 1 and 6 months after surgery. The main secondary endpoint is the social cost of both strategies. Other secondary endpoints are as follows: FCH PET/CT and MIBI SPECT/CT diagnostic performance, performance of surgical procedure and complication rate, FCH PET/CT inter- and intra-observer variability and optimization of FCH PET/CT procedure. Fifty-eight patients will be enrolled and randomized 1:1.DiscussionFCH PET/CT is a highly efficient but expensive imaging test for preoperative PTA localization and costs three to four times more than MIBI SPECT/CT. Whether FCH PET/CT improves patient outcomes compared to the reference standard MIBI SPECT/CT is unknown. To justify its added cost, FCH PET/CT-guided parathyroid surgery should lead to improved patient management, resulting in higher cure rates and fewer BCEs and surgical complications.In the previous phase II APACH1 study, we showed that second-line FCH PET/CT led to a cure in 88% of patients with negative or inconclusive MIBI SPECT/CT. BCE could be avoided in 75% of patients and surgical complication rates were low. We therefore hypothesize that upfront FCH PET/CT would improve patient care in PHPT and that the reduction in clinical costs would offset the increase in imaging costs.Trial registrationNCT04040946, registered August 1, 2019. Protocol versionVersion 2.1 dated from 2020/04/23.

Diagnostic value of ultrasonograpy and 99mTc-MIBI scintigraphy for preoperative localization of parathyroid adenomas

Aim: The primary treatment of primary hyperparathyroidism (PHPT) is parathyroidectomy. With its shorter operative time and healing period, lesser general anesthesia duration, lesser hypoparathyroidism risk and better cosmetic results minimally invasive parathyroidectomy is the most commonly performed contemporary surgical procedure. However, in order for this procedure to be successful, it is important to know the location of the parathyroid adenoma. The purpose of this study was to determine the diagnostic value of Ultrasonography (USG) and technetium methoxyisobutylisonitrile scintigraphy (99mTc-MIBI) in the preoperative localization of parathyroid adenoma. Materials and Methods: Fifty-two patients diagnosed with parathyroid adenoma were included in the study. Preoperative parathyroid USG and 99mTc-MIBI were performed on all patients. All patients’ preoperative serum calcium, phosphorus, parathormone and Vitamin D levels, parathyroid USG and 99mTc-MIBI, intraoperative parathyroid lesion location and histopathological examination results were recorded. Results: Patients aged between 22 and 81 (51.7±15.6) were eventually enrolled. When USG was used alone, the site of the adenoma was correctly determined in 26 of the 52 patients with a sensitivity of 52% and a positive predictive value of 92.8%. When scintigraphy was performed alone, the site of the adenoma was correctly identified in 39 of the 52 patients. Sensitivity was thus 76.4% and positive predictive value 97.5%. When USG and scintigraphy were assessed together, adenoma location was correctly identified in 45 of the 52 patients. Sensitivity for the two tests employed together was 88.2% and positive predictive value was 97.8%. Conclusions: Due to the high sensitivity of combined use of USG and 99mTc-MIBI, we recommend the two tests to be assessed together before parathyroid surgery.

Video-assisted thoracoscopic surgery for primary hyperparathyroidism with ectopic parathyroid adenoma in thymus

Introduction. Primary hyperparathyroidism is rare pathology in children (2?5:100,000). In more than 85% of patients, a single adenoma is present, and its extirpation is usually the only treatment a patient requires. In approximately 15?80% of cases, ectopic mediastinal parathyroid tissue can be found inside the thymus. Case outline. Our patient was a 13-year-old boy, who presented with multiple bone fractures in the previous period of time, and fatigue. Parathyroid hormone levels preoperatively were extremely high (1320 pg/ml ? more than 19 times higher than normal). Serum calcium was also elevated (total 3.55 mmol/l; ionized 1.41 mmol/l). He was examined and diagnosed as primary hyperparathyroidism by a pediatric endocrinologist. Imaging procedures for the preoperative localization of parathyroid adenomas were done (99mTc sestamibi scintigraphy and magnetic resonance imaging suggested ectopic mediastinal parathyroid adenoma). The patient underwent video-assisted thoracoscopic surgery procedure. After exploration of the mediastinum and chest, no ectopic parathyroid tissue was found, so total thoracoscopic thymectomy was performed. Final pathological section confirmed parathyroid adenoma inside the thymus. Conclusion. We believe that if no parathyroid tissue is found during surgical exploration of mediastinum, in a child with preoperatively detected parathyroid adenoma in anterior mediastinum, recommendation is to think about possible intrathymic localization and consider removing the thymus. Greater sample size is necessary for higher reliability of this statement.