Virtual neck exploration in patients with hyperparathyroidism and former cervical operations. Langenbecks Arch Surg. 2008;393:687-692. [PMID: 18575883 DOI: 10.1007/s00423-008-0359-6]

An Approach to a Patient With Primary Hyperparathyroidism and a Suspected Ectopic Parathyroid Adenoma

Primary hyperparathyroidism (PHPT) is characterized by hypercalcemia driven by excess parathyroid hormone (PTH) secretion. PHPT is a common endocrine condition with a prevalence of 1 to 7 cases per 1000 adults. PHPT typically presents in the fifth or sixth decade and shows significant female preponderance. Solitary hyperfunctioning parathyroid adenomas account for 85% to 90% of PHPT cases. The remaining 10% to 15% include cases of multiglandular disease (multiple adenomas or hyperplasia) and, rarely, parathyroid carcinoma (1%). Ectopic parathyroid adenomas may arise due to abnormal embryological migration of the parathyroid glands and can be difficult to localize preoperatively, making surgical cure challenging on the first attempt. The potential existence of multiglandular disease should be considered in all patients in whom preoperative localization fails to identify a target adenoma or following unsuccessful parathyroidectomy. Risk factors for multiglandular disease include underlying genetic syndromes (eg, MEN1/2A), lithium therapy, or previous radiotherapy. In addition to multifocal disease, the possibility of an ectopic parathyroid gland should also be considered in patients requiring repeat parathyroid surgery. In this article, we use illustrative clinical vignettes to discuss the approach to a patient with primary hyperparathyroidism (PHPT) and a suspected ectopic parathyroid adenoma.

Multiphase Iodine Contrast-Enhanced SPECT/CT Outperforms Nonenhanced SPECT/CT for Preoperative Localization of Small Parathyroid Adenomas

PURPOSE

The aim of this study was to assess the value of intravenously contrast-enhanced CT in conjunction with Tc-MIBI SPECT for preoperative localization of parathyroid adenoma.

METHODS

One hundred ninety-two patients with primary hyperparathyroidism were enrolled in the study between May 2015 and May 2017. The patients underwent a preoperative "one-stop shop" examination with Tc-MIBI SPECT/CT by using dual time-point (10 and 90 minutes) protocol and both nonenhanced CT and contrast-enhanced CT acquisition in the arterial and venous phase, 35 and 75 seconds, respectively, after contrast medium injection start. For 149 patients, the imaging results could be correlated to those at surgery and histopathology.

RESULTS

The median adenoma weight was 330 mg. The addition of contrast-enhanced CT increased the sensitivity from 81.1% to 89.9% (P = 0.003). The specificity of nonenhanced SPECT/CT was similar to contrast-enhanced CT (96.1% vs 97.9%; P = 0.077). For patients with uniglandular disease (n = 140, 94.0%), the sensitivity increased from 86.4% to 93.6% (P = 0.021) and the specificity from 96.2% to 97.9% (P = 0.118) by adding contrast-enhanced CT. In patients with multiglandular disease (n = 9, 6.0%), adding contrast-enhanced CT improved detection sensitivity from 42.1% to 63.2%. However, these patients were few and significance was not reached (P = 0.125).

CONCLUSIONS

In this cohort, with generally small parathyroid adenomas, the sensitivity in preoperative localization was greatly improved by adding contrast-enhanced CT to Tc-MIBI SPECT/CT.

Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

AIM: To review the benefits of single photon emission computed tomography (SPECT)/computed tomography (CT) hybrid imaging for diagnosis of various endocrine disorders.

METHODS: We performed MEDLINE and PubMed searches using the terms: “SPECT/CT”; “functional anatomic mapping”; “transmission emission tomography”; “parathyroid adenoma”; “thyroid cancer”; “neuroendocrine tumor”; “adrenal”; “pheochromocytoma”; “paraganglioma”; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts (case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology.

RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the bio-distribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for ^99mTc-sestamibi parathyroid scintigraphy and ^99mTc-pertechnetate thyroid scintigraphy, ¹²³I- or ¹³¹I-radioiodine for staging of differentiated thyroid carcinoma, ¹¹¹In- and ^99mTc- labeled somatostatin receptor analogues for detection of neuroendocrine tumors, ¹³¹I-norcholesterol (NP-59) scans for assessment of adrenal cortical hyperfunction, and ¹²³I- or ¹³¹I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma.

CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy from CT, translating to improved diagnostic accuracy and meaningful impact on patient care.

Parathyroid adenoma localization with 99mTc-sestamibi SPECT/CT: a meta-analysis

PURPOSE

The aim of the study was to determine the diagnostic utility of parathyroid scintigraphy with technetium-99m (99mTc)-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) for localization of parathyroid adenoma.

MATERIALS AND METHODS

We performed a systematic search of medical databases PubMed and Medline/OVID for literature on 99mTc-sestamibi SPECT/CT parathyroid scintigraphy, using the search terms hyperparathyroidism, parathyroid adenoma/hyperplasia, SPECT/CT, and SPECT-CT. Citations for 981 articles and 128 abstracts of full articles were reviewed by two coauthors for relevance. Twenty-four peer-reviewed studies on SPECT/CT parathyroid scintigraphy qualified for inclusion. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality. Meta-analytical techniques were used to obtain pooled estimates of the parathyroid adenoma localization rate using a random-effects model.

RESULTS

A total of 24 studies published between January 2003 and March 2014 with 1276 patients (334 men, 762 women, and 180 of unspecified sex) met the inclusion criteria. Data on the test performance of dual-phase 99mTc-sestamibi SPECT/CT showed an estimated pooled sensitivity (per-patient analysis) of 0.86 [confidence interval (CI) 0.81-0.90]. Sensitivity of SPECT/CT was superior to that of SPECT (0.74; CI 0.66-0.82) and planar (0.70; CI 0.61-0.80) techniques. Heterogeneity was present in the reported literature (I2=80.3%). The rate of ectopic parathyroid adenomas ranged between 4 and 20% and SPECT/CT was superior to SPECT and planar imaging for localization of ectopic sites.

CONCLUSION

Utilization of SPECT/CT fusion imaging for 99mTc-sestamibi parathyroid scintigraphy improves the test performance compared with planar and SPECT imaging; it assists preoperative planning for a minimally invasive surgical approach for the neck and is of value in subgroups with ectopic glands or coexisting nodular thyroid disease.

Enabling minimal invasive parathyroidectomy for patients with primary hyperparathyroidism using Tc-99m-sestamibi SPECT-CT, ultrasound and first results of (18)F-fluorocholine PET-CT

OBJECTIVE

Assessment of the diagnostic value of ultrasound (US), single photon-emission computed tomography-computed tomography (SPECT-CT) and (18)F-fluorocholine (FCH) PET-CT for preoperative localization of hyper-functioning parathyroid(s) in order to create a more efficient diagnostic pathway and enable minimal invasive parathyroidectomy (MIP) in patients with biochemical proven non-familial primary hyperparathyroidism (pHPT).

METHODS

A single-institution retrospective study of 63 consecutive patients with a biochemical diagnosis of non-familial pHPT who received a Tc-99m-sestamibi SPECT-CT and neck ultrasound. Surgical findings were used in calculating the sensitivity and the positive predictive value (PPV) of both imaging modalities. Furthermore we present 5 cases who received additional FCH PET-CT.

RESULTS

A total of 42 (66.7%) patients underwent MIP. The PPV and sensitivity of SPECT-CT, 93.0% and 80.3%, were significantly higher than those of US with 78.3% and 63.2%, respectively. Adding US to SPECT-CT for initial pre-operative localization did not significantly increase sensitivity but did significantly decrease PPV. Performance of US was significantly better when performed after SPECT-CT. (18)F-fluorocholine PET-CT localized the hyper-functioning parathyroid gland in 4/5 cases with discordant conventional imaging, enabling MIP.

CONCLUSION

SPECT-CT is the imaging modality of choice for initial pre-operative localization of hyper-functioning parathyroid gland(s) in patients with biochemical pHPT. Ultrasound should be performed after SPECT-CT for confirmation of positive SPECT-CT findings and for pre-operative marking allowing MIP. In cases with negative or discordant imaging additional FCH PET-CT should be considered since this might enable the surgeon to perform MIP.

Endocrine scintigraphy with hybrid SPECT/CT

Nuclear medicine imaging of endocrine disorders takes advantage of unique cellular properties of endocrine organs and tissues that can be depicted by targeted radiopharmaceuticals. Detailed functional maps of biodistributions of radiopharmaceutical uptake can be displayed in three-dimensional tomographic formats, using single photon emission computed tomography (CT) that can now be directly combined with simultaneously acquired cross-sectional anatomic maps derived from CT. The integration of function depicted by scintigraphy and anatomy with CT has synergistically improved the efficacy of nuclear medicine imaging across a broad spectrum of clinical applications, which include some of the oldest imaging studies of endocrine dysfunction.

Highly efficient localization of pathological glands in primary hyperparathyroidism using contrast-enhanced ultrasonography (CEUS) in comparison with conventional ultrasonography

INTRODUCTION

Preoperative detection of parathyroid gland adenoma in the presence of primary hyperparathyroidism (pHPT) represents a diagnostic challenge. We present the first prospective study with contrast-enhanced ultrasonography (CEUS) as the central diagnostic tool for the preoperative localization of parathyroid gland adenoma in pHPT in comparison with conventional ultrasonography.

METHODS

Between July 2010 and December 2011, 75 consecutive patients underwent surgery for pHPT. In all patients, conventional ultrasonography and CEUS were performed prospectively for localization of pathological parathyroid glands. Twenty-five patients suffered from a concomitant goiter (CG), and 12 patients had undergone previous neck surgery due to thyroid pathologies. The sensitivity of both diagnostic tools was analyzed in comparison with intraoperative and histological findings.

RESULTS

CEUS had a sensitivity of 97% for the detection of the correct quadrant of the pathological parathyroid gland and of 99% for the correct side in comparison with 70% for conventional ultrasonography. In multivariate regression analysis, CG, gland size, and body mass index had a relevant impact on incorrect findings by conventional ultrasonography as compared with CEUS. Follow-up with a minimum of 6 months after surgery showed normal serum levels of calcium and PTH in all 75 patients.

CONCLUSIONS

CEUS represents a highly reliable, noninvasive and nonradioactive diagnostic tool for localization of pathological parathyroid glands in patients with pHPT. Even in the presence of CG, previous neck surgery, or double adenomas, CEUS has a high sensitivity.

Preoperative ⁹⁹mTc-sestamibi scintigraphy in patients with primary hyperparathyroidism and concomitant nodular goiter: comparison of SPECT-CT, SPECT, and planar imaging

BACKGROUND

Investigations using a hybrid single photon emission computed tomography/computed tomography (SPECT-CT) scanning technique have been carried out in limited studies and have shown mixed results. However, the assessment of this technique for the detection of parathyroid adenoma in patients with a nodular goiter was performed in only one study with a small sample size. The aim of this prospective study was to assess the role of 99mTc-sestamibi parathyroid SPECT-CT scans for localization of parathyroid adenomas with a concomitant nodular goiter using 99mTc-methoxyisobutyl isonitrile (MIBI) scintigraphy and to compare it with SPECT and planar imaging.

METHODS

This study was conducted on 48 patients with primary hyperparathyroidism and nodular goiter, who were candidates for parathyroid surgery and had been referred for parathyroid scintigraphy. The patients underwent an early set of planar 99mTc-MIBI scanning procedures first, followed by SPECT and CT scannings, and finally a delayed set of planar 99mTc-MIBI scannings. Sensitivity, specificity, negative and positive predictive values, and accuracy were determined on a per-parathyroid-gland basis for each scanning method, as defined by histology and follow-up.

RESULTS

The surgery was successful in 48 out of 50 patients with primary hyperparathyroidism concomitant with thyroid nodularity, and data were completed for 80 sites in 48 patients. The accuracy of SPECT-CT in correctly identifying a parathyroid adenoma was 85.00, versus 75.00% for SPECT (P=0.01, significant). The sensitivity and specificity for SPECT-CT were 77.55 and 96.77%, respectively, versus 67.34 and 87.09%, respectively, for SPECT (P=0.12 and 0.12, not significant). There were nine sites that showed better localization on SPECT-CT scans relative to SPECT images, of which five sites were located in the ectopic regions.

CONCLUSION

The results of our study indicate that SPECT-CT is more accurate than sestamibi planar imaging and SPECT for the preoperative identification of parathyroid lesions in patients with primary hyperparathyroidism concomitant with thyroid nodularity. Also, we would recommend the use of SPECT-CT for a workup of all patients with ectopic glands who are scheduled for minimally invasive parathyroid surgery.

Role of SPECT and SPECT/CT in the Surgical Treatment of Primary Hyperparathyroidism

Primary hyperparathyroidism is the most common cause of hypercalcemia in the outpatient population. This condition is usually the result of a single hyperfunctioning parathyroid gland. Targeted parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IPM) through a small cervical incision has replaced traditional bilateral neck exploration (BNE) as the initial approach in the surgical treatment of primary hyperparathyroidism at many medical centers worldwide. Preoperative sestamibi-technetium 99m scintigraphy serves as an important prerequisite for successful targeted parathyroidectomy. Single-photon emission computed tomography (SPECT) and CT fusion, however, is a recent imaging technique that provides a three-dimensional functional image with advanced contrast resolution to greatly improve preoperative localization of parathyroid tumors.

Resection of ectopic mediastinal parathyroid glands with the da Vinci® robotic system

Background

Mediastinal ectopic parathyroid adenoma is a frequent cause of persistent or recurrent hyperparathyroidism, traditionally treated by open surgery. Thoracoscopic access is associated with reduced morbidity in mediastinal surgery. The aim of this study was to evaluate the feasibility and effectiveness of robot-assisted dissection for mediastinal ectopic parathyroid glands.

Methods

Two patients with recurrent secondary hyperparathyroidism and three with complicated primary hyperparathyroidism were operated on between July 2004 and August 2008 for ectopic mediastinal parathyroid glands. Fusion of single-photon emission computed tomography and computed tomography led to an exact identification of the culprit glands. Surgery was performed thoracoscopically with the da Vinci® robotic system using a three-trocar approach.

Results

All procedures were completed successfully with the robotic system. No perioperative morbidity or mortality was noted. Median operating time was 58 (range 42–125) min. Intraoperative parathyroid hormone reduction indicated complete resection. Median hospital stay was 3 (range 2–4) days.

Conclusion

Robot-assisted dissection is a promising approach for resection of ectopic parathyroid glands in remote narrow anatomical locations such as the mediastinum.

Virtual neck exploration: a new method for localizing abnormal parathyroid glands

BACKGROUND DATA

Computed tomography (CT) together with 99mTc-sestamibi single photon emission computed tomography (MIBI-SPECT) image fusion (CT-MIBI-SPECT image fusion) allows virtual exploration of the neck. The aim of this study was to evaluate whether CT-MIBI-SPECT image fusion is superior to MIBI-SPECT and CT in detecting abnormal parathyroid glands in patients with primary hyperparathyroidism.

METHODS

CT-MIBI-SPECT image fusion for preoperative localization was performed in 116 patients with primary hyperparathyroidism (pHPT). Both investigations were performed with reproducible fixation of the patient on a vacuum mattress. At a special work station the neck was virtually explored by viewing the CT images in all 3 dimensions. The MIBI-SPECT images were superimposed on underlying CT images. Only patients with single-gland disease were evaluated (pHPT: 112, persistent pHPT: 1, recurrent pHPT: 1, persistent secondary hyperparathyroidism: 1, tertiary HPT after kidney transplantation: 1). CT-MIBI-SPECT image fusion results were compared with those obtained with CT alone and MIBI-SPECT alone. The predicted positions were correlated with the intraoperative findings.

RESULTS

CT-MIBI-SPECT image fusion was able to predict the exact position of the abnormal gland in 102 (88%) of the 116 patients, whereas CT alone showed in 75 (65%) patients and MIBI-SPECT alone in 64 (55%) patients the exact position of the abnormal gland. Sixty-two patients underwent minimally invasive surgery, namely in 21 patients with a unilaterally focused approach and in 33 patients with a bilateral approach (27 of these underwent simultaneous thyroid resection). Sensitivity for CT-MIBI-SPECT image fusion was 88%, for CT alone 70%, and for MIBI-SPECT alone 59%. Specificity for CT-MIBI-SPECT image fusion was 99%, for MIBI-SPECT alone 95%, for CT alone 94%. Overall accuracy for CT-MIBI-SPECT image fusion was 97%, for CT alone 89%, for MIBI-SPECT 87%.

CONCLUSIONS

This study provides evidence that CT-MIBI-SPECT image fusion is superior to CT or MIBI-SPECT alone for preoperative localization of enlarged parathyroid glands in patients with single-gland primary hyperparathyroidism.