Surgeon-performed ultrasonography as the initial and only localizing study in sporadic primary hyperparathyroidism

Does the Use of Probe-based Near-infrared Autofluorescence Parathyroid Detection Benefit Parathyroidectomy?: A Randomized Single-center Clinical Trial

OBJECTIVE

To evaluate the benefits of probe-based near-infrared autofluorescence (NIRAF) parathyroid identification during parathyroidectomy.

BACKGROUND

Intraoperative parathyroid gland identification during parathyroidectomy can be challenging, while additionally requiring costly frozen sections. Earlier studies have established NIRAF detection as a reliable intraoperative adjunct for parathyroid identification.

METHODS

Patients undergoing parathyroidectomy for primary hyperparathyroidism were prospectively enrolled by a senior surgeon (>20 years experience) and a junior surgeon (<5 years experience), while being randomly allocated to the probe-based NIRAF or control group. Data collected included procedure type, number of parathyroids identified with high confidence by the surgeon and the resident, number of frozen sections performed, parathyroidectomy duration, and number of patients with persistent disease at the first postoperative visit.

RESULTS

One hundred sixty patients were randomly enrolled under both surgeons to the probe group (n=80) versus control (n=80). In the probe group, parathyroid identification rate of the senior surgeon improved significantly from 3.2 to 3.6 parathyroids per patient ( P <0.001), while that of the junior surgeon also rose significantly from 2.2 to 2.5 parathyroids per patient ( P =0.001). Parathyroid identification was even more prominent for residents increasing significantly from 0.9 to 2.9 parathyroids per patient ( P <0.001). Furthermore, there was a significant reduction in frozen sections utilized in the probe group versus control (17 vs 47, P =0.005).

CONCLUSION

Probe-based NIRAF detection can be a valuable intraoperative adjunct and educational tool for improving confidence in parathyroid gland identification, while potentially reducing the number of frozen sections required.

Primary Hyperparathyroidism: Outcomes of Repeated Imaging After Initial Negative Radiological Localization

BACKGROUND

Radiological localization imaging aids in the identification of abnormal parathyroid glands resulting in primary hyperparathyroidism (PHPT), thereby facilitating minimally invasive parathyroid surgery. Sometimes initial imaging may fail to identify the abnormal gland and imaging may therefore be repeated. This study explored patient outcomes of repeated parathyroid localization imaging, after initial negative gland localization, at a United Kingdom institution.

METHODOLOGY

Data was retrospectively collected and analyzed for patients with PHPT undergoing repeated imaging during a five-year period (2015-2020). The total number of episodes of scanning, types of scans performed, the time interval between scans and the imaging success of gland localization were recorded. We explored the reasons for repeated imaging and attempted to identify any factors that might predict subsequent positive radiological localization.

RESULTS

A total of 45 patients were identified who underwent repeated localizing imaging after first localizing imaging was negative. Of these, 39 did not undergo surgery despite repeat imaging being undertaken; 11 out of these 39 patients (28%) had subsequent positive localization scans. Again, a large proportion of patients were managed conservatively, despite the repeated sets of imaging being done. Patients undergoing three or four sets of repetitive imaging did not have imaging or surgical success.

CONCLUSION

A streamlined parathyroid pathway should be followed whereby patients should be triaged for suitability for surgery prior to repeated imaging. A second set of scans should be offered when patients are unsuitable for conservative management and are willing and fit to undergo surgery. There is no merit to repeating imaging more than twice.

Tricks of the trade: Techniques for preoperative localization in reoperative parathyroidectomy

BACKGROUND

Reoperative parathyroidectomy for recurrent/persistent primary hyperparathyroidism (PHPT) has high rates of failure. The goal of this study was to analyze our experience with imaging and parathyroid vein sampling (PAVS) for recurrent/persistent PHPT.

METHODS

We performed a retrospective cohort study (2002-2018) of patients with recurrent/persistent PHPT undergoing reoperative parathyroidectomy.

RESULTS

Among 181 patients, the most common imaging study was sestamibi (89.5%), followed by ultrasound (75.7%). CT had the highest rate of localization (70.8%) compared to sestamibi (58.0%) and ultrasound (47.4%). PAVS was performed in 25 patients, and localized in 96%. Ultrasound and sestamibi both demonstrated 62% PPV for operative pathology, compared to 41% in CT. PAVS was 95% sensitive with 95% PPV for predicting the correct side of abnormal parathyroid tissue.

CONCLUSIONS

We recommend a sequential imaging evaluation for reoperative parathyroidectomy, with sestamibi and/or ultrasound followed by CT. PAVS should be considered if non-invasive imaging fails to localize.

Efficacy of surgeon-performed, intra-operative ultrasound scan for localisation of parathyroid adenomas in patients with primary hyperparathyroidism

BACKGROUND

In the UK, guidance recommends ultrasound scanning alone or in combination with sestamibi scintigraphy to guide surgery in patients with primary hyperparathyroidism. If an adenoma is localised on imaging, this can facilitate targeted or minimally invasive surgery. Surgeon-performed ultrasound scan on the operating table benefits from being performed on an anaesthetised patient with optimal positioning. The aim of this study was to investigate the efficacy of intra-operative, blinded, surgeon-performed ultrasound scan in localisation of parathyroid adenomas.

METHODS

Prospective data were collected on consecutive patients undergoing surgery for primary hyperparathyroidism at a single tertiary centre from November 2019 to June 2021. Patients underwent blinded, surgeon-performed ultrasound scan under general anaesthesia immediately prior to surgery. Localisation results from pre-operative imaging and surgeon-performed ultrasound scan were then compared with the intra-operative findings.

RESULTS

Forty-nine patients underwent surgery and were found to have single-gland disease. Sestamibi scintigraphy, radiologist-performed ultrasound scan and surgeon-performed ultrasound scan had sensitivities of 59.4, 43.75 and 73.8 per cent, respectively. Surgeon-performed ultrasound scan had a statistically significantly increased sensitivity compared with radiologist-performed ultrasound (p < 0.05).

CONCLUSION

Intra-operative, surgeon-performed ultrasound scan is effective in localising parathyroid adenomas and may be a useful adjunct to facilitate minimally invasive parathyroid surgery.

Evaluation of Surgeon-Performed Ultrasonography With or Without Contrast Enhancement vs Scintigraphy in Patients With Primary Hyperparathyroidism

Importance

Scintigraphy and ultrasonography are common imaging modalities for the preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism. When comparing the 2 modalities, the benefits of ultrasonography in terms of convenience, patient comfort, duration, cost, and lack of radiation should be taken into account.

Objective

To investigate whether surgeon-performed ultrasonography, with or without contrast-enhanced ultrasonography (CEUS), is noninferior to scintigraphy for localizing pathological parathyroid glands in patients with primary hyperparathyroidism.

Design, Setting, and Participants

Prospective, paired, noninferiority cohort study performed at a high-volume tertiary referral center for parathyroidectomy with blinded examiners and a 6-month follow-up. Participants were adults (age ≥18 years) referred for parathyroidectomy due to primary hyperparathyroidism. Of 207 eligible patients, 35 were excluded, leaving 172 enrolled in the study. Inclusion lasted from September 2019 until February 2021. Follow-up ended in December 2021.

Exposures

99mTechnetium-pertechnetate/99mtechnetium-sestamibi subtraction scintigraphy with 99mtechnetium-sestamibi single-photon emission computed tomography/computed tomography, followed by surgeon-performed ultrasonography and CEUS.

Main Outcomes and Measures

The sensitivity of each imaging modality in localizing pathological parathyroid glands, calculated on a per-quadrant and a per-patient basis, respectively. The a priori noninferiority margin was a lower 95% confidence limit for the difference in sensitivity not falling below -10%.

Results

Out of 172 participants, 139 (80.8%) were women, the median (range) age was 65 (24-87) years, and the median (IQR) follow-up was 200.5 (181-280.25) days. Quadrant sensitivity (95% CI) was 70.9% (63.2%-78.5%) for ultrasonography, 68.4% (60.4%-76.5%) for ultrasonography plus CEUS, and 67.0% (60.0%-74.0%) for scintigraphy. The sensitivity difference (95% CI) compared with scintigraphy was 3.9% (-4.1% to 11.8%) for ultrasonography and 1.5% (-6.4% to 9.3%) for ultrasonography plus CEUS, establishing noninferiority for both modalities. Per-patient sensitivity was 81.4% (74.8%-86.9%) for ultrasonography and 79.1% (72.2%-84.9%) for both scintigraphy and ultrasonography plus CEUS. The sensitivity difference compared with scintigraphy was 2.3% (-6.8% to 11.4%) for ultrasonography and 0.0% (-9.1% to 9.1%) for ultrasonography plus CEUS, establishing noninferiority for both modalities.

Conclusions and Relevance

In this cohort study, conventional ultrasonography by an experienced parathyroid surgeon-sonographer was noninferior to scintigraphy and may constitute a valid first-line imaging modality in patients with primary hyperparathyroidism, even without the addition of CEUS. Further imaging should be reserved for cases that are equivocal or nonlocalizing on ultrasonography.

Investigating the effectiveness of intraoperative rapid parathyroid hormone assay in parathyroidectomy surgery in patients with secondary hyperparathyroidism

INTRODUCTION

The use of Rapid Intraoperative parathyroid hormone (Io-PTH) assay during surgery in the management of parathyroid tissue in cases of primary hyperparathyroidism has been proven to be effective, while its utilization in secondary hyperparathyroidism (SHPT) has been rarely reported. In the present study, we aim to demonstrate the application of rapid Io-PTH assay in patients with SHPT following chronic kidney disease undergoing parathyroidectomy surgery.

METHOD

In this prospective study, five blood samples were taken from patients undergoing parathyroidectomy and upper thymectomy. Among the samples, two were pre-excision, including prior to the first incision, after exploration, and before parathyroids resection. Two additional samples were taken 10 and 20 min after the excision of the parathyroid glands. Another sample was collected twenty-four hours after the operation. Serum Calcium levels and PTH levels were evaluated and analyzed.

RESULTS

We successfully managed SHPT in all 36 patients in our study. The patients included 24 males (66.7%) with a mean age of 49.97 ± 14.92. The mean PTH decreased significantly at 10 min, 20 min, one day, and six months after surgery (P < 0.001). The highest reduction occurred 10 min after removal of the parathyroid glands so the mean PTH compared to time zero was reduced from 1737 to 439, and in 100% of cases, more than 50% reduction was seen in PTH.

CONCLUSION

A 60% or more reduction in PTH Rapid at 10 min after parathyroidectomy has an accuracy of 94.4% and a positive predictive value of 100%. Thus, if the PTH level does not decrease by more than 60% at 10 min or more than 80% at 20 min, tissue exploration is continued with the aim of finding the ectopic parathyroid gland.

Surgery for primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a hypercalcemic disorder that occurs when one or more parathyroid glands produces excessive parathyroid hormone (PTH). PHPT is typically treated with surgery, and it remains the only definitive therapy, whose techniques have evolved over previous decades. Advances in preoperative localization exams and the intraoperative PTH monitoring have become the cornerstones of recent parathyroidectomy techniques, as minimally invasive techniques are appropriate for most patients. Nevertheless, these techniques, are not suitable for PHPT patients who are at risk for multiglandular disease, especially in those who present with familial forms of PHPT that require bilateral neck exploration. This manuscript also explores other conditions that warrant special consideration during surgical treatment for PHPT: normocalcemic primary hyperparathyroidism, pregnancy, reoperation for persistent or recurrent PHPT, parathyroid carcinoma, and familial and genetic forms of hyperparathyroidism.

Parathyroid Imaging: Past, Present, and Future

The goal of parathyroid imaging is to identify all sources of excess parathyroid hormone secretion pre-operatively. A variety of imaging approaches have been evaluated and utilized over the years for this purpose. Ultrasound relies solely on structural features and is without radiation, however is limited to superficial evaluation. 4DCT and 4DMRI provide enhancement characteristics in addition to structural features and dynamic enhancement has been investigated as a way to better distinguish parathyroid from adjacent structures. It is important to recognize that 4DCT provides valuable information however results in much higher radiation dose to the thyroid gland than the other available examinations, and therefore the optimal number of phases is an area of controversy. Single-photon scintigraphy with 99mTc-Sestamibi, or dual tracer 99mTc-pertechnetate and 99mTc-sestamibi with or without SPECT or SPECT/CT is part of the standard of care in many centers with availability and expertise in nuclear medicine. This molecular imaging approach detects cellular physiology such as mitochondria content found in parathyroid adenomas. Combining structural imaging such as CT or MRI with molecular imaging in a hybrid approach allows the ability to obtain robust structural and functional information in one examination. Hybrid PET/CT is widely available and provides improved imaging and quantification over SPECT or SPECT/CT. Emerging PET imaging techniques, such as 18F-Fluorocholine, have the exciting potential to reinvent parathyroid imaging. PET/MRI may be particularly well suited to parathyroid imaging, where available, because of the ability to perform dynamic contrast-enhanced imaging and co-registered 18F-Fluorocholine PET imaging simultaneously with low radiation dose to the thyroid. A targeted agent specific for a parathyroid tissue biomarker remains to be identified.

Direct Comparison of Preoperative Imaging Modalities for Localization of Primary Hyperparathyroidism: A Systematic Review and Network Meta-analysis

Importance

Accurate preoperative localization of primary hyperparathyroidism (pHPT) is an important and challenging issue for a successful parathyroidectomy. Although new imaging modalities have been introduced during the past decade, direct comparative studies on advanced imaging techniques are limited.

Objective

To compare the performance of different preoperative imaging modalities for the localization of pHPT by performing a network meta-analysis (NMA).

Data Sources

PubMed, Embase, and the Cochrane Library were searched from the earliest available indexing date through September 28, 2020.

Study Selection

The inclusion criteria were diagnostic tests with sensitivities of 2 or more different preoperative imaging modalities for the same indivduals.

Data Extraction and Synthesis

Two researchers independently reviewed the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension statement of health care intervention guidelines for network meta-analyses.

Main Outcomes and Measures

After classifying various imaging modalities into 8 representative imaging categories, the pooled estimation between the odds ratio and 95% credible intervals (CrIs) was calculated in the sensitivity for localization of pHPT. The surface under the cumulative ranking curve (SUCRA) values were obtained to calculate the probability of each imaging modality being the most effective diagnostic method.

Results

A total of 8495 patients from 119 direct comparative studies using 2 or more imaging modalities for localization of pHPT were included. The sensitivity of choline positron emission tomography and computed tomography (PET-CT) was significantly higher than that of technetium 99m sestamibi single-photon emission computed tomography (MIBI SPECT) in both patient-based and lesion-based analyses (patient-based analysis: odds ratio, 5.22; 95% CrI, 2.36-11.80; lesion-based analysis: odds ratio, 17.70; 95% CrI, 5.79-60.10). Among 8 representative imaging modality categories, choline PET-CT showed the highest SUCRA value in both patient-based and lesion-based analyses. In patient-based analysis after 2010, choline PET-CT showed the highest SUCRA value, followed by the CT category, although MIBI SPECT had the highest SUCRA value in analysis before 2009.

Conclusions and Relevance

The results from this network meta-analysis suggest that choline PET-CT showed the best performance in both patient-based and lesion-based analyses and that choline PET-CT would be the best preoperative imaging modality for localization of pHPT.

A cost-utility analysis of 18F-fluorocholine-positron emission tomography imaging for localizing primary hyperparathyroidism in the United States

BACKGROUND

Primary hyperparathyroidism historically necessitated bilateral neck exploration to remove abnormal parathyroid tissue. Improved localization allows for focused parathyroidectomy with lower complication risks. Recently, positron emission tomography using radiolabeled 18F-fluorocholine demonstrated high accuracy in detecting these lesions, but its cost-effectiveness has not been studied in the United States.

METHODS

A decision tree modeled patients who underwent parathyroidectomy for primary hyperparathyroidism using single preoperative localization modalities: (1) positron emission tomography using radiolabeled 18F-fluorocholine, (2) 4-dimensional computed tomography, (3) ultrasound, and (4) sestamibi single photon emission computed tomography (SPECT). All patients underwent either focused parathyroidectomy versus bilateral neck exploration, with associated cost ($) and clinical outcomes measured in quality-adjusted life-years gained. Model parameters were informed by literature review and Medicare costs. Incremental cost-utility ratios were calculated in US dollars/quality-adjusted life-years gained, with a willingness-to-pay threshold set at $100,000/quality-adjusted life-year. One-way, 2-way, and threshold sensitivity analyses were performed.

RESULTS

Positron emission tomography using radiolabeled 18F-fluorocholine gained the most quality-adjusted life-years (23.9) and was the costliest ($2,096), with a total treatment cost of $11,245 or $470/quality-adjusted life-year gained. Sestamibi single photon emission computed tomography and ultrasound were dominated strategies. Compared with 4-dimentional computed tomography, the incremental cost-utility ratio for positron emission tomography using radiolabeled 18F-fluorocholine was $91,066/quality-adjusted life-year gained in our base case analysis, which was below the willingness-to-pay threshold. In 1-way sensitivity analysis, the incremental cost-utility ratio was sensitive to test accuracy, positron emission tomography using radiolabeled 18F-fluorocholine price, postoperative complication probabilities, proportion of bilateral neck exploration patients needing overnight hospitalization, and life expectancy.

CONCLUSION

Our model elucidates scenarios in which positron emission tomography using radiolabeled 18F-fluorocholine can potentially be a cost-effective imaging option for primary hyperparathyroidism in the United States. Further investigation is needed to determine the maximal cost-effectiveness for positron emission tomography using radiolabeled 18F-fluorocholine in selected populations.

Preoperative Localization for Primary Hyperparathyroidism: A Clinical Review

With increasing use of minimally invasive parathyroidectomy (PTx) over traditional bilateral neck exploration in patients with primary hyperparathyroidism (PHPT), accurate preoperative localization has become more important to enable a successful surgical outcome. Traditional imaging techniques such as ultrasound (US) and sestamibi scintigraphy (MIBI) and newer techniques such as parathyroid four-dimension computed tomography (4D-CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) are available for the clinician to detect the diseased gland(s) in the preoperative workup. Invasive parathyroid venous sampling may be useful in certain circumstances such as persistent or recurrent PHPT. We review the diagnostic performance of these imaging modalities in preoperative localization and discuss the advantages and weaknesses of these techniques. US and MIBI are established techniques commonly utilized as first-line modalities. 4D-CT has excellent diagnostic performance and is increasingly performed in first-line setting and as an adjunct to US and MIBI. PET and MRI are emerging adjunct modalities when localization has been equivocal or failed. Since no evidence-based guidelines are yet available for the optimal imaging strategy, clinicians should be familiar with the range and advancement of these techniques. Choice of imaging modality should be individualized to the patient with consideration for efficacy, expertise, and availability of such techniques in clinical practice.

Use of Preoperative Imaging in Primary Hyperparathyroidism

CONTEXT

Preoperative imaging is performed routinely to guide surgical management in primary hyperparathyroidism, but the optimal imaging modalities are debated.

OBJECTIVE

Our objectives were to evaluate which imaging modalities are associated with improved cure rate and higher concordance rates with intraoperative findings. A secondary aim was to determine whether additive imaging is associated with higher cure rate.

DESIGN, SETTING, AND PATIENTS

This is a retrospective cohort review of 1485 adult patients during a 14-year period (2004-2017) at an academic tertiary referral center that presented for initial parathyroidectomy for de novo primary hyperparathyroidism.

MAIN OUTCOME MEASURES

Surgical cure rate, concordance of imaging with operative findings, and imaging performance.

RESULTS

The overall cure rate was 94.1% (95% confidence interval, 0.93-0.95). Cure rate was significantly improved if sestamibi/single-photon emission computed tomography (SPECT) was concordant with operative findings (95.9% vs. 92.5%, P = 0.010). Adding a third imaging modality did not improve cure rate (1 imaging type 91.8% vs. 2 imaging types 94.4% vs. 3 imaging types 87.2%, P = 0.59). Despite having a low number of cases (n = 28), 4-dimensional (4D) CT scan outperformed (higher sensitivity, specificity, positive predictive value, negative predictive value) all imaging modalities in multiglandular disease and double adenomas, and sestamibi/SPECT in single adenomas.

CONCLUSIONS

Preoperative ultrasound combined with sestamibi/SPECT were associated with the highest cure and concordance rates. If pathology was not found on ultrasound and sestamibi/SPECT, additional imaging did not improve the cure rate or concordance. 4D CT scan outperformed all imaging modalities in multiglandular disease and double adenomas, and sestamibi/SPECT in single adenomas, but these findings were underpowered.

Stepwise Approach for Parathyroid Localisation in Primary Hyperparathyroidism

INTRODUCTION

Primary hyperparathyroidism (PHPT) is a relatively common condition in surgical practice. Availability of localisation studies has shifted the treatment from bilateral neck exploration to selective parathyroidectomy. Several imaging modalities, each with varying sensitivities, are available to detect abnormal parathyroid glands. Ultrasound is almost universally accepted as the first line radiological investigation however its sensitivity is particularly heterogeneous and operator-dependent.

MATERIAL AND METHODS

We studied 250 consecutive patients with PHPT who underwent parathyroidectomy in our hospital over a period of 33 months. Pre-operative neck ultrasound, 99mTc-sestamibi and single-photon emission computed tomography (SPECT CT) were performed in 249, 237 and 198 patients respectively. Unilateral and bilateral neck exploration was performed in 190 and 60 patients, respectively. Sensitivity, positive predictive value (PPV) and accuracy were calculated comparing the results with surgical and pathology findings.

RESULTS

Mean pre and postoperative PTH and adjusted calcium were, 11 ± 10.6 pmol/L, 1.9 ± 3.6, 2.81 ± 0.2 and 2.45 ± 0.2 mmol/L. There were 71 (29.95%) discordant results between US, compared to sestamibi and SPECT CT. An average of 1.9 parathyroid glands were removed with a mean weight of 0.92 g. Overall success rate based on postoperative PTH levels was 94.8%. Overall sensitivity, PPV and accuracy for US were 80.80%, 92.35%, and 75.73% respectively; for sestamibi were 71.82%, 94.61%, 69.00% and for SPECT CT were; 70.21%, 97.78%, 69.11% respectively.

CONCLUSION

Ultrasound performed by an experienced specialist sonographer is highly sensitive in localising abnormal parathyroid glands. It can be used as a main and sole investigation in the majority of patients. Sestamibi, SPECT CT and other investigations should be performed in a step-wise manner and reserved for patients with negative US, failed primary procedure and recurrences.

Gonioprobe, an Innovative Gamma-probe to Guide Parathyroid Radioguided Surgery: First Clinical Experiences with Navigator and Lock-ontarget Functions

BACKGROUND

Radioguided surgery represents a validated technique for the detection and the excision of abnormal parathyroid glands responsible for primary hyperparathyroidism (PHPT). To date little attention has been paid as to how the characteristics of gamma-probes can influence surgical procedure and time, thus having an impact on postoperative morbidity, hospitalization and costs.

METHODS

We designed a new prototype of gamma-probe, the Gonioprobe, and tested its clinical utility in the operating room. Gonioprobe, thanks to its 5 scintillating independent crystals, performs the dual function of Navigator and Lock-on-target. These characteristics allow the immediate guidance of the surgeon's hand towards the source with very high precision, and with a much higher spatial resolution than commercial probes. Gonioprobe was used during intervention to detect abnormal parathyroid tissue, and to ensure no radioactivity in surgery bed after adenoma removal.

RESULTS

We tested our gamma-probe on parathyroid adenomas particularly difficult to identify at a visual inspection due to anatomy modifications from previous neck surgery and/or characterized by uncommon localization. Moreover, parathyroid adenomas were hardly removable due to the proximity to the esophagus, neck vessels and/or recurrent laryngeal nerve (RLN). An intraoperative nerve monitoring system was used to protect the recurrent laryngeal nerve from injuries. Parathyroid hormone (PTH) assay and frozen biopsy confirmed the successful excision of the adenomas.

CONCLUSION

The intraoperative use of the innovative Gonioprobe along with the nerve monitoring system allowed an accurate and safe removal of parathyroid adenomas and offered a significant advantage by reducing surgical time and postoperative complications, as well as hospitalization and costs.

Added value of ultrasonography and Tc-99m MIBI SPECT/CT combined protocol in preoperative evaluation of parathyroid adenoma

•

Concomitant use of ultrasonography and MIBI-SPECT/CT is highly recommended for better depiction of parathyroid adenoma.

•

It also helps in accurate localization of parathyroid adenoma especially those of ectopic location.

•

It will provide better success for parathyroid exploration and minimally invasive surgery.

Purpose

Evaluating the diagnostic performance of combined protocol of ultrasonography and Tc-99 m MIBI SPECT/CT in preoperative depiction and localization of parathyroid adenoma.

Methods and materials

60 patients were enrolled in this retrospective study who had primary hyperparathyroidism and parathyroidectomy for parathyroid adenoma, all of them underwent ultrasonography examination of parathyroid gland and MIBI SPECT/CT for exact pre-operative localization of parathyroid adenoma, surgical and pathological results were used as standard reference then sensitivity, specificity and accuracy for each modalility and for combined protocol of both modalities was calculated.

Results

The sensitivity, specificity and accuracy were highest with combined protocol of ultrasonography and MIBI-SPECT/CT (87 %), (71 %) and (85 %) respectively and lowest sensitivity, specificity and accuracy with ultrasonography alone (76 %), (63 %) and (73 %) respectively while (83 %), (66 %) and (80 %) with MIBI-SPECT/CT alone.

Conclusion

Concomitant use of ultrasonography and MIBI SPECT/CT is highly recommended for better preoperative depiction and localization of parathyroid adenoma.

Actual role of color-doppler high-resolution neck ultrasonography in primary hyperparathyroidism: a clinical review and an observational study with a comparison of 99mTc-sestamibi parathyroid scintigraphy

PURPOSE

Primary hyperparathyroidism (PHPT) is a frequent endocrine pathology that has surgical treatment as its only decisive measure. High-Resolution Neck Ultrasonography with color-Doppler (CDHR-NUS) and 99mTechnetium-SestaMIBI Parathyroid Scintigraphy (99mTc-MIBI PS) are the two instrumental exams more commonly used in the preoperatory localization of pathologic parathyroids. The aim of this observational study was to outline-in accordance with the latest scientific literature-the precise role of CDHR-NUS in the environment of PHPT, comparing it with that of Parathyroid Scintigraphy.

METHODS

136 patients operated on for PHPT and underwent CDHR-NUS and 99mTc-MIBI PS preoperatively. The CDHR-NUS was carried out by an expert medical sonographer. The results of the two methods were compared between each other and with the results of the operative act for the evaluation of accordance and diagnostic performances.

RESULTS

PHPT is prevalently due to monoglandular pathology (SGD). The parallel use of CDHR-NUS and of 99mTc-MIBI PS does not determine a significant increase in diagnostic accuracy. The preoperative accordance evaluation between the two methods does not exclude the presence of multiglandular pathology (MGD) with certainty.

CONCLUSIONS

CDHR-NUS is an accurate as well as cost-effective method; its role as a main and eventual unique preoperative localization method in patients affected by PHPT is confirmed. In the presence of expert medical sonographers, the sequential use of the two methods is retained correct and their use in parallel is neither justified nor cost-effective. The preoperative accordance evaluation between the two methods is neither necessary nor indispensable.

Efficacy of Scintigraphy, Ultrasound and Both Scintigraphy and Ultrasonography in Preoperative Detection and Localization of Primary Hyperparathyroidism

Objective: The aim of our study was to evaluate the efficacy of preoperative dual-phase 99mTc-methoxyisobutylnitrile (MIBI) parathyroid scintigraphy (PS), and ultrasound (US) in primary hyperparathyroidism (pHPT) diagnosis and compare the results with the surgical findings.

Methods: Forty-five patients were enrolled in this study. Preoperative serum parathyroid hormone (PTH) levels, calcium (Ca), phosphate (P), and alkaline phosphatase (AP) levels were measured. All parathyroid patients were evaluated by ultrasonography, dual phase 99mTc-MIBI. Surgical findings were used as a reference standard.

Results: Of the 45 patients included in this study, 30 were females (66.7%) with an age range between 30 years and 70 years (mean age 41± 13). The sensitivity and specificity of 99mTc-MIBI scintigraphy was 97.4% and 71.4%, respectively, while the sensitivity of ultrasound was 94.4% and specificity 44.4%. The sensitivity, specificity, and accuracy of combined scintigraphy and ultrasound was higher-97.4%, 83.3%, and 95.6%, respectively.

Conclusions: The combination of MIBI and US appears promising for localizing parathyroid pathology in patients with primary hyperparathyroidism. The concordance rate is high together with a lower chance of missing concomitant thyroid pathology, which might alter the surgical approach.

American Head and Neck Society Endocrine Surgery Section update on parathyroid imaging for surgical candidates with primary hyperparathyroidism

Health care consumer organizations and insurance companies increasingly are scrutinizing value when considering reimbursement policies for medical interventions. Recently, members of several American Academy of Otolaryngology-Head & Neck Surgery (AAO-HNS) committees worked closely with one insurance company to refine reimbursement policies for preoperative localization imaging in patients undergoing surgery for primary hyperparathyroidism. This endeavor led to an AAO-HNS parathyroid imaging consensus statement (https://www.entnet.org/content/parathyroid-imaging). The American Head and Neck Society Endocrine Surgery Section gathered an expert panel of authors to delineate imaging options for preoperative evaluation of surgical candidates with primary hyperparathyroidism. We review herein the current literature for preoperative parathyroid localization imaging, with discussion of efficacy, cost, and overall value. We recommend that planar sestamibi imaging, single photon emission computed tomography (SPECT), SPECT/CT, CT neck/mediastinum with contrast, MRI, and four dimensional CT (4D-CT) may be used in conjunction with high-resolution neck ultrasound to preoperatively localize pathologic parathyroid glands. PubMed literature on parathyroid imaging was reviewed through February 1, 2019.

Update of the role of Nuclear Medicine techniques in the pre-surgical localization of primary hyperparathyroidism

Primary hyperparathyroidism is one of the most frequent endocrine disorders. Its diagnosis is biochemical. Imaging techniques are not useful for the diagnosis of this pathology; they are just tools for pre-surgical localization. In this continuing education, we will analyze the different imaging modalities used in this indication, focusing on Nuclear Medicine. The most commonly used imaging technique in this context is the parathyroid scintigraphy, nowadays double phase protocol with ^99mTc-MIBI and the double tracer with ^99mTc-MIBI/^99mTc-pertechnetate, associated in the first case to SPECT or SPECT/CT, in an early or late phase. The PET/CT with different tracers is showing good results, especially applied to cases of failure in the pre-surgical scintigraphic localization. We expose the results of the morphological imaging techniques as well as the usefulness of combining techniques.

Twin pregnancy with triple parathyroid adenoma: A case report and review of literature

Primary hyperparathyroidism (PHPT) is rare during pregnancy. A case of twin pregnancy with three simultaneous parathyroid adenomas at the same time has not been reported. Multiple parathyroid lesions are difficult to diagnose, as pregnant women who insist upon continuing a pregnancy are not able to undergo 99mTc-sestamibi scintigraphy, so cases of PHPT are easily unobserved and often can have serious consequences for the patient and the fetus. Therefore, we reported a case of a 28-year-old woman mid-pregnancy with twins, who had hypercalcemia and was eventually diagnosed with twin pregnancy with PHPT due to a triple parathyroid adenoma, had good pregnancy outcomes after undergoing surgery in mid-pregnancy. Twin pregnancy with PHPT due to a triple parathyroid adenoma, as presented in this case, is very rare and surgery in mid-pregnancy is demonstrated here as safe. Intraoperative parathormone monitoring was and remains key to a successful operation.

A rural perspective on minimally invasive parathyroidectomy: optimal preoperative imaging and patient outcomes

BACKGROUND

Our retrospective review of prospectively collected data evaluated the efficacy of minimally invasive parathyroidectomy (MIP) and compared preoperative imaging modalities in a rural referral centre.

METHODS

Patients with a diagnosis of primary hyperparathyroidism underwent surgeon-performed ultrasound (SUS) and technetium-99 m sestamibi (MIBI). Radiologist-performed ultrasound (RUS) was sought when the diagnosis remained in doubt. Four-dimensional computed tomography (4DCT) first replaced RUS in mid-2014, then MIBI as a frontline modality in 2015. MIP was conducted if possible and bilateral neck exploration (BNE) when localization remained doubtful. Treatment was evaluated by histopathology and serum parathyroid hormone and calcium levels at 6 weeks.

RESULTS

A total of 122 of 165 (73.9%) glands were removed by MIP and 43 of 165 (26.1%) by BNE. Of 15 cases with non-localizing preoperative investigations, one patient had a negative BNE. A total of 160 of 165 (97.0%) patients underwent a successful operation, with five (3.0%) suffering persistent post-operative hypercalcaemia. SUS had a sensitivity of 79.4% (131/165) and a positive predictive value (PPV) of 97.0% (131/135). MIBI had a sensitivity of 60.0% (81/135) and a PPV of 95.3% (81/85). RUS produced a sensitivity of 65.5% (76/116) and PPV of 98.7% (76/77). When used as a second-line modality, 4DCT had a sensitivity of 76.9% (10/13) and PPV of 100%. The sensitivity and PPV were 85.7% (18/21) and 94.7% (18/19) after 4DCT's promotion to first-line use.

CONCLUSION

MIP can be safely performed in rural centres of adequate volume. We recommend that operations be guided by SUS with routine use of an adjunctive modality. Our study has seen 4DCT replace MIBI in this regard.

The Role of In-Office Ultrasound in the Diagnosis of Neck Masses

To evaluate the efficacy of otolaryngologist-performed in-office ultrasound (US) in the clinical assessment of lateral neck masses, we performed a retrospective review of patients with lateral neck masses who had both a surgeon-performed US and US-guided fine-needle aspiration (USGFNA) at our tertiary academic center from 2012 to 2015. Fifty-nine patients were included. USGFNA results included 32 (54%) malignant lesions, 23 (39%) benign lesions, and 4 (6%) nondiagnostic lesions. USGFNA demonstrated 85% accuracy. In 22 (37%) patients, in-office US revealed additional findings that were not identified on physical examination (eg, nonpalpable lymph nodes or elucidated anatomical structures), which either assisted in surgical planning or altered treatment. In-office US and USGFNA on initial evaluation by the otolaryngologist augment physical examination and have potential value as the primary imaging and diagnostic modality in the workup of lateral neck masses.

Minimally Invasive Parathyroidectomy Versus Bilateral Neck Exploration for Primary Hyperparathyroidism

Primary hyperparathyroidism is a disease that is caused by excess parathyroid hormone (PTH) secretion from 1 or more of the parathyroid glands. Surgery is the only cure. Traditional surgical management consists of a 4-gland cervical exploration. Development of imaging specific to identification of parathyroid glands and application of the rapid PTH assay to operative management have made more minimal exploration possible. There are distinct advantages and disadvantages of minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE). The advantages of MIP seem to outweigh those of BNE, and MIP has replaced BNE as the operation of choice by many surgeons.

Surgical treatment of primary hyperparathyroidism due to parathyroid tumor: A 15-year experience

The aim of this study was to highlight our experience over a 15-year period in dealing with primary hyperparathyroidism (PHPT) due to a parathyroid tumor. Parathyroidectomy is the standard therapy for patients with PHPT. Our study included all patients with PHPT treated by parathyroidectomy at the Affiliated Cancer Hospital of Zhengzhou University, China. Between 1998 and 2013, a total of 107 patients were recruited. Their clinical data, presentation, laboratory examinations, imageological diagnoses and surgical approaches were analyzed retrospectively. Eighty-four cases (78.5%) were followed up. During a median follow-up period of 5.7 years, a total of 80 patients were without recurrence and metastasis. The main symptoms of PHPT patients were palpable neck mass, joint pains and pathological fracture. The high levels of preoperative parathyroid hormone (PTH) and serum calcium in PHPT patients decreased to below the normal upper limit within 3 days of surgery. The sensitivity of neck ultrasonography, sestamibi scanning, CT, MRI and the combination of three or four types of test were 86.0%, 90.4%, 80.8%, 79.6% and 96.1%, respectively. A 50% or greater drop in PTH levels within 20 min compared with the highest PTH levels before surgery occurred in 95/107 cases (88.8%). Transient hypocalcemia was the most common surgical complication. The ultrasonography and sestamibi scan is the most effective examination for parathyroid tumor. The 20 min PTH measurement appears to be extremely useful, and avoids unnecessary bilateral exploration.

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

AIM

To evaluate the value of ^99mTc-MIBI double-phase scintigraphy (DPS) and early SPECT/CT in the pre-surgical assessment of patients with primary hyperparathyroidism (PHPT). Also, to calculate the correlation between uptake and some biological parameters.

MATERIAL AND METHODS

Forty patients with PHPT were included: 37 solitary adenomas, 1 hyperplasia, and 2 double adenomas. Fifteen patients had ectopic glands. DPS and early SPECT/CT were acquired in all patients. Ultrasound was performed in 31/40. All patients underwent surgery, intra-operative iPTH measurements, and histopathological examinations. Qualitative DPS uptake was assessed and correlated to pre-surgical calcium, iPTH levels, gland weight, and maximum diameter.

RESULTS

In the planar study, there were 23 positive cases, 8 doubtful, and 9 negatives. With the SPECT/CT, 8/9 negatives cases were located. All doubtful cases were confirmed as positives. Gland location improved in 16 cases (12 ectopic). DPS+SPECT/CT failed to detect a solitary adenoma and at least one gland in three cases of multiglandular disease (MGD). The sensitivity by patient was: DPS 72.5%, DPS+SPECT/CT 90%, and ultrasound 42%. Ultrasound and scintigraphy (DPS+SPECT/CT) were concordant in 16/31 patients. For the rest of them, scintigraphy proved correct in 14/15, and both techniques failed in one case. There was a significant correlation between level of uptake and iPTH level, gland weight, and maximum diameter.

CONCLUSION

Early SPECT/CT improves sensitivity and the locating of parathyroid pathological glands and increases diagnostic confidence. iPTH level, glandular size, and weight are related to the qualitative assessment of ^99mTc-MIBI uptake in early DPS.

Sporadic multiple parathyroid gland disease--a consensus report of the European Society of Endocrine Surgeons (ESES)

BACKGROUND

Sporadic multiglandular disease (MGD) has been reported in literature in 8-33 % of patients with primary hyperparathyroidism (pHPT). This paper aimed to review controversies in the pathogenesis and management of sporadic MGD.

METHODS

A literature search and review was made to evaluate the level of evidence concerning diagnosis and management of sporadic MGD according to criteria proposed by Sackett, with recommendation grading by Heinrich et al. and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Results were discussed at the 6th Workshop of the European Society of Endocrine Surgeons entitled 'Hyperparathyroidism due to multiple gland disease: An evidence-based perspective'.

RESULTS

Literature reports no prospective randomised studies; thus, a relatively low level of evidence was achieved. Appropriate surgical therapy of sporadic MGD should consist of a bilateral approach in most patients. Unilateral neck exploration guided by preoperative imaging should be reserved for selected patients, performed by an experienced endocrine surgeon and monitored by intraoperative parathormone assay (levels of evidence III-V, grade C recommendation). There is conflicting or equally weighted levels IV-V evidence supporting that cure rates can be similar or worse for sporadic MGD than for single adenomas (no recommendation). Best outcomes can be expected if surgery is performed by an experienced parathyroid surgeon working in a high-volume centre (grade C recommendation). Levels IV-V evidence supports that recurrent/persistence pHPT occurs more frequently in patients with double adenomas hence in situations where a double adenoma has been identified, the surgeon should have a high index of suspicion during surgery and postoperatively for the possibility of a four-gland disease (grade C recommendation).

CONCLUSIONS

Identifying preoperatively patients at risk for MGD remains challenging, intraoperative decisions are important for achieving acceptable cure rates and long-term follow-up is mandatory in such patients.

Ultrasonography alone can reliably locate parathyroid tumours and facilitates minimally invasive parathyroidectomy

INTRODUCTION

Minimally invasive parathyroidectomy (MIP) is performed via a short incision (≤3cm). Previous studies have employed multiple imaging modalities including ultrasonography, sestamibi imaging and/or intraoperative parathyroid hormone assay. We present our eight-year experience of MIP using ultrasonography alone.

METHODS

One hundred parathyroidectomies performed by a single surgeon between April 2004 and December 2012 were identified in a prospectively maintained database. All patients underwent ultrasonography including preoperative marking of the lesion by a single radiologist. No other localising diagnostic tests were performed.

RESULTS

Of the 100 patients (69% female) who underwent parathyroidectomy, 93 had MIP. The median age of all cases was 58 years (range: 19-90 years). All patients exhibited an elevated parathyroid hormone level (median: 19pmol) in the presence of hypercalcaemia (median: 2.86mmol/l, range: 2.54-3.94mmol/l). Conventional surgery was indicated in seven patients owing to the need for concurrent thyroidectomy. The median operative time was 30 minutes (range: 10-130 minutes). Ultrasonography localised parathyroid tumour position correctly in 98% of patients who underwent MIP, and in 97% across both MIP and non-MIP groups. Postoperative complications requiring treatment included pancreatitis and symptomatic hypocalcaemia. Follow-up review at 6-8 weeks demonstrated that 86% of open cases (6/7) and 94% of MIP cases (87/93) were rendered normocalcaemic.

CONCLUSIONS

Our study is the first to demonstrate that the sole use of ultrasonography including preoperative marking can localise parathyroid tumours correctly in 98% of cases suitable for MIP.

Ultrasound training among endocrine oncology surgeons: what is best practice?

Background: We aimed to determine training levels and utilization of surgeon-performed ultrasound (SPUS) among endocrine surgeons. Methods: Survey of American Association of Endocrine Surgeons members and recent endocrine surgery fellowship graduates. Results: Thirty-four percent (165/481) recipients completed the survey. Of 60% endocrine surgery fellowship-trained surgeons, 58% performed ultrasound during fellowship and 18% during residency. Currently, 65% employ SPUS, with significant variability: 31% without biopsy; 60% not in the operating room; 39% for lymph node mapping; 22% for long-term thyroid cancer surveillance. SPUS altered surgical decision making ‘sometimes’ (>50%) or ‘most of the time’ (31%). Support for ‘rich ultrasound exposure’ was nearly universal. Although 76% felt comfortable with SPUS interpretation, 43% nevertheless obtained additional radiology-performed ultrasound. The majority (53%) rated SPUS as ‘indispensable’. Conclusion: Ultrasound is employed by a growing number of endocrine surgeons, who view it as necessary for clinical practice though usage patterns differ. Formal SPUS education during fellowship training appears advantageous.

Radioguided Parathyroidectomy with Portable Mini Gamma-Camera for the Treatment of Primary Hyperparathyroidism

Background. A proper localisation of pathological parathyroid glands is essential for a minimally invasive approach in the surgical treatment of primary hyperparathyroidism (PHP). The recent introduction of portable mini gamma-cameras (pMGCs) enabled intraoperative scintigraphic scanning. The aim of our study is to evaluate the efficacy of this new method and compare it with the preoperative localisation surveys. Methods. 20 patients were studied; they were evaluated preoperatively by neck ultrasound and (99mm)Tc-sestaMIBI-scintigraphy and intraoperatively with the pMGC IP Guardian 2. The results obtained from the three evaluations were compared. Results. The pMGC presented a sensitivity of 95%, a specificity of 98.89%, and a diagnostic accuracy of 98.18%, which were higher than those of preoperative ultrasound (sensitivity 55%; specificity 95%; diagnostic accuracy 87%) and scintigraphy with (99mm)Tc-sestaMIBI (sensitivity 73.68%; specificity 96.05%; diagnostic accuracy 91.58%). Conclusions. The pMGC can be used effectively as an intraoperative method to find the correct location of the pathological parathyroid glands. The pMGC is more reliable than the currently used preoperative and intraoperative localisation techniques.

An analysis of whether surgeon-performed neck ultrasound can be used as the main localizing study in primary hyperparathyroidism

BACKGROUND

Tc-99 sestamibi (MIBI) scan is the imaging study most frequently used in primary hyperparathyroidism (PHP). Transcutaneous cervical ultrasonography (US) is the other modality used for preoperative localization. The aim of this study was to determine whether surgeon-performed neck US can be used as the primary localizing study in PHP.

METHODS

This was a prospective study of 1,000 consecutive patients with first-time, sporadic PHP who underwent parathyroidectomy at a tertiary academic center. All patients had surgeon-performed neck US and MIBI before bilateral neck exploration.

RESULTS

The findings at exploration were 72% single adenoma, 15% double adenoma, and 13% hyperplasia. When US suggested single-gland disease (n = 842), MIBI was concordant in 82.5%, discordant and false in 8%, negative in 7%, and discordant but correct in 2.5%. When US suggested multigland disease (n = 68), MIBI was concordant in 47%, discordant and false in 41%, and negative in 12%. When US was negative (n = 90), MIBI was positive and correct in 43%, negative in 31%, and positive but false in 26%. Surgeon-performed neck US identified unrecognized thyroid nodules in 326 patients (33%), which led to fine-needle aspiration biopsy in 161 (49%) patients and thyroid surgery in 103 (32%) patients, with a final diagnosis of thyroid cancer in 24 (7%) patients.

CONCLUSION

Our results show that MIBI provides additional useful information in only a minority of patients with a positive US in PHP. Nevertheless, MIBI benefits about half of patients with a negative US. Because one-third of this patient population has unrecognized thyroid nodules as well, we propose that the most cost-effective algorithm would be to do US first and reserve MIBI for US-negative cases.

Increased prediction of right nonrecurrent laryngeal nerve in thyroid surgery using preoperative computed tomography with intraoperative neuromonitoring identification

Background

A nonrecurrent laryngeal nerve (NRLN) is a rare but potentially serious anatomical variant. Although the incidence is reported to be 0.3% to 1.3%, it carries a much higher risk of palsy during thyroid surgery. The objective of this study is to investigate the usefulness of computed tomography (CT) for preoperative identification and intraoperative neuromonitoring identification (IONM) of NRLN in thyroid cancer patients.

Methods

The preoperative neck CT scans from 1,574 patients who needed thyroid surgery were examined. Absence of the brachiocephalic artery (BCA) and the presence of arteria lusoria were defined as positive with NRLN. Systematic intraoperative neuromonitoring (IONM) was also carried out for these 1,574 patients to localize and identify NRLN. A negative electromyography (EMG) response from lower vagal stimulation but a positive EMG response from the upper position indicated the occurrence of an NRLN.

Results

Nine NRLN (0.57%) were intraoperatively identified out of the 1,574 patients, and no patient with a NRLN showed preoperative clinical symptoms related to NRLN. Prior to the operation, surgeons identified only seven suspected NRLN cases based on identification of arteria lusoria. But a review of CT scans revealed that all cases could be identified by vascular anomalies. All patients were successfully detected at an early stage of operation using intraoperative neuromonitoring (IONM). Postoperative vocal cord function was normal in all patients.

Conclusions

CT of the neck is a reliable method for predicting NRLN before thyroid cancer surgery. However, some image features can be easily missed. Neurophysiology helps the surgeon to identify the NRLNs more precisely. Combining the two evaluation methods may decrease the incidence of nerve palsy, especially in cases of NRLN. Considering that CT is expensive, requires an X-ray, and achieves less information than ultrasound (US) concerning thyroid nodules, we suggest that applying US and IONM is more reasonable.

The biochemical severity of primary hyperparathyroidism correlates with the localization accuracy of sestamibi and surgeon-performed ultrasound

BACKGROUND

Minimally invasive parathyroidectomy for primary hyperparathyroidism is dependent on preoperative localization, commonly with ultrasound and sestamibi imaging. This study sought to determine if preoperative serum calcium and parathyroid hormone (PTH) levels correlate with localization sensitivity and positive predictive value (PPV).

STUDY DESIGN

This is a retrospective analysis of a prospective database of 1,910 patients with primary hyperparathyroidism from 2002 to 2013, who had surgeon-performed ultrasound and/or sestamibi for preoperative localization. The sensitivity and PPV of ultrasound and sestamibi were analyzed by degree of preoperative serum calcium and parathyroid hormone level perturbation.

RESULTS

In 1,910 parathyroidectomy patients, ultrasound was localizing in 1,411 of 1,644 (86%) and sestamibi in 802 of 1,165 (69%) (p < 0.01). The PPV of ultrasound was 1,135 of 1,411 (80%) and sestamibi was 705 of 802 (88%) (p < 0.01). Using logistic regression analysis, there was statistically significant positive correlation between localization and preoperative serum calcium for both sestamibi (odds ratio [OR] 1.21 [95% CI 1.00 to 1.47; p < 0.05]) and ultrasound (OR 1.29 [95% CI 1.03 to 1.60; p < 0.05]). There was a weak, but statistically significant positive correlation of PTH with sestamibi localization (OR 1.00 [95% CI 1.00 to 1.01; p < 0.05]). There was no statistically significant correlation between the PPV and serum calcium or PTH for either study. When patients were divided into quartiles of preoperative serum calcium and PTH levels, localization rates and PPV of both ultrasound and sestamibi increased with higher calcium and PTH levels. Surgeon-performed ultrasound had higher localization rates than sestamibi, with lower calcium and PTH values. Sestamibi demonstrated higher PPV values across all quartiles.

CONCLUSIONS

Surgeon-performed ultrasound and sestamibi have higher localization rates and PPV, with increasing preoperative serum calcium and PTH levels. Surgeon-performed ultrasound may be a better initial test for patients with lower calcium (<10.5 mg/dL) and PTH (<90 pg/mL) values due to significantly higher localization rates; however, a localizing sestamibi has higher PPV.

A novel technique to improve the diagnostic yield of negative sestamibi scans

INTRODUCTION

Minimally invasive parathyroidectomy is successful in achieving cure for most patients with primary hyperparathyroidism. Most surgeons rely on preoperative imaging as part of the workup for localization. Ultrasonography and sestamibi are the 2 most commonly used preoperative imaging studies. When these 2 studies are positive and concordant the preoperative localization is straightforward. However, when ≥1 of these studies is negative, the preoperative localization is suspect. We hypothesize that the yield of useful localizing information from "negative" sestamibi scans can be increased in certain situations. Specifically, in cases where the thyroid lobe length seen on sestamibi is discordant from the lobe length of the ultrasonography, this often represents a "hidden" parathyroid adenoma. If our hypothesis is correct, this could lead to decreased resource utilization in cases of nonlocalized parathyroid adenomas.

METHODS

We retrospectively analyzed our database of patients with primary hyperparathyroidism who underwent parathyroidectomy from 2005 to 2011. The anteroposterior views of early phase sestamibi were analyzed for thyroid lobe lengths. A ratio of the length of the right lobe to left lobe was calculated. The thyroid lobe lengths on ultrasonography were measured and similar ratios were calculated. The difference in ratios between sestamibi and ultrasonography was calculated for each patient. A difference in ratios from sestamibi and ultrasonography that corresponded with a "hidden" parathyroid on the side of the additional length on sestamibi at the time of surgery was considered a positive finding. When the difference in ratios from the 2 images did not correspond with a "hidden" parathyroid at the time of operation, it was considered a negative finding.

RESULTS

There were 59 patients with single-gland disease, negative sestamibi, and images available for review. There were 32 patients (54%) with the positive finding of a "hidden" parathyroid corresponding with a difference in thyroid lobe length ratios from sestamibi and ultrasonography. The overall mean difference in ratios between sestamibi and ultrasonography was 0.37 ± 0.32. The mean ratio difference in the group of patients with a negative "hidden" parathyroid was 0.11 ± 0.02, and the mean ratio difference in the group of patients with a positive "hidden" parathyroid was 0.58 ± 0.05 (P < .001). When a difference in ratios of ≥0.23 was obtained, this predicted a "hidden" parathyroid with a sensitivity of 93.8% and specificity of 85.2%. There were 39 patients with multigland disease, negative sestamibi, and images available for review. None of these patients had a ratio difference of ≥0.23. The mean ratio difference for patients with multigland disease was significantly lower than that of the single-gland disease (0.08 ± 0.06 vs 0.37 ± 0.32; P < .001).

CONCLUSION

Discordance between thyroid lobe lengths on the early phase sestamibi compared with ultrasonography has led to successful preoperative identification of parathyroid adenomas, even though the sestamibi was traditionally read as negative. This finding has not been previously described, seems to be reliable, and can lead to improved preoperative localization and decreased resource utilization in this subset patients.

Otolaryngologist-performed head and neck ultrasound: outcomes and challenges in learning the technique

Objective:

To assess the feasibility and accuracy of otolaryngologist-performed ultrasound in evaluating head and neck pathology.

Method:

An ENT trainee, who had undergone basic training in neck ultrasonography, performed this on patients referred with suspected neck pathology. The trainee recorded the presence and nature of any abnormality. Findings were compared with those from a repeated scan performed by an experienced head and neck radiologist.

Results:

The study included 250 patients. The absence or presence of lesion as reported by the trainee correlated with the radiologist's findings in 207 cases (83 per cent). There were 144 true positives, 63 true negatives, 32 false negatives and 11 false positives, yielding a sensitivity of 82 per cent, specificity of 85 per cent and accuracy of 83 per cent. Of the 144 true positive lesions, 81 per cent were interpreted concordantly with the radiologist.

Conclusion:

Neck ultrasonography performed by an otolaryngologist is less accurate than that performed by an experienced radiologist, but is still a useful adjunct to clinical assessment, facilitating assessment in a ‘one-stop’ clinical setting.

Operative treatment of primary hyperparathyroidism: balancing cost-effectiveness with successful outcomes

Parathyroidectomy is the most cost-effective treatment for hyperparathyroidism. Randomized prospective trials have shown no difference in cure rate between focused parathyroidectomy and bilateral exploration. Costs of the two techniques differ depending on the preoperative and intraoperative localization used, speed of the operation, ability to discharge the patient on the same day as the operation, cure rate, and complications. It may be less costly and more effective to use a policy of routine 4-gland exploration without the use of preoperative or intraoperative localization studies. The potential economic impact and the expected outcome of the various strategies should be formally evaluated.

Factors in conversion from minimally invasive parathyroidectomy to bilateral parathyroid exploration for primary hyperparathyroidism

BACKGROUND

Ongoing experience has documented equivalence of minimally invasive parathyroidectomy (MIP) and standard bilateral parathyroid exploration (BPE) for primary hyperparathyroidism in most patients; however, intraoperative conversion of MIP to BPE is required for multiple indications. This study analyzes the factors, predictors, and cure rates in converted MIP.

METHODS

We retrospectively analyzed a database of 1,002 patients undergoing initial parathyroidectomy for primary hyperparathyroidism from 2008 to 2011 for rate of successful MIP, converted MIP, planned BPE, and factors leading to conversion from MIP to BPE.

RESULTS

Of 989 included parathyroidectomies, 647 (65%) were successful MIP, 186 (19%) were converted MIP, and 156 (16%) were planned BPE. The most common indication for conversion included intraoperative parathyroid hormone (IOPTH) criteria not met (46%), localization incorrect (36%), and evidence of multigland disease (17%). Converted MIP had lower preoperative calcium and PTH and lower baseline IOPTH compared with successful MIP. Complication rates were similar; however, rates of persistent hyperparathyroidism were highest in converted MIPs (6%) versus planned BPEs (3%) and successful MIPs (2%; P < .01).

CONCLUSION

Patients requiring conversion of MIP to BPE have lower preoperative serum calcium and PTH levels, a less dramatic decrease in IOPTH, and a greater rate of persistent disease than successful MIP.

Predictors of accuracy in preoperative parathyroid adenoma localization using ultrasound and Tc-99m-Sestamibi: a 4-quadrant analysis

PURPOSE

To compare the accuracy of preoperative parathyroid adenoma localization in patients with primary hyperparathyroidism (pHPT) due to a single adenoma using a detailed 4-quadrant analysis and to identify patient and tumor characteristics associated with accurate preoperative localization.

MATERIALS AND METHODS

Retrospective review of 203 patients who underwent parathyroidectomy for pHPT due to a single adenoma between 2008 and 2011. Results from preoperative ultrasound and Tc-99m-sestamibi were compared to operative findings to determine accuracy of localization studies. Associations between clinicopathologic features and accurate preoperative adenoma localization were evaluated.

RESULTS

Ultrasound was performed on 198 patients, sestamibi on 177 patients, and both on 172 patients. Accurate localization occurred significantly more often for ultrasound than sestamibi (63% vs. 41%, P<0.001). For ultrasound, accurate localization was found in patients with larger or heavier adenomas, those with adenomas located inferiorly, patients not having a reoperative procedure, and patients with higher post-operative serum calcium levels. For sestamibi, greater adenoma size or weight, adenomas located inferiorly, and patients with associated thyroid cancer on pathology were most predictive of accurate preoperative localization.

CONCLUSIONS

Our results provide evidence that ultrasound is more accurate in localizing parathyroid adenomas in patients with pHPT due to a single adenoma when compared to sestamibi scan using 4-quadrant location analysis and may be the preferred preoperative imaging modality in these patients. No significant preoperative patient factors were associated with accurate localization by ultrasound or sestamibi, but adenoma size, weight, and location in an inferior position were predictive of accurate preoperative localization.

Preoperative Localization of Parathyroid Adenomas Using 4-Dimensional Computed Tomography: A Pictorial Essay

Accurate preoperative localization is the key to successful parathyroid surgery in the era of minimally invasive parathyroid surgery. This article presents and discusses the embryologic basis of parathyroid gland and ectopic location and different imaging modalities helpful in diagnosing and localizing parathyroid adenomas and/or hyperplasia. We also aim to review the current surgical concepts in treatment of parathyroid adenomas and/or hyperplasia, the utility of 4-dimensional computed tomography for accurate preoperative localization of hyperfunctioning parathyroid glands, imaging classification of adenomas and/or hyperplasia, and, finally, present some of the limitations of 4-dimensional computed tomography.