Parathyroid glands: combination of (99m)Tc MIBI scintigraphy and US for demonstration of parathyroid glands and nodules

Near-infrared fluorescent imaging for parathyroid identification and/or preservation in surgery for primary hyperparathyroidism

Introduction

Near infrared autofluorescence (NIRAF) is a novel intraoperative technology that has shown promising results in the localisation of parathyroid glands (PGs) over the last decade. This study aimed to assess the potential utility of NIRAF in first time surgery for primary hyperparathyroidism (PHPT).

Methods

An observational study over a period of 3 years in patients who underwent surgery for PHPT was designed. Data on the use of NIRAF and fluorescent patterns in different organs (thyroid and parathyroid) and parathyroid pathology (single versus multi-gland disease) were explored. In addition, cure rates and operating times were compared between the NIRAF and no-NIRAF groups to determine the potential value of NIRAF in this cohort.

Results

In 230 patients undergoing first time surgery for PHPT, NIRAF was used in 50 patients. Of these 50 patients, NIRAF was considered to aid parathyroid identification in 9 patients (18%). The overall cure rate at 6 months of follow-up was 96.5% (98% in NIRAF and 96.1% without NIRAF; p=1.0). The median (interquartile range) operating time was longer in the NIRAF arm at 102 minutes (74-120 minutes) compared to the no-NIRAF arm at 75 minutes (75-109 minutes); however, this difference was not statistically significant (p=0.542). Although the median parathyroid to thyroid (P/T) auto-fluorescence (AF) ratio was similar between single gland and multi gland disease (2.5 vs to 2.76; p=1.0), the P/T AF ratio correlated negatively with increasing gland weight (p=0.038).

Conclusion

The use of NIRAF resulted in some potential "surgeon-perceived" benefit but did not lead to improvements in cure rates. The negative correlation between fluorescent intensity and gland weight suggests loss of fluorescence with pathology, which needs further investigation. Further studies on larger cohorts of patients, in depth analysis of fluorescence patterns between normal, adenomatous, and hyperplastic glands and evaluation of user experience are needed. Primary hyperparathyroidism, hyperparathyroidism, autofluorescence, near-infrared fluorescence, parathyroid glands, endocrine, surgery.

A Rare Occurrence of Ectopic Parathyroid Carcinoma Presenting as a Case of Recurrent Fractures

Ectopic parathyroid tumors are uncommon, accounting for only 6% of parathyroid adenomas, and even fewer cases are attributed to parathyroid carcinomas. While ectopic parathyroid carcinoma in the anterior mediastinum is a rare condition, the occurrence of recurrent skeletal fractures in the presence of mild hypercalcemia is even rarer. In this report, we present the case of a 52-year-old man with a medical history of hypertension, chronic kidney disease, and a previous right-sided intertrochanteric fracture of the femur one year earlier. He presented to the emergency room with left-sided hip pain and shortness of breath due to volume overload. Laboratory tests revealed mild hypercalcemia and hyperparathyroidism, with normal vitamin D levels. An X-ray showed a left neck of femur fracture. Further evaluation with a three-phase skeletal scintigraphy indicated the presence of metabolic bone disease. A contrast-enhanced computed tomography of the chest revealed a solitary soft tissue nodule in the anterior mediastinum, representing an ectopic parathyroid adenoma. The lesion was successfully removed using video-assisted thoracic surgery, and the histopathological analysis confirmed the diagnosis of parathyroid carcinoma. The combination of mild hypercalcemia and recurrent fractures is an unusual presentation of ectopic parathyroid carcinoma, underscoring the importance of considering this condition as a potential cause in similar cases to ensure timely and appropriate treatment.

FCH-PET/CT in Primary Hyperparathyroidism With Discordant/Negative MIBI Scintigraphy and Ultrasonography

CONTEXT

The contribution of [18F]F-fluorocholine (FCH)-positron emission tomography (PET)/computed tomography (CT) in normocalcemic primary hyperparathyroidism (nPHPT) remains unknown.

OBJECTIVE

To evaluate the sensitivity and specificity of FCH-PET/CT in a cohort of osteoporotic patients with nPHPT and discordant or negative [99mTc]Tc-sestamibi scintigraphy and ultrasonography who all underwent parathyroidectomy (PTX).

DESIGN

Longitudinal retrospective cohort study in patients referred for osteoporosis with mild biological primary hyperparathyroidism.

SETTING

Tertiary referral center with expertise in bone metabolism and surgical management of hyperparathyroidism.

PATIENTS

Among 109 patients with PHPT analyzed, 3 groups were individualized according to total serum calcium (tCa) and ionized calcium (iCa): 32 patients with hypercalcemia (HtCa group), 39 patients with normal tCa and elevated iCa (NtCa group), and 38 patients with both normal tCa and iCa (NiCa). All patients had biochemical follow-up confirming or not the success of PTX.

MAIN OUTCOME MEASURES

To evaluate the performance of FCH-PET/CT in terms of sensitivity and specificity, and to compare with first-line imaging procedures in the setting of nPHPT.

RESULTS

The sensitivity of FCH-PET/CT was 67% in the hypercalcemic group, 48% in the NtCa group (P = .05 vs HtCa), and 33% in the NiCa group (P = .004 vs HtCa). Specificity ranged from 97% to 99%. FCH-PET/CT was positive in 64.3% of patients with negative conventional imaging, with biochemical resolution after PTX in 77.8% of patients. Triple negative imaging was observed in 20 patients, with PHPT resolution in 85% of these patients.

CONCLUSION

This study highlights the contribution of FCH-PET/CT in a well-phenotyped cohort of normocalcemic patients with discordant or negative findings in [99mTc]Tc-sestamibi scintigraphy and ultrasonography. However, negative imaging in nPHPT does not rule out the possibility of surgical cure by an experienced surgeon.

Diagnosis of parathyroid incidentaloma detected on thyroid ultrasonography: the role of fine-needle aspiration cytology and washout parathyroid hormone measurements

PURPOSE

The aim of this study was to assess the diagnostic role of fine-needle aspiration cytology (FNAC) and analyze factors associated with false-negative FNAC results in patients with parathyroid incidentaloma who were referred for ultrasonography (US)-guided fine-needle aspiration (FNA) of thyroid nodules.

METHODS

In this study, 121 patients with suspected parathyroid lesions were enrolled. The patients underwent US-guided FNAC with measurements of washout parathyroid hormone (PTH) between January 2015 and May 2020. The diagnostic performance of FNAC for the diagnosis of parathyroid lesions was assessed using surgical results and elevated washout PTH as a reference standard. The clinical and radiologic features associated with false-negative results on FNAC for the diagnosis of parathyroid lesions were evaluated.

RESULTS

Among the 121 nodules assessed, 38 were parathyroid lesions (31.4%), and 83 were non-parathyroid lesions (68.6%). The diagnostic performance of FNAC for parathyroid incidentaloma showed a sensitivity of 31.6% (12/38), specificity of 100% (83/83), positive predictive values of 100% (12/12), negative predictive values of 76.1% (83/109), and accuracy of 78.5% (95/121). The FNAC results of non-parathyroid lesions included thyroid nodules, lymph nodes, neurogenic tumors, and fat tissue. True-positive results on FNAC were significantly associated with performing FNA twice (58.3% vs. 23.1%, P=0.043).

CONCLUSION

Considering the low sensitivity of FNAC, measuring washout PTH in addition to FNAC may help accurately diagnose parathyroid incidentaloma on thyroid US. Further, the falsenegative rate for FNAC can be reduced by obtaining two or more FNA samples.

"Before skin incision" high-resolution ultrasound in primary hyperparathyroidism: a new imaging tool for surgeons?

PURPOSE

Various diagnostic methods have been utilized for localizing pathologic parathyroid glands to consequently provide the possibility of avoiding bilateral neck dissection in cases of primary hyperparathyroidism. Scintigraphy, combined with ultrasound, became established as the standard method of localization in the 2000s. The aim of this study was to evaluate the role of the "before skin incision" surgeon-performed ultrasound in determining the improvement in the diagnostic accuracy in a large case series.

METHOD

The method used in this research is a retrospective observational study (study period: between 1-2014 and 12-2020) comparing two patient groups before (control group: 31 patients) and after (study group: 70 patients) the introduction of the ultrasonography surgical protocol: combined preoperative and "before skin incision" surgeon-performed ultrasound.

RESULTS

The sensitivity of the combined preoperative "before skin incision" surgeon-performed ultrasound was 97%, and the positive predictive value was 93% in regard to detecting the number of diseased glands and the appropriate anatomic location (right versus left, upper versus lower). The sensitivity of the parathyroid scan (Tc-MIBI-scintigraphy) was 74%, and the positive predictive value was 92%. The duration of surgery was significantly shorter in the test group (84.7 vs. 66.4 min; Mann‒Whitney U: 0.006). No differences were detected between the two groups in regard to avoiding intraoperative or postoperative complications.

CONCLUSION

The combination of the preoperative "before skin incision" surgeon-performed ultrasound could improve the efficiency of the preoperative location and anatomic classification using the standard literature-suggested diagnostic methods.

CDKN1B mutation analyses and biochemical characteristics in patients with symptomatic or asymptomatic primary hyperparathyroidism

Purpose: The aim of this study was to compare clinical, biochemical and treatment modalities of the patients with symptomatic and asymptomatic PHPT (primary hyperparathyroidism), and evaluate whether the CDKN1B mutation from these patients contributes to the pathogenesis of typical, sporadic parathyroid adenomas. Materials and Methods: In this prospective study 80 patients (66 women and 14 men, mean age 50.8 ± 12.01 years) with PHPT were enrolled. Biochemical and clinical information were collected on patients’ sex, age, biochemical examination and radiological findings (nuclear 99 mTc sestamibi scans scintigraphy, cervical ultrasound). CDKN1B sequencing, and DNA isolation was performed by using GeneMATRIX Quick Blood DNA Purification Kit. Selected primer of CDKN1BF (rs786201010, c.-456_-453delCCTT) (CAGGTTTGTTGGCAGCAGTA) and CDKN1BR (rs786201010, c.-456_-453delCCTT) (GGAGCCAAAAGACACAGACC) were amplified by polymerase chain reaction (PCR) (Solis Biodyne, Estonia). Results: A total of 80 patients diagnosed with PHPT were included, of which 22 were symptomatic. Serum calcium and 24-hour calcium excretion were significantly increased in patients with symptomatic PHTP. Serum PTH levels were similar between the two group. PHPT. CDKN1B mutation was not detected in any patients. Conclusion: Symptomatic patients were found to have elevated levels of calcium levels (hypercalcaemic), 24-hour urine calcium excretion and target organ damage (bone disease and nephrolithiasis). Independent of PTH levels, clinical signs and symptoms could be related with serum calcium parameters in these patients.

OUP accepted manuscript

Chronic kidney disease mineral and bone disorder may persist after successful kidney transplantation. Persistent hyperparathyroidism has been identified in up to 80% of patients throughout the first year after kidney transplantation. International guidelines lack strict recommendations about the management of persistent hyperparathyroidism. However, it is associated with adverse graft and patient outcomes, including higher fracture risk and an increased risk of all-cause mortality and allograft loss. Secondary hyperparathyroidism may be treated medically (vitamin D, phosphate binders and calcimimetics) or surgically (parathyroidectomy). Guideline recommendations suggest medical therapy first but do not clarify optimal parathyroid hormone targets or indications and timing of parathyroidectomy. There are no clear guidelines or long-term studies about the impact of hyperparathyroidism therapy. Parathyroidectomy is more effective than medical treatment, although it is associated with increased short-term risks. Ideally parathyroidectomy should be performed before kidney transplantation to prevent persistent hyperparathyroidism and improve graft outcomes. We now propose a roadmap for the management of secondary hyperparathyroidism in patients eligible for kidney transplantation that includes the indications and timing (pre- or post-kidney transplantation) of parathyroidectomy, the evaluation of parathyroid gland size and the integration of parathyroid gland size in the decision-making process by a multidisciplinary team of nephrologists, radiologists and surgeons.

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.

Rapid intraoperative perfusion assessment of parathyroid adenomas with ICG using a wide-field portable hand-held fluorescence imaging system

BACKGROUND

Fluorescence angiography (FA) using indocyanine green dye (ICG) has recently been introduced for real-time identification of parathyroid adenomas. However, time to peak fluorescence has not yet been critically evaluated.

METHODS

This was a retrospective review of parathyroidectomies with ICG FA over a one-year period.

RESULTS

There were 66 patients with average age of 64 years. The average time to initial fluorescence was 26.7 s and to peak fluorescence was 38.0 s. The time to saline flush administration significantly correlated with times to initial and peak fluorescence (p < .0001). The rate of in-situ fluorescence was 97%. The rates of suspected adenoma detection were 69% for sestamibi scan, 71% for ultrasound, and 96% for CT scan. Imaging was discordant in 13 cases (20%), with the adenoma located on the opposite side of the neck in 4 cases.

CONCLUSIONS

ICG FA is a rapid and effective adjunct for the intraoperative identification of parathyroid adenomas.

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.

Frequency of Preoperative Localization Techniques of Parathyroid Adenoma at King Abdulaziz University Hospital, Saudi Arabia

Background Accurate preoperative radiological localization of parathyroid pathologies paves the way to enable less invasive surgical procedures. Results on the accuracy of the different diagnostic measures are conflicting. Also, little is known about the most common location of parathyroid lesions. This paper aims to determine the most common location of parathyroid adenoma and evaluate the diagnostic performance of radiological modalities such as ultrasonography, sestamibi scintigraphy/single-photon emission computerized tomography (SPECT), magnetic resonance imaging (MRI), and computed tomography (CT) scan for the preoperative localization of parathyroid pathologies. Methods This is a retrospective study. Data were collected from patients who underwent total or partial parathyroidectomy at King Abdulaziz University Hospital between January 2000 and March 2020. The parathyroid adenoma site was detected preoperatively by a radiological method and confirmed postoperatively by the histopathology report. The performance of each preoperative localizing radiological method was evaluated based on the accuracy in localizing parathyroid pathology. Results A total of 73 patients were included in the analysis, with females being the most common gender in the study at 64%. Only complete data files were included and incomplete data files were excluded. The most frequent mode of detecting parathyroid adenoma was a sestamibi/SPECT scan (62.5%) followed by a CT scan (50%), ultrasound (34.6%), and MRI (25%). The most common location of a parathyroid adenoma was the left side. Conclusion Sestamibi/SPECT is a frequent radiological method for detecting the parathyroid lesion site as compared with CT, MRI, and ultrasonography.

18F-fluorocholine PET/CT in MEN1 Patients with Primary Hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (HPT1) is the most frequent endocrinopathy in multiple endocrine neoplasia type 1 (MEN1). Its surgical management is challenging. We aimed to describe and compare the imaging findings of parathyroid ultrasound (US), sestaMIBI scintigraphy (sestaMIBI), and ¹⁸F-fluorocholine (FCH) PET/CT in a series of MEN1 patients with HPT1.

METHODS

Retrospective analysis of a cohort of MEN1 patients with HPT1 assessed by parathyroid US, sestaMIBI scintigraphy and SPECT/CT, and FCH-PET/CT for potential surgery between 2015 and 2019.

RESULTS

Twenty-two patients with a confirmed diagnosis of MEN1 who presented with HPT1 and were assessed by the 3 imaging modalities were included. After imaging workups, 11 patients were operated on for the first time, 4 underwent a redo surgery, and 7 did not undergo an operation. The overall patient-based positivity rate of imaging was 91% (20 of 22) for parathyroid US and 96% (21 of 22) for both sestaMIBI and FCH-PET/CT. The 3 imaging modalities demonstrated negative findings in 1/22 patient who did not undergo surgery. Overall, 3 pathologic glands were not detected by any imaging technique. SestaMIBI and FCH-PET/CT both resulted in the same 3 false-positive results in ectopic areas with a significant uptake on two thymic carcinoid tumors and one inflammatory lymph node. FCH-PET/CT provided more surgically relevant data than sestaMIBI in 4/11 patients with initial surgery and in 1/4 patient who underwent redo surgery.

CONCLUSIONS

Compared to sestaMIBI scintigraphy, FCH-PET/CT provides additional information regarding the number of pathologic parathyroid glands and their localization in MEN1 patients with HPT1.

Persistent Hypercalcemia Crisis and Recurrent Acute Pancreatitis Due to Multiple Ectopic Parathyroid Carcinomas: Case Report and Literature Review of Mediastinal Parathyroid Carcinoma

Mediastinal parathyroid carcinoma (PC) is a rare entity in primary hyperparathyroidism. The aim of this report is to demonstrate a case of mediastinal PC, and to provide a systemic literature review of this rare condition. A 34-year-old woman who had already undergone two cervical operations for hyperparathyroidism suffered from another recurrence, presenting with recurrent acute pancreatitis and persistent hypercalcemic crisis. Technetium-99 methoxyisobutylisonitrile imaging (MIBI) and computed tomography scanning (CT) identified three possible parathyroid tumors, one of which was the recurrence of residual tumor locating in the thyroid region, while the other two were ectopic tumors locating in the suprasternal fossa and thymus region, respectively. Pathological examination confirmed the diagnosis of PC. We conducted a systemic literature review by searching the PubMed MEDLINE from 1951 to 2019 for studies of all types in the English language only, using terms "mediastinal, mediastinum, parathyroid, carcinoma." Including our reported case, a total of 21 cases with ectopic mediastinal PCs were assessed for demographic data, tumor location and size, biochemical findings, and symptomatology, etc. Two thirds of the patients were men, with a mean age of 44 years old, a mean serum calcium of 14.2 mg/dl, and a mean serum intact parathyroid hormone of 1,216 pg/ml. We identified 89.5% of carcinomas in the anterosuperior mediastinum, and 10.5% in the middle mediastinum, with a mean diameter of 54 mm, and a mean weight of 216 g. MIBI and CT were the most commonly used methods to localize these mediastinal tumors, with 69.2 and 100% sensitivity, respectively. Half of the patients underwent more than one operation. Diagnosis and treatment of mediastinal PCs represent a challenge. Early suspicion, appropriate preoperative localization studies, and the cooperation of endocrinologists and surgeons are crucial in the effective management.

Practice Patterns in Parathyroid Surgery: A Survey of Asia-Pacific Parathyroid Surgeons

BACKGROUND

Practice variations exist amongst parathyroid surgeons depending on their expertise and resources. Our study aims to elucidate the choice of surgical techniques and adjuncts used in parathyroid surgery by surgeons in the Asia-Pacific region.

METHODS

A 25-question online survey was sent to members of five endocrine surgery associations. Questions covered training background, practice environment and preferred techniques in parathyroid surgery. Respondents were divided into three regions: Australia/New Zealand, South/South East Asia and East Asia, and responses were analysed according to region, specialty, case volume and years in practice.

RESULTS

One hundred ninety-six surgeons returned the questionnaire. Most surgeons (98%) routinely perform preoperative imaging, with 75% preferring dual imaging with ^99mTcsestamibi and ultrasound. Ten per cent of surgeons use parathyroid 4DCT as first-line imaging, more commonly in East Asia (p = 0.038). Minimally invasive parathyroidectomy is the favoured technique of choice (97%). Most surgeons reporting robotic or endoscopic approaches are from East Asia. Rapid intraoperative parathyroid hormone is accessible to just under half of the surgeons but less available in Australian/New Zealand (p < 0.001). The use of intraoperative neuromonitoring is not commonly used, even less so amongst Asian surgeons (p = 0.048) and surgeons with low case load (p = 0.013).

CONCLUSION

Dual localisation techniques are the preferred choice of investigations in preparation for parathyroid surgery, with minimally invasive surgery without neuromonitoring the preferred approach. Use of adjuncts is sporadic and limited to certain centres.

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.

Clinical Value of Tc99m-MIBI SPECT/CT Versus 4D-CT or US in Management of Patients With Hyperparathyroidism

Localization of parathyroid adenomas for treatment of primary hyperparathyroidism can be challenging. This retrospective study compared single-photon emission computed tomography/computed tomography (SPECT/CT), 4D-CT, and US studies in detection of adenomas prior to surgery. A retrospective chart review was performed on all consecutive patients with parathyroid adenoma presenting to an urban tertiary care medical center. A total of 58 patients (45 female, 13 male) underwent surgery for parathyroid adenoma. Patients aged 28 to 80 years (mean: 58.8) with parathyroid hormone levels ranging from 42 to 424 pg/mL (mean: 168). All patients underwent preoperative SPECT/CT with 20 mCi technetium-99m MIBI (^99mTc-MIBI). Fifty-three patients had additional US imaging and 14 patients had 4D-CT scans. Additionally, 34 patients had injection of 20 mCi ^99mTc-MIBI on the day of surgery. Pathological correlation was performed. Comparing SPECT/CT versus 4D-CT resulted in sensitivity (77% vs 80%), specificity (71% vs 75%), and accuracy (77% vs 79%). Ultrasound was less sensitive with similar specificity (44%, 86%, respectively). Combination of SPECT/CT and 4D-CT increased sensitivity to 88%, specificity to 100%, and accuracy to 89%. Combining SPECT/CT with US resulted in sensitivity of 85%, specificity of 83%, and accuracy of 85%. Intraoperative localization substantially improved in patients who received preoperative injections. The SPECT/CT remains the best imaging modality for preoperative localization of parathyroid adenomas with high sensitivity. Combining SPECT/CT with US resulted in increased sensitivity and accuracy. For suspicion of ectopic cases or suspicion of unidentifiable adenoma with negative scintigraphy, addition of 4D-CT is recommended. Intraoperative localization and adjunctive imaging may improve surgical management of patients with hyperparathyroidism.

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.

MRI findings and utility of DWI in the evaluation of solid parathyroid lesions

PURPOSE

To evaluate the MRI findings of solid parathyroid lesions and to elaborate on a possible improvement of MRI detection of parathyroid lesions by the use of additional DWI.

MATERIALS AND METHODS

MRI and DWI properties of pathologically proven 20 solid parathyroid lesions were retrospectively reviewed. Mean ADC values (b50 + b400 + b800/3) of parathyroid lesions were compared with that of normal appearing thyroid parenchyma (TP), sternocleidomastoid muscle (SCM) and jugulodigastric lymph nodes (JDLN).

RESULTS

Of lesions, 4 were parathyroid hyperplasia, 13 parathyroid adenoma and 3 parathyroid adenocarcinoma. All parathyroid lesions were very bright on fat-saturated T2W images. Parathyroid hyperplasia and adenoma were small sized, homogenous, well-defined and low on T1W, high on T2W and avidly enhancing. Parathyroid carcinoma was large sized, ill-defined and very heterogeneous on MRI including DWI. Means ADC values of parathyroid hyperplasia, adenoma, and adenocarcinoma, TP, SCM and JDLN were measured as 2.3 ± 0.14 × 10^-3, 1.7 ± 0.45 × 10^-3, 1.5 ± 1.48 × 10^-3, 0.87 ± 0.40 × 10^-3, 0.55 ± 0.21 × 10^-3 and 0.96 ± 0.33 × 10^-3 mm²/s, respectively. All parathyroid lesions had high diffusion properties comparing other soft tissue structures of head and neck region. By increasing strength (b value) of diffusion tensor on DWI, solid parathyroid lesions still kept their brightness comparing other soft tissue structures of head and neck region because of their high T2 properties.

CONCLUSION

Solid parathyroid lesions had higher diffusion properties comparing other soft tissues structures of head and neck region. This feature makes them easily differentiate from nearby structures on fat-saturated T2W and DWI.

Selective parathyroid venous sampling in primary hyperparathyroidism: A systematic review and meta-analysis

OBJECTIVE

Minimally invasive parathyroidectomy requires accurate preoperative localization techniques. There is considerable controversy about the effectiveness of selective parathyroid venous sampling (sPVS) in primary hyperparathyroidism (PHPT) patients. The aim of this meta-analysis is to examine the diagnostic accuracy of sPVS as a preoperative localization modality in PHPT.

METHODS

Studies evaluating the diagnostic accuracy of sPVS for PHPT were electronically searched in the PubMed, EMBASE, Web of Science, and Cochrane Controlled Trials Register databases. Two independent authors reviewed the studies, and revised quality assessment of diagnostic accuracy study tool was used for the quality assessment. Study heterogeneity and pooled estimates were calculated.

RESULTS

Two hundred and two unique studies were identified. Of those, 12 studies were included in the meta-analysis. Pooled sensitivity, specificity, and positive likelihood ratio (PLR) of sPVS were 74%, 41%, and 1.55, respectively. The area-under-the-receiver operating characteristic curve was 0.684, indicating an average discriminatory ability of sPVS. On comparison between sPVS and noninvasive imaging modalities, sensitivity, PLR, and positive posttest probability were significantly higher in sPVS compared to noninvasive imaging modalities. Interestingly, super-selective venous sampling had the highest sensitivity, accuracy, and positive posttest probability compared to other parathyroid venous sampling techniques.

CONCLUSION

This is the first meta-analysis to examine the accuracy of sPVS in PHPT. sPVS had higher pooled sensitivity when compared to noninvasive modalities in revision parathyroid surgery. However, the invasiveness of this technique does not favor its routine use for preoperative localization. Super-selective venous sampling was the most accurate among all other parathyroid venous sampling techniques. Laryngoscope, 2662-2667, 2018.

Preoperative localization modalities in primary hyperparathyroidism: Correlation with postoperative cure

BACKGROUND

Accurate preoperative localization is critical to the success of minimally invasive parathyroidectomy. This investigation aimed to assess the correlation among preoperative imaging results, intraoperative findings, and postoperative cure rates in patients undergoing operation for primary hyperparathyroidism.

METHODS

A retrospective review of all patients who underwent operation for primary hyperparathyroidism between June 2010 and March 2016 was performed.

RESULTS

During the study period, 398 patients underwent parathyroidectomy. The overall cure rate was 97.5%. The ultrasonography performed by the surgeon was superior to the ultrasonography performed by the radiologist and to the sestamibi scan in lateralizing the adenoma correctly (80% vs 62% vs 70%, P < .001, respectively), and had the greatest sensitivity (93%) and accuracy (80%) among all tests (P < .001). Age ≥65 was found to be associated with lesser cure rates (94% vs 99.2%, P = .003). The number of positive preoperative studies correlated with cure rate, ranging from 80% for patients with 0 positive studies, to 100% in those with 4 positive studies (P = .0004). In patients with a negative sestamibi and an ultrasonography performed by the radiologist, there was no significant difference in the cure rates among those with no preoperative computed tomography, a positive preoperative computed tomography, or a negative preoperative computed tomography.

CONCLUSION

An ultrasonography performed by an experienced surgeon is an extremely valuable preoperative localization modality. The cure rate obtained is proportional to the number of positive imaging studies. In patients with negative ultrasonography performed by a nonexperienced radiologist and a negative sestamibi scan, the performance of computed tomography does not seem to increase cure rate. Patients with no positive preoperative scans represent a challenging subgroup, with cure rates of approximately 80%.

Diagnosis performance of 99mTc-MIBI and multimodality imaging for hyperparathyroidism

This study aimed to examine the diagnosis performance of ^99mTc-methoxyisobutylisonitrisonitrile (^99mTc-MIBI) and multimodality imaging [ultrasound, single-photon emission computed tomography/computed tomography (SPECT/CT)] for hyperparathyroidism (HPT). From Nov. 2009 to Dec. 2015, clinical data of a total of 43 HPT patients (16 males and 27 females; 26-70 years old, average age: 51.60±10.66 years old) were retrospectively analyzed. Among them, 19 patients with primary hyperparathyroidism (PHPT) underwent ^99mTc-MIBI planar imaging, 24 [15 with PHPT and 9 with secondary hyperparathyroidism (SHPT)] underwent SPECT/CT hybrid imaging, and 41 (33 with PHPT and 8 with SHPT) had neck ultrasound imaging. Final diagnosis was determined by pathological examination after surgery. The positive rate was compared between different imaging modalities, and the correlation analysis was conducted between imaging results and lesion size or serum parathyroid hormone (PTH) level. The results showed that the total positive rates of ^99mTc-MIBI imaging, ultrasound, and the two combined imaging in the 43 HPT cases were 90.70% (39/43), 58.54% (24/41), and 100% (41/41), respectively. According to lesion numbers, the positive rates were 79.10% (53/67), 53.23% (33/62), and 88.71% (55/62), respectively. SPECT/CT hybrid images were positive in all the 24 patients who underwent this examination. The mean maximum diameters of the lesions in ^99mTc-MIBI positive and negative patients were 1.96±0.95 cm and 1.36±0.67 cm respectively, with statistically significant difference noted (P=0.03). The T/NT of ^99mTc-MIBI imaging at the early phase was correlated positively with serum PTH level (r=0.40, P=0.01). The T/NT of ^99mTc-MIBI imaging at both the early phase and the delay phase was correlated positively with lesion size (r=0.51, and r=0.45, respectively; P<0.01 for both). It was concluded that ^99mTc-MIBI imaging presents significant value for location diagnosis of HPT, especially when combined with SPECT/CT hybrid imaging or ultrasound. The ^99mTc-MIBI uptake correlates positively with serum PTH level and lesion size.

Multiparametric ultrasonography and ultrasound elastography in the differentiation of parathyroid lesions from ectopic thyroid lesions or lymphadenopathies

To evaluate the accuracy of ultrasound elastography with Elastoscan^TM Core Index in the differential diagnosis of parathyroid lesions from ectopic thyroid nodules and lymph nodes. Seventy nine patients with repeatedly high levels of circulating intact parathyroid hormone, normal vitamin D and renal function tests, with an ultrasound scan showing a neck lesion, sharply demarcated from the thyroid lobules, were consecutively enrolled. Ultrasound with and without Color Doppler and ultrasound elastography were performed before histological examination. All ultrasound features, vascularization and ultrasound elastography diagnostic performance were assessed using ROC curves. Histological examination confirmed 47 parathyroid lesions, 18 thyroid ectopic nodules and 14 reactive lymph nodes. In distinguishing parathyroid from thyroid nodules, shape had a 100 % sensitivity (95 % CI 92.4-100) and 50 % specificity (95 % CI 37.2-64.7), cleavage had a 85.1 % sensitivity (95 % CI 72.3-92.6) and 77.8 % specificity (95 % CI 65.1-88) while peripheral vascularization had a sensitivity of 91.5 (95 % CI 79.6-97.6) and specificity of 72.2 (95 % CI 46.5-90.3). An Elastoscan^TM Core Indexof 1.28 was 46 % sensitive (95 % CI 33.4-58.7) and 77 % specific (95 % CI 66.2-89.1) in discriminating parathyroid lesions from thyroid nodules. An Elastoscan^TM Core Index of 1.0 was 78 % sensitive (95 % CI 65.1-88) and 71 % specific (95 % CI 56-81.3) in discriminating parathyroid lesions from lymph nodes (p = 0.045). An Elastoscan^TM Core Index greater than 2.58 had a 100 % sensitivity (95 % CI 43.8-100) and 95.4 % specificity (95 % CI 38.3-99.7) in discriminating malignant from benign parathyroid nodules. Elastoscan^TM Core Index was significantly higher in thyroid nodules than in reactive lymph nodes (1.18 ± 0.62, p = 0.008). The ultrasound features of cleavage and peripheral vascularization help to differentiate parathyroid from thyroid nodules. Elastoscan^TM Core Index can improve ultrasound discrimination of parathyroid lesions from lymph nodes. The Elastoscan^TM Core Index is significantly higher in malignant than in benign parathyroid lesions.

Ultrasound detection of normal parathyroid glands: a preliminary study

OBJECTIVE

No previous prospective study has investigated the detection of normal parathyroid glands (PTGs) and their features using real-time ultrasound (US). This study aimed to assess the preoperative US detection of normal PTGs in patients who underwent hemithyroidectomy.

METHODS

Between August and October 2016, 44 patients underwent hemithyroidectomy using a low-collar incision, and 5 were excluded from the study. A single radiologist performed the preoperative US examination in all patients, and the surgical data for the PTGs were obtained by a single surgeon. Based on the surgical findings of PTGs, the preoperative US detection of PTGs was determined.

RESULTS

Of the 39 patients, 3 had no surgical data for PTG (n = 2) and the presence of parathyroid hyperplasia (n = 1). In the 36 remaining patients, in 3 patients, US identification of a normal PTG was corroborated by surgical findings, whereas in 2 patients, US findings differed from surgical findings, and in 31 patients, US did not detect a normal PTG. The successful US detection rate of normal PTG was only 8.3% (3/36).

CONCLUSIONS

US cannot be used for identification of normal PTGs.

Comparison of scintigraphy and ultrasound imaging in patients with primary, secondary and tertiary hyperparathyroidism - own experience

BACKGROUND

The imaging techniques most commonly used in the diagnosis of hyperparathyroidisms are ultrasound and scintigraphy. The diagnostic algorithms vary, depending mainly on the population, and experience of physicians.

AIM

Aim of the present research was to determine the usefulness of parathyroid scintigraphy and ultrasonography in patients diagnosed for hyperparathyroidism in own material.

MATERIAL AND METHOD

In the present research, 96 operated patients with documented primary, secondary and tertiary hyperparathyroidism were retrospectively analyzed. All patients underwent a ^99mTc hexakis-2-methoxyisobutylisonitrile scintigraphy of the neck with the use of subtraction and two-phase examinations. Ultrasonography of the neck was performed in all the patients in B mode 2D presentation. A total number of 172 parathyroid glands were analyzed.

RESULTS

The sensitivity and specificity of scintigraphy was 68% and 60%, respectively. The sensitivity of ultrasound was 49% and specificity 85%. Both techniques allowed visualization of 76 parathyroid glands. Ultrasound revealed 19 glands that were not visible in scintigraphy. Scintigraphy showed 76 parathyroid glands that were not visualized on ultrasound. Having combined the results of scintigraphy and ultrasound, the sensitivity of 76% and specificity of 50% were obtained. Considering the ability to locate the parathyroid glands in both techniques as a positive result, the sensitivity decreased to 37% and specificity rose to 95%.

CONCLUSIONS

Scintigraphy showed greater sensitivity than ultrasound in the localization of enlarged parathyroid glands. Ultrasound, in turn, was characterized by a higher specificity. The combined use of scintigraphy and ultrasonography allowed to obtain the specificity of 95%. In the light of obtained results, scintigraphy and ultrasonography are complementary and should be used together.

Ambulatory surgery for primary hyperparathyroidism: A 67-case series

INTRODUCTION

Surgery for primary hyperparathyroidism, targeted by ultrasound and scintigraphy, satisfies the theoretical criteria allowing ambulatory surgery. The purpose of this study was to validate this strategy on a homogeneous case series assessed by this imaging strategy.

MATERIAL AND METHODS

All patients operated for primary hyperparathyroidism by ambulatory surgery from 01/01/13 to 30/04/15 were included in this retrospective study. The usual endpoints of ambulatory surgery were evaluated.

RESULTS

A total of 144 patients were operated for primary hyperparathyroidism during the study period. Ambulatory surgery was possible in 67 patients, who all had a preoperative diagnosis of parathyroid adenoma. All patients were assessed by ultrasound and 66 patients were assessed by sestamibi scintigraphy, resulting in targeted unilateral neck surgery in 98.5% of cases. Two patients had to be hospitalised overnight due to minor complications.

CONCLUSION

Surgery for primary hyperparathyroidism can be performed with short operating times in carefully selected patients with a low complication rate, thereby allowing ambulatory surgery.

2D-Shear Wave Elastography in the Evaluation of Parathyroid Lesions in Patients with Hyperparathyroidism

BACKGROUND AND AIMS

2D-shear wave elastography (2D-SWE) is a relatively new elastographic technique. The aim of the present study is to determine the values of the elasticity indexes (EI) measured by 2D-SWE in parathyroid benign lesions (adenomas or hyperplasia) and to establish if this investigation is helpful for the preoperative identification of the parathyroid adenoma.

MATERIAL AND METHODS

The study groups were represented by 22 patients with primary or tertiary hyperparathyroidism, diagnosed by specific tests, and 43 healthy controls, in whom the thyroid parenchyma was evaluated, in order to compare the EI of the thyroid tissue with those of the parathyroid lesions.

RESULTS

The mean EI measured by 2D-SWE in the parathyroid lesions was 10.2 ± 4.9 kPa, significantly lower than that of the normal thyroid parenchyma (19.5 ± 7.6 kPa; p = 0.007), indicating soft tissue. For a cutoff value of 12.5 kPa, the EI assessed by 2D-SWE had a sensitivity of 93% and a specificity of 86% (AUC = 0.949; p < 0.001) for predicting parathyroid lesions.

CONCLUSION

A value lower than 12.5 kPa for the mean EI measured by 2D-SWE can be used to confirm that the lesion/nodule is a parathyroid adenoma.

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.

Cost-benefit analysis of the intraoperative parathyroid hormone assay in primary hyperparathyroidism

BACKGROUND

The purpose of this study was to evaluate the usefulness of the routine intraoperative intact parathyroid hormone (IOPTH) assay, the role of unilateral and bilateral cervical exploration and of preoperative imaging, and to do a cost-benefit analysis in parathyroidectomy for primary hyperparathyroidism.

METHODS

Two hundred sixty-four patients who underwent operations between January 2000 and March 2015 were retrospectively divided into 2 groups.

RESULTS

Group A (IOPTH) was composed of 64 patients. Ultrasonography and technetium-99m-sestamibi (MIBI) identified the adenoma in 38 cases. Bilateral exploration was performed in 43 patients; of which 2 failures occurred. The IOPTH false-negative rate was 18.4%. The average cost was €1297.30. Group B (without IOPTH) was composed of 200 patients. Ultrasonography and MIBI identified the adenoma in 113 cases. Bilateral exploration was performed in 129 patients; of which 2 failures occurred. The average cost was €618.75.

CONCLUSION

The IOPTH assay should be used only in few selected cases because of its high cost. The experience of the team is essential to obtain a high cure rate. © 2016 Wiley Periodicals, Inc. Head Neck 39: 241-246, 2017.

ROLE OF IMAGING TESTS FOR PREOPERATIVE LOCATION OF PATHOLOGIC PARATHYROID TISSUE IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM

OBJECTIVE

Primary hyperparathyroidism (PHPT) can be cured by parathyroidectomy, and the preoperative location of enlarged pathologic parathyroid glands is determined by imaging studies, especially cervical ultrasonography and scintigraphy scanning. The aim of this retrospective study was to evaluate the use of preoperative cervical ultrasonography and/or parathyroid scintigraphy in locating pathologic parathyroid tissue in a group of patients with PHPT followed in the same endocrine center.

METHODS

We examined the records of 61 patients who had undergone parathyroidectomy for PHPT following (99m)Tc-sestamibi scintigraphy scan and/or cervical ultrasonography. Scintigraphic and ultrasonographic findings were compared to histopathologic results of the surgical specimens.

RESULTS

Ultrasonography detected enlarged parathyroid glands in 87% (48/55) of patients with PHPT and (99m)Tc-sestamibi scintigraphy in 79% (37/47) of the cases. Ultrasonography was able to correctly predict the surgical findings in 75% (41/55) of patients and scintigraphy in 72% (34/47). Of 7 patients who had negative ultrasonography, scintigraphy correctly predicted the surgical results in 2 (29%). Of 10 patients who had negative scintigraphy, ultrasonography correctly predicted the surgical results in 4 (40%). When we analyzed only patients with solitary eutopic parathyroid adenomas, the predictive positive values of ultrasonography and scintigraphy were 90% and 86%, respectively.

CONCLUSION

Cervical ultrasonography had a higher likelihood of a correct positive test and a greater predictive positive value for solitary adenoma compared to (99m)Tc-sestamibi and should be used as the first diagnostic tool for preoperative localization of affected parathyroid glands in PHPT.

ABBREVIATIONS

Ca = calcium IEDE = Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione PHPT = primary hyperparathyroidism PTH = parathyroid hormone.

The utility of indocyanine green near infrared fluorescent imaging in the identification of parathyroid glands during surgery for primary hyperparathyroidism

BACKGROUND AND OBJECTIVES

Intraoperative adjuncts for the localization of parathyroid glands in parathyroid surgery are limited. The aim of this study is to assess the usefulness of indocyanine green (ICG) near-infrared (NIR) fluorescent imaging in patients undergoing surgery for primary hyperparathyroidism (PHPT).

METHODS

ICG imaging was performed in 33 patients undergoing parathyroidectomy (PTX). Thyroid and parathyroid ICG uptake were assessed and independently verified on a grading scale. Clinical variables were recorded and analyzed for factors associated with ICG uptake.

RESULTS

Of 112 glands identified by naked eye, 104 (92.9%) demonstrated ICG uptake. Concomitant ICG fluorescence was identified in the thyroid in all patients. There was a trend toward increased ICG fluorescence in patients <60 years of age (P = 0.05). A higher degree of fluorescence was seen in patients presenting with pre-operative calcium values >11 mg/dl (P = 0.04) and in those parathyroids larger than 10 mm (P < 0.01). All patients had biochemically proven cure. No patients who underwent subtotal PTX (n = 6) developed postoperative hypoparathyroidism.

CONCLUSION

ICG can reliably localize parathyroid glands during PTX and additionally allow for assessment of parathyroid perfusion in patients undergoing subtotal resection. Concomitant fluorescence of the thyroid gland limits ICG's usefulness in directing the course of PTX. J. Surg. Oncol. 2016;113:771-774. © 2016 Wiley Periodicals, Inc.

Focused parathyroidectomy without intra-operative parathormone monitoring: The value of PTH assay in preoperative ultrasound guided fine needle aspiration washout

Background

The accurate identification of hyperfunctioning parathyroid (HP) gland is the only issue for definitive surgical treatment in primary hyperparathyroidism (pHPT). Various imaging and operative techniques have been proposed to confirm the localization of the diseased gland. Nevertheless, none of these methods proved to be the gold standard. The presented study aimed to assess the value of parathyroid hormone assay in preoperative ultrasound guided fine needle aspiration (FNA)-PTH washout fluid to verify the correct localisation for focused parathyroidectomy without intra-operative PTH monitoring.

Material and Methods

The retrospective analysis of 57 patients with pHPT who underwent FNA-PTH was conducted from a prospective database. Biochemical assessment together with radiological (ultrasonography) and nuclear (MIBI scan) imaging was reviewed. Associations between FNA-PTH washout values and localization technics were evaluated and compared in terms of operative findings.

Results

Focused parathyroidectomy without intraoperative PTH monitoring was performed to 45 patients with high FNA-PTH values. The median largest diameter of the target parathyroid lesion identified by ultrasonography was 13 mm (range, 6 to 36). The median serum PTH level was 190 pg/mL (range, 78 to 1709; reference range, 15 to 65) whereas the median washout PTH was 2500 pg/mL (range, 480 to 3389). According to operative findings high FNA-PTH levels correctly identified parathyroid adenoma in 40 cases (89% of sensitivity and 100% of specificity and positive predictive value) whereas MIBI scan localized the lesion in 36 of these cases (80% of sensitivity).

Conclusions

The higher level of PTH in preoperative ultrasound guided FNA washout is a considerable data to predict the correct localization of HP, particularly in circumstances of greater values than the serum PTH level. However, although its specificity is high, in cases of coexisting nodular thyroid disease, associated additional HP might be missed at focused parathyroidectomy without PTH monitoring, leading to recurrent disease.

•

Preoperative FNA-PTH washout and intraoperative US together give accurate information about localization of parathyroid adenomas.

•

In this circumstances, focused parathyroidectomy without intraoperative PTH monitoring might be feasible and successful.

•

Nevertheless, misdiagnosis due to concomitant nodular thyroid disease is a fact that always merit consideration.

The role of ultrasound and nuclear medicine methods in the preoperative diagnostics of primary hyperparathyroidism

Primary hyperparathyroidism (PH) represents one of the most common endocrine diseases. In most cases, the disorder is caused by parathyroid adenomas. Bilateral neck exploration has been a widely used treatment method for adenomas since the 20's of the twentieth century. In the last decade, however, it has been increasingly replaced by a minimally invasive surgical treatment. Smaller extent, shorter duration and lower complication rate of such a procedure are emphasized. Its efficacy depends on a precise location of parathyroid tissue during the preoperative imaging. Scintigraphy and ultrasound play a major role in the diagnostic algorithms. The efficacy of both methods has been repeatedly verified and compared. The still-current guidelines of the European Association of Nuclear Medicine (2009) emphasize the complementary role of scintigraphy and ultrasonography in the preoperative diagnostics in patients with primary hyperparathyroidism. At the same time, attempts are made to improve both these techniques by implementing new study protocols or innovative technologies. Publications have emerged in the recent years in the field of ultrasonography, whose authors pointed out the usefulness of elastography and contrast media. Nuclear medicine studies, on the other hand, focus mainly on the assessment of new radiotracers used in the positron emission tomography (PET). The aim of this article is to present, based on literature data, the possibilities of ultrasound and scintigraphy in the preoperative diagnostics in patients with primary hyperparathyroidism. Furthermore, the main directions in the development of imaging techniques in PH patients were evaluated.

Parathyroid ultrasonography: the evolving role of the radiologist

Previously, radiologists played a limited role in the treatment of parathyroid disease, primary focusing on the preoperative localization of parathyroid lesions responsible for hyperparathyroidism. But, the widespread use of high-resolution ultrasound has lead to the increasing detection of parathyroid incidentalomas (PTIs). Consequently, radiologists may be required to differentiate PTIs from thyroid lesions, which is most reliably accomplished through the fine needle aspiration-parathyroid hormone analysis. Various nonsurgical treatment modalities for hyperfunctioning parathyroid lesions have been developed with some efficacy. Especially for symptomatic nonfunctioning parathyroid cysts, simple aspiration is a first-line procedure for diagnosis and treatment, while ethanol ablation is a subsequent treatment modality for recurrent cases.

Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography

OBJECTIVE

The objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT).

DESIGN AND METHODS

The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15-92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images.

RESULTS

All superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01±1.30 cm (range, 0.5-6.19) and 2.04±0.91 cm (0.5-4.4) in the left inferior thyroid vein and common trunk, and 1.96±1.05 cm (0.81-4.8) and 1.65±0.69 cm (0.63-2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively.

CONCLUSIONS

The numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This strategy can provide anatomical information before selective venous sampling for measurements of parathyroid hormone.

Evaluation of conventional imaging techniques on preoperative localization in primary hyperparathyroidism

We aimed to evaluate the diagnostic and preoperative localization capacity of 99mTc methoxyisobutylnitrile (MIBI) parathyroid scintigraphy and ultrasonography (USG) in enlarged parathyroid glands in the primary hyperparathyroidism (pHPT) as well as the relationship between the success rate of these techniques and biochemical values. In this study, we retrospectively evaluated 39 patients with clinical and biological evidence of pHPT who referred to the university hospital for MIBI parathyroid scintigraphy. Patients were examined with USG and double-phase MIBI parathyroid scintigraphy for the detection of enlarged parathyroid glands. Preoperative serum intact parathyroid hormone (iPTH) levels, calcium (Ca), phosphate and alkaline phosphatase measurements were obtained. A total of 45 parathyroid lesions in 39 patients were reviewed. Thirty-four patients had a single adenoma and 5 patients with multi-gland disease had 11 abnormal parathyroid glands including three adenomas, whereas the remaining 8 glands showed hyperplasia. The overall sensitivities of MIBI parathyroid scintigraphy, USG and combined techniques were 85.3%, 72.5% and 90.4%, respectively; the positive predictive values (PPV) were 89.7%, 85.2% and 92.6%, respectively. The most successful approach for detection of enlarged parathyroid glands in hyperparathyroidism is the concurrent application of USG and MIBI parathyroid scintigraphy modalities. The concomitancy of thyroid diseases decreases the sensitivity of both MIBI parathyroid scintigraphy and USG in enlarged parathyroid glands.