Technetium-99m-sestamibi subtraction scintigraphy vs. ultrasonography combined with a rapid parathyroid hormone assay in parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach

Is intraoperative parathyroid monitoring during minimally invasive parathyroidectomy still justified?

Introduction

Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. With parathyroidectomy, a cure rate of over 95% at initial surgery is reported. Localization of the abnormal parathyroid gland is critical for the operation to be successful. The aim of this study is to analyze data of patients with single gland disease (SGD) and positive concordant localization imaging undergoing minimally invasive parathyroidectomy (MIP) and intraoperative parathyroid hormone monitoring (IOPTH) to evaluate if IOPTH is still justified in patients with localized SGD.

Methods

A retrospective database analysis of all minimally invasive operations with IOPTH for PHPT and positive concordant localization in ultrasound (US) and 99mTc-sestamibi scintigraphy (MIBI) between 2016-2021. When both US and MIBI were negative, patients underwent either choline or methionine PET-CT. The patients were also analyzed a second time without applying IOPTH.

Results

In total, 198 patients were included in the study. The sensitivity of US, MIBI and PET-CT was 96%, 94% and 100%, respectively. Positive predictive value was 88%, 89% and 94% with US, MIBI and PET-CT, respectively. IOPTH was true positive in 185 (93.4%) patients. In 13 (6.6%) patients, no adequate IOPTH decline was observed after localizing and extirpating the assumed enlarged parathyroid gland. Without IOPTH, the cure rate decreased from 195 (98.5%) to 182 (92%) patients and the rate of persisting disease increased from 2 (1.0%) to 15 (7.5%) patients.

Conclusion

Discontinuing IOPTH significantly increases the persistence rate by a factor of 7.5 in patients with concordantly localized adenoma. Therefore, IOPTH appears to remain necessary even for this group of patients.

Parathyroid carcinoma located in the thyroid gland: A case report

BACKGROUND

Parathyroid carcinoma (PC) is a difficult-to-diagnose rare disease with low incidence. Relatively accurate preoperative diagnosis is very important in choosing surgical methods and patient prognosis.

CASE SUMMARY

This study reported the clinical diagnosis and treatment of a rare patient with PC located in the thyroid gland and provided a case reference for the diagnosis and treatment of PC. A case of a 64-year-old male patient who presented to our hospital with systemic muscle and joint pain and palpitations is outlined. Subsequently, the patient was admitted to the Department of Nephrology for the treatment of "multiple myeloma nephropathy pending investigation". The patient was diagnosed with "primary hyperparathyroidism and hypercalcemic crisis" using thyroid color ultrasound.

CONCLUSION

The intraoperative frozen section report considered the parathyroid tumor. Surgical tumor resection was promptly performed, and the diagnosis of PC was confirmed.

Incremental value of 99m Tc-MIBI single-photon emission computed tomography/computed tomography fusion imaging for the diagnosis of secondary hyperparathyroidism

PURPOSE

To assess the added value of 99m Tc-MIBI single-photon emission computed tomography/computed tomography (SPECT/CT) fusion imaging over dual-phase scintigraphy in the diagnosis of secondary hyperparathyroidism (SHPT).

METHODS

This retrospective study included 23 patients with SHPT. The diagnostic efficacy of 99m Tc-MIBI dual-phase scintigraphy and SPECT/CT fusion imaging was analyzed and compared based on the result of postoperative pathology and follow-up. To evaluate the diagnostic ability of 99m Tc-MIBI dual-phase scintigraphy, the volume and radioactive count of parathyroid lesions were assessed using the region of interest method.

RESULTS

A total of 79 hyperplastic parathyroid glands and two thyroid tissues were surgically removed from 23 SHPT patients and 13 normal parathyroid glands were preserved. 99m Tc-MIBI SPECT/CT fusion imaging showed higher sensitivity and accuracy than 99m Tc-MIBI dual-phase scintigraphy [sensitivity, 77.2% (61/79) vs 46.8% (37/79); accuracy, 80.4% (74/92) vs 54.3% (50/92), respectively], but comparable specificity [100% (13/13)). Among 61 positive lesions detected by 99m Tc-MIBI SPECT/CT fusion imaging, 37 were dual-phase scintigraphy positive and 24 were dual-phase scintigraphy false negative. The radioactivity counts and radioactivity per unit volume in dual-phase scintigraphy positive were higher than that in dual-phase scintigraphy false negative ( P  < 0.05), but the volume of parathyroid lesions between the two groups had no significant difference ( P  > 0.05).

CONCLUSION

Compared with 99m Tc-MIBI dual-phase scintigraphy, 99m Tc-MIBI SPECT/CT fusion imaging has incremental value in the diagnosis of SHPT. The low uptake of MIBI in the whole gland and low MIBI uptake per unit volume are easy to cause dual-phase scintigraphy false negative.

Tissue Parathyroid Hormone Washout: A Reliable Method for the Localization and Exclusion of Parathyroid Adenomas

Background and objective Accurate identification of parathyroid adenoma (PA) is essential for minimally invasive treatment of primary hyperparathyroidism (PHPT). The aim of this study is to evaluate the results of parathyroid hormone (PTH) assay in aspirates of suspicious neck lesions and to clarify its reliability in determining whether the lesion is of parathyroid origin. Methods A total of 134 lesions (104 imaging-suspected PA and 30 concomitant thyroid nodules as a control group) of 101 patients were retrospectively analyzed. Patients with positive, negative, or never scintigraphy were included in our study. Ultrasound (US) was performed again and US-guided tissue fine needle aspiration with PTH washout (PTH-WO) was performed from suspicious lesions. A PTH-WO level higher than the patient's serum PTH levels is proposed for a positive test, and a PTH-WO level lower than the upper limit of the laboratory PTH level is proposed for a negative test. A definitive diagnosis was made postoperatively histopathologically. Results PTH-WO levels (median (IQR)) were significantly higher in the positive group (n = 93, 5000 (1600) ng/L) compared to the negative group (n = 11, 17 (13.1) ng/L) and thyroid nodule aspirate group (n = 30, 14 (4.3) ng/L) (p < 0.001). Among 93 PTH-WO-positive lesions, 42 lesions (45.1%) were not identified by parathyroid scintigraphy (PS), 20 (21.5%) lesions were suspiciously PS, and 33 lesions (35.4%) were negative or suspicious by first US findings. Of the 93 patients localized with PTH-WO, two were cystic PAs ablated by aspiration. The final pathology result of 91 operated patients proved PA. The sensitivity, specificity, negative predictive value, and positive predictive value of the PTH-WO were observed as 1.00, 0.82, 0.09, and 0.91, respectively. Conclusion Comprehensive repeated US and PTH-WO from the lesion increase the accurate localization of PAs. PTH-WO is a highly reliable method for differentiating parathyroid lesions from other cervical lesions.

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 in Germany, Switzerland, and Austria: an analysis of data from the EUROCRINE registry

PURPOSE

EUROCRINE is an endocrine surgical register documenting diagnostic processes, indication for surgical treatment, surgical procedures, and outcomes. The purpose was to analyse data for PHPT in German speaking countries regarding differences in clinical presentation, diagnostic workup, and treatment.

METHODS

All operations for PHPT performed from 07/2015 to 12/2019 were analysed.

RESULTS

Three thousand two hundred ninety-one patients in Germany (9 centres; 1762 patients), Switzerland (16 centres; 971 patients) and Austria (5 centres; 558 patients) were analysed. Hereditary disease was seen in 36 patients in Germany, 16 patients in Switzerland and 8 patients in Austria. In sporadic disease before primary operation, PET-CT showed the highest sensitivity in all countries. In re-operations, CT and PET-CT achieved the highest sensitivities. The highest sensitivity of IOPTH was seen in Austria (98.1%), followed by Germany (96.4%) and Switzerland (91.3%). Operation methods and mean operative time reached statistical significance (p<0.05). Complication rates are low. Overall, 656 (19.9%) patients were asymptomatic; the remainder showed bone manifestations, kidney stones, fatigue and/or neuropsychiatric symptoms.

CONCLUSION

Early postoperative normocalcaemia ranged between 96.8 and 97.1%. Complication rates are low. PET-CT had the highest sensitivity in all three countries in patients undergoing primary operation as well as in Switzerland and Austria in patients undergoing re-operation. PET-CT could be considered a first-line preoperative imaging modality in patients with inconclusive ultrasound examination. The EUROCRINE registry is a beneficial and comprehensive data source for outcome analysis of endocrine procedures on a supranational level.

Positive predictive values of ultrasound-guided fine-needle aspiration with parathyroid hormone assay and Tc-99m sestamibi scintigraphy in sporadic primary hyperparathyroidism

OBJECTIVES

Ultrasonography (US) and Tc-99m sestamibi scintigraphy (SS) are usually performed as preoperative imaging modalities for patients with sporadic primary hyperparathyroidism (SPHP). Fine-needle aspiration (FNA) under US guidance for parathyroid hormone (PH) assay can enhance the diagnostic accuracy of US. The main aim of the present study was to compare positive predictive values between US-FNA and SS. The secondary aim was to draw up a decision-tree for FNA and SS.

METHODS

The single-center retrospective study included patients with previously non-operated SPHP. They underwent US-guided FNA, PET-CT SS, and 18 F-choline scintigraphy if the first two methods were inconclusive. PH washout level was considered pathological when greater than the serum PH level. Postoperative histology data were correlated to imaging data.

RESULTS

In total, 117 patients were included, with a mean age of 64 years (range, 26-89 years). A single adenoma was identified on pathology in 101 patients (89%). FNA findings were pathologic for 64 patients (55%), with a mean PH level of 2,604ng/L [range, 585-9,074ng/L], higher than the serum level of 179ng/L [range, 60-1,000ng/L]. US-guided FNA showed sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of respectively 72%, 92%, 99% and 28%, compared to 89%, 42%, 93% and 32% for SS. The rate of error in locating the parathyroid gland was 8% for US-guided FNA versus 12% for SS. Comparison of the two methods showed better sensitivity for SS (P=0.0052) and better specificity for FNA (P=0.0143), with no significant difference in PPV or NPV. 18 F-choline scintigraphy detected the hyperfunctioning parathyroid in 11 out of the 15 patients.

CONCLUSION

PPV did not significantly differ between FNA and SS. US-guided FNA performed by an experienced operator could be a simple first-line method for more than 50% of patients with non-operated SPHP, with 99% PPV. In case of negative or doubtful FNA findings, SS can be performed in second line.

Accessing the influence of 99mTc-Sesta-MIBI-positive thyroid nodules on preoperative localisation studies in patients with primary hyperparathyroidism

Purpose

Curative treatment for primary hyperparathyroidism (PHPT) is parathyroidectomy (PTX) with removal of the hyperfunctioning gland(s). In an endemic goitre region, 35–78% of PHPT patients show concomitant thyroid disease. This study aimed to evaluate if ^99mTc-sestamibi (MIBI)-positive thyroid nodules decrease sensitivity in regard to localising the hyperfunctioning parathyroid gland(s) in PHPT patients.

Methods

Within 5 years, 497 consecutive patients with biochemically proven PHPT were included in this study. The data was analysed retrospectively.

Results

In total, 198 patients underwent PTX with thyroid surgery and 299 patients underwent sole PTX. Sensitivity of MIBI scan for PTX with and without thyroid surgery was 72.1% and 73.6%, respectively. A statistically significant difference in sensitivity of ultrasound for PTX with and without thyroid surgery (57.0% and 70.9%, respectively) was observed (p = 0.029). Thyroid nodule histology did not have a significant effect on the MIBI scan. Unilateral neck exploration (UNE) was performed in 110 patients and bilateral neck exploration (BNE) in 177 patients. The probability of surgical conversion from UNE to BNE due to incorrect localisation was 1.733 times higher in patients with thyroid nodules.

Conclusions

Concomitant benign thyroid nodules did not influence MIBI sensitivity. No correlation between thyroid carcinoma and MIBI uptake was determined. However, MIBI detection of thyroid malignancy is important in patients initially being considered for minimal invasive parathyroidectomy. Sensitivity and positive predictive value of ultrasound were significantly lower in patients with thyroid nodules. The probability of conversion from UNE to BNE due to incorrect localisation was 1.733 times higher in patients with thyroid nodules.

[The clinical practice guidelines for primary hyperparathyroidism, short version]

Primary hyperparathyroidism (PHPT) is an endocrine disorder of parathyroid glands characterized by excessive secretion of parathyroid hormone (PTH) with an upper normal or elevated blood calcium level. Classical PHPT refers to a symptomatic, multi-system disorder, wich can lead to a significant decrease in the quality of life, disability of patients, and even an increased risk of premature death. Hypercalcemia and the catabolic effect of PTH on various cells are considered as the main pathogenetic mechanisms of the PHPT associated complications. In the last two decades, there has been an increase in the incidence of PHPT, mainly due to the mild forms of the disease, primarily due to the routine calcium screening in North America, Western Europe and, Asia. High prevalence of the disease, as well as the variety of clinical manifestations, cause the attention of different specialists - physicians, rheumatologists, urologists, nephrologists, cardiologists and other doctors. This review cover the main issues of Russian guidelines for the management of PHPT, approved in 2020, including laboratory and instrumental methods, differential diagnosis, surgical and conservative approach, short-term and long-term follow-up. This guidelines also include the recommendations for special groups of patients with hereditary forms of PHPT, parathyroid carcinoma, PHPT during pregnancy.

Safety and diagnostic performance of parathyroid hormone assay in fine-needle aspirate in suspicious parathyroid adenomas

OBJECTIVE

To evaluate the safety and diagnostic performance of parathyroid hormone assay in fine-needle aspirate (PTH-FNA) in patients with primary hyperparathyroidism and suspicious parathyroid adenomas.

METHODOLOGY

A retrospective observational study was performed in 47 patients (57.7 ± 11.2 years of average age, 74% women) attending an endocrinology clinic for primary hyperparathyroidism (average calcemia: 11.6 ± 1.6 mg/dl and PTH: 276 ± 477 pg/mL) in which PTH-FNA was made. Sensibility, specificity, positive predictive value and negative predictive value were calculated in all surgical patients.

RESULTS

Forty-seven lesions were punctured (mean adenoma maximum diameter: 1.8 ± 2.6 cm): negative image in the sestamibi scan (26 patients); the discordance between ultrasonography and the sestamibi scan (6 patients); possible intrathyroidal adenomas (4 patients); a positive sestamibi scan in 2 or more localizations (4 patients); ectopic adenoma (3 patients); persistent primary hyperparathyroidism (2 patients) and atypical adenomas (2 patients). Mean PTH-FNA was 2853 ± 3957 pg/mL and 68% were considered positive (PTH-FNA ≥ 100 pg/mL). No complications were detected during or after the puncture. Thirty-seven patients were operated on, 95% were cured and no parathyromatosis cases were detected. PTH-FNA ≥ 100 pg/mL as a diagnostic test had a sensitivity of 93.7%, a specificity of 100%, a positive predictive value of 100% and an negative predictive value of 71.4%.

CONCLUSION

PTH-FNA is an easy and safe diagnostic test and has a high sensitivity and specificity for differentiating between parathyroid adenomas and other cervical masses in patients with primary hyperparathyroidism.

Intrapericardial parathyroid carcinoma: a case report

PURPOSE

Ectopic parathyroid glands are thought to be the cause of a significant portion of failed primary surgery for hyperparathyroidism. Parathyroid carcinoma (PTCA) is a rare malignant tumor, and ectopic PTCA is a particularly unusual situation. Here, we describe, for the first time, a case of intrapericardial PTCA.

METHODS

We describe the case of a 53-year-old female presented with 1-year history of backache, multiple fractures, nephrolithiasis, nausea, vomiting, fatigue, and unexplained myocardial ischemia-like symptoms. Physical examination revealed a barrel chest and sternal tenderness with stable vital signs. Blood tests confirmed hypercalcemia (3.70 mmol/L) and hyperparathyroidism (>1900 pg/ml). ^99mTc-sestamibi scan indicated ectopic findings in the mediastinum highly suggestive of parathyroid adenoma.

RESULTS

After more tests, cardiac magnetic resonance imaging (MRI) revealed a mass closely related to the great vessels of the heart. The ectopic tumor in the pericardium was successfully resected through sternotomy, with subsequent histopathological confirmation of PTCA. The metabolism of calcium and phosphorus and the level of PTH returned to normal after surgery.

CONCLUSION

This unique case reinforces the tremendous variety of possible ectopic locations of parathyroid glands. Although most patients with primary hyperparathyroidism (PHPT) carry a high suspicion of a benign course, the entity of ectopic PTCA also needs to be considered. Accurate preoperative locating diagnosis as well as en bloc tumor resection offers the highest chance of cure in patients with PHPT.

Surgical implications of recent modalities for parathyroid imaging

Clinical or subclinical primary hyperparathyroidism (PHPT) is one of the most common endocrine disorders in the world. Parathyroidectomy is the treatment of choice in symptomatic patients, stabilizing the progression of complications caused by the destruction activity of parathyroid hormone (PTH). Parathyroid surgical techniques have evolved over the years from bilateral neck exploration, to minimally invasive single parathyroid gland exploration, to minimally invasive video-assisted parathyroidectomy. Localization of the abnormal parathyroid gland before surgery is crucial for the operation to be effective. Increased incidences of reoperations of the parathyroid glands and the rapid development of minimally invasive methods led to the development of new localization techniques. The noninvasive studies include ultrasound (US), computed tomography (CT), magnetic resonance (MR) and ^99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy combined with single-photon emission CT (SPECT/CT). Among the latest technologies, the four-dimensional (4D)-CT scan, positron emission tomography (PET)/CT and PET/MR are very promising, and are going to have surgical implications in the future.

The Effectiveness of Preoperative Ultrasonography and Scintigraphy in the Pathological Gland Localization in Primary Hyperparathyroidism Patients

OBJECTIVES

Primary hyperparathyroidism (pHPT) is a common disease, and its curative treatment is surgical. Nowadays, preoperative localization studies have become standard before surgical treatment, and the first stage imaging methods are ultrasonography and/or scintigraphy. With the contribution of these studies to the localization of the pathological gland, focused surgery has become the first standard of choice. In this study, we aimed to evaluate the efficacy of ultrasonography and scintigraphy in the preoperative localization of the pathologic gland or glands in patients who underwent surgical treatment and cure for pHPT.

METHODS

In this study; the data of the biochemically diagnosed pHPT patients, who had Tc 99m-MIBI scintigraphy and/or ultrasonography for localisation preoperatively, were evaluated retrospectively. The lesion, which was positive in USG or scintigraphy for localization, was evaluated according to the neck side or neck quadrant, and the results were compared with intraoperative localization findings. The effectiveness of both methods and combinations was evaluated with the localization rates, sensitivity and positive predictive values (PPV). The three methods were compared with the Youden index (J).

RESULTS

The mean age of 380 patients included in this study was 54.8±12.8 years (20-83). Three hundred eight of them were female, and 72 were male. Scintigraphy was performed in 339 patients, USG was performed in 344 patients, and both USG and scintigraphy were performed in 306 patients. One hundred twenty patients (32%) underwent bilateral neck exploration (BNE), and 260 patients (68.4%) underwent minimally invasive parathyroidectomy (MIP) (unilateral exploration or focused surgery). Single adenoma was detected in 358 (94%), double adenoma in 10 (3%) and hyperplasia in 12 (3%) patients.Localization rates of USG, scintigraphy, USG and scintigraphy combinations were 53%, 74%, 75%; their sensitivity was 56%, 85%, 89%; PPDs were 90%, 86%, 83%. The efficiency of scintigraphy is higher than USG (J: 0.743 vs 0.527). The contribution of scintigraphy to USG in combination with USG was limited (J: 0.743 vs 0.754).The localization rates of USG, scintigraphy, USG and scintigraphy combinations were 46%, 64%, 66%; their sensitivity was 51%, 83%, 88%; PPDs were 79%, 74%, 73%. The efficiency of scintigraphy is higher than that of USG (J: 0.64 vs 0.427). The contribution of scintigraphy to USG in combination with USG was limited (J: 0.64 vs 0.66).

CONCLUSION

In patients with pHPT, scintigraphy is a more effective method for USG as the first step preoperative imaging and should be preferred as the first method if there is no contraindication. A combination of scintigraphy with USG may contribute minimally to the efficacy of scintigraphy. It may be advantageous for early detection of the pathologic gland in patients with incompatible two imaging and initiating surgery on the positive side of the first scintigraphy. Scintigraphy and USG methods may allow successful MRP surgery in the majority of patients with pHPT.

Diagnostic accuracy of parathyroid hormone levels in washout samples of suspicious parathyroid adenomas: A single-centre retrospective cohort study

INTRODUCTION

Minimally invasive surgery is an alternative surgical approach for primary hyperparathyroidism with less surgical trauma and anaesthesia complications. When combined with intraoperative measurement of parathyroid hormone (PTH), cure rates are exceeding 97%. Preoperative intact PTH determination in washout samples is really very useful when parathyroid lesions cannot be easily distinguished from thyroid lesions or sometimes lymph nodes. Herein, we aimed to report our institutional experience about parathyroid fine-needle aspiration (FNA) method and suggest a cut-off ratio for this purpose.

METHODS

In our clinic, we performed ultrasonography (USG)-guided parathyroid FNA procedure for 131 patients diagnosed with primary hyperparathyroidism between January 2005 and January 2016. Both cytologic evaluation and intact PTH determination were performed in washout samples. Eighty-seven of the study group also had a parathyroid scintigraphy. Both demographic features and laboratory results were all recorded.

RESULTS

Median serum PTH level was 142 (113-197), while mean PTH washout level was 1824 (0-3953). When three of the localization techniques are compared with each other, FNA-PTH washout group had a better diagnostic accuracy (90.8%) when compared to cytology (7.92%) and MIBI (67.8%) groups. Both MIBI and FNA-PTH washout group had 100% positive predictive value (PPV) and 100% specificity. We found values greater than 436.5 pg/mL for FNA-PTH washout with a sensitivity of 90.3% and specificity of 88.9% (P < 0.01 and AUC 94.3 (87.8-100)) and a cut-off for FNA/serum PTH greater than 3.05 with a sensitivity of 91.2% and specificity of 89% (P = 0.02 and AUC 94.5 (88.8-100)) which implicate parathyroid lesions.

CONCLUSION

According to the literature, PTH determination in washout samples has a specificity of 75%-100% and sensitivity of 70%-100%. This approach has better results than both cytology and scintigraphy in case of concomitant multinodular thyroid disease in experienced hands. Although there is not a definite cut-off for PTH levels in washout samples, we agree with the need of ratios rather than cut-offs in this issue.

Comparative Diagnostic Performance of Ultrasonography and 99mTc-Sestamibi Scintigraphy for Parathyroid Adenoma in Primary Hyperparathyroidism; Systematic Review and Meta- Analysis

Objective:

Ultrasonography (US) and parathyroid scintigraphy (PS) with 99mTc-MIBI are common methods for preoperative localization of parathyroid adenomas but there discrepancies exist with regard to diagnostic accuracy. The aim of the study was to compare PS and US for localization of parathyroid adenoma with a systematic review and meta-analysis of the literature.

Methods:

Pub Med, Scopus (EMbase), Web of Science and the reference lists of all included studies were searched up to 1st January 2016. The search strategy was according PICO characteristics. Heterogeneity between the studies was accounted by P < 0.1. Point estimates were pooled estimate of sensitivity, specificity and positive predictive value of SPECT and ultrasonography with 99% confidence intervals (CIs) by pooling available data. Data analysis was performed using Meta-DiSc software (version 1.4).

Results:

Among 188 studies and after deletion of duplicated studies (75), a total of 113 titles and abstracts were studied. From these, 12 studies were selected. The meta-analysis determined a pooled sensitivity for scintigraphy of 83% [99% confidence interval (CI) 96.358 -97.412] and for ultra-sonography of 80% [99% confidence interval (CI) 76-83]. Similar results for specificity were also obtained for both approache.

Conclusion:

According this meta- analysis, there were no significant differences between the two methods in terms of sensitivity and specificity. There were overlaps in 99% confidence intervals. Also features of the two methods are similar.

Measurement of thyroglobulin, calcitonin, and PTH in FNA washout fluids

Different imaging tools, circulating endocrine markers, and fine-needle aspiration (FNA) cytology are of great importance in the diagnosis and follow-up of different thyroid and parathyroid diseases. Sometimes, however, they are conflicting or inconclusive: interestingly, measuring endocrine markers (i.e. thyroglobulin, calcitonin, parathyroid hormone) in fluids from FNA proved to be a very useful complementary diagnostic tool in such cases. The determination of endocrine markers in fluids other than serum/plasma has been developed in the last years. Although studies have reported overall satisfactory results, a good standardization of procedures has not yet been reached, and further efforts should be made in order to better define pre-analytical, analytical, and post-analytical aspects. Here we reviewed critically the literature on the measurement of FNA endocrine markers, focusing on laboratory issues, such as preparation of the sample, choice of solution, and technical features of determination of these markers. Indeed, information for use of FNA-Tg, FNA-CT, and FNA-PTH in clinical practice was also provided.

The Significance of 18F-Fluorocholine-PET/CT as Localizing Imaging Technique in Patients with Primary Hyperparathyroidism and Negative Conventional Imaging

OBJECTIVE

The essential prerequisite for focused parathyroidectomy in patients with primary hyperparathyroidism (pHPT) is proper localization of all autonomic tissue. Sensitivity of conventional imaging modalities (ultrasound, ^99mTc-sestamibi scintigraphy/SPECT/CT) is influenced by different factors (i.e., size/weight and position of autonomic tissue) and decreases in the presence of a multinodular goiter. Therefore, a considerable percentage of pHPT patients have negative or equivocal localization studies before surgery. The aim of this study is to evaluate the utility of FCH-PET/CT for preoperative localization in patients with pHPT and negative/equivocal ^99mTc-sestamibi scintigraphy/SPECT/CT and/or ultrasound.

METHODS AND MEASUREMENTS

Between 2014 and 2017, a total of 39 patients with pHPT and negative/equivocal conventional imaging were referred for FCH-PET/CT. In the analysis, we included those (n = 23) who had surgery and a histopathologic workup of the lesions.

RESULTS

19 of 23 patients demonstrated no tracer uptake with ^99mTc-sestamibi scintigraphy/SPECT/CT, 6 patients had an equivocal sonographic lesion, and multinodular goiter was present in 43% (10/23). In 21 of 23 patients, hyperfunctioning parathyroid tissue was identified correctly by FCH-PET/CT [21 true positive, 1 false negative, and 1 false positive; per-patient sensitivity 95.5% (95% confidence interval {CI}, 77.2-99.9)]. 29 lesions were resected [21 true positives, 3 false negatives, 1 false positive, and 4 true negatives; per-lesion sensitivity 87.5% (95% CI, 67.6-97.3)]. All patients were classified as having surgical success according to a decrease of intraoperative parathyroid hormone of ≥50% and normalization of postoperative serum calcium levels.

CONCLUSION

Despite a high prevalence of multinodular goiter, diagnostic accuracy of FCH-PET/CT in our patient group was excellent. Therefore, FCH-PET/CT is a promising new imaging tool in patients with pHPT and negative/equivocal results by conventional imaging techniques.

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.

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.

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.

A Pilot Comparison of 18F-fluorocholine PET/CT, Ultrasonography and 123I/99mTc-sestaMIBI Dual-Phase Dual-Isotope Scintigraphy in the Preoperative Localization of Hyperfunctioning Parathyroid Glands in Primary or Secondary Hyperparathyroidism: Influence of Thyroid Anomalies

We compared (18)F-fluorocholine hybrid positron emission tomography/X-ray computed tomography (FCH-PET/CT) with ultrasonography (US) and scintigraphy in patients with hyperparathyroidism and discordant, or equivocal results of US and (123)I/(99m)Tc-sesta-methoxyisobutylisonitrile (sestaMIBI) dual-phase parathyroid scintigraphy. FCH-PET/CT was performed in 17 patients with primary (n = 11) lithium induced (n = 1) or secondary hyperparathyroidism (1 dialyzed, 4 renal-transplanted).The reference standard was based on results of surgical exploration and histopathological examination. The results of imaging modalities were evaluated, on site and by masked reading, on per-patient and per-lesion bases.In a first approach, equivocal images/foci were considered as negative. On a per-patient level, the sensitivity was for US 38%, for scintigraphy 69% by open and 94% by masked reading, and for FCH-PET/CT 88% by open and 94% by masked reading. On a per-lesion level, sensitivity was for US 42%, for scintigraphy 58% by open and 83% by masked reading, and for FCH-PET/CT 88% by open and 96% by masked reading. One ectopic adenoma was missed by the 3 imaging modalities. Considering equivocal images/foci as positive increased the accuracy of the open reading of scintigraphy or of FCH-PET/CT, but not of US. FCH-PET/CT was significantly superior to US in all approaches, whereas it was more sensitive than scintigraphy only for open reading considering equivocal images/foci as negative (P = 0.04). FCH uptake was more intense in adenomas than in hyperplastic parathyroid glands. Thyroid lesions were suspected in 9 patients. They may induce false-positive results as in one case of oncocytic thyroid adenoma, or false-negative results as in one case of intrathyroidal parathyroid adenoma. Thyroid cancer (4 cases) can be visualized with FCH as with (99m)Tc-sestaMIBI, but the intensity of uptake was moderate, similar to that of parathyroid hyperplasia.This pilot study confirmed that FCH-PET/CT is an adequate imaging tool in patients with primary or secondary hyperparathyroidism, since both adenomas and hyperplastic parathyroid glands can be detected. The sensitivity of FCH-PET/CT was better than that of US and was not inferior to that of dual-phase dual-isotope (123)I/(99m)Tc-scintigraphy. Further studies should evaluate whether FCH could replace (99m)Tc-sestaMIBI as the functional agent for parathyroid imaging, but US would still be useful to identify thyroid lesions.

The current status of intraoperative iPTH assay in surgery for primary hyperparathyroidism

Intraoperative intact parathyroid hormone (iPTH) monitoring has been accepted by many centers specializing in parathyroid surgery as a useful adjunct during surgery for primary hyperparathyroidism. This method can be utilized in three discreet modes of application: (I) to guide surgical decisions during parathyroidectomy in one of the following clinical contexts: (i) to confirm complete removal of all hyperfunctioning parathyroid tissue, which allows for termination of surgery with confidence that the hyperparathyroid state has been successfully corrected; (ii) to identify patients with additional hyperfunctioning parathyroid tissue following the incomplete removal of diseased parathyroid/s, which necessitates extended neck exploration in order to minimize the risk of operative failure; (II) to differentiate parathyroid from non-parathyroid tissue by iPTH measurement in the fine-needle aspiration washout; (III) to lateralize the side of the neck harboring hyperfunctioning parathyroid tissue by determination of jugular venous gradient in patients with negative or discordant preoperative imaging studies, in order to increase the number of patients eligible for unilateral neck exploration. There are many advantages of minimally invasive parathyroidectomy guided by intraoperative iPTH monitoring, including focused dissection in order to remove the image-indexed parathyroid adenoma with a similar or even higher operative success rate, lower prevalence of complications and shorter operative time when compared to conventional bilateral neck exploration. However, to achieve such excellent results, the surgeon needs to be aware of hormone dynamics during parathyroidectomy and carefully choose the protocol and interpretation criteria that best fit the individual practice. Understanding the nuances of intraoperative iPTH monitoring allows the surgeon for achieving intraoperative confidence in predicting operative success and preventing failure in cases of unsuspected multiglandular disease, while safely limiting neck exploration in the majority of patients with sporadic primary hyperparathyroidism. Thus, parathyroidectomy guided by intraoperative iPTH monitoring for the management of sporadic primary hyperparathyroidism is an ideal option for the treatment of this disease entity. However, the cost-benefit aspects of the standard application of this method still remain a matter of controversy.

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.

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.

Reoperations for persistent or recurrent primary hyperparathyroidism: results of a retrospective cohort study at a tertiary referral center

BACKGROUND

Parathyroid reoperations are challenging and achieving a cure requires multidisciplinary treatment team cooperation. The aims of this study were to summarize our experience in revision surgery for persistent (pHPT) or recurrent primary hyperparathyroidism (rHPT) and to explore factors underlying failure to cure at initial surgery.

MATERIAL AND METHODS

This was a retrospective cohort study of patients who underwent reoperations for pHPT or rHPT at a tertiary referral center. The database of parathyroid surgery was searched for eligible patients (treated in the years 2000-2012). The primary outcome was the cure rate. All the patients were followed-up for at least 12 months postoperatively. Factors underlying failure to cure at initial surgery were reviewed based on hospital records.

RESULTS

The study group comprised 88 patients (69 women, 19 men) operated on for persistent (n=57) or recurrent disease (n=31), who underwent 98 reoperations, including 26 (2.4%) patients first operated on at our institution, and 72 (81.8%) patients operated on elsewhere, but referred for revision surgery. A long-term cure was achieved in 83/88 patients (94.3%). The mean post-reoperation follow-up was 91.7 (12-176) months. Missed hyperfunctioning parathyroid gland was found on reoperation in eutopic position in 49 (55.5%) patients, and in ectopic position in 39 (44.3%) patients, including 20 (22.7%) cases of cervical ectopy and 19 (21.6%) cases of mediastinal ectopy.

CONCLUSIONS

Multidisciplinary treatment team cooperation at a tertiary referral center, consisting of an accurate preoperative localization, expertise in parathyroid re-explorations, and correct use of intraoperative adjuncts, contribute to the high success rate of parathyroid reoperations.

Gamma Probe Guided Minimally Invasive Parathyroidectomy without Quick Parathyroid Hormone Measurement in the Cases of Solitary Parathyroid Adenomas

OBJECTIVE

In this study, our aim was to study the efficiency of gamma probe guided minimally invasive parathyroidectomy (GP-MIP), conducted without the intra-operative quick parathyroid hormone (QPTH) measurement in the cases of solitary parathyroid adenomas (SPA) detected with USG and dual phase 99mTc-MIBI parathyroid scintigraphy (PS) in the preoperative period.

MATERIAL AND METHODS

This clinical study was performed in 31 SPA patients (27 female, 4 male; mean age 51±11years) between February 2006 and January 2009. All patients were operated within 30 days after the detection of the SPA with dual phase 99mTc-MIBI PS and USG. The GP-MIP was done 90-120 min after the iv injection of 740 MBq 99mTc-MIBI. In all cases, except 1 patient, the GP-MIP was performed under local anesthesia; due to the enormity of size of SPA, then general anesthesia is chosen.

RESULTS

The operation time was 30-60 min, mean 38,2±7 min. In the first postoperative day, there was a more than 50% decrease in PTH levels in all patients and all but one had normal serum calcium levels. Transient hypocalcemia was detected in one patient.

CONCLUSION

GP-MIP without intra-operative QPTH measurement is a suitable method in the surgical treatment of SPA detected by dual phase 99mTc-MIBI PS and USG.

CONFLICT OF INTEREST

None declared.

Risks and benefits of parathyroid fine-needle aspiration with parathyroid hormone washout

OBJECTIVE

To describe the experience with parathyroid fine-needle aspiration (FNA) and parathyroid hormone (PTH) washout at Mayo Clinic Rochester, Rochester, Minnesota.

METHODS

We retrospectively reviewed all parathyroid FNA procedures performed at Mayo Clinic Rochester between January 2000 and December 2007. Clinical, biochemical, and imaging information, parathyroid FNA procedure, and cytology, surgical, and pathology reports were reviewed, and descriptive statistics, sensitivity, specificity, and positive predictive values are presented.

RESULTS

During the study period, 75 parathyroid FNAs were performed on 74 patients. Cytology results were available for 74 of 75 procedures, with only 31% interpreted as parathyroid cells. PTH washout was performed in 67 patients (91%). Parathyroid FNA with PTH washout had a sensitivity of 84%, specificity of 100%, positive predictive value of 100%, and accuracy of 84%. At the time of surgical treatment, 2 patients were noted to have an inflammatory response from the parathyroid FNA biopsy, 1 had a parathyroid abscess, and 2 had a hematoma. In 3 of these 5 patients, the necessary conversion of a minimally invasive surgical procedure to the standard surgical approach prolonged the surgical time.

CONCLUSION

Parathyroid FNA with PTH washout had a superior performance in comparison with parathyroid scanning or ultrasonography alone. The main limitations of parathyroid FNA with PTH washout are (1) the need for initial identification of a potential parathyroid adenoma by ultrasonography and (2) the number of false-negative results. Parathyroid FNA resulted in complications affecting the surgical procedure in 3 patients.

Thyroid diseases cause mismatch between MIBI scan and neck ultrasound in the diagnosis of hyperfunctioning parathyroids: usefulness of FNA-PTH assay

DESIGN

To evaluate the efficacy of the main tools in the diagnostic localization of hyperfunctioning parathyroids (HP) in primary hyperparathyroidism (pHPT) with concomitant thyroid diseases.

METHODS

Forty-three patients with pHPT associated with nodular goiter (NG, n=32) and/or autoimmune thyroid diseases (AITDs, n=11) for a total of 63 neck lesions were considered. Sixteen patients displaying HP (16 lesions), unequivocally localized by sestaMIBI scintigraphy (MIBI) and neck ultrasound (US) (group I), were compared with 27 patients (47 neck lesions) displaying equivocal parathyroid localization (group II). In all cases, neck US, MIBI scan, cytology, and parathyroid hormone assay in fine-needle aspiration washout fluid (FNA-PTH) were performed. All patients finally underwent surgery.

RESULTS

According to histological examination, high FNA-PTH values (>103 pg/ml) correctly identified all HP in both groups of patients (100% of sensitivity and specificity). Both MIBI and US correctly identified all HP only in group I patients; in contrast, four patterns of mismatch between these techniques were observed in group II patients, leading to low diagnostic performances of neck US (71.4% sensitivity and 78.9% specificity) and of MIBI scan (35.7% sensitivity and 42.1% specificity). The latter was due to both false-negative (mainly in AITD) and false-positive (mainly in NG) scan images.

CONCLUSIONS

Coexistent thyroid diseases are responsible for mismatch between MIBI and US images resulting in equivocal HP localization. In these cases, FNA-PTH resulted in the most accurate tool to identify HP. However, although safe, it should be advised only to patients with uncertain HP localization.

Techniques for parathyroid localization with ultrasound

Four-gland parathyroid exploration has been the gold standard for parathyroid surgery until recently. Emphasis is now placed on minimally invasive and focused parathyroidectomy. In conjunction with functional sestamibi scanning, ultrasonography permits accurate localization of enlarged parathyroid glands in the vast majority of patients with hyperparathyroidism. Consequently, ultrasound technology applied to parathyroid pathology facilitates directed surgical therapy and minimally invasive applications. As such, ultrasonography holds great promise as a tool that enables cost-effective and advanced patient care.

4D parathyroid CT as the initial localization study for patients with de novo primary hyperparathyroidism

BACKGROUND

Preoperative localization of parathyroid tumors of primary hyperparathyroidism (pHPT) is required for minimally invasive parathyroidectomy (MIP). Parathyroid four-dimensional computed tomography (4DCT) has mainly been used as an adjunct to other imaging modalities in the remedial setting. 4DCT was evaluated as the initial localization study in de novo patients with pHPT.

MATERIALS AND METHODS

A total of 87 consecutive patients underwent parathyroidectomy for pHPT from August 2008 to November 2009. 4DCT was introduced as the preferred imaging modality instead of sestamibi with SPECT (SeS) in April 2009. Results of the imaging studies [4DCT, SeS, and ultrasonography (US)], operative and, pathologic findings, and biochemical measurements were evaluated.

RESULTS

In this study, 84% of patients (73 of 87) underwent an US, 59.8% (52 of 87) a SeS, and 38.0% (33 of 87) had a 4DCT. 4DCT had improved sensitivity (85.7%) over SeS (40.4%) and US (48.0%) to localize parathyroid tumors to the correct quadrant of the neck (P < 0.005) as well as to localize (lateralize) the parathyroid lesions to one side of the neck (93.9% for 4DCT vs. 71.2% for US and 61.5% for SeS; P < 0.005). 4DCT correctly predicted multiglandular disease (MGD) in 85.7% (6 of 7) patients, whereas US and SeS were unable to detect MGD in any case. All patients achieved cure based on intraoperative parathyroid hormone (PTH) measurements and normalization of intact PTH and S-Ca during follow-up.

CONCLUSIONS

4DCT provides significantly greater sensitivity than SeS and US for precise localization of parathyroid tumors of pHPT. Additionally, it correctly predicted MGD in a majority of patients.

Validity of dual tracer 99mTc-tetrofosmin and 99mTc-pertechnetate subtraction parathyroid scintigraphy in patients with primary and secondary hyperparathyroidism

BACKGROUND/AIM

Primary hyperparathyroidism (pHPT) is an endocrine disease with the third highest incidence of all endocrine disorders after diabetes mellitus and hyperthyroidism. pHPT is typically caused by a solitary parathyroid adenoma, less frequently by multiple parathyroid gland disease (MGD) and rarely by parathyroid carcinoma. Secondary hyperparatyroidism (sHPT) is a common complication in patients with chronic renal failure. The aim of this study was to estimate sensitivity of dual tracer 99mTc-tetrofosmin and 99mTc-pertechnetate subtraction scintigraphy in detection of abnormal parathyroid glands in patients with pHPT and sHPT confirmed by histopathology.

METHODS

In 46 patients, (77 abnormal parathyroid glands), 30 with pHPT and 16 with sHPT parathyroid scintigraphy was done preoperatively. All the patients had histopathological confirmation of diagnosis. Abnormal parathyroid glands weighted from 0.1 to 7 g. After iv injection dynamic scintigraphy during 25 minutes (one frame-one minute) using 555 MBq of 99mTc-tetrofosmin, and three hours latter using 111 MBq of 99mTc/pertechnetate was performed. 99mTc-tetrofosmin dynamic study was followed by static scintigraphy of the neck and chest 30 minutes, 1, 2 and 3 hours after iv injection.

RESULTS

An abnormal scintigraphic finding was found in 44 of 46 patients with sensitivity of 96%. In pHPT sensitivity was 93% (28 of 30 patients, and 28 of 30 glands). In sHPT scintigraphy was abnormal in all the patients (sensitivity 100%). In the patients with sHPT scintigraphy detected 30 of 47 abnormal parathyroid glands (sensitivity 64%). An overall sensitivity of scintigraphy per gland, for pHPT and sHPT in detecting 58 of 77 abnormal parathyroid glands was 75%.

CONCLUSION

An abnormal scintigraphic result per patient was found in 44 patients (sensitivity 96%) and 58 of 77 abnormal parathyroid glands were detected (sensitivity 750/0). A high sensitivity of dual tracer subtraction 99mTc-tetrofosmin/99mTc-pertechnetate parathyroid scintigraphy in detecting abnormal parathyroid glands in primary and secondary hyperparathyroidism was achieved.

Institutional experience of PTH evaluation on fine-needle washing after aspiration biopsy to locate hyperfunctioning parathyroid tissue

Assaying parathyroid hormone (PTH) in the washing liquid after fine-needle aspiration biopsy (FNAB) seems to be a valid approach to locate parathyroid tissue. PTH-FNAB was evaluated in 47 patients with a clinical picture of primary hyperparathyroidism (PHP) and ultrasonography (US) suggestive of parathyroid lesion. The patients were subdivided into two groups on the basis of the absence or presence of US thyroid alterations. The result of PTH-FNAB was compared with those of cytology, scintigraphy and, in 24 patients, surgical outcome. PTH-FNAB samples with a value higher than that recorded in the serum and higher than our institutional cut-off were deemed to be probable samples of parathyroid tissue. Cytology proved diagnostic for benign thyroid lesions, non-diagnostic for thyroid lesions, hyperplastic parathyroid tissue, undetermined or malignant thyroid lesions and other lesions in 45%, 30%, 17%, 4%, and 4% of cases, respectively. In 47% of cases, PTH-FNAB indicated that the sample had been taken in parathyroid tissue. In patients without US alterations, the diagnostic accuracy of PTH-FNAB was greater than that of scintigraphy. After surgery, comparison between the results of PTH-FNAB and scintigraphy, in terms of positive predictive value (PPV), revealed the superiority of PTH-FNAB; PPV was 94% for FNAB and 71% for scintigraphy, while sensitivity was 83% and 69%, respectively. PTH-FNAB evaluation after FNAB appears to be more diagnostic than cytology and scintigraphy. Of all the procedures used, PTH-FNAB appears to be the method of choice when the target is US suggestive and reachable. PTH-FNAB appears to be a useful method of guiding surgical intervention.