A prospective evaluation of preoperative localization by technetium-99m sestamibi scintigraphy and ultrasonography in primary hyperparathyroidism

A New Technique for Localization of Parathyroid Adenoma: Infrared Thermal Scanning of the Neck

Many radiological techniques are used to locate the adenoma preoperatively in cases of primary hyperparathyroidism, but the location of many adenomas still cannot be detected. Since adenomas are hypervascular lesions, their temperature is high. Infrared thermal scanning can reveal local temperature differences in hypervascular lesions. The location of the adenoma could not be determined by preoperative radiological examinations in a 58-year-old male patient who was scheduled for surgery with the diagnosis of primary hyperparathyroidism. By infrared thermal scanning, a nearly 2°F higher temperature was measured in the inferior of the right thyroid lobe compared to the other perithyroidal regions. During the exploration, the adenoma was found at this point and removed. Infrared thermal scanning of the neck is promising as a new technique that can be used both preoperatively and intraoperatively to locate the adenoma in primary hyperparathyroidism cases.

Head-to-head comparison among 18F-choline PET/CT, 4D contrast-enhanced CT, and 18F-choline PET/4D contrast-enhanced CT in the detection of hyperfunctioning parathyroid glands: a systematic review and meta-analysis

INTRODUCTION

In primary hyperparathyroidism (PHPT), the localization of hyperfunctioning parathyroid gland (HPTG) allows tailored surgery. Although Four-Dimensional Contrast-enhanced Computed Tomography (4DCeCT) and ¹⁸F-choline Positron Emission Tomography/Computed Tomography (PET/CT) are reported to be promising second-line imaging procedures, no meta-analysis of their comparison exists.

DESIGN

we conducted a systematic review and meta-analysis to find original papers reporting the head-to-head comparison of 4DCeCT, ¹⁸F-choline PET/CT and integrated ¹⁸F-choline-PET/4DCeCT.

METHODS

this systematic review was conducted according to PRISMA. PubMed, CENTRAL, Scopus, and Web of Science were searched until January 2021. Studies comparing the ability of 4DCeCT, ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT to identify HPTG in patients with PHPT were selected. A per patient-based analysis of the three procedures was conducted in all patients (detection rate, DR) and in those with histologically confirmed HPTG (sensitivity).

RESULTS

Of the 78 records identified, five articles (153 PHPT patients) published between January the 1st, 2018 and January the 31st, 2021 were included. The pooled DR of ¹⁸F-choline PET/CT, 4DCeCT and ¹⁸F-choline PET/4DCeCT was 0.86, 0.69, and 0.86, respectively, while their pooled sensitivity was 0.89, 0.77 and 0.93, respectively. The analysis of pooled discrepancy showed that the sensitivity of ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT was higher than that of 4DCeCT by 0.11 and 0.13, respectively, the sensitivity of ¹⁸F-choline PET/4DCeCT being 0.06 higher than that of ¹⁸F-Choline PET/CT.

CONCLUSIONS

This meta-analysis suggests that the sensitivity of ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT is higher than that of 4DCeCT, while only a slight difference was observed between ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT.

The use of computed tomography as a first-line imaging modality in patients with primary hyperparathyroidism

BACKGROUND

The success of minimally invasive parathyroidectomy (MIP) relies on accurate localization of the abnormal parathyroid glands. Concordant findings on ultrasound (US) and ^99mTc-scintigraphy (sestamibi) are currently considered the 'gold standard'. Computed tomography (CT) has also recently been used in preoperative planning. We sought to assess the accuracy of CT for localization of abnormal parathyroid glands in such patients.

METHODS

An audit of 75 patients with primary hyperparathyroidism (PHPT) who underwent neck US and CT between 2017 and 2019 at our center as their first-line imaging.

RESULTS

All 75 patients underwent US and CT and 54 (72.0%) also had sestamibi. CT alone identified a potential target in all patients, of which the location was correct in 63 (84.0%). The overall combined sensitivity of US and CT was 88% (95% CI 78-94) and was higher than the combined sensitivity of US and sestamibi (65% [95% CI 53-76]; p < 0.001). Twenty-one patients (28.0%) had an ectopic gland, and the sensitivity of US and CT was 86% (95% CI 64-96) versus US and sestamibi (57% [95% CI 34-77]; p = 0.016). For adenomas < 1.0 g (n = 36; 48%), the accuracy of CT was 81% (95% CI 64-91) compared with 62% (95% CI 44-77) for US and sestamibi (p = 0.04). The correct preoperative diagnosis of multiglandular disease (n = 9; 12%) seemed to be the most difficult, with similar accuracy for US and sestamibi (40% [95% CI 14-73]) and US and CT (50% [95% CI 20-80]) (p > 0.99).

CONCLUSION

The combination of US and CT was able to correctly identify the location of the abnormal parathyroid in 88% of patients and, in comparison with US and sestamibi, had better diagnostic accuracy, especially for smaller and ectopic adenomas. This finding suggests that US and CT could be considered as a first-line imaging modality in patients with PHPT considered for MIP.

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.

Parathyroid Disease in Pregnancy and Lactation: A Narrative Review of the Literature

Pregnancy and lactation are characterized by sophisticated adaptations of calcium homeostasis, aiming to meet fetal, neonatal, and maternal calcium requirements. Pregnancy is primarily characterized by an enhancement of intestinal calcium absorption, whereas during lactation additional calcium is obtained through resorption from the maternal skeleton, a process which leads to bone loss but is reversible following weaning. These maternal adaptations during pregnancy and lactation may influence or confound the presentation, diagnosis, and management of parathyroid disorders such as primary hyperparathyroidism or hypoparathyroidism. Parathyroid diseases are uncommon in these settings but can be severe when they occur and may affect both maternal and fetal health. This review aims to delineate the changes in calcium physiology that occur with pregnancy and lactation, describe the disorders of calcium and parathyroid physiology that can occur, and outline treatment strategies for these diseases in the above settings.

The Potential Role of Preoperative Trabecular Bone Score in Predicting Changes in Bone Mineral Density After Parathyroidectomy

BACKGROUND

The skeletal indication for parathyroidectomy for primary hyperparathyroidism (PHPT) is based on bone mineral density (BMD) T-score <  - 2.5. Whether trabecular bone score (TBS) additionally identifies patients who benefit from parathyroidectomy in terms of bone health is unknown. We aimed to study changes in BMD and TBS among Chinese who underwent curative parathyroidectomy for PHPT, in relation to their preoperative parameters, especially in those with worst site BMD T-score ≥  - 2.5 (non-osteoporotic range).

METHODS

We included consecutive Chinese individuals who underwent curative parathyroidectomy during 2002-2015 for PHPT and completed preoperative and postoperative BMD and TBS measurements in Queen Mary Hospital. Correlations between preoperative parameters and changes in densitometric parameters were studied.

RESULTS

45 Chinese individuals (13 men, 32 women) were included (mean age 62.0 ± 10.0 years and BMI 24.6 ± 4.7 kg/m²). After parathyroidectomy, BMD at lumbar spine (LS) improved by 6.7% (p < 0.001) while TBS did not change. Among women, peak preoperative parathyroid hormone and calcium levels independently predicted LS BMD gain. Among women with BMD in non-osteoporotic range, LS BMD also improved after parathyroidectomy, where preoperative TBS was the only significant variable inversely correlating with percentage change in LS BMD (ρ - 0.775, p = 0.005). Particularly, those with preoperative TBS ≤ 1.25 gained 7.1% LS BMD post-parathyroidectomy (p = 0.003).

CONCLUSIONS

LS BMD, but not TBS, improved after parathyroidectomy. Among non-osteoporotic PHPT women, preoperative TBS inversely correlated with postoperative BMD improvement. Hence, low preoperative TBS may be an additional indication for surgical benefit with parathyroidectomy in non-osteoporotic PHPT women, as those with worse preoperative TBS tend to benefit more from surgery.

Intraoperative parathyroid hormone (IOPTH) assay might be better than the second-generation assay in parathyroidectomy for primary hyperparathyroidism

BACKGROUND

It is unclear whether the third-generation intraoperative parathyroid hormone assay can improve surgical outcomes over second-generation assay in primary hyperparathyroidism. We aimed to compare the rate of decrease and diagnostic accuracy between the two assays after parathyroid adenoma excision.

METHODS

Consecutive patients undergoing parathyroidectomy with intraoperative parathyroid hormone were analyzed. Blood was drawn before and 10 minutes and 20 minutes after excision of the adenoma. The same blood sample was run simultaneously in the second-generation assays (Elecsys PTH STAT) and third-generation assays (Elecsys 1-84 PTH). Biochemical cure meant >50% intraoperative parathyroid hormone decrease at 10 minutes. Cure meant normocalcemia 6 months after operation.

RESULTS

Relative to the second-generation assay, the value of the intraoperative parathyroid hormone level was less in the third-generation assay before excision (P < .001), at 10 minutes (P < .001), and at 20 minutes (P < .001). The intraoperative parathyroid hormone rate of decrease and the proportion of normalized post-excision intraoperative parathyroid hormone were greater in the third-generation assay (P < .001), but the prediction accuracy appeared similar between the 2 (91.5% vs 91.0%). Patients with worse renal function (estimated glomerular filtration rate <80mL/min/1.73m²) had a slower intraoperative parathyroid hormone decrease in the second-generation but not in the third-generation assay.

CONCLUSION

Despite comparable accuracy between the two generations of assay, the third-generation assay might be better than the second-generation assay because of the more rapid decrease in the intraoperative parathyroid hormone and a greater percentage of normalized intraoperative parathyroid hormone, regardless of baseline renal function.

Preoperative and Intraoperative Methods of Parathyroid Gland Localization and the Diagnosis of Parathyroid Adenomas

Accurate pre-operative determination of parathyroid glands localization is critical in the selection of minimally invasive parathyroidectomy as a surgical treatment approach in patients with primary hyperparathyroidism (PHPT). Its importance cannot be overemphasized as it helps to minimize the harmful side effects associated with damage to the parathyroid glands such as in hypocalcemia, severe hemorrhage or recurrent laryngeal nerve dysfunction. Preoperative and intraoperative methods decrease the incidence of mistakenly injuring the parathyroid glands and allow for the timely diagnosis of various abnormalities, including parathyroid adenomas. This article reviews 139 studies conducted between 1970 and 2020 (49 years). Studies that were reviewed focused on several techniques including application of carbon nanoparticles, carbon nanoparticles with technetium sestamibi (99m Tc-MIBI), Raman spectroscopy, near-infrared autofluorescence, dynamic optical contrast imaging, laser speckle contrast imaging, shear wave elastography, and indocyanine green to test their potential in providing proper parathyroid glands' localization. Apart from reviewing the aforementioned techniques, this study focused on the applications that helped in the detection of parathyroid adenomas. Results suggest that applying all the reviewed techniques significantly improves the possibility of providing proper localization of parathyroid glands, and the application of indocyanine green has proven to be the 'ideal' approach for the diagnosis of parathyroid adenomas.

Identification of Occult Adenomas in Primary Hyperparathyroidism With 18F-fluorocholine PET/CT

INTRODUCTION

Single parathyroid adenomas are the most common cause of primary hyperparathyroidism (PHP) in our population. Parathyroidectomy is still the only potentially curative treatment and requires preoperative localization imaging studies to perform selective surgery. In patients with negative results on conventional tests, PET/CT has demonstrated higher sensitivity rates.

METHODS

A prospective cohort study was designed, including 34 patients diagnosed with PHP between 2017 and 2019, candidates for surgery with negative preoperative localization tests with scintigraphy and MIBI SPECT/CT. All patients underwent PET/CT with 18F-Fluorocholine. The clinical, biochemical and postoperative outcome results were compared with a control group of 30 patients with positive standard tests.

RESULTS

Hyperfunctional parathyroid tissue was detected in 85% of the patients that had undergone choline PET/CT. The selective resection of the adenoma identified in these patients achieved curative criteria in 87% of the cases without undergoing bilateral cervical surgical exploration. The preoperative levels of PTH, calcemia and gland weight were significantly lower in this group compared to the control group. No differences were identified in cure criteria or approach between the 2groups.

CONCLUSION

In our study, choline PET/CT showed higher detection rates compared to the gold standard. The increase provides the opportunity to perform unilateral selected adenoma resection, especially in patients with smaller adenomas associated with lower calcemia and PTH levels and patients with previous cervical surgery.

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.

Preoperative Localization of Adenomas in Primary Hyperparathyroidism: The Value of 11C-Choline PET/CT in Patients with Negative or Discordant Findings on Ultrasonography and 99mTc-Sestamibi SPECT/CT

We aimed to assess the value of ¹¹C-choline PET in patients with primary hyperparathyroidism and negative or discordant results on ^99mTc-sestamibi imaging and neck ultrasound. Methods: Eighty-seven such patients were assessed and subsequently underwent parathyroidectomy. PET/CT image data were analyzed semiquantitatively using SUV_max and SUV ratios (target to contralateral thyroid gland and carotid artery). A positive PET/CT result was defined as focal uptake significantly higher than regular thyroid tissue. Ectopic foci were also considered positive. Inconclusive PET/CT cases were defined as a lesion with uptake equal to normal thyroid tissue. If no prominent or ectopic uptake was detectable, the PET/CT result was considered negative. Results: When dichotomizing the ¹¹C-choline PET/CT imaging results by defining lesions with both positive and inconclusive uptake as positive, we found 84 of 92 lesions (91.3%) to have true-positive uptake whereas 8 lesions (8.7%) had false-positive uptake. One lesion showed false-negative uptake; the sensitivity was 98.8%. The corresponding positive predictive value for lesions was 91.3%. The mean SUV_max was 6.15 ± 4.92 in 72 lesions with positive uptake (70 patients) and 2.96 ± 2.32 in 20 lesions with inconclusive uptake (18 patients). Conclusion: These results in a large group of patients indicate that ¹¹C-choline PET/CT is a promising tool for parathyroid adenoma localization when ultrasound and ^99mTc-sestamibi imaging yield negative or discordant results.

Novel PET tracers: added value for endocrine disorders

Nuclear medicine has been implicated in the diagnosis and treatment of endocrine disorders for several decades. With recent development of PET tracers, functional imaging now plays a major role in endocrine tumors enabling with high performance to their localization, characterization, and staging. Besides ¹⁸F-FDG, which may be used in the management and follow-up of endocrine tumors, new tracers have emerged, such as ¹⁸F-DOPA for neuroendocrine tumors (NETs) (medullary thyroid carcinoma, pheochromocytomas and paragangliomas and well-differentiated NETs originating from the midgut) and ¹⁸F-Choline in the field of primary hyperparathyroidism. Moreover, some peptides such as somatostatin analogs can also be used for peptide receptor radionuclide therapy. In this context, Gallium-68 labeled somatostatin analogs (⁶⁸Ga-SSA) can help to tailor therapeutic choices and follow the response to treatment in the so-called "theranostic" approach. This review emphasizes the usefulness of these three novel PET tracers (¹⁸F-Choline, ¹⁸F-FDOPA, and ⁶⁸Ga-SSA) for primary hyperparathyroidism and neuroendocrine tumors.

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.

F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive: the APACH1 study

Purpose

To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT.

Methods

We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up.

Results

Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0–98.9) and 90.5% (95%CI: 69.6–98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6–97.3) and 86.4% (95%CI: 65.1–97.1), respectively.

Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l.

Conclusions

Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients with primary hyperparathyroidism and negative or inconclusive conventional imaging results. Bilateral cervical exploration could be avoided in the majority (75%) of patients.

Evaluation of a TPTX model induced by ischemia

Parathyroidectomy (PTX), especially total parathyroidectomy (TPTX), is often recommended for severe secondary hyperparathyroidism (SHPT) if other medical treatments fail. Accurate identification and resection of parathyroid gland (PTG) tissue is the cornerstone of PTX. The establishment of a rat TPTX model would be beneficial for several applications but faces the same problems. In this experiment, we studied the mechanisms of ischemia for the accurate identification and excision of PTG tissue to establish TPTX rat models and to analyze the effects of surgical removal of PTG tissue as well as the effects of different types of water intake in rats on clinical indices. We found that the ischemia method had advantages when establishing a rat TPTX model. Removal of the PTG tissue resulted in significantly changed postoperative indices, and varying the types of water intake induced significant differences in these indices after removal of the PTG tissue. The absolute value of the difference between the serum calcium and phosphorus concentrations (|Ca−P|) accurately reflected the effect of removal of the PTG tissue and was superior to the calcium-phosphorus product (Ca × P); Ca × P accurately reflected the effect of varying the types of water intake in rats and was superior to the |Ca−P|.

Impact of preoperative imaging on surgical approach for primary hyperparathyroidism: Data from single institution in India

CONTEXT

Preoperative localization of parathyroid adenoma is essential in deciding the surgical approach of parathyroidectomy.

AIM

To describe clinical and biochemical profile, evaluate preoperative imaging modalities and surgical approach in patients with primary hyperparathyroidism (PHPT).

METHODOLOGY

This was a retrospective study conducted at the single institution. All patients who underwent evaluation and surgery for PHPT from 2011 to 2015 were included in the study.

RESULTS

A total of 100 patients underwent surgery for PHPT. Mean (standard deviation) age was 51.6 (15.9) years with female to male ratio of 1.7:1. Forty patients had severe symptoms, and sixty had mild to moderate symptoms. The sensitivity of technetium-99m hexakis (2-methoxyisobutylisonitrile) (MIBI) scan and ultrasonography (USG) neck in identifying abnormal parathyroid gland was 93% (93/100) and 98% (98/100), respectively. The MIBI scan results of 90/93 (96.7%) patients corresponded with their surgical findings whereas preoperative USG findings of 96/98 patients (98%) showed correlation with operative findings. Intraoperative intact parathyroid hormone (IOPTH) levels at 10 min postexcision were measured in forty patients (minimally invasive parathyroidectomy = 38, bilateral neck exploration = 1, and unilateral neck exploration = 1). All patients except two had <50% fall in IOPTH. Adenoma weight was positively correlated with preoperative intact PTH.

CONCLUSION

We found that USG has higher sensitivity (98%) than MIBI scan (93%) in localizing abnormal parathyroid gland. Moreover, USG had a higher preoperative localization accuracy (93%) than MIBI scan (90%), allowing to choose an appropriate surgical approach. A higher proportion of patients (60%) had mild/asymptomatic form of PHPT.

Is focused parathyroidectomy appropriate for patients with primary hyperparathyroidism?

Purpose

The aim of this study was to determine whether focused or complete parathyroidectomy was more appropriate and to compare follow-up data in primary hyperparathyroidism (PHPT).

Methods

We retrospectively analyzed 225 operations for PHPT at Yonsei University Health System between 2000 and 2012. After excluding 93 patients, the remaining 132 were divided into 2 groups: those who underwent focused parathyroidectomy (FP) and those who underwent conventional parathyroidectomy (CP). We compared clinicopathological features; preoperative calcium, parathyroid hormone (PTH), phosphorus, vitamin D, 24-hour urine calcium, and alkaline phosphatase levels; postoperative calcium and PTH levels; pathologic diagnosis; multiplicity; and results of a localization study between the 2 groups.

Results

There was no significant difference in the rates of development of postoperative persistent hyperparathyroidism (1/122 FP patients and 1/10 CP patients) between the 2 groups due to a technical reason (FP 0.8% vs. CP 10.0%, P = 0.146). Multiglandular disease (MGD) was uncommon in all cases (6 of 132, 4.5%). All MGD cases were diagnosed using a preoperative localization study. Sestamibi scan and ultrasonography sensitivity were 94.2% and 90.2%, respectively.

Conclusion

We suggest that FP is appropriate in PHPT, except in cases of MGD if detected before the operation using preoperative imaging. Knowledge of hereditary PHPT and improved preoperative localization studies, such as high-resolution ultrasonography, contributed to the decision to perform FP rather than CP in all cases of unilateral results of the localizing study.

Combined application of ultrasound and SPECT/CT has incremental value in detecting parathyroid tissue in SHPT patients

PURPOSE

The goal of this study is to investigate whether combined application of ultrasound and 99mTc-sestamibi SPECT/CT had the incremental value in accurately detecting parathyroid tissue in patients with SHPT over either method alone.

PATIENTS AND METHODS

Sixty patients with SHPT on hemodialysis were evaluated preoperatively with parathyroid 99mTc-sestamibi SPECT/CT scintigraphy and ultrasound prior to parathyroidectomy. The sensitivity, specificity and accuracy of 99mTc-sestamibi SPECT/CT scintigraphy, ultrasound and combined application were determined respectively.

RESULTS

The sensitivity, specificity and accuracy of ultrasound were 81% (155/192), 47% (17/36) and 82% (172/228), respectively. The sensitivity, specificity and accuracy of 99mTc-sestamibi SPECT/CT were 85% (163/192), 58% (21/36) and 89% (184/228) respectively. The accuracy of 99mTc-sestamibi SPECT/CT in the diagnosis of parathyroid tissue in patients with SHPT is significantly higher than that of ultrasound. The sensitivity, specificity and accuracy of combined application of ultrasound and 99mTc-sestamibi SPECT/CT were 93% (178/192), 61% (22/36) and 97% (200/228). The sensitivity, specificity and accuracy of combined application of ultrasound and 99mTc-sestamibi SPECT/CT were higher than those of either ultrasound or 99mTc-sestamibi SPECT/CT.

CONCLUSIONS

The combined application of ultrasound and 99mTc-sestamibi SPECT/CT had incremental value in accurately detecting parathyroid tissue in patients with SHPT over either method alone.

Focused parathyroidectomy without intra-operative parathyroid hormone monitoring for primary hyperparathyroidism: results in a low-volume hospital

BACKGROUND

The role of routine intra-operative parathyroid hormone monitoring for sporadic primary hyperparathyroidism is contentious. Satisfactory results can be achieved in high-volume centres. The results of low-volume hospitals are rarely studied.

METHODS

A retrospective, non-comparative study was conducted. From November 2002 to October 2012, 105 patients with clinically sporadic primary hyperparathyroidism underwent focused parathyroidectomy without intra-operative parathyroid hormone monitoring. Single adenoma was localised on pre-operative ultrasonography or sestamibi scan. The cure rate, surgical complication rate and pathology findings were evaluated.

RESULTS

Most of the operations (63.8 per cent) were performed under local anaesthesia. All but two patients (98.1 per cent) were cured after surgery. There was only one case of double adenomas. No recurrent hyperparathyroidism was observed after a mean follow up of 56.9 months. Surgical complications comprised two cases (1.9 per cent) of transient vocal fold palsy and one case (1.0 per cent) of permanent vocal fold palsy. Seven patients (6.7 per cent) suffered temporary hypocalcaemia.

CONCLUSION

Satisfactory results of focused parathyroidectomy without routine intra-operative parathyroid hormone monitoring for appropriately selected primary hyperparathyroidism cases can be attained in a low-volume hospital.

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.

Primary hyperparathyroidism: an analysis of failure of parathyroidectomy

BACKGROUND

Preoperative imaging in patients undergoing surgery for primary hyperparathyroidism (PHPT) is used primarily to facilitate targeted parathyroidectomy. Failure of preoperative localisation mandates a bilateral exploration. It is thought that the results of imaging may also predict the success of surgery. The aims of this study were to assess whether the findings on preoperative localisation influenced outcomes following parathyroidectomy for PHPT and to explore factors underlying failure to cure at surgery.

METHODS

We analysed outcomes of all patients who underwent first-time surgery for PHPT in two centres over a 5-year period to determine an association with demographic characteristics and findings on preoperative imaging. Records of patients not cured by initial surgery were reviewed to explore factors underlying failure to cure.

RESULTS

The failure rate (persistent disease) in the entire cohort was 5 % (25/541) (bilateral neck explorations, 5 %; unilateral exploration, 7 %; targeted approach, 4 %), while two patients developed recurrent disease. In patients who had undergone dual imaging with an ultrasound scan and (99m)Tc-sestamibi scintigraphy, failure rates with "lateralised and concordant" imaging, "nonconcordant" imaging, and "dual-negative" imaging were 2, 9, and 11 %, respectively (p = 0.01). Of the 25 patients with persistent disease, multigland disease (MGD) was present in 52 % (13/25) and ectopic adenoma in 24 % (6/12).

CONCLUSIONS

Patients with PHPT who do not have lateralised and concordant dual imaging are at higher risk of persistent disease. A significant proportion of failures are due to the inability to recognise the presence and/or extent of MGD.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A comparative study of pre-operative imaging methods in patients with primary hyperparathyroidism: ultrasonography, 99mTc sestamibi, single photon emission computed tomography, and magnetic resonance imaging

AIM

This study compares the accuracy rates achieved in ultrasonography (US), 99mTc-sestamibi (MIBI), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) as imaging methods used in the pre-operative localization of the enlarged parathyroid glands.

SUBJECTS AND METHODS

For the purposes of this study, US, MIBI, SPECT, and MRI were performed on 98 patients with primary hyperparathyroidism (pHPT). All patients underwent parathyroidectomy.

RESULTS

Pre-operative localization of an abnormal parathyroid gland was successfully performed in 82 of the cases scanned with US (83.7%), while the result was 66 in the cases scanned with MIBI (67.3%), 71 of the cases were successfully localized with SPECT (72.4%), while MRI revealed the diseased gland in only 60 of the total cases (61.2%). In MIBI-positive and -negative patients there was a statistically significant difference among cases in terms of adenoma volume (1.30±1.51 vs 0.58±0.91, p<0.05). Sensitivity, specificity and diagnostic accuracy values were 87.2%, 25.0%, and 83.0%; 70.2%, 50.0%, and 69.4%; 75.5%, 50.0%, and 74.5%; 63.8%, 50.0%, and 63.3% for US, MIBI, SPECT, and MRI, respectively. The respective values for sensitivity, specificity, and diagnostic accuracy were 94.9%, 25.0%, and 91.1% when US was combined with MIBI.

CONCLUSIONS

Combining US and MIBI as imaging methods for pre-operative imaging of pHPT often produces more satisfactory results. While the accuracy of US is relatively low in the ectopic localizations, the size of the lesion can be an important factor in the accuracy achieved with MIBI.

Association of parathyroid pathology with well-differentiated thyroid carcinoma

OBJECTIVE

The objective was to evaluate the association of well-differentiated thyroid carcinoma and parathyroid pathology.

METHODS

The medical records of 14 patients with concomitant pathologies were retrospectively reviewed.

RESULTS

Parathyroidectomies (1.3%) and thyroidectomies (3.5%) performed for well-differentiated thyroid carcinoma resulted in the diagnosis of concomitant pathologies. Five patients had a primary hyperparathyroidism (PHPT) and nine were operated for thyroidectomy with intraoperative finding of an enlarged parathyroid gland. Patients (64%) were normocalcemic preoperatively. Thirteen had papillary carcinoma. Fifty percent of patients had multiple foci of papillary microcarcinoma. Twenty-nine percent of patients had parathyroid hyperplasia. All patients with preoperative hypercalcemia normalized their serum calcium. During follow-up, thyroglobuline, calcium serum values and cervical ultrasound showed no evidence of recurrence of the diseases.

CONCLUSIONS

These observations stress the importance of pre and intraoperative evaluation to detect overt thyroid and parathyroid pathology before performing a parathyroidectomy for hyperparathyroidism or a thyroidectomy for a well-differentiated thyroid carcinoma.

Eucalcemic parathyroid hormone elevation after parathyroidectomy for primary sporadic hyperparathyroidism: risk factors, trend, and outcome

BACKGROUND

Patients with eucalcemic parathyroid hormone elevation (ePTH) after parathyroidectomy for primary hyperparathyroidism (HPT) may be at risk of recurrence. We aimed to examine risk factors, trend of PTH level, and outcome of patients with ePTH 6 months after parathyroidectomy.

METHODS

A total of 161 primary HPT were analyzed. The 6-month postoperative calcium and PTH levels were obtained. ePTH was defined as an elevated PTH level in the presence of normocalcemia. At 6 months, 98 had eucalcemic normal PTH and 63 (39.1%) had ePTH. Perioperative variables, PTH trend, and outcome were compared between 2 groups. Multivariable analyses were performed to identify independent preoperative and operative/postoperative risk factors for ePTH.

RESULTS

Among preoperative factors, advanced age (odds ratio [OR] = 1.042, P = .027) and low 25-hydroxyvitamin D(3) (25OHD(3)) (OR = 1.043, P = .009) were independently associated with ePTH, whereas among operative/postoperative factors, high 10-min intraoperative PTH level (OR = 1.015, P = .040) and high postoperative 3-month PTH (OR = 1.048, P < .001) were independently associated with ePTH. After a mean follow-up of 38.7 months, recurrence rate was similar between the 2 groups (P = 1.00). In the first 2 postoperative years, 75 (46.6%) had ePTH on at least 1 occasion and 8 (5.0%) had persistently ePTH on every occasion.

CONCLUSIONS

Advanced age, low 25OHD(3), high 10-min intraoperative PTH, and high postoperative 3-month PTH were independently associated with ePTH at 6-month. Although 39.1% of patients had ePTH at 6 months, more than 50% had at least 1 ePTH within the first 2 years of follow-up. Recurrence appeared similar between those with or without ePTH at 6 months.

A meta-analysis of preoperative localization techniques for patients with primary hyperparathyroidism

BACKGROUND

Reported accuracy of preoperative localization imaging for primary hyperparathyroidism (pHPT) varies. The purpose of this study is to determine the accuracy of ultrasound, sestamibi-single photon emission computed tomography (SPECT), and four-dimensional computed tomography (4D-CT) as preoperative localization strategies.

METHODS

A meta-analysis was performed of studies investigating the accuracy of ultrasound, sestamibi-SPECT, and 4D-CT for preoperative localization in pHPT. Electronic databases were systematically searched, and two independent reviewers reviewed results using specific criteria. Study quality was assessed using a validated measure for diagnostic imaging studies. Study heterogeneity and pooled results were calculated.

RESULTS

43 studies met criteria for inclusion, and data were available for extraction in 19 ultrasound, 9 sestamibi-SPECT, and 4 4D-CT studies. Ultrasound had pooled sensitivity and positive predictive value (PPV) of 76.1% (95% CI 70.4-81.4%) and 93.2% (90.7-95.3%), respectively. Sestamibi-SPECT had pooled sensitivity and PPV of 78.9% (64-90.6%) and 90.7% (83.5-96.0%), respectively. Only two 4D-CT studies investigated patients undergoing initial parathyroidectomy. Results suggested sensitivity and PPV of 89.4% and 93.5%, respectively.

CONCLUSIONS

Ultrasound and sestamibi-SPECT are similar in ability to preoperatively localize abnormal parathyroid glands in pHPT. Accuracy may be improved with 4D-CT; however, further investigation is required. Choice of preoperative imaging strategy depends on numerous patient, institutional, and economic factors of which the surgeon must be aware.

Limitations of Tc99m-MIBI-SPECT imaging scans in persistent primary hyperparathyroidism

Background

In primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological parathyroid glands before a first parathyroidectomy (PTx) is 83–100%. Data are scarce in patients undergoing reoperative parathyroidectomy for persistent hyperparathyroidism. The aim of the present study was to determine the value of Tc99m-MIBI-SPECT in localizing residual hyperactive parathyroid tissue in patients with persistent primary hyperparathyroidism (PHPT) after initial excision of one or more pathological glands.

Method

We retrospectively evaluated the localizing accuracy of Tc99m-MIBI-SPECT scans in 19 consecutive patients with persistent PHPT who had a scan before reoperative parathyroidectomy. We used as controls 23 patients with sporadic PHPT who had a scan before initial surgery.

Results

In patients with persistent PHPT, Tc99m-MIBI-SPECT accurately localized a pathological parathyroid gland in 33% of cases before reoperative parathyroidectomy, compared to 61% before first PTx for sporadic PHPT. The Tc99m-MIBI-SPECT scan accurately localized intra-thyroidal glands in 2 of 7 cases and a mediastinal gland in 1 of 3 cases either before initial or reoperative parathyroidectomy.

Conclusions

Our data suggest that the accuracy of Tc99m-MIBI-SPECT in localizing residual hyperactive glands is significantly lower before reoperative parathyroidectomy for persistent PHPT than before initial surgery for sporadic PHPT. These findings should be taken in consideration in the preoperative workup of patients with persistent primary hyperparathyroidism.

Clinical appraisal of 99m technetium-sestamibi SPECT/CT compared to conventional SPECT in patients with primary hyperparathyroidism and concomitant nodular goiter

BACKGROUND

Although 99m Technetium-sestamibi scintigraphy with single-photon emission computed tomography (SPECT) and, recently, hybrid SPECT/computed tomography (CT) have been claimed to be the preoperative methods of choice for parathyroid localization in patients with primary hyperparathyroidism (PHPT) and concomitant nodular goiter (NG), they have never been compared in this setting. We aimed at testing the hypothesis that SPECT/CT may be superior to SPECT for parathyroid localization in patients with PHPT and NG.

METHODS

Thirty-three patients with PHPT and NG (one or more nodular lesions based on cervical ultrasound) who underwent open parathyroidectomy during 2004-2009 were reviewed. All patients had preoperative 99m Tc-sestamibi planar scintigraphy and SPECT (18 patients) or SPECT/CT (15 patients) after cervical ultrasound. Sensitivity, specificity, and positive predictive value (PPV) (for both correct neck side and quadrant identification) were calculated for the two procedures through comparison with intraoperative findings. In addition, operative times were assessed if the surgery was only for PHPT and not for the six patients who also had thyroidectomy.

RESULTS

The sensitivity of SPECT/CT for correctly identifying the neck side containing an abnormal parathyroid was 93.7% versus 80% for SPECT (p = 0.21, not significant [ns]). The specificity and PPV for this attribute were 92.9% and 93.7%, respectively, for SPECT/CT versus 87.5% and 88.9%, respectively, for SPECT (p = 0.75 and 0.8, ns). SPECT/CT showed higher sensitivity than SPECT (87.5% vs. 55.6%; p = 0.0001) and higher PPV (87.5% vs. 62.5%; p = 0.0022) for correctly identifying the neck quadrant affected by PHPT. The specificity for this was 95.5% for SPECT/CT versus 88.5% for SPECT (p = 0.26, ns). Mean operative time was shorter after SPECT/CT than after SPECT (38 vs. 56 minutes; p = 0.034). One of the patients having SPECT/CT had double adenomas, and two had ectopic parathyroid glands, all of which were recognized preoperatively by this technique. Two of the patients having SPECT had double adenomas, and two had ectopic glands, none of which were recognized preoperatively. No patient had persistent or recurrent PHPT.

CONCLUSIONS

SPECT/CT is superior to SPECT for preoperative imaging of patients with PHPT and NG. We recommend the routine use of SPECT/CT for work-up of all such patients, particularly if minimally invasive parathyroid surgery is planned.

Weight difference between double parathyroid adenomas is the cause of false-positive IOPTH test after resection of the first lesion

BACKGROUND

Some patients with double parathyroid adenoma show a greater than 50% decline in intraoperative parathyroid hormone (IOPTH) after resection of the first lesion. The present study was designed to test the hypothesis that significant adenoma weight differences may explain this inappropriate decline of IOPTH.

METHODS

We reviewed prospective database records at two tertiary institutions. Patients with a histopathologic diagnosis of double adenoma and no familial history of hyperparathyroidism were included. Diagnosis of double adenoma was confirmed either preoperatively (double uptake), intraoperatively (bilateral exploration), or at reintervention. IOPTH was determined following the Miami protocol. The 10-min postexcision sample was considered as the 0-min sample for IOPTH determinations at the time of resection of the second lesion.

RESULTS

Thirteen patients met the inclusion criteria. After resection of the first lesion, IOPTH failed to decline in four patients and a second adenoma was removed. They had similar weight (404 vs. 598 mg). In nine patients IOPTH showed a false greater than 50% decline. These patients had the largest adenoma removed first (846 +/- 226 mg), and only two had normal PTH serum concentrations 10 min after resection. The second adenoma was always smaller (284 +/- 177 mg; P = 0.02) and its resection either during the same operation (7 cases) or at reoperation (2 cases) led to normalization of IOPTH at 10 min in all cases.

CONCLUSIONS

Two-thirds of patients with double parathyroid adenoma show a false-positive decline of IOPTH after resection of the first adenoma. This appears to be due to the initial removal of the larger lesion.

Primary hyperparathyroidism from parathyroid microadenoma: specific features and implications for a surgical strategy in the era of minimally invasive parathyroidectomy

BACKGROUND

The aim of this study was to identify the specific preoperative characteristics of patients with parathyroid microadenoma and to report their outcomes after surgical treatment.

STUDY DESIGN

Parathyroid microadenomas (weight < 100 mg) were identified in 62 (6%) of the 1,012 patients operated on for a parathyroid adenoma between 1995 and 2004. Presentation and outcomes after surgery were compared with those of 124 patients operated on consecutively for parathyroid adenoma (>100 mg) during the last year of the study. All patients underwent bilateral surgical exploration of the neck. Success was defined as resection of a pathologic gland combined with normocalcemia at 6 months after operation. Logistic regression was used to test the relationship between groups and potential predictive factors of microadenoma.

RESULTS

There were 57 women (92%) and the median age was 57 years (range 29 to 77 years). Median preoperative calcemia and parathyroid hormone (PTH) serum levels were 2.64 mmol/L (range 2.31 to 3 mmol/L) and 79 pg/mL (range 30 to 189 pg/mL), respectively. There was no difference in the clinical presentation between patients with microadenoma and adenoma. Preoperative calcium (p < 0.001) and PTH serum levels (p = 0.014) were significantly higher in patients with adenoma. Calcium and PTH serum levels lower than 2.6 mmol/L and 60 pg/mL, respectively, predicted the presence of microadenoma with respective specificities of 0.89 and 0.87. Success rates were similar in the microadenoma and adenoma groups (92% vs 98%; p = 0.11).

CONCLUSIONS

Mild preoperative elevations of calcium or PTH serum levels should warn about the risk of microadenoma. In this setting, intraoperative difficulties should be expected in identifying the pathologic gland, and bilateral neck exploration should be the preferred surgical approach.

Minimally invasive thyroid and parathyroid operations: surgical techniques and pearls

With advances in technology and greater demand for minimally invasive procedures, novel minimally invasive approaches to thyroid and parathyroid glands increasingly have been described and practiced worldwide. For the MIT approaches, the direct/cervical approaches truly can be considered minimally invasive, as they require less surgical dissection than the conventional thyroidectomy. The indirect/extracervical approaches, however, only can be considered endoscopic, however, because they generally do require greater surgical dissection. Still, among the indirect/extracervical approaches, the axillary approach appears the preferred choice, as it requires the least amount of dissection while offering the advantage of being scarless in the neck. The addition of the robot such as the de Vinci surgical system could make some of the extracervical approaches technically less challenging and improve patient outcomes. Unlike MIT, MIP has become the standard approach for surgical management of primary hyperparathyroidism caused by localized solitary parathyroid adenoma.

Neurocognitive dysfunction: a predictor of parathyroid hyperplasia

BACKGROUND

To determine whether a symptomatic presentation was associated with parathyroid hyperplasia, we retrospectively examined pre-operative symptom profiles of patients who underwent parathyroidectomy.

METHODS

From October 2007 to July 2008, 111 patients with primary hyperparathyroidism completed a preoperative symptom questionnaire prior to parathyroidectomy. The symptom profiles of patients with and without hyperplasia were compared.

RESULTS

Neurocognitive symptoms occurred in 51.4% of patients. Patients with 1 neurocognitive symptom had a 25% risk of parathyroid hyperplasia. Additional neurocognitive symptoms increased the risk of hyperplasia linearly, with hyperplasia occurring in 38% of patients reporting 2 neurocognitive symptoms (P < .001) and 61% of patients reporting 3 or more of these symptoms (P < .001). A negative sestamibi scan was associated with a 33% risk of hyperplasia. Coupled with at least 1 neurocognitive symptom, the risk of hyperplasia was 53.3% (P < .001). Of patients with 3 or more neurocognitive symptoms and a negative localizing scan, 100% were found to have parathyroid hyperplasia (P < .001).

CONCLUSION

The presence of neurocognitive dysfunction in a patient with hyperparathyroidism may be used as a predictor of hyperplastic disease. Three or more of these symptoms, coupled with a negative sestamibi scan, was 100% predictive of parathyroid hyperplasia in our cohort.

Parathyroid surgery in pregnancy: review of the literature and localization by aspiration for parathyroid hormone levels

OBJECTIVE

To review the management of primary hyperparathyroidism in pregnant women by focusing on the use of preoperative localization procedures and minimally invasive parathyroid surgery during pregnancy.

STUDY DESIGN

We report the clinical course of two pregnant women with severe hypercalcemia due to primary hyperparathyroidism, as well as review the literature.

RESULTS

Primary hyperparathyroidism in pregnant women is associated with high prevalence of maternal and neonatal complications. In women, with severe hypercalcemia, parathyroid surgery during pregnancy reduces fetal and maternal morbidities. Preoperative localization of parathyroid adenomas during pregnancy remains challenging. In selected cases aspiration of nodules suspected of being parathyroid adenomas with the measurement of the parathyroid hormone (PTH) from the aspirate can localize the adenoma, and allow the surgeon to carry out a minimally invasive parathyroidectomy.

CONCLUSION

Localization of a suspected parathyroid adenoma by ultrasound-guided aspiration of a lesion and the measurement of the PTH has previously been described in non-pregnant women. Our review of the literature did not identify any previous case of a pregnant woman with primary hyperparathyroidism, where preoperative localization of a parathyroid adenoma was accomplished by aspiration of a suspected lesion followed by a successful minimally invasive parathyroidectomy carried out during pregnancy.

Significance of biochemical parameters in differentiating uniglandular from multiglandular disease and limiting use of intraoperative parathormone assay

BACKGROUND

We studied whether serum calcium and parathormone (PTH) levels are significantly different for uniglandular disease (UGD) and multiglandular disease (MGD) and whether intraoperative rapid intact parathormone (IOPTH) monitoring can be avoided in some cases of minimally invasive parathyroidectomy (MIP) without affecting cure rates, substantiating various previous published studies.

METHOD

This is a single-referral-center retrospective review of prospectively collected data for 281 patients with sporadic primary hyperparathyroidism (sPHPT) from January 1999 to February 2005. The calcium and PTH values were categorized using the following parameters: calcium > or = 3 mmol/l = 1, < 3 mmol/l = 0, PTH > or = 100 pg/ml = 1, PTH < 100 = 1.

RESULTS

P values for serum calcium and PTH by ANOVA were 0.0547 and 0.3936, respectively, and by the Mann-Whitney test were 0.1606 and 0.6208, respectively. We had 118 patients with concordant technetium 99 m sestamibi scintigraphy (MIBI) and neck ultrasonography (US) and UGD was confirmed in 118 (100%) cases.

CONCLUSIONS

No significant difference between serum calcium and PTH for UGD and MGD was found. IOPTH monitoring could be avoided when there is concordant positive MIBI and neck US for single, unilateral, hyperfunctioning gland without affecting cure rates.

The characteristics of concomitant thyroid nodules cause false-positive ultrasonography results in primary hyperparathyroidism

BACKGROUND

Concomitant thyroid nodules are the most common reason for false-positive ultrasonography (US) results in primary hyperparathyroidism. The aims of this prospective clinical study were to evaluate false-positive US results according to the characteristics of concomitant thyroid nodules and to determine which characteristics of thyroid nodules are important.

STUDY DESIGN

This prospective study included 120 consecutive patients with primary hyperparathyroidism. The patients were divided into 2 groups according to preoperative US results. Group 1 consisted of 32 patients with false-positive US results and group 2 consisted of 88 patients with true-positive US results.

RESULTS

The risk for false-positive US result was increased 25-fold for patients with parathyroid adenoma weight of more than 500 mg (odds ratio [OR], 25; 95% confidence interval [CI], 8.6-74.5), 75-fold for more than 1 posteriorly located thyroid (OR, 75; 95% CI, 19.3-293.4), 358-fold for the presence of exophytic thyroid nodules (OR, 358; 95% CI, 42.3-3036), and 423-fold for the presence of posteriorly located thyroid nodules (OR, 423; 95% CI, 49-3662).

CONCLUSION

Although there was no particular characteristic of concomitant thyroid nodules that contributes to false-positive US results, the posteriorly located thyroid nodules were the strongest correlate for the false-positive US results to other features.

Focused approach to parathyroidectomy

Minimally invasive parathyroidectomy is performed after preoperative parathyroid localization-usually with high-quality sestamibi scans and/or ultrasonography-often under cervical block anesthesia during which a limited exploration is performed. The rapid intraoperative parathyroid hormone assay is then employed to confirm an adequate resection and cure of primary hyperparathyroidism. This article discusses imaging, anesthesia, results, and the surgical management of patients undergoing minimally invasive parathyroidectomy.