Impact of localization studies on feasibility of minimally invasive parathyroidectomy in an endemic goiter region

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.

Primary Hyperparathyroidism and Intraoperative Parathyroid Hormone Monitoring: Application of a Modified Interpretation in Patients With "Parathyroid Hormone Spikes"

INTRODUCTION

Intraoperative parathyroid hormone (PTH) spikes occur in up to 30% of patients during surgery for primary hyperparathyroidism. This can lead to a prolonged PTH decline and cause difficulties in using current interpretation criteria of intraoperative PTH monitoring. The aim of this study aim was to evaluate an alternative interpretation model in patients with PTH spikes during exploration.

METHODS

1035 consecutive patients underwent surgery for primary hyperparathyroidism in a single center. A subgroup of patients with intraoperative PTH spikes of >50 pg/mL were selected (n = 277; 27.0%). The prediction of cure applying the Miami and Vienna criteria was compared with a decay of ≥50% 10 min after excision of the enlarged parathyroid gland using the "visualization value" (VV; =PTH level immediately after visualization of the gland) as basal value. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated.

RESULTS

Using the VV, sensitivity was 99.2% (Vienna 71.0%; Miami 97.7%), specificity was 18.2 (Vienna 63.6%; Miami 36.4%), and accuracy was 92.8 (Vienna 70.4%; Miami 92.8%). Of 255 single-gland disease patients, 72 were identified correctly as cured by applying the VV (P < 0.001), yet 10 of 22 patients with multiple-gland disease were missed compared with the Vienna Criterion (P = 0.002). The comparison with the Miami Criterion showed that six more patients were correctly identified as cured (P = 0.219), whereas four patients with multiple-gland disease were missed (P = 0.125).

CONCLUSIONS

Using the VV as a baseline in patients with intraoperative PTH spikes may prove to be an alternative and therefore can be recommended. However, if the VV is higher than the preexcision value, it should not be applied.

Primary Hyperparathyroidism: Is Image Localization Alone Sufficient to Ensure Long-Term Cure in Unifocal Disease?

INTRODUCTION

Advances in imaging have facilitated precise preoperative localization and focused resection of hyperfunctional parathyroids in primary hyperparathyroidism (PHPT). Combining imaging techniques or a "dual" approach, when concordant, improves adenoma-localizing accuracy above individual modalities. This study sought to assess biochemical cure and failure rates (persistence or recurrence) of surgery directed by dual imaging alone in PHPT.

METHODOLOGY

This observational, single-center analysis comprised 31 patients diagnosed with PHPT and imaged with both ultrasound (USG) of the neck and sestamibi scintigraphy. The extent of surgery was based solely on inter-modality concurrence for adenoma localization; imaging-concordant patients underwent focused parathyroidectomy, whereas discordant patients necessitated neck exploration (with extent altered according to scintigraphic lesion lateralization). No intraoperative localizing adjuncts were used.

RESULTS

Twenty-three patients had concordant imaging, of which 19 underwent focused exploration, with sensitivity and positive predictive value (PPV) for dual imaging of 100% and 95.7%, respectively. The overall sensitivity and PPV were 92.9% and 89.7% for USG alone and 100% and 93.6% for scintigraphy, respectively. The mean age and prevalence of thyroid disease were significantly higher in the discordant group. All patients achieved postoperative normocalcemia. There were no cases of persistent or recurrent hyperparathyroidism on follow-up.

CONCLUSIONS

In the imaging-concordant setting, focused surgery may be safely performed with the omission of other adjuncts for localization. Older age and concomitant thyroid pathology predispose to discordant imaging and are risk factors for surgical failure when attempting an image-directed approach. Neck exploration is an alternative in these patients with excellent cure rates and acceptable morbidity.

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.

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.

Primary hyperparathyroidism: Dynamic postoperative metabolic changes

OBJECTIVE

Little is known about the natural changes in parathyroid function after successful parathyroid surgery for primary hyperparathyroidism. The association of intact parathyroid hormone (iPTH) and calcium (Ca) with "temporary hypoparathyroidism" and "hungry bone syndrome" (HBS) was evaluated.

DESIGN

Potential risk factors for temporary hypoparathyroidism and HBS were evaluated by taking blood samples before surgery, intra-operatively, at postoperative day (POD) 1, at POD 5 to 7, in postoperative week (POW) 8 and in postoperative month (POM) 6.

PATIENTS

Of 425 patients, 43 (10.1%) had temporary hypoparathyroidism and 36 (8.5%) had HBS.

MEASUREMENTS

The discriminative ability of iPTH and Ca on POD 1 for temporary hypoparathyroidism and HBS.

RESULTS

Intact parathyroid hormone (IPTH) on POD 1 showed the highest discriminative ability for temporary hypoparathyroidism (C-index = 0.952), but not for HBS. IPTH was helpful in diagnosing HBS between POD 5 and 7 (C-index = 0.708). Extending the model by including Ca resulted in little improvement of the discriminative ability for temporary hypoparathyroidism (C-index = 0.964) and a decreased discriminative ability for HBS (C-index = 0.705). Normal parathyroid metabolism was documented in 139 (32.7%) patients on POD 1 and in 423 (99.5%) 6 months postoperatively, while 2 (0.5%) patients had persistent hyperparathyroidism, one diagnosed between POD 5 and 7 and another at POW 8. No patients suffered from permanent hypoparathyroidism.

CONCLUSIONS

The necessity for Ca and vitamin D3 substitution cannot be predicted with certainty before POD 5 to 7 without serial laboratory measurements. Based on the results, a routine 8-week course of Ca and vitamin D3 treatment seems reasonable and its necessity should be evaluated in a follow-up study.

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.

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.

Ultrasound features of malignancy in the preoperative diagnosis of parathyroid cancer: a retrospective analysis of parathyroid tumours larger than 15 mm

OBJECTIVE

Nearly all reported parathyroid cancers are >15 mm at presentation. The objective was to identify ultrasound criteria of malignancy in parathyroid lesions of >15 mm in size.

MATERIALS AND METHODS

This study was approved by a local ethics committee. A retrospective review of patients identified from a database from 2004-2009 was performed. All patients underwent ultrasound imaging according to the protocol. Two trained observers categorized findings using the pre-determined features: shape, calcification, pattern of vascularity, local infiltration and internal lesion gray scale appearances.

RESULTS

Sixty-nine patients (mean age 54.3 years, range 19-79 years; male = 16, female = 53) fulfilled the criteria of a parathyroid lesion >15 mm; 8/69 (11.6%) with parathyroid cancer and 61/69 (88.4%) with benign solitary parathyroid adenoma. A high positive predictive value (PPV) for cancer was identified for infiltration (PPV 100%) and calcification (PPV 100%), whilst a high negative predictive value (NPV) was found for the absence of suspicious vascularity (NPV 97.6%), a thick capsule (NPV 96.7) and inhomogeneity (NPV 100%).

CONCLUSION

In lesions >15 mm systematic ultrasound assessment of specific features provides a valuable tool to identify parathyroid cancers before surgery.

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.

Impact of thyroid nodular disease on 99mTc-sestamibi scintigraphy in patients with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism with coexisting thyroid nodular disease (TND) has been considered a contraindication for selective parathyroidectomy because the low sensitivity of preoperative localization studies, especially 99(m)Tc-sestamibi scanning (MIBI) and ultrasound. The aim of this study was to assess the impact of concomitant TND in the preoperative image studies.

METHODS

A total of 236 consecutive patients who had parathyroidectomy for sporadic hyperparathyroidism and the preoperative localization study that was done with MIBI were reviewed. Patients were divided into three groups: those who did not have any thyroid disease, those who had concomitant TND not necessary to resect, and those in whom thyroid resection due to TND was necessary at the time of parathyroidectomy.

RESULTS

MIBI showed a sensitivity of 78.5% in patients without concomitant TND, 73% in patients with TND but not thyroidectomy needed, and 54.5% in the cases that thyroid resection was necessary. When MIBI and ultrasound were both suspicious for an adenoma, the sensitivity was not influenced by the TND.

CONCLUSION

In patients with coexisting thyroid disease but not thyroidectomy needed, MIBI scintigraphy contributes to the detection of a solitary adenoma. When thyroid resection is required, MIBI imaging is often negative.

Is minimally invasive parathyroidectomy without QPTH monitoring justified?

BACKGROUND

It is matter of discussion if quick parathyroid hormone (QPTH) monitoring is helpful in patients with primary hyperparathyroidism (PHPT) and "localized single-gland disease" (SGD; concordant sestamibi and ultrasound results) to further increase the rate of success (permanent normocalcemia) of performing selective parathyroidectomy by minimally invasive parathyroid exploration (MIP). The aim of this study was to evaluate if a randomized controlled trial was justified in order to clarify this discussion.

MATERIALS AND METHODS

The prospective database of patients with sporadic PHPT, SGD, MIP, and QPTH monitoring (1999-2005) was evaluated regarding the "conversion rate" to bilateral exploration and permanent normocalcemia ("QPTH" group). Retrospectively, the patients were analyzed a second time "without" applying QPTH monitoring ("non-QPTH" group). Statistical differences between both groups were calculated (McNemar's test).

RESULTS

By definition, 338 patients with "localized SGD" underwent MIP. MIP was finished in 308 (91.1%) patients. Five of 308 patients (1.6%) showed persisting (n = 1) or recurrent disease (n = 4). In 30 of 338 patients (8.9%), a conversion to bilateral exploration was necessary (false preoperative localization 15 patients--one patient not cured; multiple-gland disease correctly indicated by QPTH monitoring 15 patients--one patient not cured). Analyzing the "non-QPTH" group, 14 additional patients showed persisting disease. Thus, without using QPTH monitoring, the rate of persisting PHPT would increase from 0.9% (three patients) to 5.0% (17 patients; p = 0.0005).

CONCLUSION

Intraoperative QPTH assay seems necessary even in patients with "localized SGD" by two techniques in an endemic goiter region. Abandoning QPTH monitoring would more than double the rate of persisting disease. A randomized trial seems not to be justified.

Targeted parathyroidectomy: effectiveness and intraoperative rapid-parathormone dynamics

OBJECTIVE

The objective of this study is to assess the effectiveness of selective parathyroid exploration, using preoperative image localization and intraoperative rapid-parathormone (rPTH) assay. The kinetics of intraoperative rPTH in parathyroid adenoma vs. multiglandular disease is assessed.

DESIGN

This is a prospective noncontrolled study of a cohort of 100 patients with primary hyperparathyroidism, at a single academic institution. The patients underwent selective parathyroidectomy after preoperative localization, including sestamibi scan and ultrasonography. Intraoperative rPTH assay was used to determine the extent and success of parathyroidectomy. Frozen sections were used as additional confirmation. Follow-up serum calcium levels were used to assess the effectiveness of selective parathyroidedcomy.

RESULTS

Mean preoperative serum calcium (Ca) and baseline intact-parathormone were 11.6 mg/dL and 136, respectively. Data were available in 96 cases: 87 single-gland adenoma with two in ectopic mediastinal position, two double adenoma and seven cases of hyperplasia. Ten percent of patients with adenoma needed bilateral exploration for nonlocalizing or false negative imaging, or for intraoperative rPTH failure to decay. All of the patients undergoing unilateral targeted exploration were normocalcemic on follow up. There were only one failed exploration and two cases of recurrent mild hypercalcemia, all three in bilateral exploration cases. Intraoperative rPTH reduction by standard curves was predictive of successful excision of all of the abnormal glands, as confirmed by postoperative serum calcium levels. More than one postexcision rPTH measurement was useful by showing failure of a decaying slope in multiglandular disease.

CONCLUSION

Targeted parathyroidectomy, when appropriately selected and carried out, is an effective treatment of primary hyperparathyroidism in most cases. Intraoperative rPTH can correctly guide removal of hyperfunctioning glands. Targeted parathyroidectomy offers the advantage of less invasive surgery with less tissue dissection confined to one side and avoids surgically disturbing the remainder of the neck. This should reduce postoperative complications and allow for easier and safer re-exploration in the few cases with persistent or recurrent disease.

A "defined baseline" in PTH monitoring increases surgical success in patients with multiple gland disease

BACKGROUND

Parathyroid hormone (PTH) monitoring with a quick intact PTH (QIPTH) assay is used in minimally invasive exploration for primary hyperparathyroidism (PHPT) in order not to miss multiple gland disease (MGD). Controversy exists on which criterion is most reliable to predict cure.

METHODS

QIPTH values of 310 consecutive patients (single gland disease [SGD]: n = 289; MGD: n = 21) with sporadic PHPT were analyzed using 3 different criteria: "Vienna Criterion": >/=50% decay from a defined "baseline" level (right after induction of anesthesia before skin incision) 10 min after excision. "Miami Criterion": >/=50% decay from highest (preincision or preexcision) value 10 min after excision; "Halle Criterion": decay of the PTH- level to less than or equal to 35 pg/mL within 15 min after excision.

RESULTS

The "Vienna" and "Halle Criteria" correctly detected MGD in 19 (91%) and the "Miami Criterion" in 12 (57%) of 21 patients. Incorrect prediction of incomplete excision occurred in 22 patients (8%) with SGD, using the "Vienna Criterion" ("Miami Criterion": 2%, "Halle Criterion": 29%). All of these were recognized intraoperatively from unintended intraoperative manipulation (n = 18), technical failure (n = 2), or borderline increased PTH values (n = 2), and they did not lead to bilateral exploration. Analyzing patients with SGD and MGD, accuracy and specificity were 92% and 89% for the "Vienna Criterion," 93% and 54% applying the "Miami Criterion," and 72% and 89% using the "Halle Criterion."

CONCLUSION

Strict definition of a PTH "baseline level" ("Vienna Criterion") improves intraoperative diagnosis of MGD, thus reducing reoperations and increasing long-term cure.

Preoperative localization and minimally invasive management of primary hyperparathyroidism concomitant with thyroid disease

The coexistence of thyroid diseases with primary hyperparathyroidism (PHPT) can present a challenge in the clinical diagnosis and management for these patients. This study aims to determine the frequency of coexisting thyroid gland lesions in a consecutive series patients with PHPT, and to analyze the clinical features, diagnosis and treatment of these patients. Twenty-two cases of a total of 52 PHPT patients who had synchronous thyroid and parathyroid pathology were surgically managed in this study. Thirteen patients had ipsilateral thyroid nodules, and 9 patients had thyroid nodules in contralateral or bilateral side. Seven patients underwent direct parathyroidectomy and hemithyroidectomy via a mini-incision (about 3 cm), while other 15 procedures were converted to Kocher incision. Seventeen nodular goiter (32.7%), 2 thyroiditis (3.8%), 2 thyroid adenoma (3.8%) and 1 thyroid carcinoma (1.9%) coexisting with parathyroid adenoma were pathologically diagnosed. The sensitivity of preoperative ultrasonography (US) and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for parathyroid lesions was 63.6% and 85.7%; and the overall positive predictive values for MIBI and US were 100% and 95.5% respectively. A high incidence of thyroid diseases that coexisted with PHPT in literatures was briefly reviewed. Our study illustrated the need for clinical awareness of concomitant PHPT and thyroid disease. A combination of US, computed tomography (CT) and MIBI scintigraphy would be recommended for preoperative localization of enlarged parathyroid adenoma and for evaluation of thyroid lesions. Synchronous treatment of associated thyroid abnormalities is desirable, and open minimally invasive surgical approach with additional resection of isolated ipsilateral thyroid nodules is possible in some of these patients.

PTH spikes during parathyroid exploration--a possible pitfall during PTH monitoring?

BACKGROUND AND AIMS

Parathyroid hormone (PTH) spikes caused by unintentional manipulation of the hypersecreting glands may lead to interpretation problems in intraoperative PTH monitoring. Their frequency and surgical consequences were evaluated.

MATERIALS AND METHODS

Intraoperative PTH values of 401 patients with primary hyperparathyroidism and single gland disease were analysed. Patients were divided into four groups: extensive increase (>150 pg/ml), moderate PTH increase (<150 pg/ml), no increase (+/-50 pg/ml) and decrease before excision as referred to the baseline level before skin incision. PTH was measured before and up to 25 min after removal of the enlarged gland.

RESULTS

Twenty-two (5.5%) patients had an extensive and 36 (9%) a moderate intraoperative PTH increase. The PTH decline was prolonged to 15 min in 7 (31.8%) and to 25 min in 12 (54.5%) patients after extensive manipulation and in 9 patients (25%) each after moderate manipulation, respectively. No increase occurred in 162 (40.4%) and a decrease in 181 (45.1%) patients. The surgical approach (bilateral exploration vs open, minimally invasive parathyroidectomy) did not show a difference in the rate of PTH spikes.

CONCLUSION

PTH spikes often cause a prolonged PTH decline but, when recognized, do not lead to a change in the surgical strategy.

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

OBJECTIVE

To determine the sensitivity and positive predictive value (PPV) of subtraction scintigraphy (SS) vs. ultrasonography (US) of the neck combined with rapid intact parathyroid hormone (iPTH) assay in US-guided fine-needle parathyroid aspirates in preoperative localization of parathyroid adenomas and in directing surgical approach.

DESIGN

The results of SS for localization of parathyroid adenoma were determined in 121 patients with primary hyperparathyroidism (pHPT) and compared with findings at surgery and with the results of US alone (in patients without nodular goitre) and US in combination with the iPTH assay in US-guided fine-needle aspirates (FNAs) of suspicious parathyroid lesions (in patients with concomitant nodular goitre).

PATIENTS

All 121 patients had biochemically documented pHPT; all were referred for first-time surgery.

MEASUREMENTS

SS was performed with 99mTc-sestamibi and 99mTc-pertechnetate. High-resolution US of the neck was performed by a single endocrine surgeon and combined with US-guided FNAs of suspicious parathyroid lesions in all patients with nodular goitre (n = 43).

RESULTS

The sensitivity and PPV of SS were significantly higher in patients without vs. with goitre (89.3% and 95.7%vs. 74.3% and 76.5%, respectively; P < 0.001). The sensitivity and PPV of US were significantly higher in patients without vs. with goitre (96% and 97.3%vs. 67.7% and 71.9%, respectively; P < 0.001). The iPTH assay of US-guided FNAs of suspicious parathyroid lesions in patients with nodular goitre significantly improved both the sensitivity and PPV of US imaging (90.7% and 100%, respectively), allowing for an accurate choice of surgical approach in 118 (97.5%) of 121 patients. SS was more accurate than US alone in detection of ectopic parathyroid adenomas. However, US alone was characterized by a higher sensitivity in detection of small parathyroid adenomas (< 500 mg) at typical sites (P < 0.01).

CONCLUSIONS

Both the sensitivity and PPV of SS and US alone are comparable, with significantly less accurate results obtained in patients with goitre. In cases of equivocal results of US and/or in patients with concomitant goitre, an iPTH assay in US-guided FNAs of suspicious parathyroid lesions may be used to establish the nature of the mass, distinguish between parathyroid and nonparathyroid tissue (goitre, lymph nodes) and improve the accuracy of US parathyroid imaging, allowing for successful directing of surgical approach in a majority of patients.

Minimally Invasive Video-Assisted Parathyroidectomy Versus Open Minimally Invasive Parathyroidectomy for a Solitary Parathyroid Adenoma: A Prospective, Randomized, Blinded Trial

BACKGROUND

A variety of minimally invasive parathyroidectomy (MIP) techniques have been currently introduced to surgical management of primary hyperparathyroidism (pHPT) caused by a solitary parathyroid adenoma. This study aimed at comparing the video-assisted MIP (MIVAP) and open MIP (OMIP) in a prospective, randomized, blinded trial.

MATERIALS AND METHODS

Among 84 consecutive pHPT patients referred for surgery, 60 individuals with concordant localization of parathyroid adenoma on ultrasound and subtraction Tc99m-MIBI scintigraphy were found eligible for MIP under general anesthesia and were randomized to two groups (n = 30 each): MIVAP and OMIP. An intraoperative intact parathyroid hormone (iPTH) assay was routinely used in both groups to determine the cure. Primary end-points were the success rate in achieving the cure from hyperparathyroid state and hypocalcemia rate. Secondary end-points were operating time, scar length, pain intensity assessed by the visual-analogue scale, analgesia request rate, analgesic consumption, quality of life within 7 postoperative days (SF-36), cosmetic satisfaction, duration of postoperative hospitalization, and cost-effectiveness analysis.

RESULTS

All patients were cured. In 2 patients, an intraoperative iPTH assay revealed a need for further exploration: in one MIVAP patient, subtotal parathyroidectomy for parathyroid hyperplasia was performed with the video-assisted approach, and in an OMIP patient, the approach was converted to unilateral neck exploration with the final diagnosis of double adenoma. MIVAP versus OMIP patients were characterized by similar operative time (44.2 +/- 18.9 vs. 49.7 +/- 15.9 minutes; P = 0.22), transient hypocalcemia rate (3 vs. 3 individuals; P = 1.0), lower pain intensity at 4, 8, 12, and 24 hours after surgery (24.9 +/- 6.1 vs. 32.2 +/- 4.6; 26.4 +/- 4.5 vs. 32.0 +/- 4.0; 19.6 +/- 4.9 vs. 25.4 +/- 3.8; 15.5 +/- 5.5 vs. 20.4 +/- 4.7 points, respectively; P < 0.001), lower analgesia request rate (63.3% vs. 90%; P = 0.01), lower analgesic consumption (51.6 +/- 46.4 mg vs. 121.6 +/- 50.3 mg of ketoprofen; P < 0.001), better physical functioning aspect and bodily pain aspect of the quality of life on early recovery (88.4 +/- 6.9 vs. 84.6 +/- 4.7 and 90.3 +/- 4.7 vs. 87.5 +/- 5.8; P = 0.02 and P = 0.003, respectively), shorter scar length (17.2 +/- 2.2 mm vs. 30.8 +/- 4.0 mm; P < 0.001), and higher cosmetic satisfaction rate at 1 month after surgery (85.4 +/- 12.4% vs. 77.4 +/- 9.7%; P = 0.006). Cosmetic satisfaction was increasing with time, and there were no significant differences at 6 months postoperatively. MIVAP was more expensive (US$1,150 +/- 63.4 vs. 1,015 +/- 61.8; P < 0.001) while the mean hospital stay was similar (28 +/- 10.1 vs. 31.1 +/- 9.7 hours; P = 0.22). Differences in serum calcium values and iPTH during 6 months of follow-up were nonsignificant. Transient laryngeal nerve palsy appeared in one OMIP patient (P = 0.31). There was no other morbidity or mortality.

CONCLUSIONS

Both MIVAP and OMIP offer a valuable approach for solitary parathyroid adenoma with a similar excellent success rate and a minimal morbidity rate. Routine use of the intraoperative iPTH assay is essential in both approaches to avoid surgical failures of overlooked multiglandular disease. The advantages of MIVAP include easier recognition of recurrent laryngeal nerve (RLN), lower pain intensity within 24 hours following surgery, lower analgesia request rate, lower analgesic consumption, shorter scar length, better physical functioning and bodily pain aspects of the quality of life on early recovery, and higher early cosmetic satisfaction rate. However, these advantages are achieved at higher costs because of endoscopic tool involvement.

Surgical management strategies in patients with primary hyperparathyroidism: which technique in which patients?

OBJECTIVE

This study was planned to investigate the efficacy of either 99mTc-sestamibi scan or ultrasonography in predicting the operative treatment in patients with primary hyperparathyroidism (PHPT).

SUBJECTS AND METHOD

Thirty patients (25 female, 5 male; mean age: 53 years) being operated for symptomatic primary PHPT were included in this study. Ultrasonography was used in 29 patients while 99mTc-sestamibi scintigraphy was done in 28 patients to localize the hyperfunctioning gland(s). Standard bilateral neck exploration was done in 6 patients. Although unilateral intervention had been planned for 24 patients, bilateral intervention was performed in 9 of them.

RESULTS

Sensitivity of 99mTc-sestamibi was 81%, while that of ultrasonography was 42%. 99mTc-sestamibi localization method led to misleading results in 10/28 (35.7%) patients. False-positive localization and accompanying thyroid pathologies played an important role in determining transition from unilateral to bilateral intervention.

CONCLUSION

Our findings indicate that bilateral intervention remains a successful management option without prior localization in patients with PHPT especially in an endemic goiter region.

A systematic review of the diagnosis and treatment of primary hyperparathyroidism from 1995 to 2003

OBJECTIVE

To systematically review the current preoperative diagnostic modalities, surgical treatments, and glandular pathologies associated with primary hyperparathyroidism.

STUDY DESIGN

A systematic literature review.

RESULTS

Of the 20,225 cases of primary hyperparathyroidism reported, solitary adenomas (SA), multiple gland hyperplasia disease (MGHD), double adenomas (DA), and parathyroid carcinomas (CAR) occurred in 88.90%, 5.74%, 4.14%, and 0.74% of cases respectively. Tc 99m -sestamibi and ultrasound were 88.44% and 78.55% sensitive, respectively, for SA, 44.46% and 34.86% for MGHD, and 29.95% and 16.20% for DA, respectively. Postoperative normocalcemia was achieved in 96.66%, 95.25%, and 97.69% of patients offered minimally invasive radio-guided parathyroidectomy (MIRP), unilateral, and bilateral neck exploration (BNE). Intraoperative PTH assays (IOPTH) were helpful in approximately 60% of bilateral neck exploration conversion (BNEC) surgeries.

CONCLUSION

The overall prevalence of multiple gland disease (MGD and DA) was lower than often suggested by conventional wisdom. Furthermore, preoperative imaging was less accurate than it is often perceived for accurately imaging MGD. MIRP and UNE were more successful in achieving normocalcemia than is typically quoted. IOPTH was a helpful but not "fool-proof" adjunct in parathyroid exploration surgery.

SIGNIFICANCE

These results support a greater role for the treatment of primary hyperparathyroidism using less invasive approaches. EMB rating: B-3.

Technetium-99m 2-Methoxyisobutyl isonitrile-scintigraphy: Preoperative and Intraoperative Guidance for Primary Hyperparathyroidism

As refinement of technetium-99m 2-methoxyisobutyl isonitrile-scintigraphy (MIBI)-scintigraphy of parathyroid glands has continued since its initial use in 1989, the sensitivity, specificity, and overall accuracy of the technique have improved greatly, approaching 100% for larger, solitary adenomas. Preoperative use of sestamibi scintigraphy has become commonplace and allows surgeons the option of a minimally invasive, or focused approach for their patients with primary hyperparathyroidism. Intraoperative use of the gamma probe based on sestamibi localization has not caught on due to lesser accuracy, cumbersome gamma probes, small doses of radiation exposure for patients and staff, and the greater accuracy and current confidence in intraoperative parathormone (PTH) monitoring. However, with the potential for smaller and more accurate gamma probes that truly assist in localizing abnormal parathyroid glands, the potential for cost reduction by shortening operative times, avoiding expensive PTH assays, and eliminating the need for pathologic analysis, gamma scintigraphy may yet become a viable option for many parathyroid surgeons.

Primary hyperparathyroidism

PURPOSE OF REVIEW

This contribution presents research progress concerning primary hyperparathyroidism (pHPT), and the background for recent notable changes in treatment policy.

RECENT FINDINGS

Research has clarified that most patients with pHPT require surgery due to risk for osteoporosis, renal stones, and possibly silent complications of renal impairment, cardiovascular disease, and common psychiatric disability. Genetic studies have advanced, but the cause of the disease remains unclear for most patients. Localization methods for parathyroid tumors have improved and increased the interest for less invasive operative methods with shorter hospital stays and reduced costs for the patient. It is important to delineate when this really will imply progress and to use the new diagnostic methods in discussions of appropriate treatment strategies. It has also become evident that older pHPT patients especially could benefit from medical treatment of bone mineral deficit, and they may also need vitamin D or vitamin D analogues to prevent progress of the disease.

SUMMARY

pHPT is a common disorder among postmenopausal women, in whom most commonly applied surgical treatment has proven markedly efficient. There is now increased interest to better understand possible causes of the disease and schedule the most efficient surgical and medical treatment and discuss possible prophylaxis.