PTH secretion of “manipulated” parathyroid adenomas

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.

The value of intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism and varying baseline parathyroid hormone levels

BACKGROUND

When applying intraoperative parathyroid hormone monitoring (IOPTH) to patients with primary hyperparathyroidism (PHPT), there are established criteria predicting biochemical cure in patients with basal parathyroid hormone (PTH) levels in the medium range (100-400 pg/ml); however, there is a challenge concerning patients with low (less than 100 pg/ml) or high (more than 400 pg/ml) basal PTH levels. The aim of this study was to investigate the value of the 'Vienna criterion' applied during IOPTH in patients with PHPT and various basal PTH concentrations.

METHODS

Consecutive patients between 1999-2009 with a biochemical diagnosis of PHPT who underwent surgical parathyroidectomy were included. Based on preoperative PTH levels they were divided into three groups: group 1 (low) (<100 pg/ml), group 2 (medium) (100-400 pg/ml) and group 3 (high) (>400 pg/ml) basal PTH. PTH was measured at the start of the operation, when the gland was excised and then at 5, 10 and 15 min after. Calcium and PTH levels were measured at 7 days and 12 months postoperatively. Sensitivity, specificity, positive and negative predictive value, as well as accuracy of IOPTH were calculated for the different groups postoperatively.

RESULTS

675 patients with PHPT were analysed. Sensitivity and specificity were 83.7 per cent and 66.7 per cent in group 1 (n = 187), 90.7 per cent and 69.2 per cent in group 2 (n = 433), and 94.4 per cent and 100 per cent in group 3 (n = 55) to predict cure. Preoperative creatinine (p = 0.002) showed significant statistical difference between the groups but was not related to intraoperative PTH decline. At 12 months follow-up normocalcaemia was documented in 98.9 per cent in group 1, 99.0 per cent group 2, and 98.0 per cent of group 3 patients.

CONCLUSION

Normocalcaemia was predicted intraoperatively by applying the 'Vienna criterion' in 98 to 100 per cent and was confirmed after 12 months follow-up in up to 99.0 per cent of patients. Low specificity and a high false-negative rate in patients with low basal PTH show that other criteria might be better suited for this group.

PTH Spikes During Surgical Treatment for Secondary and Tertiary Hyperparathyroidism: A Prospective Observational Study

BACKGROUND

The aim of the present study was to determine whether PTH spikes in renal hyperparathyroidism can interfere with the interpretation of intraoperative PTH monitoring and to determine its frequency and characteristics.

METHODS

This was a prospective observational study of consecutive patients who underwent surgical treatment in a single tertiary institution. Patients were divided into two groups: spike and no spike. Patients with secondary and tertiary hyperparathyroidism were analyzed separately. Intraoperative PTH monitoring by venous serial samples: two samples were taken before the excision of the parathyroid gland, and two others were taken after resection.

RESULTS

PTH spikes occurred in 23.5% (53 of 226), and their occurrence was similar between secondary and tertiary hyperparathyroidism patients (p = 0.074). The relative PTH spike intensity was higher in transplanted patients than in dialysis patients (55 vs. 20%, p = 0.029). A characteristic of the secondary hyperparathyroidism patients was the highest frequency of surgical failure (23 vs. 7.5%, p = 0.016) and the higher occurrence of supernumerary glands in the spike group (23 vs. 10.3%, p = 0.035). Supernumerary parathyroid was associated with surgical failure [19.1 (6.5-55.7) odds ratio [confidence interval], p < 0.001). In the studies evaluating the diagnostic test validity for patients on dialysis and experiencing spikes, the most significant impacts were in the sensitivity, accuracy, and negative predictive value of the method.

CONCLUSIONS

PTH spikes occurred in up to 23.5% of renal hyperparathyroidism surgical treatments and can negatively influence the intraoperative parathyroid hormone monitoring. Regarding the phenomenon of PTH spikes, it is prudent to think about the possibility of a hyperplastic supernumerary gland.

Ultrasound combined with biochemical parameters can be used to differentiate parathyroid carcinoma from benign tumors in patients with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT) results from excessive secretion of parathyroid hormone from parathyroid tumors. Differentiating parathyroid tumors can be challenging before operation.

OBJECTIVES

To differentiate parathyroid carcinoma from benign tumors in patients with PHPT by the application of ultrasound and biochemical parameters.

METHODS

This study is a retrospective study. The study enrolled 17 patients with parathyroid carcinoma (PC) and 57 patients with parathyroid adenoma (PA), confirmed by postoperative pathology, between September 2010 and July 2017. This study retrospectively compared the ultrasonic features of the tumors included echotexture, maximum lesion diameter, shape, margin, blood flow inside the mass, intralesional calcifications, cysts in the mass, and biochemical parameters included serum calcium, phosphorus, parathyroid hormone (PTH), alkaline phosphatase (ALP) levels, gender distribution and age of patients between patients with PC and those with PA.

RESULTS

In the US images, the two groups showed significant differences in heterogeneity, the appearance of a taller-than-wide shape, irregular or lobulated margins, and intralesional calcifications (p < #x003C;< #x200A;0.05). However, no significant difference was found in echogenicity, maximum lesion diameter, blood flow, and cystic components of the mass (p > #x003E;> #x200A;0.05). The mean PTH levels were significantly different between the two groups (p < #x003C;< #x200A;0.05). The PC and PA patients did not differ significantly in terms of mean serum calcium, mean serum phosphorus, and mean ALP levels (p > #x003E;> #x200A;0.05). There were significant differences to distinguish PC from PA in calcifications in mass or/and taller-than-wide shape combine with PTH > #x003E;> #x200A;1000 pg/mL (p < #x003C;< #x200A;0.05). Significant difference existed in the age between the two groups (p < #x003C;< #x200A;0.001). No significant difference existed in the gender distribution between the two groups (p > #x003E;> #x200A;0.05).

CONCLUSION

Ultrasound features especially intralesional calcifications and taller-than-wide shape combine with an extremely high serum PTH (>1000 pg/mL) are helpful in differentiating between benign and parathyroid tumors in patients with PHPT.

The role of intraoperative parathyroid hormone (IOPTH) determination for identification and surgical strategy of sporadic multiglandular disease in primary hyperparathyroidism (pHPT)

Intraoperative PTH monitoring (IOPTH) made minimally invasive parathyroidectomy in patients with primary HPT possible. However, with the increasing accuracy of preoperative localization studies there is a growing discussion if IOPTH is necessary in patients with localized single gland disease (concordant preoperative localization studies). Different interpretation criteria have been developed - each with their particular advantages and disadvantages, but the "perfect" criterion is still missing. Despite several pitfalls, which can be recognized intraoperatively and do not necessarily lead to a more extensive surgery, IOPTH seems to be a useful adjunct in surgery for PHPT. However, according to current guidelines, selected patients may be operated without IOPTH but need to be informed about the possibly increased risk of recurrent disease.

Intraoperative parathormone spikes during parathyroidectomy may be associated with multiglandular disease

BACKGROUND

The importance of intraoperative parathormone "spikes" during parathyroidectomy remains unclear. This study compared patients with and without intraoperative parathormone spikes during parathyroidectomy using the criterion of a > 50% parathormone and determined the effect of intraoperative parathormone spikes on operative outcome.

METHODS

We performed a retrospective review of prospectively collected data on 683 patients who underwent parathyroidectomy guided by intraoperative parathormone monitoring. An intraoperative parathormone "spike value" was calculated by subtracting the preincision intraoperative parathormone value from the pre-excision intraoperative parathormone value (SV = PE - PI). An intraoperative parathormone spike was defined as having a positive spike value ≥9 pg/mL (≥10th percentile of all spike values).

RESULTS

Of 683 patients, 224 (33%) had intraoperative parathormone spikes and a greater rate of multiglandular disease (8% vs. 3%, P < 0.05) and bilateral neck exploration (10% vs. 5%, P < 0.05) compared with patients without intraoperative parathormone spikes. Overall, there were no differences between parathyroidectomy patients with and without intraoperative parathormone spikes in terms of operative success (98.2% vs. 98.0%), failure (1.8% vs. 2.0%), or recurrence rates (0.4% vs. 1.3%).

CONCLUSIONS

Although the presence of intraoperative parathormone spikes may increase suspicion for multiglandular disease, the ability of intraoperative parathormone monitoring to predict operative success after parathyroidectomy is not affected by spikes.

Perioperative kinetics of parathyroid hormone in unilateral, primary thyroid surgery

Dysfunction of the parathyroid glands is an important cause of complications after thyroid surgery. Intraoperative monitoring of the function of the parathyroid glands can be performed using parathyroid hormone (PTH) kinetics. Unilateral thyroid surgery is associated with a decreased risk for postoperative hypocalcemia (POH) and permanent hypoparathyroidism (PEH). We focused on unilateral thyroid surgery by monitoring the functionality of the parathyroid glands and comparing the perioperative PTH kinetics of patients with and without POH. In a prospective study, 143 patients scheduled for unilateral thyroid surgery underwent monitoring of perioperative changes in serum PTH and serum calcium levels, and of clinical symptoms of hypocalcemia. The rates of POH and PEH were 18.2 and 0%, respectively. In patients without POH, PTH significantly increased from the time of skin incision to the end of the operation and after the operation (20.1 pg/ml, IQR 15.5-26.8 vs. 21.4 pg/ml, IQR 16.4-29.5; p=0.005), which was not the case in patients who developed POH. In a multivariate analysis of predictive factors for POH, two parameters became significant, namely female gender (odds ratio 6.87, 95% confidence interval 0.92-51.01) and lower initial serum calcium levels (odds ratio 3.54*e(-8), 95% confidence interval 3.63*e(-12); 0.00). The rate of POH was unexpectedly high. Rather than intraoperative PTH declines, an unstable balance of factors that influence calcium metabolism likely is the major contributor to POH after unilateral thyroid surgery. There was no case of PEH after unilateral, primary thyroid surgery, which underlines the need for an individualized approach to the extent of resection.

[Intraoperative parathyroid hormone determination for primary hyperparathyroidism]

Intraoperative parathyroid hormone measurement (IOPTH) has proved to be an important promoter for focused and minimally invasive parathyroidectomy procedures in primary hyperparathyroidism. IOPTH enables multiglandular disease to be excluded with a high degree of certainty at the time of operation. The choice of the cut-off value for IOPTH as the criterion for success is of utmost importance with respect to the prognosis for operative success (biochemical healing). Advantages and disadvantages of the variety of existing IOPTH success criteria are confusing and their assessment is contradictory. Particularly with respect to cost-benefit aspects the standard application of IOPTH as "biochemical frozen section" even in conventional open parathyroidectomy remains a matter of controversy. This article gives an up-date on current knowledge and provides practical guidelines for clinical use of IOPTH.