Impact of concomitant thyroid pathology on preoperative workup for primary hyperparathyroidism

Abstract

Background The former standard surgical treatment in patients with primary hyperparathyroidism (pHPT) has been bilateral cervical exploration. New localization techniques and the possibility of intraoperative measurement of intact parathormone (iPTH) permit a focused, minimally invasive parathyroidectomy (MIP). The introduction of MIP without complete neck exploration leads to the potential risk of missing thyroid pathology. The aim of the present study is to evaluate the value of MIP in respect to coexisting thyroid findings and their impact on preoperative workup for primary hyperparathyroidism. Methods This is a prospective study including 30 consecutive patients with pHPT (median age 65 years; 17 females, 13 males). In all patients preoperative localization was performed by ultrasonography and 99m Tc-MIBI scintigraphy-Intraoperative iPTH monitoring was routinely done. Results Ten patients (33%) had a concurrent thyroid finding requiring additional thyroid surgery, and two patients (7%) with negative localization results underwent bilateral neck exploration. Therefore, MIP was attempted in 18 (60%) patients. The conversion rate to a four gland exploration was 6% (1/18). The sensitivities of 99m Tc-MIBI scanning and ultrasonography were 83.3% and 76.6%, respectively. The respective accuracy rates were 83.3% and 76.6%. Of note, the combination of the two modalities did not improve the sensitivity and accuracy in our patient population. During a median follow-up of 40 months, none of the patients developed persistent or recurrent hypocalcaemia, resulting in a 100% cure rate. Conclusion Coexisting thyroid pathology is relatively frequent in patients with pHPT in our region. Among patients having pHPT without any thyroid pathology, the adenoma localization is correct with either ultrasonography or 99m Tc-MIBI scintigraphy in the majority of cases. MIP with iPTH monitoring are highly successful in this group of patients and this operative technique should be the method of choice.

Preoperative imaging for parathyroid localization in patients with concurrent thyroid disease: A systematic review

“…All studies were deemed applicable to the review question and at low risk for significant bias. Thirteen studies were prospective [10][11][12][16][17][18][19][20][21][22][23][24][25] and 15 were retrospective. 4,5,[26][27][28][29][30][31][32][33][34][35][36][37][38] Levels of evidence analysis were determined to be level III (cohort studies) and V (case series).…”

“…Ultrasound was assessed in 18 studies. 4,5,[10][11][12]16,17,19,20,22,23,25,26,30,31,[36][37][38] Based on 10 studies, 4,5,10,11,16,19,20,22,23,30 ultrasound alone had a pooled sensitivity of 0.72 (95% CI 0.67-0.77), and PPV of 0.86 (95% CI 0.82-0.90). Sensitivity and PPV of ultrasound in patients without thyroid pathology, reported by 12 studies, both ranged from 0.67 to 1.00.…”

“…4,5,[10][11][12]17,19,20,22,23,30,31 Dual-phase 99m Tc-sestamibi (MIBI) was assessed in 13 studies. 4,10,11,[19][20][21]24,[28][29][30]32,37,38 Based on 11 studies, 4,10,11,19,20,22,24,28,31,32,38 MIBI had a pooled sensitivity of 0.76 (95% CI 0.71-0.80) and PPV of 0.86 (95% CI 0.82-0.90). Interestingly, some of these studies (n 5 10) also included comparative cohorts without concurrent thyroid pathology showing sensitivity of MIBI ranging from 0.63 to 1.00 and PPV from 0.92 to 1.00.…”

“…4,5,10,19,20,22,[28][29][30]32,38 Combined ultrasound and scintigraphy was investigated in 7 studies. 4,10,12,19,20,24,36 Six studies evaluated ultrasound with dual-phase sestamibi (MIBI), 4,10,19,20,25,36 1 study evaluated ultrasound with MIBI/pertechnetate subtraction, 5 and another evaluated ultrasound with either MIBI (n 5 27) or MIBI/pertechnetate subtraction (n 5 50). 12 Based on 5 studies involving these modalities, 4,5,10,19,20 pooled sensitivity was 0.86 (95% CI 0.80-0.92) and PPV was 0.88 (95% CI 0.83-0.94).…”

“…4,10,12,19,20,24,36 Six studies evaluated ultrasound with dual-phase sestamibi (MIBI), 4,10,19,20,25,36 1 study evaluated ultrasound with MIBI/pertechnetate subtraction, 5 and another evaluated ultrasound with either MIBI (n 5 27) or MIBI/pertechnetate subtraction (n 5 50). 12 Based on 5 studies involving these modalities, 4,5,10,19,20 pooled sensitivity was 0.86 (95% CI 0.80-0.92) and PPV was 0.88 (95% CI 0.83-0.94). In patients without thyroid pathology, reported by 5 studies, 4,5,10,19,20 sensitivity ranged from 0.89 to 1.00 and PPV was 1.00.…”