Utility of intraoperative digital scintigraphy in radioguided parathyroidectomy

BACKGROUND

Intraoperative scintigraphy (IoS) has been proposed as a tool for real-time intraoperative decision-making regarding parathyroid adenoma localization and confirmation of excision.

METHODS

Retrospective review of patients who underwent minimally invasive parathyroidectomies with scintigraphy performed intraoperatively. Preoperative neck ultrasound, 4D computed tomography, as well as intraoperative parathyroid hormone (IOPTH) and gamma probe measurements were conducted per standard practice. IoS images were obtained prior to and following parathyroid excision. Cases were reviewed to determine accuracy of IoS for localizing parathyroid pathology and confirming successful excision.

RESULTS

Fifty-six cases met the inclusion criteria. Twenty-nine patients (51.8%) showed confirmation of excision of an abnormal gland on post-excision IoS. There were no significant differences in IOPTH reduction and postoperative laboratory values between patients with IoS-identified resolution and those without IoS-identified resolution.

CONCLUSIONS

With low accuracy in correctly localizing abnormal glands and confirming their excision, there is no appreciable benefit of IoS at this time.

Individualised Timing of Radio-Guided Parathyroidectomy Using Multi-Phase SPECT/CT Increases In Vivo Sensitivity and Accuracy and Reduces Operating Time: A Randomised Clinical Trial

Background: Minimally invasive parathyroidectomy is the preferred treatment for primary hyperparathyroidism. Despite relatively accurate preoperative information, minimally invasive parathyroidectomy can be challenging, especially in the case of small and ectopic adenomas. Radio guidance aids in both in vivo identification and ex vivo confirmation of adenoma. In vivo accuracy is currently not satisfactory. The present study evaluated whether a beneficial effect (increased sensitivity, specificity, accuracy) is obtained with individualised timing of minimally invasive radio-guided parathyroidectomy (MIRGP) using preoperative multi-phase 99mTc-MIBI single photon emission computed tomography (SPECT)/computed tomography (CT). Methods: This randomised clinical trial was conducted from May 2016 to January 2020 in a tertiary referral hospital. Adult patients with primary hyperparathyroidism sent for 99mTc-MIBI SPECT/CT were included consecutively and randomly assigned to conventional (dual-phase) SPECT/CT and conventional MIRGP (group I) or multi-phase SPECT/CT and individualised MIRGP (group II). One hundred of 106 eligible patients were included, and 83 patients underwent complete intervention. Results: A total of 47 patients in group I and 35 patients in group II were analysed. Group II had a shorter operating time (p = 0.003). The in vivo sensitivity and accuracy of radio guidance was 85.1% in group I and 100% in group II (p = 0.046), and 90.4% in group I and 100% in group II (p = 0.021), respectively. We found no difference in the in vivo specificity and ex vivo parameters between groups. Conclusion: Individualised timing increased the in vivo sensitivity and accuracy of radio guidance and reduced operating time, as some parathyroid adenomas rapidly wash out the radionuclide.

Operative Failure Rate and Documentation of Family History in Young Patients Undergoing Focused Parathyroidectomy for Primary Hyperparathyroidism

Primary hyperparathyroidism in multiple endocrine neoplasia type I usually affects all parathyroid glands, making focused parathyroidectomy (FP) inappropriate. The risk of previously undiagnosed multiple endocrine neoplasia type I in a younger patient with primary hyperparathyroidism is higher than in an older patient. We hypothesized that FP may lead to a higher failure rate in younger versus older patients. A retrospective review was performed of a single-institution database of patients who underwent parathyroidectomy for primary hyperparathyroidism. Routine statistical analysis was performed, including Fisher's exact test. A total of 635 patients were included. Operative failure occurred in 7/55 (13%) younger patients and 21/580 (4%) older patients ( P = 0.007). In conclusion, operative failure occurred in a statistically significantly higher percentage of younger versus older patients undergoing FP. This is partly explained by undiagnosed multiple endocrine neoplasia syndrome type I in the younger patient group. Endocrine surgeons must make every effort to preoperatively identify multiple endocrine neoplasia syndrome type I in the younger patient population.

Radioguided parathyroidectomy effective in pediatric patients

BACKGROUND

Radioguided parathyroidectomy (RGP) has been shown to be effective in adult patients with hyperparathyroidism (HPT), but the utility of RGP in pediatric patients has not been systematically examined. It is not known if adult criteria for radioactive counts can accurately detect hyperfunctioning parathyroid glands in pediatric patients. The purpose of our study was to determine the utility of RGP in children with primary HPT.

MATERIALS AND METHODS

A retrospective review of our prospectively maintained single-institution database for patients who underwent a RGP for primary HPT identified 1694 adult and 19 pediatric patients aged 19 y or younger. From the adult population, we selected a control group matched three to one for gland weight and gender and compared pre- and postoperative laboratory values, surgical findings, pathology, and radioguidance values between the control and the pediatric groups.

RESULTS

Excised glands from pediatric patients were smaller than those in the total adult population (437 ± 60 mg versus 718 ± 31 mg, P = 0.0004). When controlled for gland weight, ex vivo counts as a percentage of background were lower in the pediatric group (51% ± 5% versus 91% ± 11%, P = 0.04). However, ex vivo radionuclide counts >20% of the background were found in 100% of pediatric patients and 95% of the adult-matched control group.

CONCLUSIONS

All pediatric patients met the adult detection criteria for parathyroid tissue removal when a RGP was performed, and 100% cure was achieved. We conclude that RGP is a useful treatment option for pediatric patients with primary HPT.