Preoperative imaging studies are used to identify and accurately locate the affected parathyroid gland or glands. In order to perform minimally invasive focused surgical parathyroidectomy two imaging studies, parathyroid ultrasound and Sestamibi scan, are require for precise preoperative localization of parathyroid lesions in patients with hyperparathyroidism.
Patients with primary hyperparathyroidism who do not have Sestamibi and ultrasound imaging showing parathyroid adenoma are at higher risk of persistent disease. Staudy have shown that in patients who had undergone dual imaging with an ultrasound scan and sestamibi scintigraphy, failure rates with surgery was 2% if both imaging have shown the same site of the adenoma (with specific indication on the upper or lower gland), 9% - if both imagining only have agreed on the side (without specific indication on the upper or lower gland), and 11% - if both imaging are negative for findings of the adenoma.
Our Parathyroid Canter is utilizing high sensitivity parathyroid ultrasound machine. Dr Shifrin performs his own parathyroid ultrasounds (US) on all parathyroid patients prior to surgery (Figure 1 and 2). The sensitivity rate is approximately 75-80% for localizing of parathyroid adenoma.
Figure 1. Parathyroid ultrasound showing right inferior parathyroid adenoma (transverse view)
Figure 2. Parathyroid ultrasound showing right inferior parathyroid adenoma (sagittal view)
The second study is 99mTc-sestamibi fusion single-photon computed tomography (SPECT) and computed tomography (CT) images (SPECT-CT) is the newest and highly sophisticated imaging technology that designed by fusing 99mTc-sestamibi SPECT and CT slices using fusion software. Dual-phase 99mTc-sestamibi scintigraphy with SPECT-CT enables to identify a parathyroid adenoma in about two-thirds of patients with primary hyperparathyroidism and allows the surgeon to plan appropriate surgery (Figure 3, 4, 5, and 6). Combination of two positive tests, US and 99mTc-sestamibi scintigraphy with SPECT-CT, results in 90-95% sensitivity in localization of parathyroid adenoma and success of minimally invasive surgical exploration. Dr Pritinder K. Thind, MD is an expert in nuclear medicine imaging of parathyroid glands. She has adopted and developed next generation SPECT–CT Statamibi in our center and all parathyroid studies are done and read by her.
Figure 3. Spect CT Sestamibi (the same patient as on prior ultrasound Figure 1 and 2)
Figure 4. Spect CT Sestamibi (the same patient as on prior ultrasound Figure 1 and 2)
Figure 5. Spect CT Sestamibi (the same patient as on prior ultrasound Figure 1 and 2)
Figure 6. Spect CT Sestamibi (the same patient as on prior ultrasound Figure 1 and 2)
A. Bagul, H. P. Patel, D. Chadwick, B. J. Harrison, S. P. Balasubramanian. Primary Hyperparathyroidism: An Analysis of Failure of Parathyroidectomy. World J Surg (2014) 38:534–541