Efficacy of 4D-CT Preoperative Localization in 2 Patients with MEN 2A

Multiple endocrine neoplasia type 2A (MEN2A) is an autosomal dominant syndrome that is associated with hyperparathyroidism in 20% to 30% of adult gene carriers. The appropriate surgical management of these patients remains in question. Approaches to this disease range from selective gland resection to a subtotal parathyroidectomy with or without autotransplantation. Despite surgical intervention, disease recurrence is problematic. Surgical management of patients found to have recurrence relies on localizing the anatomic location of the hyperfunctional gland(s). The primary imaging modality for localization of hyperfunctioning parathyroid glands is technetium 99m sestamibi single photon emission computed tomography (SPECT). Although sestamibi imaging has a sensitivity of 60% to 90%, specific anatomic detail is not always present by this imaging modality. Four-dimensional computed tomography (4D-CT) scans allow localization of ectopic parathyroid glands and autotransplanted parathyroid tissue, and they provide the anatomic detail necessary for decisions about appropriate surgical management. Another benefit of the 4D-CT scan is that enhancement characteristics, which are determined by contrast opacification of the hyperfunctional parathyroid tissue over 4 phases of the scan, correlate with metabolic activity. We recommend the use of 4D-CT scanning because of its capacity to identify hyperfunctional parathyroid glands and to provide anatomic information important in preoperative planning.

Key Words: multiple endocrine neoplasia, four dimensional CT, parathyroid gland localization studies, parathyroid autotransplantation, recurrent hyperparathyroidism

Competency: Patient Care, Medical Knowledge, Practice Based Learning and Improvement