Comparison of Radiation Exposure and Cost Between Dynamic Computed Tomography and Sestamibi Scintigraphy for Preoperative Localization of Parathyroid Lesions

Abstract

Importance: Dynamic computed tomography (CT) is emerging as a first-line alternative to sestamibi scintigraphy for preoperative localization of parathyroid lesions. In recent years, there has been increased concern over the impact of radiation exposure from medical imaging, as well as on the cost of diagnostic medical procedures. An ideal diagnostic procedure would be cost effective while minimizing hazardous exposures and complication rates.Objective: To compare the radiation dose and financial cost of dynamic CT with sestamibi scintigraphy. Main Outcomes and Measures:The 2 primary study outcomes were radiation exposure measured in millisieverts (mSv) and medical charges for the respective diagnostic procedures. The study was conducted with the hypothesis that dynamic parathyroid CT would have slightly greater radiation exposure with similar cost to sestamibi scintigraphy.Results: Dynamic parathyroid CT and sestamibi scintigraphy delivered mean radiation doses of 5.56 and 3.33 mSv, respectively (P Ͻ .05). Charges totaled $1296 for thin-cut dynamic parathyroid CT and a mean of $1112 for sestamibi scintigraphy, depending on the type and amount of radiotracer injected. Although multiphase CT scanning took less than 5 minutes, sestamibi scintigraphy lasted a mean time of 306 minutes. A total of 62 of 119 patients (52%) in the CT group have undergone operative treatment to date, whereas all patients in the sestamibi arm underwent operative treatment of their hyperparathyroidism. Of the patients who underwent a surgical procedure, CT correctly identified the side of the parathyroid adenoma in 54 of 62 patients (87%), while sestamibi scintigraphy only correctly lateralized 90 of 122 adenomas (74%) as confirmed by exploratory surgery, intraoperative parathyroid hormone levels, and pathologic features. A dynamic parathyroid CT correctly predicted multiglandular disease in 1 of 7 patients (14%), while sestamibi scintigraphy correctly predicted multiglandular disease in 8 of 23 patients (35%). Conclusions and Relevance:In patients who underwent directed parathyroid surgery, dynamic CT is comparable to sestamibi scintigraphy in patients with hyperparathyroidism. Although CT delivers a higher dose of radiation, the average background radiation exposure in the United States is 3 mSv/y, and added exposures of less than 15 mSv are considered low risk for carcinogenesis. Overall, dynamic parathyroid CT is a safe, cost-effective alternative to sestamibi scintigraphy.

Evaluation of the radiation dose exposure and associated cancer risks in patients having preoperative parathyroid localization

“…Previous reported effective radiation doses for four phase or 4D CT have ranged from 5.56 mSv to 26.4 mSv. 6,11,19,21 These differences in radiation dose highlight the variation in protocols for parathyroid 4D CT imaging between institutions. Our results demonstrated that there was a significant reduction in the total effective radiation dose using three-phase CT scans compared with fourphase CT scans (15.9 vs 20.2 mSV, P < 0.0001).…”

Imaging of the parathyroid glands in primary hyperparathyroidism

“…A chest X-ray has a typical dose of 0.02 mSv. The average radiation doses in parathyroid imaging are as follows: MIBI (3.33 mSv); dynamic CT (5.56 mSv), SPECT-MIBI (7.8 mSv) (55). However, the greatest radiation dose is 4D-CT (10.4 mSv), which is the equivalent of 520 chest-X-rays (56).…”

Dynamic 4D MRI for Characterization of Parathyroid Adenomas: Multiparametric Analysis

“…This discussion is beyond the scope of this article; however, effective radiation doses ranging from 5.56 to 10.4 mSv [4][5][6] have been reported, depending on the acquisition scheme used. Our second finding is that the described MR perfusion technique can successfully exploit the hypervascular nature of PTAs, a feature that can be used to differentiate them from PTA candidates such as subjacent cervical lymph node and thyroid tissue.…”

“…4D CT has shown superior accuracy compared with scintigraphy, 3 though the radiation dose remains as high as 5.56 -10.4 mSv. [4][5][6] MR imaging is an attractive alternative to both scintigraphy and 4D CT due to the lack of radiation and has been used for the evaluation of PTAs with some success, [7][8][9] though not with the same effectiveness as 4D CT. Traditional technical limitations to localizing PTAs with MR imaging have recently been addressed with modern MR imaging technology.…”