Mild hypercalcemia: an indication to select 4-dimensional computed tomography scan for preoperative localization of parathyroid adenomas.

BACKGROUND: Technetium sestamibi scanning is the most accepted method of imaging used for preoperative localization of parathyroid adenomas. Four-dimensional computed tomography (4D-CT) scanning is a relatively new localization technique that has not been as rigorously evaluated.

METHODS: One hundred thirty-five consecutive patients who underwent preoperative sestamibi scanning, 4D-CT scanning, and parathyroidectomy for primary hyperparathyroidism were evaluated. Patient characteristics, parathyroid gland weights, and the probability of having positive preoperative localization were examined.

RESULTS: Four-dimensional computed tomography scanning was significantly more accurate than sestamibi (73% vs 62%, P = .016). In those with serum calcium levels less than 10.8 mg/dL, 4D-CT scanning was significantly more accurate than sestamibi scanning for the quadrant (45% vs 29%, P = .013) and hemisphere (66% vs 48%, P = .012). Also, 4D-CT scanning was more accurate among patients with parathyroid gland weights less than 500 mg (69% vs 45%, P < .001).

CONCLUSIONS: Four-dimensional computed tomography scanning provides better preoperative localization than sestamibi scanning, particularly in patients with mild hypercalcemia and smaller parathyroid adenomas.