Abstract |
Purpose: The purpose of this study was to evaluate and
compare the scintigraphic findings and diagnostic
accuracy of double-phase Tc-99m sestamibi scan in
primary and secondary hyperparathyroidism (HPT).
Materials and Methods: We retrospectively reviewed 16
cases of primary (18 lesions) and 11 cases of secondary
HPT (44 lesions) who underwent Tc-99m-sestamibi scan
before the surgical intervention. Scan was performed
using LEM camera (Siemens, Germany) after the injection
of 740MBq of Tc-99m sestamibi. Routine image consisted
of baseline and 3-hour delayed images and each image
was obtained using both parallel and pine hole
collimator. The study population was 27 patients
(male/female=5/22, age: 49.1¡¾10.8). Results:
Eighteen lesions of primary HPT consisted of 13
adenomas and 5 hyperplasias, while all lesions of
secondary HPT were hyperplasias. Among the case of
primary HPT, we could detect all the lesions of 13
adenomas but only 2 lesions of 5 hyperplasias (40%)
could be detected by double phase scintigraphy. Three
cases of primary lesion showed decreased uptake in
delayed images compared with baseline. The sensitivity,
specificity, positive predictive value and accuracy of
primary and secondary HPT were 58.8% (10/17), 83.3%
(10/12), 83.3% (10/12), 75.9% (22/29), and 37.5%
(15/40), 50% (2/4), 88.2% (15/17), 38.6% (17/44),
respectively. Overall sensitivity, specificity,
positive predictive value and accuracy were 43.9%
(25/57), 75% (12/16), 86.2% (25/29), and 53.4% (39/73).
There were no statistical difference between the weight
of primary and secondary HPT lesion (p>0.05).
Conclusion: Tc-99m sestamibi scan is fairly good
modality to detect parathyroid lesion in patient with
primary HPT before the surgical intervention. However,
since some of cases may reveal decreased uptake in
delayed image, a careful attention to the findings of
baseline images may be helpful. Still the low accuracy
of sestamibi scan in diagnosis of secondary HPT
prohibits routine use of it for this disease. (Korean J
Nucl Med 1999;33:368-80) |