Diagnostic value of 99Tcm-pertechnetate salivary gland scintigraphy in patients with Sjögren′s syndrome

Abstract

Objective To investigate the diagnostic value of the residual ratio and the ratio of 99Tcm-pertechnetate uptake at 10 min (UR10 min) in patients with Sjogren′s syndrome (SS). Methods The retrospective study included 94 cases of SS (9 males, 85 females; average age (48±13) years) and 60 cases of non-SS (control group; 14 males, 46 females, average age (46±13) years). All patients underwent 99Tcm-pertechnetate salivary gland scintigraphy. According to the uptake of 99Tcm-pertechnetate in parotid gland, 94 SS patients were divided into 3 groups: group A including 15 normal cases and 7 cases with mild injury, group B including 56 cases with moderate injury, and group C including 16 cases with severe injury. ROI was drawn, then UR10 min and the residual ratio of 99Tcm-pertechnetate in parotid gland were calculated. One-way analysis of variance, q test and ROC curve analysis were used. Results UR10 min in control group, group A and group B(1.48±0.43, 1.56±0.38, 1.38±0.55, respectively) was significantly higher than that of group C (0.53±0.21; F=20.3, q values: 15.8, 7.9, 8.5, all P<0.05). The residual ratio of parotid gland in control group(0.63±0.08)was significantly lower than those of the SS patients in the 3 groups (0.83±0.14, 1.14±0.08, 1.09±0.08 respectively, F=315.0, q values: 14.3, 41.0, 32.8, all P<0.05). The residual ratio in group A was lower than that in group B and group C(q values: 31.0, 13.0, both P<0.05). The AUC of ROC curve was 0.62 for UR10 min and 0.97 for residual ratio. Conclusions The UR10 min of parotid gland is sensitive for the diagnosis of the advanced SS, while the residual ratio is sensitive for the diagnosis of the early SS. Residual ratio could be a quantitative parameter to detect the function of parotid gland. Key words: Sjogren′s syndrome; Parotid gland; Radionuclide imaging; Sodium pertechnetate Tc 99m