BACKGROUND: The aim of this study was to evaluate the value of semiquantitative analysis (SQA) of 99mTc-MIBI imaging in predicting early-stage cervical lymph node metastasis (CLNM) in thyroid carcinoma (TC).

MATERIAL AND METHODS: TC patients (n =106) undergoing surgical resection and histopathological examination were enrolled. All patients received 99mTc-MIBI imaging prior to surgery. P-glycoprotein (P-gp) expression was detected by PT-PCR and immunohistochemistry. With pathological results as the criterion standard, the diagnostic efficiency of 99mTc-MIBI imaging in predicting early-stage CLNM was evaluated. The correlation of P-gp with 99mTc-MIBI imaging was investigated. Logistic regression analysis was applied for analyzing the factors affecting early-stage CLNM.

RESULTS: The detection rate and misdiagnosis rate of 99mTc-MIBI imaging for early-stage CLNM diagnosis were 87.3% and 12.7%, respectively. Receiver operating characteristic (ROC) curve analysis showed an accuracy of 99mTc-MIBI imaging of 85.85%. Preoperative 99mTc-MIBI scan showed statistical differences between metastasis and non-metastasis groups in early and delayed T/NT and washout rate (all P<0.05). The percentage of P-gp-expressing cells and the expression rate of P-gp gene both exhibited statistical differences between metastasis and no-metastasis groups (both P<0.05). Tumor diameter, lesion distribution, the percentage of P-gp-expressing cells, and the expression rate of P-gp gene were risk factors for CLNM (all P<0.05).

CONCLUSIONS: 99mTc-MIBI imaging has value in qualitative diagnosis of early-stage CLNM in TC. Tumor diameter, lesion distribution, the percentage of P-gp-expressing cells, and the expression rate of P-gp gene were risk factors for CLNM.

Keywords: Diagnosis, P-Glycoprotein