Integrin Receptor Imaging ^99mTc-3PRGD2 SPECT/CT in Diagnosis and Lymph Node Staging of Non-Small Cell Lung Cancer

  Objective  To prospectively evaluate the value of integrin α_vβ₃ receptor imaging approach basedon single photon emission computed tomography/computed tomography (SPECT/CT), using ^99mTc-3PRGD2 as the tracer, in diagnosis and staging of non-small cell lung cancer (NSCLC) compared with ¹⁸F-FDG positron emisson tomography/computed tomography(PET/CT).

  Methods  From February 2011 to December 2012, 65 patients with suspicious lung lesions were recruited with informed consent in Peking Union Medical College Hospital, including 41 males and 24 females, with a mean age of (60±11) years. The patients underwent both ^99mTc-3PRGD2 SPECT/CT and ¹⁸F-FDG PET/CT within one week. After pathological diagnosis, all the patients were followed up until death or for at least two years. Receiver operating characteristic (ROC) curve, Z test, and Chi-square test were used to compare the diagnostic performance of the two imaging methods in assessing lung lesions and mediastinal lymph nodes.

  Results  Sixty-five lung lesions in 53 patients were pathologically diagnosed as NSCLC, and 14 lung lesions in 12 patients were proved as benign. Based on the American Joint Committee on Cancer/Union for International Cancer Control(AJCC-UICC) standard, 248 regions of lymph nodes had metastasis and 56 were negative regions. ^99mTc-3PRGD2 SPECT/CT was found to have higher specificity compared with ¹⁸F-FDG PET/CT in the per-region diagnosis of lymph node metastasis (94.6% vs. 75.0%, P=0.008), whereas the sensitivity of the two methods showed no statistically significant difference (88.3% vs. 90.7%, P=0.557). There was no significant difference between the two methods in diagnostic performance for lung lesion (Z=0.82, P=0.410).

  Conclusion  ^99mTc-3PRGD2 SPECT/CT shows high specificity in the diagnosis of lymph node metastasis from NSCLC, which may complement ¹⁸F-FDG PET/CT in diagnosis and benefit surgical decision-making for patients with lung cancer.