RESUMO
Objective:To evaluate the additional value of chest thin layer CT over 99Tc m-hydrazinonicotinyl-(polyethylene glycol) 4-E[(polyethylene glycol) 4-c(RGDfK)] 2(HYNIC-PEG 4-E[PEG 4-c(RGDfK)] 2; 3PRGD 2) SPECT/CT in detecting isolated pulmonary space. Methods:This was a prospective study conducted in General Hospital of Ningxia Medical University. There were 87 patients with solitary pulmonary space occupying between July 2015 and December 2016, and 74 of those patients (49 males, 25 females, age range: 37-80 (58.4±9.6) years) who had pathological results were enrolled. 99Tc m-3PRGD 2 SPECT/CT imaging was performed routinely, and then the chest thin layer CT images were acquired. The maximum radioactive counts ratio of tumor to non-tumor (T/N)≥1.5 was the standard for positive planer 99Tc m-3PRGD 2 imaging, and that ≥2.0 was the standard for positive SPECT/CT imaging. According to the pathological results as gold standard, the diagnostic efficiencies of 99Tc m-3PRGD 2 planer and SPECT/CT imaging, chest thin layer CT and chest thin layer CT+ 99Tc m-3PRGD 2 SPECT/CT imaging for malignant pulmonary lesions were calculated. Kappa test was used to compare the consistency of the imaging methods and pathological results. Results:The post-surgery histopathology confirmed that 51 patients were with malignancy and 23 had benign lesions. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 99Tc m-3PRGD 2 planer imaging, SPECT/CT imaging and chest thin layer CT in the diagnosis of malignant pulmonary lesions were 47.1%(24/51), 65.2%(15/23), 52.7%(39/74), 75.0%(24/32), 35.7%(15/42); 86.3%(44/51), 47.8%(11/23), 74.3%(55/74), 78.6%(44/56), 11/18 and 84.3%(43/51), 52.2%(12/23), 74.3%(55/74), 79.6%(43/54), 12/20, respectively. Those of the chest thin layer CT+ SPECT/CT were 98.0%(50/51), 73.9%(17/23), 90.5%(67/74), 89.3%(50/56) and 17/18 respectively. The Kappa values between the imaging methods ( 99Tc m-3PRGD 2 planer imaging, SPECT/CT imaging, chest thin layer CT and the chest thin layer CT+ SPECT/CT) and pathological examination were 0.100, 0.250, 0.354 and 0.765 (all P<0.001). Conclusion:Chest thin layer CT has an incremental value over 99Tc m-3PRGD 2 SPECT/CT imaging in the differential diagnosis of benign and malignant pulmonary lesions.