The clinical value of PET/CT in diagnosis and management of the lung nodule

Full text: The aim of this study is to investigate the clinical value of hybrid PET/CT in diagnosis and management of the lung nodule. 20 patients were evaluated: 15 patients with suspected cancer, 5 patients with known cancer. PET/CT scans were performed using Discovery LS-PET/CT system, after injection of 5.55MBq/kg FDG. The diagnostic accuracy of PET/CT was 100% in these 20 patients. Of the 15 patients suspected to have malignancy, 7 were diagnosed to have benign disease and 8 malignant. 5 patients with known cancer were positive on FDG. Of the 7 benign diseases, FDG was positive in 4 and negative in remaining 3. All the 13 patients with malignancy showed positive FDG scan. PET/CT provided additional data in 8 patients having 11 single lesions on CT. Of the 8 lesions, 6 were diagnosed metastasis to the tissue outside lung and the other 2 metastasis itself. Originally, it was planned to operate 16 of the 20 patients, give anti-inflammation therapy in 2 and chemotherapy in other 2 patients. However, in 16 (80%) of them therapy scheme was changed after PET/CT scanning: 2 of 20 were kept on observation, 5 anti-inflammatory therapy, 2 operation, 4 local radiotherapy, 3 chemotherapy only and 4 radiotherapy and chemotherapy or operation together. PET/CT fusion imaging was helpful to direct radiotherapy orientation to 8 patients. One of them, treated by MM50 for one sitting of treatment, was reexamined with PET/CT after one and half month. It showed disappearance of previous parenchymal nodule and the metabolism of glucose returned to normal. Two patients were operated after seeing the PET/CT fusion images. The pathological results showed no carcinoma cell in cutting margins or removed lymph nodes. Hybrid PET/CT imaging may offer an important tool in diagnosis and management of the lung nodule. The diagnostic accuracy of PET/CT was 100% in 20 patients. It provided better discrimination between malignant and benign FDG positive lesions and more sensitivity than CT as well as led to significant changes in clinical management in 80% of the study population. (author)