Study Of The Clinical Application Of Hybrid PET/CT Imaging In Non-small Cell Lung Cancer

Objective 1. To investigate the influence of ¹⁸F-fluorodeoxyglucose hybrid PET/CT(¹⁸F-FDG hPET/CT) imaging on the clinical staging of non-small cell lung cancer (NSCLC) in comparison to the convention staging as well as the changes in treatment planning. 2. To investigate the potential benefit of incorporating ¹⁸F-FDG hPET/CT to delineate the gross tumor volume(GTV) in patients with NSCLC complicated with atelectasis who are to be treated with three dimensional conformal radiation therapy(3DCRT). 3. To investigate the impact of hypoxia imaging with ¹⁸F-misonidazole hybrid PET/CT(¹⁸F-FMISO hPET/CT) in NSCLC.Methods 1. Thirty six patients with pathologically confirmed NSCLC complete with history, physical examination, routine roentgenography and clinical staging by the conventional method were entered into the present study. An initial staging and treatment plan were established basing on all the above information. After FDG hPET/CT,a revised staging and treatment plan were then made. The emphasis of the present study was laid upon the changes in staging and treatment plan with and without the participation of FDG hPET/CT. 2. Twelve patients histopathologically proven as having NSCLC with image diagnosed as complicated with various degrees of atelectasis were studied in this study. All patients were scanned with thoracic CT and thoracic or whole body FDG hPET/CT. The GTV was delineated basing on both CT image and FDG image(GTV_FDG,GTV_CT) and the volume of each GTV(designated GTV_FDG,GTV_CT) was compared by 3DCRT plan. 3. Seven patients with lung cancer were scanned with FMISO hPET/CT, FDG hPET/CT and CT.Results 1. Before FDG hPET/CT, curative plan was intended for 26 patients and palliative plan for 10 among these 36 patients. After hPET/CT, 36.1 %(13/36) found their clinical stage changed: 10 elevated and 5 lowered. The treatment plan was also changed in 19.4 %(7/36). 2. Each paired GTV_FDG and GTV_CT was different from each other. Ten patients'GTV was reduced to an average of 33cm³(20.1%)with median GTV fdg of 131 cm³ (34～460 cm³) and median GTV_CT of 164 cm (60～671 cm³) , with two increase of 67 cm³ (78.8%) and 247 cm³ (116%) . The reduction of GTV_FDG was due to hPET/CT could so differ cancer-induced atelectasis from gross tumor that it reduced the target volume and spared more surrounding normal tissues. 3. Among the 10 lesions imaged by FDG hPET/CT in 7 patients with lung cancer, 7 lesions showed intense uptake of FMISO, The other 3 lesions had no uptake of FMISO showed well response to radiotherapy.Conclusion 1. The participation of FDG hPET/CT obviously influences the clinical staging and treatment planning of NSCLC. 2. The incorporation of FDG hPET/CT data with gross tumor delineation is able to improve the accuracy of 3DCRT for non-small cell lung cancer patients complicated with atelectasis. 3. Hypoxia in lung cancer can be detected by FMISO hPET/CT imaging and the results can be beneficial to Biological IMRT and indicate the outcome after radiotherapy.