Metabolic tumor volume on PET reduced more than gross tumor volume on CT during radiotherapy in patients with non-small cell lung cancer treated with 3DCRT or SBRT

摘要: Objective We have previously demonstrated that tumor reduces in activity and size during the course of radiotherapy (RT) a limited number patients with non-small cell lung cancer (NSCLC). This study aimed to quantify metabolic volume (MTV) on positron emission tomography (PET) compare its changes those gross (GTV) computed (CT) during-RT for 3D conformal (3DCRT) stereotactic body (SBRT). Methods Patients stage I–III NSCLC treated definitive RT ± chemotherapy were eligible this prospective study. FDG-PET/CT scans acquired within 2 weeks before (pre-RT) at about two thirds total dose during-RT. PET volumes (PET-MTVs) delineated using method combining tumor/aorta ratio autosegmentation CT anatomybased manual editing. Data are presented as mean (95 % confident interval). Results The MTV delineation methodology was first confirmed be highly reproducible by comparing defined different physicians systems (coefficiency>0.98). Fifty 88 primary nodal lesions evaluated. ratios MTV/GTV 0.70 (−0.07∼1.47) 0.33 (−0.30∼0.95) pre-RT during-RT, respectively. PET-MTV reduced 70 (62– 77 %), while CT-GTV 41 (33–49 %) (p<0.001) reduction 72.9 15.4 3DCRT SBRT, respectively (p<0.001). Conclusion more than duringRT, SBRT. RTOG1106 is adapt radiation therapy 3DCRT.