Geometrical differences in target volumes based on 18F‐fluorodeoxyglucose positron emission tomography/computed tomography and four‐dimensional computed tomography maximum intensity projection images of primary thoracic esophageal cancer

摘要: Summary The objective of the study was to compare geometrical differences target volumes based on four-dimensional computed tomography (4DCT) maximum intensity projection (MIP) and 18F-fluorodeoxyglucose positron emission tomography/computed (18F-FDG PET/CT) images primary thoracic esophageal cancer for radiation treatment. Twenty-one patients with sequentially underwent contrast-enhanced three-dimensional (3DCT), 4DCT, 18F-FDG PET/CT simulation scans during normal free breathing. The internal gross volume defined as IGTVMIP obtained by contouring MIP images. (GTVPET) were determined nine different standardized uptake value (SUV) thresholds manual contouring: SUV ≥ 2.0, 2.5, 3.0, 3.5 (SUVn); ≥20%, 25%, 30%, 35%, 40% (percentages SUVmax, SUVn%). in ratio (VR), conformity index (CI), degree inclusion (DI) between GTVPET investigated. mean centroid distance ranged from 4.98 mm 6.53 mm. VR 0.37 1.34, being significantly (P < 0.05) closest 1 at SUV2.5 (0.94), SUV20% (1.07), or (1.10). CI 0.34 0.58, SUV2.0 (0.55), (0.56), SUV25% (0.53), (0.58). DI 0.61 0.91, 0.86. threshold setting SUV2.5, yields best tumor internal-gross contoured 4DCT dataset, but 3DPET/CT could not replace each other motion encompassing delineation