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. Issue 8 (11th June 2014)

• Record Type: Journal Article
• Authors: Guo, Y.; Li, J.; Wang, W.; Zhang, Y.; Wang, J.; Duan, Y.; Shang, D.; Fu, Z.
• Is Part Of: Diseases of the esophagus. Volume 27:Issue 8(2014)
• Page Start: 744
• Page End: 750
• Publication Date: 2014-06-11
• Subjects: Esophagus -- Diseases -- Periodicals; 616.32
• DOI: 10.1111/dote.12247
• Languages: English
• ISSNs: 1120-8694

Abstract

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