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TH‐EF‐BRA‐04: Individually Optimized Contrast‐Enhanced 4D‐CT for Radiotherapy Simulation in Pancreatic Ductal Adenocarcinoma
Author(s) -
Choi W,
Xue M,
Lane B,
Kang M,
Patel K,
Regine W,
Klahr P,
Wang J,
Chen S,
D'souza W,
Lu W
Publication year - 2016
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4958261
Subject(s) - contouring , medicine , nuclear medicine , pancreatic ductal adenocarcinoma , radiation therapy , pancreas , pancreatic cancer , computed tomography , contrast to noise ratio , radiology , image quality , cancer , engineering drawing , artificial intelligence , computer science , engineering , image (mathematics)
Purpose: To develop an individually optimized contrast‐enhanced (CE) 4D‐CT for radiotherapy simulation in pancreatic ductal adenocarcinomas (PDA). Methods: Ten PDA patients were enrolled. Each underwent 3 CT scans: a 4D‐CT immediately following a CE 3D‐CT and an individually optimized CE 4D‐CT using test injection. Three physicians contoured the tumor and pancreatic tissues. We compared image quality scores, tumor volume, motion, tumor‐to‐pancreas contrast, and contrast‐to‐noise ratio (CNR) in the 3 CTs. We also evaluated interobserver variations in contouring the tumor using simultaneous truth and performance level estimation (STAPLE). Results: Average image quality scores for CE 3DCT and CE 4D‐CT were comparable (4.0 and 3.8, respectively; P=0.47), and both were significantly better than that for 4D‐CT (2.6, P<0.001). Tumor‐to‐pancreas contrast results were comparable in CE 3D‐CT and CE 4D‐CT (15.5 and 16.7 HU, respectively; P=0.71), and the latter was significantly higher than in 4D‐CT (9.2 HU, P=0.03). Image noise in CE 3D‐CT (12.5 HU) was significantly lower than in CE 4D‐CT (22.1 HU, P<0.001) and 4D‐CT (19.4 HU, P=0.005). CNRs were comparable in CE 3D‐CT and CE 4DCT (1.4 and 0.8, respectively; P=0.23), and the former was significantly better than in 4D‐CT (0.6, P = 0.04). Mean tumor volumes were smaller in CE 3D‐CT (29.8 cm 3 ) and CE 4D‐CT (22.8 cm 3 ) than in 4D‐CT (42.0 cm 3 ), although these differences were not statistically significant. Mean tumor motion was comparable in 4D‐CT and CE 4D‐CT (7.2 and 6.2 mm, P=0.23). Interobserver variations were comparable in CE 3D‐CT and CE 4D‐CT (Jaccard index 66.0% and 61.9%, respectively) and were worse for 4D‐CT (55.6%) than CE 3D‐CT. Conclusion: CE 4D‐CT demonstrated characteristics comparable to CE 3D‐CT, with high potential for simultaneously delineating the tumor and quantifying tumor motion with a single scan. Supported in part by Philips Healthcare.