Program Information

Individually Optimized Contrast-Enhancement 4D-CT for Pancreatic Adenocarcinoma in Radiotherapy Simulation

M Xue

M Xue¹*, K Patel¹ , W Regine¹ , B Lane¹ , W D'Souza¹ , P Klahr² , W Lu¹ , (1) University of Maryland School of Medicine, Baltimore, MD, (2) Philips Healthcare, Cleveland, Ohio

Presentations

SU-E-J-187 Sunday 3:00PM - 6:00PM Room: Exhibit Hall

Purpose: To study the feasibility of individually optimized contrast-enhancement (CE) 4D-CT for pancreatic adenocarcinoma (PDA) in radiotherapy simulation. To evaluate the image quality and contrast enhancement of tumor in the CE 4D-CT, compared to the clinical standard of CE 3D-CT and 4D-CT.

Methods: In this IRB-approved study, each of the 7 PDA patients enrolled underwent 3 CT scans: a free-breathing 3D-CT with contrast (CE 3D-CT) followed by a 4D-CT without contrast (4D-CT) in the first study session, and a 4D-CT with individually synchronized contrast injection (CE 4D-CT) in the second study session. In CE 4D-CT, the time of full contrast injection was determined based on the time of peak enhancement for the test injection, injection rate, table speed, and longitudinal location and span of the pancreatic region. Physicians contoured both the tumor (T) and the normal pancreatic parenchyma (P) on the three CTs (end-of-exhalation for 4D-CT). The contrast between the tumor and normal pancreatic tissue was computed as the difference of the mean enhancement level of three 1 cm3 regions of interests in T and P, respectively. Wilcoxon rank sum test was used to statistically compare the scores and contrasts.

Results: In qualitative evaluations, both CE 3D-CT and CE 4D-CT scored significantly better than 4D-CT (4.0 and 3.6 vs. 2.6). There was no significant difference between CE 3D-CT and CE 4D-CT. In quantitative evaluations, the contrasts between the tumor and the normal pancreatic parenchyma were 0.6±23.4, -2.1±8.0, and -19.6±28.8 HU, in CE 3D-CT, 4D-CT, and CE 4D-CT, respectively. Although not statistically significant, CE 4D-CT achieved better contrast enhancement between the tumor and the normal pancreatic parenchyma than both CE 3D-CT and 4D-CT.

Conclusion: CE 4D-CT achieved equivalent image quality and better contrast enhancement between tumor and normal pancreatic parenchyma than the clinical standard of CE 3D-CT and 4D-CT.


Funding Support, Disclosures, and Conflict of Interest: This study was supported in part by Philips Healthcare.


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