Influence of intravenous contrast medium on dose calculation using CT in treatment planning for oesophageal cancer

• Published in: Asian Pacific journal of cancer prevention : APJCP Vol. 14; no. 3; pp. 1609 - 1614
• Main Authors: Li, Hong-Sheng, Chen, Jin-Hu, Zhang, Wei, Shang, Dong-Ping, Li, Bao-Sheng, Sun, Tao, Lin, Xiu-Tong, Yin, Yong
• Format: Journal Article
• Language: English
• Published: Thailand 01.01.2013
• Subjects: Aged; Carcinoma, Squamous Cell - diagnostic imaging; Carcinoma, Squamous Cell - radiotherapy; Contrast Media; Esophageal Neoplasms - diagnostic imaging; Esophageal Neoplasms - radiotherapy; Female; Follow-Up Studies; Humans; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - radiotherapy; Male; Middle Aged; Neoplasm Staging; Prognosis; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Tomography, X-Ray Computed
• ISSN: 1513-7368; 2476-762X
• DOI: 10.7314/apjcp.2013.14.3.1609

To evaluate the effect of intravenous contrast on dose calculation in radiation treatment planning for oesophageal cancer. A total of 22 intravein-contrasted patients with oesophageal cancer were included. The Hounsfield unit (HU) value of the enhanced blood stream in thoracic great vessels and heart was overridden with 45 HU to simulate the non-contrast CT image, and 145 HU, 245 HU, 345 HU, and 445 HU to model the different contrast-enhanced scenarios. 1000 HU and -1000 HU were used to evaluate two non-physiologic extreme scenarios. Variation in dose distribution of the different scenarios was calculated to quantify the effect of contrast enhancement. In the contrast-enhanced scenarios, the mean variation in dose for planning target volume (PTV) was less than 1.0%, and those for the total lung and spinal cord were less than 0.5%. When the HU value of the blood stream exceeded 245 the average variation exceeded 1.0% for the heart V40. In the non-physiologic extreme scenarios, the dose variationof PTV was less than 1.0%, while the dose calculations of the organs at risk were greater than 2.0%. The use of contrast agent does not significantly influence dose calculation of PTV, lung and spinal cord. However, it does have influence on dose accuracy for heart.