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SU‐E‐J‐198: Preliminary Study On Liver Radiation Response to Stereotactic Body Radiotherapy in Patients with Hepatocellular Carcinoma Based On MRI
Author(s) -
Liang Y,
Kirichenko A,
Klepchick P,
Gayou O
Publication year - 2013
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 - 10.1118/1.4814410
Subject(s) - medicine , hepatocellular carcinoma , nuclear medicine , dosimetry , voxel , magnetic resonance imaging , radiology , radiation therapy , radiosurgery , radiation treatment planning
Purpose: To develop a method to study the MRI response of tumor and hepatic parenchyma to stereotactic body radiotherapy (SBRT) in patients with hepatocellular carcinoma (HCC). Methods: Two adult patients with HCC who received SBRT were recruited in this IRB‐approved study. T1‐weighted delayed phase contrast Eovist enhanced MRI were performed immediately prior to and three months after SBRT. The time between contrast injection and MRI acquisition was identical for both pre‐and post‐SBRT imaging sessions. The patients received 3D conformal SBRT with a total dose of 40 Gy in 5 fractions. Both MRI images were rigidly registered to the planning computed tomography (CT) data set and the 3‐dimensional (3D) dosimetry data, focusing on local alignment in the tumor region. The average MRI intensity in the spleen was calculated for the pre‐and post‐SBRT images, and subtracted to reduce the effects of different imaging conditions. For each 4.9mm by 4.9mm by 6mm voxel in a region of interest (ROI) delimited by the liver contour and the 20 Gy isodose line, the difference in MRI intensity between pre‐and post‐SBRT images was generated and correlated to radiation dose deposited in that voxel. Results: The Pearson correlation coefficient between MRI intensity change and dose was 0.58 (p<0.0001) for patient A and 0.33 (p<0.0001) for the patient B. Conclusion: We have developed a method to study tumor and hepatic parenchyma response to radiation dose in HCC patients treated with SBRT. Our preliminary data suggest a correlation between the radiologic response and dose in HCC p 333 atients treated with SBRT, and warrant further study with more patients.