The prediction of radiation-induced liver dysfunction using a local dose and regional venous perfusion model.
We have shown that high dose conformal radiation combined with chemotherapy appears to prolong the survival of patients with unresectable intrahepatic cancers. The ability to safely deliver higher doses is primarily limited by the development of radiation-induced liver disease, characterized by venous occlusion. In this study, we investigated whether portal venous perfusion measured prior to the end of radiation therapy (RT) together with dose could predict liver venous perfusion dysfunction after treatment. Ten patients with unresectable intrahepatic cancer participated in an IRB-approved computer tomography (CT) perfusion study. Hepatic arterial and portal vein perfusion distributions were estimated by using dynamic contrast enhanced CT and the single compartmental model. Scans were obtained at four time points: prior to treatment, after 15 and 30 fractions of 1.5 Gy treatments, and one month following the completion of RT. Multivariant linear regression was used to determine covariances among the first three time point measurements plus dose for prediction of the post RT measurement. The reduction in the regional venous perfusion one month following RT was predicted by the local accumulated dose and the change in the regional venous perfusion after -30 fractions (F=90.6,p <0.000 01). Each Gy produced an approximately 1.2% of reduction in the venous perfusion. This local dose and venous perfusion model has the potential to predict individual sensitivity to radiation. This is the first step toward developing a method to deliver higher and potentially more curative radiation doses to the patients who can safely receive these higher doses.
Cao
Yue
Y
Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109-0010, USA. yuecao@umich.edu
Platt
Joel F
JF
Francis
Isaac R
IR
Balter
James M
JM
Pan
Charlie
C
Normolle
Daniel
D
Ben-Josef
Edgar
E
Haken
Randall K Ten
RK
Lawrence
Theodore S
TS
D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D003198:Computer Simulation; D005260:Female; D006503:Hepatic Veins / Q000503:physiopathology; D006504:Hepatic Veno-Occlusive Disease / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008113:Liver Neoplasms / Q000503:physiopathology / Q000532:radiotherapy; D008875:Middle Aged; D008954:Models, Biological; D011379:Prognosis; D011832:Radiation Injuries / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D018570:Risk Assessment / Q000379:methods*