Assessing treatment accuracy of image-guided liver stereotactic body radiotherapy: a quantitative analysis based on 4D CT through post-therapeutic MRI-morphologic alterations.

Background: Stereotactic body radiotherapy (SBRT) has become a promising alternative for patients with inoperable liver cancer. However, the accurate delivery of high doses to moving liver tumors remains challenging. Treatment accuracy can be quantified by comparing post-radiotherapeutic magnetic resonance imaging (MRI)-morphologic alterations (MMA) and corresponding isodose-structure cropped to the liver (ISL) upon planning computed tomography (CT).