MR-guided radiotherapy for liver tumors: Hepatocarcinomas, cholangiocarcinomas, and liver metastases

Stereotactic Body Radiotherapy (SBRT) is an interesting treatment for liver tumors despite a lack of consensus on technique, dose, fractionation, motion management, or contouring. MRI-guided radiotherapy (MRgRT) is a new modality of radiotherapy delivery that is of particular interest for liver tumor treatment. In this chapter, we first describe SBRT state of the art for liver tumor before the MRgRT era. A focus on the advantages of MRgRT for this tumor site is then developed. The main advantages are improved visualization of the tumor and ideal motion management, thanks to target tracking and the possibility to perform the adaptive procedure when required. The specific aspects of liver MRgRT simulation, contouring, planning, and delivery are detailed afterward. Finally, the current results and published studies of MRgRT for liver tumors are summarized.