Step-by-Step Stereotactic Radiotherapy Planning of Liver Metastasis: A Radiation Oncology from Simulation to Execution (ROSE) Guide

Abstract

Background: Stereotactic body radiotherapy (SBRT) is an important treatment modality in liver metastasis in which surgery is not feasible or when the patient denies surgery. With the recent advances in treatment planning systems and real-time image-guided treatment delivery, we can now deliver high doses of radiation in a small number of fractions to the target with high precision and minimal dose to the organs at risk (OARs). Objective: To describe the procedural steps for radiation planning of SBRT of Liver Metastasis. Methods: The step-by-step procedure for stereotactic planning of liver metastasis has been described using a clinical scenario of liver metastasis. Results: The stereotactic radiation planning of liver metastasis starts with the basic history and relevant clinical evaluation followed by tissue confirmation of the diagnosis of liver metastasis. The SBRT planning for liver metastasis starts with the positioning of the patient using a body immobilization device. This is followed by the use of any of the motion management techniques during the computed tomography (CT) simulation. Magnetic resonance imaging (MRI) of the abdomen should be done in the prescribed format to achieve uniformity in radiation planning. After CT and MRI image fusion, contouring of the target, OARs, and radiation planning should be done. The plan evaluation includes target and OAR coverage index, conformity, homogeneity gradient index, and beam arrangement. After radiation plan evaluation, quality assurance and dry run are done. Then treatment is delivered using the same motion management technique that was used during the CT simulation. Conclusion: The article highlights the sequential process of radiation planning for SBRT in liver metastasis―starting from simulation, planning, evaluation of plan, and treatment