Abstract

The purpose of external beam radiation therapy is to precisely deliver a specified dose into target volumes, while minimizing radiation dose to at-risk organs (OARs). Radiation therapy requires precision throughout entire process from simulation to planning and administering radiation therapy. Cranial Spinal Irradiation (CSI) is a complex technique, due to the large target volumes and the limited field-size of the accelerator machine, requiring multiple isocenters and coupling fields. The irradiation field coupling must be highly accurate. Setup errors lead to field-overlaping resulting in OARs overdose and recurrence risk due to underdose to target volumes. New radiation techniques which help highly optimizing radiation dose to the target volumes and better protecting organs at risk, even require more accuracy in setting up process. Here, we introduce the patient setting up procedure using for VMAT- CSI process at the TrueBeam machine in Ho Chi Minh City Cancer Hospital.