The TBI STEP system is a rotatable tabletop designed for Volumetric Modulated Arc Therapy (VMAT) in Total Body Irradiation (TBI). It allows clinicians to overcome the limitations of standard linear accelerator couch shifts by enabling a seamless 180° rotation of the patient—from head-first supine (HFS) to feet-first supine (FFS)—within seconds and without the need for patient repositioning. The rotatable tabletop consists completely of carbon fiber, including the ball bearing within the base plate of the rotation unit. The system attaches directly to the original Linac couch top, making setup fast and straightforward. VMAT-TBI techniques typically require patients to be repositioned due to the Linac’s limited cranial-caudal couch shift range. With TBI STEP, patient rotation becomes effortless, allowing clinicians to use standard positioning devices while achieving consistent, reproducible alignment and optimal dose delivery across the full treatment volume.