Stanford Experience With Commissioning, Quality Assurance and IMRT/ SBRT Treatment of the First Biology-Guided Radiation Therapy Machine

formed by all MLC leaves retracted is 40 cm. The jaw pairs open 1 or 2 cm at the isocenter in the longitudinal direction. The nominal beam dose rate is 850 monitor units (MU)/min for the original IMRT/SBRT version of the machine. With the BgRT upgrade, the dose rate is 1000 MU/ min. The kVCT scanner is located on a plane 61.4 cm superior to the room laser. The X1 machine consists of 2 symmetrically opposing 90-degree arcs of PET detectors incorporated into the architecture of a ring-gantry at the same plane to the linac 100 cm superior to the room laser. The treatment delivery with the X1 system is achieved axially with the couch advancing at discrete intervals of 2.1 mm, making 1 or 4 passes through the treated region Abstract Biology-guided radiation therapy (BgRT) is an emerging technology that integrates real-time PET imaging with radiation therapy to improve tumor targeting and treatment outcomes. This systematic review aims to summarize the Stanford experience on the current state of knowledge on machine commissioning, quality assurance, treat-ment planning, clinical applications, safety, and efficacy of BgRT in cancer treatment. The review underscores advancements in the clinical implementation of intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) technologies, facilitated by the introduction of the novel BgRT machine. It also highlights challenges related to improving workflow efficiency and validating tracking accuracy in real-world patient situations. This document serves as a valuable resource for researchers, clinicians, and decision-makers within the realm of radiation oncology, providing insights into the status of the PET-based BgRT machine and guiding the trajectory of future research.