On October, 2017, MPSi worked on the commissioning of the first Varian Halcyon Linear Accelerator to become operational in the United Kingdom. This project was undertaken in cooperation with the radiotherapy physics staff of Barking, Havering & Redbridge University Hospitals. The commissioning measurements were completed in just over one week meeting the go-live deadline for patient treatment set by the hospital. Introduced at the ESTRO Meeting in May, 2017, the new Halycon treatment system revolutionizes clinical workflow through the enhancement and simplification of all aspects of image-guided IMRT and RapidArc radiotherapy. MPSi personnel were delighted to work with the BHR Radiotherapy Physics Staff to bring the benefits of the new Halcyon treatment system to patients in the UK.