Mevion is currently studying approaches to deliver FLASH dose rates to a larger volume of several hundred cubic centimeters or more, which is a common irradiation volume for typical cancer patients. It previously used the FLASH effect in a preclinical trial with its S250i proton accelerator. In this trial, the FLASH effect was delivered at the Bragg peak, which plots the energy loss of ionizing radiation as it travels through matter and occurs immediately before protons, Alpha-rays and other ion ray particles come to rest.

The treatment was applied to mice, with the goal being to increase their survivability by delivering doses at FLASH rates that would be lethal if applied at conventional rates. By hitting the Bragg peak, Mevion succeeded in applying the rapid doses to the tumor, while sparing healthy tissues within the FLASH field. Its use of pulse proton beams instead of electron beams demonstrated the opportunity to investigate the application of FLASH at clinically significant depths.

Mevion’s S250i proton accelerator is equipped with Direct Beam Delivery (DBD) system architecture, which has a beam line where transmission efficiency does not drop below 70%. This enables a Bragg peak FLASH effect at ultra-high dose rates. HYPERSCAN enables faster and sharper delivery of therapeutic radiation to tumors while sparing healthy tissue.

RaySearch and Mevion have previously developed advanced treatment planning capabilities for HYPERSCAN pencil-beam scanning and Adaptive Aperture pMLC.

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