Speaker
Description
Conventional therapy to treat cancer is through surgery, chemotherapy, radiation therapy and immunotherapy with 2/3 of cancer patients receiving radiation therapy during the course of their treatment. Conventional radiation therapy with X-ray, protons and ions increases the therapeutic index by creating a physical dose differential between tumors and normal tissues through precision dose targeting, image guidance, and radiation beams that deliver a radiation dose with conformality with the highest conformality produced by pencil proton and ion beams. However, the treatment and cure are still limited by normal tissue radiation toxicity, primarily necrotic side effects. Recently a new paradigm for increasing the therapeutic index of radiation therapy has emerged based on the FLASH radiation effect. FLASH radiation therapy (FLASHRT) is an ultra-high-dose-rate delivery of a therapeutic radiation dose within a fraction of a second. Experimental studies and preclinical research have shown that normal tissues are universally spared at these high dose rates, whereas tumors respond “normally” to the delivered dose. Dose delivery conditions to achieve a FLASH effect are not yet fully characterized and evidence for FLASH varies with radiation type and delivery in terms of beam macro and micro-structure. Current estimates are that doses delivered in less than 200 ms at high instantaneous dose rates (~105 Gy/sec or higher) produce normal-tissue-sparing effects yet kill tumor cells at a level corresponding to the dose delivered. At these high instantaneous dose rates and short integrated dose timescales, the accelerator community faces many technical challenges to create the high dose and intensity rates with compact accelerators and ensure safe delivery of FLASH-level radiation beams. The subject of this presentation will be a review of accelerator intensity and structure requirements and advances in novel accelerator technologies towards a practical realization of FLASH-RT.
- Work supported by Fermi Research Alliance, LLC under contract no. DE-AC02-07CH11359
1cjj@fnal.gov, 2rschulte@llu.edu
