Ultra-high dose rate irradiation or “FLASH RT” has recently gained attention because of the surprising observation of markedly increased therapeutic index compared to conventional dose rate irradiation in preclinical studies of in vivo animal models. Most accelerator-based radiation delivery systems used for FLASH were uniquely modified to produce high radiation outputs. However, FLASH RT requires accurate dosimetry in such intense treatment beams. Dosimetry in high dose rate and high dose-per-pulse beams is challenging due to the lack of appropriate radiotherapy dosimetry protocols. Current protocols are not designed for such beam parameters mainly because of the lack of adequate radiation detectors, such as ionization chambers, diodes, diamond detectors, etc. Most of these detectors exhibit non-negligible ion recombination when the dose rate and/or the dose per pulse is increased beyond what is used in conventional radiotherapy. Furthermore, all experiments to date produce pulsed radiation, and there are many aspects of delivery speed, for example, total dose and delivery time, dose per pulse, pulse timing structure, etc., that may be critical to the effect and have not been comprehensively evaluated, since an exhaustive study is an experimentally daunting combinatorial problem. In this session we will discuss the aspects of FLASH dosimetry and potential optimal beam parameters to achieve the maximum FLASH effect.
The meeting is designed to meet the interests of practicing radiation oncologists, radiation oncology residents, medical and clinical physicists, nurses and all other health professionals involved in the field of radiation oncology.
Upon completion of this activity, participants should be able to do the following:
- Discuss the unique challenges associated with FLASH dosimetry.
- Explain the responses for various dosimeters under FLASH conditions.
- Determine the beam parameter space to achieve the maximum FLASH effect.
Peter Maxim, PhD is employed by Indiana University and has a financial interest in TibaRay, Inc.
All relevant relationships have been mitigated.
The American Society for Radiation Oncology (ASTRO) is accredited by the Accreditation Council of Continuing Medical Education to provide continuing education to physicians.
ASTRO is awarded Deemed Status by the American Board of Radiology to provide SA-CME as part of Part II Maintenance of Certification.
- 0.50 AMA PRA Category 1 Credit™The American Society for Radiation Oncology (ASTRO) is accredited by the Accreditation Council for Continuing Medical Education for physicians. ASTRO designates this for a maximum of 0.50 AMA PRA Category 1 Credit™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
- 0.50 Certificate of AttendanceThis activity was designated for 0.50 AMA PRA Category 1 Credit™.