PhD Thesis Proposal: Austin Sloop

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Meeting ID: 920 6653 7183
Passcode: 953300

"Designing control platforms to augment UHDR deliveries for enhanced safety, accuracy, and temporal control"

Abstract

The field of radiation oncology seeks novel techniques to increase the therapeutic ratio to treat malignancies while minimizing damage and toxicities in healthy tissues. While it was observed that delivering therapeutic doses in brief, intense manner could elicit different biological effects over a half-century ago, the field of ultra-high dose rate (UHDR) radiation therapy (colloquially known as FLASH RT) has seen a resurgence in recent years due to an alignment of accelerator capability, dosimetric advances, and improved biotechnological techniques that has opened the door to studying potential underlying mechanisms such that we may leverage the effects of FLASH tissue sparing in the near future. Collaboration of Dartmouth with the Dartmouth Cancer Center established a leading FLASH development platform with two linacs currently being used for preclinical studies while gearing towards an early clinical study. 

Patient safety is a core tenet; however, FLASH RT currently has the potential to cause harm if radiation is improperly applied. Modern linear accelerators can produce UHDR fluences but safely delivering a precise amount of dose and verifying what was delivered are two of the biggest challenges to FLASH RT. Under UHDR operation, desired doses can be achieved in a small number of pulses delivered over several milliseconds so a single unwanted pulse can contribute to a significant deviation from the therapy plan. The high-fluence environment also saturates many monitoring systems, necessitating evaluation of novel UHDR dosimeters and integrating them into safety critical control systems. This work develops critical control systems of electron clinical irradiators to produce clinically usable, safe UHDR beams. Specifically:

• Linac modification and beam controller (clinical Varian C-arm linac and an IntraOp intraoperative unit)
• Dosimeters as inputs for a more robust controller (including diamond, semiconductor, and current transfer dosimeters)
• New calibration methods and workflows

Thesis Committee

• Petr Bruza (Chair)
• David Gladstone
• Lesley Jarvis
• Kyle Gallagher (U Nebraska Medical Center)

Contact

For more information, contact Thayer Registrar at thayer.registrar@dartmouth.edu.