| Question 1: What beam parameters need to be considered when investigating the response of detectors in UHDR beams? |
| Reference: | Schuller et al, “The European Joint Research Project UHDPulse – Metrology for advanced radiotherapy using particle beams with ultra-high pulse dose rates:, Physica Medica, 80 (2020) |
| Choice A: | Dose per pulse |
| Choice B: | Instantaneous dose rate |
| Choice C: | Mean dose rate |
| Choice D: | Pulse width |
| Choice E: | All of the above |
| Question 2: TG-51 cannot be used for ionization chamber dosimetry in beams where the ion recombination correction factor is greater than 1.05. |
| Reference: | Almond et al, Medical Physics, 1999 |
| Choice A: | TRUE |
| Choice B: | FALSE |
| Question 3: Why are the ionization chambers currently used in clinics not ideal? |
| Reference: | Petersson K, et al. High dose-per-pulse electron beam dosimetry - A model to correct for the ion recombination in the Advanced Markus ionization chamber. Med Phys (2017) 44(3):1157-1167.
Di Martino, et al. Ion recombination correction for very high dose-per-pulse high-energy electron beams. Med Phys. (2005) 32(7):2204-10. |
| Choice A: | Because of the long chamber response time with respect to the exposure time |
| Choice B: | Due to ion collection efficiency dependence on dose-per-pulse |
| Choice C: | Due to decrease of ion collection efficiency at high dose rates |
| Choice D: | Due to decrease of ion collection efficiency at low dose rates |
| Choice E: | b & c |
| Question 4: Which detector(s) are NOT considered to be dose-rate independent? |
| Reference: | Karsch L, et al. Dose rate dependence for different dosimeters and detectors. Med Phys. (2012) 39(5):2447-55. |
| Choice A: | EBT films |
| Choice B: | Alanine |
| Choice C: | TLDs |
| Choice D: | Calorimeters |
| Choice E: | OSLs |
| Choice F: | Diamond detectors |
| Question 5: What factors influence the collection efficiency and recombination effects of an ion chamber in a proton FLASH beam? |
| Reference: | E Diffenderfer et al. “The current status of preclinical proton FLASH radiation and future directions”. Med Phys. 2022 Mar;49(3):2039-2054. doi: 10.1002/mp.15276. PMID: 34644403. |
| Choice A: | Pulse structure |
| Choice B: | Bias voltage |
| Choice C: | Electrode separation |
| Choice D: | Ion source current |
| Choice E: | All of the above |
| Question 6: Which statement about the use of a Faraday Cup in dose validation for FLASH beams is NOT true? |
| Reference: | E Diffenderfer et al. “Design, Implementation, and in Vivo Validation of a Novel Proton FLASH Radiation Therapy System”. Int J Radiat Oncol Biol Phys. 2020 Feb 1;106(2):440-448. doi: 10.1016/j.ijrobp.2019.10.049. PMID: 31928642. |
| Choice A: | Validation of a Faraday Cup for collection efficiency dose rate independence requires the relative comparison of low and high dose rates. |
| Choice B: | Within clinical FLASH range, Faraday Cup dosimetry and parallel plate ion chamber dosimetry agree within 0.5%. |
| Choice C: | Faraday Cup dosimetry is energy dependent and therefore cannot be used across therapeutic proton energy spectrum. |
| Choice D: | A Faraday Cup is essentially a “proton counter” and demonstrates high collection efficiency and low charge lose. |
| Choice E: | All of the above |
