| Question 1: What parameter is important when performing ionization chamber measurements in the presence of a strong magnetic field? |
| Reference: | Reference 1: Reference dosimetry in magnetic fields: formalism and ionization chamber correction factors, Daniel J. O’Brien, David A. Roberts, Geoffrey S. Ibbott, and Gabriel O. Sawakuchi, Med. Phys. 43, 4915, 2016.
Reference 2: Relative dosimetry with an MR-linac: Response of ion chambers, diamond, and diode detectors for off-axis, depth dose, and output factor measurements, Daniel J. O’Brien, James Dolan, Stefan Pencea, and Nicholas Schupp and Gabriel O. Sawakuchi, Med. Phys. 45, 884, 2018
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| Choice A: | Chamber orientation. |
| Choice B: | Effective point of measurement (EPOM). |
| Choice C: | Air gaps. |
| Choice D: | All of the above. |
| Question 2: Which of the following is affected by the presence of a strong magnetic field that is oriented perpendicular to the photon beam? |
| Reference: | Relative dosimetry with an MR-linac: Response of ion chambers, diamond, and diode detectors for off-axis, depth dose, and output factor measurements, Daniel J. O’Brien, James Dolan, Stefan Pencea, and Nicholas Schupp and Gabriel O. Sawakuchi, Med. Phys. 45, 884, 2018 |
| Choice A: | Depth dose distribution. |
| Choice B: | Lateral dose distribution. |
| Choice C: | Depth of maximum dose. |
| Choice D: | All of the above. |
| Question 3: Which of the following dosimeters is currently commercially available for commissioning MRgRT? |
| Reference: | Reference 1: L. J. Rankine, S. Mein, J. Adamovics, B. Cai, A. Curcuru, T. Juang, D. Miles, S. Mutic, Y. Wang, M. Oldham, H. Li. “Three-dimensional dosimetric validation of a magnetic resonance-guided intensity modulated radiation therapy system.” Int. J. Radiat. Oncol. Biol. Phys. 97(5) 1095-1104 2017
Reference 2: H. Li, V.L. Rodriguez, O.L. Green, Y. Hu, R. Kashani, H.O. Wooten, D. Yang, S. Mutic. “Patient-specific quality assurance for the delivery of 60Co intensity modulated radiation therapy subject to a 0.35 T lateral magnetic field.” Int. J. Radiat. Oncol. Biol. Phys. Vol. 91(1) 65-72 2015
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| Choice A: | Ionization chamber and ionization chamber array. |
| Choice B: | Radiographic and radiochromic films. |
| Choice C: | Diode array. |
| Choice D: | 3D plastic dosimeters using optical CT readout. |
| Choice E: | All of the above. |
| Question 4: Which of the following tasks are recommended for commissioning MRgRT? |
| Reference: | Y. Wang, T.R. Mazur, O.L. Green, Y. Hu, H. Li, H.O. Wooten, D. Yang, T. Zhao, S. Mutic, H. Li. “A GPU-accelerated Monte Carlo dose calculation platform and its application toward validating an MRI-guided radiation therapy beam model.” Med. Phys. 43(7) 4040-4052 2016 |
| Choice A: | Conventional ionization chamber and film measurements. |
| Choice B: | AAPM TG-119 measurements. |
| Choice C: | End-to-end dosimetry verification using 3D dosimeters. |
| Choice D: | Dose recalculations using an independent Monte Carlo calculation system. |
| Choice E: | All of the above. |
| Question 5: What are the main components of an online adaptive dosimetry QA program to assure safe and accurate MRgART treatments? |
| Reference: | Cai B, Green OL, Kashani R, Rodriguez VL, Mutic S, Yang D. A practical implementation of physics quality assurance for photon adaptive radiotherapy. Z Med Phys. 2018 (In press) |
| Choice A: | Manual verifications of image registration, contouring, electron density mapping, and adaptive plan’s quality. |
| Choice B: | Semi-automatic verifications of treatment plan parameters’ integrity and consistency. |
| Choice C: | An independent secondary dose calculation to verify the TPS computed dose. |
| Choice D: | Treatment delivery QA using treatment delivery machine log files. |
| Choice E: | All of the above. |
| Question 6: Which of the following procedures is recommended to enable accurate estimation of the actual dose delivered to the upper abdominal cancer patients, for example, pancreatic cancer patients, including the doses to both targets and OARs? It is known that the inter-fractional anatomical variations of the digestive organs are substantial. |
| Reference: | Cai B, Green OL, Kashani R, Rodriguez VL, Mutic S, Yang D. A practical implementation of physics quality assurance for photon adaptive radiotherapy. Z Med Phys. 2018 (In press) |
| Choice A: | Directly add the TPS calculated dose volumes of multiple online adaptive treatment fractions. |
| Choice B: | Register the fractional volumetric images, thus the fractional dose volumes, using a conventional intensity-based deformable image registration method, then add the fractional dose volumes. |
| Choice C: | Register individual digestive organs and GTV/CTV separately using a model-based deformable image registration method, then perform separate dose accumulation for GTV/CTV and individual digestive organs. |
