| Question 1: The condition of charged particle disequilibrium in small photon fields: |
| Reference: | Journal of the International Commission on Radiation Units and Measurements, Volume 14, Issue 2, 1 December 2014, Pages 1–160, https://doi.org/10.1093/jicru/ndx017 |
| Choice A: | Only manifests itself when attempting to measure absorbed dose to water using an air-filled ionization chamber in small fields. |
| Choice B: | Does not matter if we use an unshielded diode to measure the relative output factor. |
| Choice C: | Has a large (>10%) effect on the stopping power ratio water-to-air in small fields. |
| Choice D: | May affect the accuracy of a measurement of absorbed dose using any detector as well as a dose calculation by a treatment planning system. |
| Question 2: The two largest contributors to small output correction factor uncertainty when measured with a cylindrical, air filled ionization chamber are: |
| Reference: | Journal of the International Commission on Radiation Units and Measurements, Volume 14, Issue 2, 1 December 2014, Pages 1–160, https://doi.org/10.1093/jicru/ndx017 |
| Choice A: | The stopping power ratio water-to-air and the central electrode effect |
| Choice B: | The stopping power ratio water-to-air and the chamber wall effect |
| Choice C: | The fluence perturbation effect and the volume averaging effect |
| Choice D: | The stopping power ratio water-to-air and the volume averaging effect |
| Choice E: | The ionization chamber wall effect and the stem effect |
| Question 3: A nonstandard machine-specific reference (msr) field is typically different from a 10 x 10 cm2 calibration field. Calibration in such a field requires a beam quality specifier for the equivalent square field size. The choice of this equivalent square field size is best determined as follows: |
| Reference: | IAEA-AAPM Code of Practice. IAEA Technical Report Series 481, International Atomic Energy Agency, Vienna, 2017 |
| Choice A: | By finding the equivalent square field that equates the electron scatter to that in the msr field. |
| Choice B: | By finding the equivalent square field that equates the photon scatter to that in the msr field. |
| Choice C: | By determining the full-width half maximum (FWHM) of the dose profile in the in- and cross plane direction and calculating the equivalent square as the geometric mean of these two quantities. |
| Choice D: | By defining the equivalent square field as having the same field area as the msr field. |
| Choice E: | An equivalent square field given a certain msr field cannot be determined. |
| Question 4: A pencil beam convolution algorithm used to calculate absorbed dose in a small, tissue-density target embedded in a low-density medium irradiated by one or few coplanar or non-coplanar small 6 MV or 10 MV beams, will typically report an absorbed dose to the target that is: |
| Reference: | Journal of the International Commission on Radiation Units and Measurements, Volume 14, Issue 2, 1 December 2014, Pages 1–160, https://doi.org/10.1093/jicru/ndx017 |
| Choice A: | Significantly overestimating the real absorbed dose. |
| Choice B: | Significantly underestimating the real absorbed dose. |
| Choice C: | Almost equal to the real absorbed dose. |
| Choice D: | Not different from a dose calculation in a homogeneous water configuration. |
| Choice E: | More accurate than a collapsed-cone convolution calculation. |
| Question 5: Which image acquisition procedure has the lowest dose? |
| Reference: | Ding GX, Munro P., “Radiation exposure to patients from image guidance procedures and techniques to reduce the imaging dose”. Radiother Oncol. Jul 2013;108:91–98 |
| Choice A: | MV portal image |
| Choice B: | kV Radiograph |
| Choice C: | MVCT |
| Choice D: | kV-CBCT |
| Choice E: | MV-CBCT |
| Question 6: What is the eye dose resulting from a typical head kV-CBCT image acquisition? |
| Reference: | AAPM TG-180: “Image guidance doses delivered during radiotherapy: Quantification, management, and reduction. Med Phys, 2018 |
| Choice A: | 0.1 – 0.3 cGy |
| Choice B: | 0.3 – 1.0 cGy |
| Choice C: | 1.0 – 2.0 cGy |
| Choice D: | 2.0 – 3.0 cGy |
| Choice E: | > 3.0 cGy |
| Question 7: What is the most important element in QA procedures for an image guidance system? |
| Reference: | Dawson, L. A. and Jaffray D. A.. (2007.) “Advances in image-guided radiation therapy.” J. Clin. Oncol. 25(8): 938–46. |
| Choice A: | Image contrast. |
| Choice B: | Image resolution. |
| Choice C: | Image dose. |
| Choice D: | Isocenter coincidence between imaging system and therapeutic treatment unit. |
| Choice E: | Image deformation. |
| Question 8: A problem encountered in attempting pooled analyses of outcomes in hypofractionated radiation therapy is |
| Reference: | Each HyTEC article has a section on “Future Studies” and a following section on “Reporting Standards”, in which the adequacy of current reporting standards and the impact of current reporting on the ability to pool data from different publications. For related issues, see also Jackson, A et al, “The lessons of Quantec: recommendations for reporting and gathering data on dose-volume dependencies of treatment outcome.” Int J Radiat Oncol Biol Phys 2010, 76: S155-S160. |
| Choice A: | There are very few publications on hypofractionated radiation therapy. |
| Choice B: | Lack of detailed information about dose computation and how doses to structures are reported. |
| Choice C: | Variable outcomes grading schemes. |
| Choice D: | B and C. |
| Question 9: Which of the following is a reasonable spinal cord PRV? |
| Reference: | A planning risk volume (PRV) includes some margin for contouring and setup error, thus providing additional protection for a critical structure. The thecal sac is an identifiable anatomical structure which, conveniently, plays this role for the true spinal cord. Sahgal A, et al. Probabilities of radiation myelopathy specific to stereotactic body radiation therapy to guide safe practice. Int J Radiat Oncol Biol Phys 2013;85:341-347. |
| Choice A: | Thecal sac. |
| Choice B: | Thecal sac+ 1.0 mm. |
| Choice C: | Thecal sac+ 1.5 mm. |
| Choice D: | Thecal sac+ 2.0 mm. |
| Question 10: The complication rate for the spinal cord receiving a dose of 25 Gy in 5 fractions likely ranges from: |
| Reference: | Grimm J, et al. Estimated Risk Level of Unified Stereotactic Body Radiation Therapy Dose Tolerance Limits for Spinal Cord. Semin Radiat Oncol 2016;26:165-171.
Sahgal A, et al. Probabilities of radiation myelopathy specific to stereotactic body radiation therapy to guide safe practice. Int J Radiat Oncol Biol Phys 2013;85:341-347.
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| Choice A: | 30% to 35% |
| Choice B: | 20% to 25% |
| Choice C: | 10% to 15% |
| Choice D: | 1% to 5% |
