Question 1: Why is scanning proton beam more sensitive to motion than passive scatter proton beams? |
Reference: | Reference: Principles and Practice of Proton Beam Therapy. Ed(s) Indra J. Das and Harald Paganetti. Medical Physics Publishing, 2015, chapter 25, motion management. |
Choice A: | The motion of the beam could interfere with the motion of target and result in the distortion of the dose distribution. |
Choice B: | Due to the finite range of the protons, the beam could stop in the target and compromise target coverage. |
Choice C: | The scanning beam plans are usually more conformal than the passive scatter plans. |
Choice D: | Scanning beam proton beams are no more sensitive to motion than passive scatter proton beams. |
Question 2: Which technique will NOT reduce/mitigate dose uncertainties due to respiratory motion for scanning proton beams (i.e., improve dose homogeneity to the target)? |
Reference: | Reference: Principles and Practice of Proton Beam Therapy. Ed(s) Indra J. Das and Harald Paganetti. Medical Physics Publishing, 2015, chapter 25, motion management. |
Choice A: | Increasing PTV margin. |
Choice B: | Repainting. |
Choice C: | Gating. |
Choice D: | Using breath-hold technique. |
Question 3: Which component of patient motion contributes most to the interplay effect? |
Reference: | Reference: Principles and Practice of Proton Beam Therapy, Das and Paganetti, editors, Chapter 9, Field Shaping: Scanning Beam (Medical Physics Publishing, Madison, 2015) |
Choice A: | The component parallel to the incident proton beam. |
Choice B: | The component perpendicular to the incident proton beam. |
Choice C: | Both (A) and (B). |
Choice D: | None of the above. |
Question 4: The change in water equivalent thickness (WET) along the beam path between inhale and exhale can be used to select: |
Reference: | Principles and Practice of Proton Beam Therapy, Das and Paganetti, editors, Chapter 9, Field Shaping: Scanning Beam (Medical Physics Publishing, Madison, 2015) |
Choice A: | The scanning direction of PBS. |
Choice B: | The method for repainting. |
Choice C: | The gantry angles. |
Choice D: | All above. |
Question 5: Which of the following statements is not a reason why pencil beam scanning treatments for liver tumors is less controversial than that of lung tumors? |
Reference: | Knopf, A. C., Boye, D., Lomax, A., & Mori, S. (2013). Adequate margin definition for scanned particle therapy in the incidence of intrafractional motion. Physics in Medicine and Biology, 58(17), 6079. |
Choice A: | A range-adapted ITV is closer to a traditional ITV because adjacent regions are not low density. |
Choice B: | The interplay effect is negligible without rescanning or any other mitigation strategy. |
Question 6: Which of the following is not a reason why abdominal compression is used in radiation therapy treatments of liver and lung tumors? |
Reference: | : Heinzerling, J. H., Anderson, J. F., Papiez, L., Boike, T., Chien, S., Zhang, G., ... & Timmerman, R. (2008). Four-dimensional computed tomography scan analysis of tumor and organ motion at varying levels of abdominal compression during stereotactic treatment of lung and liver. International Journal of Radiation Oncology* Biology* Physics, 70(5), 1571-1578. |
Choice A: | It reduces intrafraction motion. |
Choice B: | It reduces interfraction motion. |
Choice C: | It can decrease the magnitude of motion according to patient tolerance. |
Choice D: | It reduces organ motion especially those related to diaphragm. |