2016 AAPM Annual Meeting
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Session Title: Educational Point Counter/Point: Has Photon RT Hit the Limits?
Question 1: Which of the following statements about proton therapy is correct?
Reference:“Proton Therapy Physics”: Ed. Harald Paganetti; Taylor & Francis / CRC Press 2012; ISBN-10: 1439836442
Choice A:Proton therapy increases the overall dose to critical structures compared to photon therapy
Choice B:Proton therapy will always result in lower dose to all critical organs compared to photon therapy
Choice C:Proton beams can always mimic photon dose distributions with the exception of deep seated tumors.
Choice D:VMAT allows dose distributions equal to proton therapy.
Choice E:IMRT in combination with VMAT allows dose distributions equal to proton therapy
Question 2: Which of the following imaging techniques for delivery verification is unique to proton therapy?
Reference:Energy- and time-resolved detection of prompt gamma-rays for proton range verification. Verburg JM, Riley K, Bortfeld T, Seco J. Phys Med Biol. 2013 Oct 21;58(20):L37-49.
Choice A:Cone-beam CT.
Choice B:MRI.
Choice C:Prompt-gamma imaging.
Choice D:Cerenkov imaging.
Choice E:Fluoroscopy imaging.
Question 3: What is the limiting factor for the achievable quality of coplanar photon beam plans?
Reference:1. Yu CX, Amies CJ, Svatos M, Vision 2020: Planning and Delivery of Intensity modulated radiation therapy. Med. Phys. 35(12) pp. 5233-5241, Dec. 2008. 2. Yu, CX: Intensity modulated arc therapy using dynamic multileaf collimation: An alternative to tomotherapy. Phys. Med. Biol. 40(9), 1435-1449, 1995 3. Yu CX, Tang G: Intensity modulated arc therapy: Principles, Technologies, and Clinical Implementations, Phys. Med. Biol., 56(5):R31-54. 2011
Choice A:Limited number of beam angles.
Choice B:Limited number of field shapes.
Choice C:Limited number of independent beams characterized by both beam angle and aperture shapes.
Choice D:All of the Above.
Question 4: Besides high cost, proton beam therapy also have issues with
Reference:1. J. Unkelbach et al., “Reducing the sensitivity of IMPT treatment plans to setup errors and range uncertainties via probabilistic treatment planning,”   Med. Phys. 36, 149–163 (2009) 2. Paganetti H. 2002. Nuclear Interactions in Proton Therapy: Dose and Relative Biological Effect Distributions Originating From Primary and Secondary Particles. Physics in Medicine and Biology 47:747-764.
Choice A:Broader penumbra.
Choice B:Proton beam range uncertainties.
Choice C:Dose calculation uncertainties due to anatomical changes and CT artifacts.
Choice D:RBE uncertainties.
Choice E:All of the above.
Question 5: Proton therapy provides for a reduction in integral radiation dose to normal tissues which may translate into a clinical benefit. Factors related to passive scattering proton therapy that may reduce the clinical benefit of proton therapy are all of the following EXCEPT:
Reference:Proton Therapy Physics Paganetti, H ed. CRC Press, 2012 Boca Raton, FL
Choice A:Tissue inhomogeneity.
Choice B:Proton range.
Choice C:Fixed beam delivery.
Choice D:Reduced Conformality.
Question 6: Randomized trials of proton therapy versus conventional therapy have established the clinical benefit of proton therapy in which of the following:
Reference:Radiother Oncol. 2012 Apr;103(1):8-11. doi: 10.1016/j.radonc.2012.02.001. Epub 2012 Mar 9. An evidence based review of proton beam therapy: the report of ASTRO's emerging technology committee. Allen AM, Pawlicki T, Dong L, Fourkal E, Buyyounouski M, Cengel K,Plastaras J, Bucci MK, Yock TI, Bonilla L, Price R, Harris EE, Konski AA
Choice A:Oropharyngeal cancer.
Choice B:Non-small cell lung cancer.
Choice C:Left-sided breast cancer.
Choice D:Esophageal cancer
Choice E:None of the above
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