Question 1: Why do we not use full track structure (nanometer scale) Monte Carlo simulations for treatment plan evaluation? |
Reference: | Paganetti, H., Jiang, H., Parodi, K., Slopsema, R., & Engelsman, M. (2008). Clinical implementation of full Monte Carlo dose calculation in proton beam therapy. Physics in Medicine and Biology, 53(17), 4825–4853. http://doi.org/10.1088/0031-9155/53/17/023)? |
Choice A: | The computational time is too large to allow full track structure simulations and still too complex to influence clinical decisions. |
Choice B: | The effects are too small to matter when determining treatment outcome. |
Choice C: | Treatments are determined by physical doses to the target, and the delivered dose to the target is the same for macroscopic and microscopic Monte Carlo simulations. |
Question 2: Nanometer scale Monte Carlo simulations are limited by physics (Heisenberg uncertainty) and our knowledge of cross sections and material compositions of sub-cellular components. Despite these limitations, for what applications are such simulations expected to be beneficial? |
Reference: | Thomson, R. M., & Kawrakow, I. (2011). On the Monte Carlo simulation of electron transport in the sub-1 keV energy range. Medical Physics, 38(8), 4531–4534. http://doi.org/10.1118/1.3608904 |
Choice A: | Determining cell survival. |
Choice B: | Model developments for cell effects. |
Choice C: | Nothing. |
Choice D: | Predict cure rates. |
Question 3: In clinical radiobiology, cells with a high a/ß ratio are most commonly associated with cells of what sort of tissue? |
Reference: | Radiobiology for the Radiologist 7th ed, Hall & Garcia, p393-407 |
Choice A: | Rapidly-dividing and early responding tissues (e.g. skin, muscoa, most tumours). |
Choice B: | Slowly-dividing and late responding tissues (e.g. lung, Central Nervous System). |
Choice C: | No association with proliferation. |
Question 4: In a typical repair-competent cell, approximately what fraction of DSBs lead to a lethal event? |
Reference: | Reference: Basic Clinical Radiobiology 4th ed, Joiner & van der Kogel, p13 |
Choice A: | 100% |
Choice B: | 50% |
Choice C: | 10% |
Choice D: | 1% |
Question 5: Which statement correctly describes the activity of DNA repair processes in a repair-competent cell throughout the cell cycle? |
Reference: | Pathways of DNA Double-Strand Break Repair During the Mammalian Cell Cycle, K Rothkamm et al, Mol Cell Biol 2003, 23(16):5706 |
Choice A: | Which statement correctly describes the activity of DNA repair processes in a repair-competent cell throughout the cell cycle? |
Choice B: | Nonhomologous End Joining (NHEJ) is active only in the G1 and S phases, Homologous |
Choice C: | Recombination (HR) only in the G2 phase. |
Choice D: | HR is active in the G1 phase, NHEJ in the S and G2 phases. |
Choice E: | NHEJ is active throughout the cell cycle, HR in S and G2 phases. |
Question 6: Which statement or statements best describe the formation of a cluster of DNA lesions by ionizing radiation? |
Reference: | Georgakilas AG, O'Neill P, Stewart RD. Induction and repair of clustered DNA lesions: what do we know so far? Radiat Res. 2013 Jul;180(1):100-9. doi: 10.1667/RR3041.1. |
Choice A: | Clusters of DNA lesions are formed by the action of individual particle tracks. |
Choice B: | Reactive chemical species produced outside the nuclear membrane are likely to diffusion and create DSB within the cell nucleus. |
Choice C: | Individual clusters of DNA lesions are formed by the direct and indirection action of two or more independent particle tracks. |
Choice D: | B and C. |
Choice E: | A and B. |
Question 7: Reproductive cell death encompasses which of the following modes of cell death? |
Reference: | • Chu K, Teele N, Dewey MW, Albright N, Dewey WC. Computerized video time lapse study of cell cycle delay and arrest, mitotic catastrophe, apoptosis and clonogenic survival in irradiated 14-3-3sigma and CDKN1A (p21) knockout cell lines. Radiat Res. 2004 Sep;162(3):270-86.
• Stewart RD, Yu VK, Georgakilas AG, Koumenis C, Park JH, Carlson DJ. Effects of radiation quality and oxygen on clustered DNA lesions and cell death. Radiat Res. 2011 Nov;176(5):587-602
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Choice A: | Apoptosis |
Choice B: | Permanent inhibition of mitosis. |
Choice C: | Mitotic catastrophe |
Choice D: | Delayed cell death days or weeks after irradiation. |
Choice E: | All of the above |
Question 8: The RBE for reproductive cellular death is most closely related to which molecular endpoint? |
Reference: | • Goodhead DT. Initial events in the cellular effects of ionizing radiations: clustered damage in DNA. Int J Radiat Biol. 1994 Jan;65(1):7-17.
• Hlatky L, Sachs RK, Vazquez M, Cornforth MN. Radiation-induced chromosome aberrations: insights gained from biophysical modeling. Bioessays. 2002 Aug;24(8):714-23.
• Stewart RD, Yu VK, Georgakilas AG, Koumenis C, Park JH, Carlson DJ. Effects of radiation quality and oxygen on clustered DNA lesions and cell death. Radiat Res. 2011 Nov;176(5):587-602.
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Choice A: | SSB induction. |
Choice B: | DSB induction. |
Choice C: | Base damage, including complex clusters of base damage. |
Choice D: | Chromosome aberrations. |
Choice E: | None of the above. |
Question 9: Particle RBE for the endpoint of organ at risk (OAR) tolerance doses.... |
Reference: | • Asbell SO, Grimm J, Xue J, Chew MS, LaCouture TA. Introduction and Clinical Overview of the DVH Risk Map. Semin Radiat Oncol. 2016 Apr;26(2):89-96. doi: 10.1016/j.semradonc.2015.11.005. Epub 2015 Dec 4.
• Hall EJ, Giaccia AJ, Radiobiology for the Radiologist, 6th Edition, 2006 Lippincott Williams & Wilkins, (2006)
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Choice A: | Depend on the fractionation schedule selected for the MV x-ray (reference radiation) fractionation schedule. |
Choice B: | Increase with decreasing tissue (α/β). |
Choice C: | Decrease with increasing tissue (α/β). |
Choice D: | A and B. |
Choice E: | A and C. |
Question 10: Are track structure simulations truly needed for radiobiology at the cellular and tissue levels? |
Reference: | Are track structure simulations truly needed for radiobiology
at the cellular and tissue levels?
Robert D. Stewart, Ph.D.
|
Choice A: | Yes |
Choice B: | No |
Choice C: | Maybe |
Choice D: | All of the Above |