2022 AAPM 64th Annual Meeting
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Session Title: Clinical Implementation of Spatially Fractionated Radiotherapy (SFRT)
Question 1: Which of the following is NOT a characteristic of grid therapy treatment delivery?
Reference:Yan et al. Spatially Fractionated radiation therapy: History, present, and the future. Clin Transl Radiat Oncol. 2020. 20: 30-38.
Choice A:Spatially fractionated radiation
Choice B:Heterogeneous dose distribution with alternating regions of high dose peaks and low dose valleys
Choice C:Partial tumor radiation
Choice D:Ultra-high FLASH dose rates
Question 2: What is the minimum single fraction dose that is typically used for grid therapy?
Reference:Billena and Khan. A Current Review of Spatial Fractionation: Back to the Future? Int J Radiat Oncol Biol Phys. 2020. 104 (1): 177-187.
Choice A:8 Gy
Choice B:10 Gy
Choice C:12 Gy
Choice D:15 Gy
Question 3: What is a possible radiobiologic mechanism responsible for the effectiveness of grid therapy?
Reference:Billena and Khan. A Current Review of Spatial Fractionation: Back to the Future? Int J Radiat Oncol Biol Phys. 2020. 104 (1): 177-187.
Choice A:Radiation Induced Bystander Effects
Choice B:Anti-tumor immune responses
Choice C:Tumor microvasculature changes
Choice D:All of the above
Question 4: What is a proposed dose heterogeneity metric used to evaluate the quality of VMAT-based Lattice Radiotherapy dose distributions?
Reference:Zhang H, Wu X, Zhang X, et al. Photon GRID Radiation Therapy: A Physics and Dosimetry White Paper from the Radiosurgery Society (RSS) GRID/LATTICE, Microbeam and FLASH Radiotherapy Working Group. Radiat Res. 2020;194(6):665-677.
Choice A:V95% for the high dose target
Choice B:Mean dose
Choice C:D10%/D90% for the target
Choice D:The prescription dose divided by the target volume
Question 5: According to many clinical trials, what is the optimal method of delivering grid therapy treatments?
Reference:Gholami, S., H. A. Nedaie, F. Longo, M. R. Ay, S. Wright and A. S. Meigooni (2016). "Is grid therapy useful for all tumors and every grid block design?" Journal of Applied Clinical Medical Physics 17(2): 206-219. Billena, C. and A. J. Khan (2019). "A Current Review of Spatial Fractionation: Back to the Future?" Int J Radiat Oncol Biol Phys 104(1): 177-187. Yan, W., M. K. Khan, X. Wu, C. B. Simone, 2nd, J. Fan, E. Gressen, X. Zhang, C. L. Limoli, H. Bahig, S. Tubin and W. F. Mourad (2020). "Spatially fractionated radiation therapy: History, present and the future." Clin Transl Radiat Oncol 20: 30-38.
Choice A:A brass block and 6 MV photons
Choice B:A VMAT Lattice technique with 6 MV FFF photons
Choice C:Proton techniques which duplicate the aperture arrangement of the brass block
Choice D:There have been no clinical trials which have established one method as superior to another.
Question 6: The volume ratio of high dose “spheres” to the gross tumor volume (VV/VGTV) is typically:
Reference:Wu, X., Perez, NC., Zheng, Y., Jiang, L., Amendola, BE., Xu, B., Mayr, N., Lu, JJ., Hatoum, GF., Zhang, H., Chang, SX., Griffen, RJ., Guha, C. (2020). “The technical and clinical implementation of LATTICE Radiation Therapy (LRT).” Radiation Research 194 (6): 737 - 746. Kavanaugh, JA., Spraker, MB., Duriseti, S., Basarabescu, F., Price, A., Goddu, M., Knutson, N., Prusator, M., Robinson, CG., Mazur, T. (2022). “LITE SABR M1: Planning design and dosimetric endpoints for a phase I trial of lattice SBRT.” Radiotherapy and Oncology. 167: 172-178
Choice A:0.01 – 0.03
Choice B:0.05 – 0.10
Choice C:0.10 – 0.30
Choice D:0.30 – 0.50
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