2016 AAPM Annual Meeting
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Session Title: Emerging Technologies in SRS/SBRT Delivery
Question 1: Which of the following technology is uniquely developed for the latest Gamma Knife radiosurgery?
Choice A:Stereoscopic CBCT.
Choice B:MV CBCT.
Choice C:Stereoscopic planar imaging.
Choice D:MV planar imaging.
Question 2: Flattening filter free (FFF) photo beams are commonly employed in which of the following treatments?
Choice A:RapidArc
Choice B:CyberKnife
Choice C:Gamma Knife
Choice D:Tomotherapy
Choice E:All of the Above
Question 3: During the brain SRS treatment with robotic radiosurgery, the target localization system frequently detects the patient shifts/rotations (every 30-60 seconds) by comparing the live images with the DRRs. The detected shifts/rotations are used to compensate the patient motion through which of the following methods?
Reference:Kilby, W., et al., The CyberKnife Robotic Radiosurgery System in 2010. Technol Cancer Res Treat, 2010. 9(5): p. 433-52.
Choice A:The robot manipulator automatically adjusts the beam position and orientation relative the new patient position.
Choice B:The couch automatically moves to re-align the patient position.
Choice C:The operator corrects the patient position manually when the detected shifts/rotations are above thresholds.
Choice D:All of above.
Question 4: Comparing to cone based robotic radiosurgery, MLC based robotic radiosurgery have which of the following advantages for large targets (such as prostates):
Reference:SU‐GG‐T‐143: MLC‐Based CyberKnife Radiotherapy for Prostate Cancer , J Fan1, J Li1, R Price1, L Jin1, L Wang1, L Chen1 and C Ma1 Med. Phys. 37, 3217 (2010); http://dx.doi.org/10.1118/1.3468533 SU‐E‐T‐603: Evaluation of MLC‐Based Robotic Radiotherapy , B Fahimian1, S Soltys1, L Xing1, I Gibbs1, S Chang1 and L Wang1 , Med. Phys. 40, 344 (2013); http://dx.doi.org/10.1118/1.4815031
Choice A:The MLC plans require less delivery time.
Choice B:The MLC plans require less MUs.
Choice C:The MLC plans generally have faster dose drop off.
Choice D:All of above.
Question 5: Which of the following statements about conformity index is NOT true?
Reference:Mayo, Charles S., Linda Ding, Anthony Addesa, Sidney Kadish, T. J. Fitzgerald, and Richard Moser. "Initial experience with volumetric IMRT (RapidArc) for intracranial stereotactic radiosurgery." International Journal of Radiation Oncology* Biology* Physics 78, no. 5 (2010): 1457-1466.
Choice A:The conformity index defined by ICRU 62 is calculated as the ratio of the volume enclosed by the prescription isodose surface to the volume of the PTV: CI icru=vrx/vptv
Choice B:Based on the ICRU definition, a CI of 1 would mean an ideal case where the prescription isodose surface only covers the PTV without any volume outside PTV.
Choice C:Conformity index defined by ICRU may not be directly correlated with PTV coverage.
Choice D:Smaller target volumes are generally associated with higher conformity index.
Question 6: Which of the following is NOT true about using a single iso modulated arc therapy (MAT) plan to treat multiple targets?
Reference:Clark, Grant M., Richard A. Popple, P. Edward Young, and John B. Fiveash. "Feasibility of single-isocenter volumetric modulated arc radiosurgery for treatment of multiple brain metastases." International Journal of Radiation Oncology* Biology* Physics 76, no. 1 (2010): 296-302.
Choice A:Using multiple non-coplanar single iso-center arcs can potentially improve the dose conformity compared to using only coplanar arcs.
Choice B:Using single iso MAT plan to treat multiple targets reduces not only the beam time but also the patient set up and imaging time compared to multi-iso treatments.
Choice C:It is important to correct for rotational errors in single iso multiple target MAT treatments, as it can lead to large set up errors especially for targets further away from the isocenter.
Choice D:The actual dose rate delivered during the arc rotation of MAT is always maintained at the highest dose rate for the beam energy specified to maximize its efficiency.
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