| Question 1: TG-218 recommends using gamma analysis criteria of 3%/2mm and a 10% threshold for patient specific-IMRT QA measurements. It notes that tighter criteria might be helpful for: |
| Reference: | Miften et al. Tolerance Limits and methodologies for IMRT measurement-based verification QA: Recommendations of AAPM Task Group No. 218. Med. Phys. 45(4): e54-e83, 2018. |
| Choice A: | Competency testing for medical physics residents (set-up accuracy). |
| Choice B: | For measurements for SBRT techniques. |
| Choice C: | To detect specific systematic errors in delivery. |
| Choice D: | To help determine tolerance levels. |
| Question 2: Which statement describes the sensitivity and specificity of current measurement-based IMRT QA methods? |
| Reference: | Kry SF, Molineu A, Kerns JR, et al. Institutional patient specific IMRT QA does not predict unacceptable plan delivery. Int J Radiat Oncol Biol Phys. 90(5):1195-1201; 2014. |
| Choice A: | Poor sensitivity and poor specificity |
| Choice B: | Poor sensitivity and good specificity |
| Choice C: | Good sensitivity but poor specificity |
| Choice D: | Good sensitivity and good specificity |
| Question 3: Let’s compare the simulated beam-by-beam EPID measurement with induced errors to calculated 3D doses in CTV and various organs at risk, which one of the following statements is wrong? |
| Reference: | Nelms B, Zhen H, Tome W. Per-beam, Planar IMRT QA Passing Rates Do Not Predict Clinically Relevant Patient Dose Errors. Medical physics, 38(2), 1037-44; 2011. |
| Choice A: | There is a strong correlation between Gamma metric and DVH difference-based metrics. |
| Choice B: | There is a large rate of false negatives (you think the plan is ok but it is not). |
| Choice C: | The larger clinical errors happen for higher IMRT QA Gamma passing rates. |
| Question 4: Which of the following is NOT a possible advantage of log-file based IMRT/VMAT QA: |
| Reference: | Stanhope C, Drake D, Liang J, Alber M, Sohn M, Habib C, Willcut V, Yan D. Evaluation of machine log files/MC-based treatment planning and delivery QA as compared to ArcCHECK QA. Med Phys. 45(7): 2864-2874; 2018.
Rangaraj D, Zhu M, Yang D, Palaniswaamy G, Yadddanpudi S, Wooten O, Brame S, Mutic S. Catching errors with patient-specific pretreatment machine log file analysis. Practical Radiation Oncology. 3(2): 80-90; 2013. |
| Choice A: | Reduced set-up time at the linac for measurements. |
| Choice B: | No thresholds needed in the analysis process. |
| Choice C: | No concerns about saturated detectors. |
| Choice D: | Can easily acquire log files prior to and during treatment. |
| Question 5: Plan complexity can be characterized using different metrics, including the MCS score. Which of the following statements is true? |
| Reference: | Agnew C, Irvine D, McGarry C. Correlation of phantom-based and log file patient-specific QA with complexity scores for VMAT. JACMP. 15(6): 204-216; 2014.
McNiven A, Sharpe M, Purdie T. A new metric for assessing IMRT modulation complexity and plan deliverability. Med Phys. 37(2): 505-15; 2010. |
| Choice A: | PSQA results depend upon the MCS score. |
| Choice B: | Log-file analysis results do not depend on the MCS score. |
| Choice C: | MCS score is dependent on treatment site/technique. |
| Choice D: | A and B |
| Choice E: | A and C |
| Question 6: What percent of pixels passing a 3%/3mm gamma criteria is typically an appropriate threshold to correctly flag most unacceptable plans. I.e., what percent of pixels passing should be used? |
| Reference: | Kry SF, Glenn MC, Peterson CB, et al. Independent recalculation outperforms traditional measurement-based IMRT QA methods in detecting unacceptable plans. Med Phys. 46(8):3700-3708; 2019. |
| Choice A: | 85% |
| Choice B: | 90% |
| Choice C: | 95% |
| Choice D: | 99% |
