| Question 1: Which of the following could be considered a “blackbox or closed†system in a radiation oncology department? |
| Reference: | AAPM TG 135: Quality assurance for robotic radiosurgery and AAPM TG 148: QA for helical tomotherapy: Report of the AAPM Task Group 148 |
| Choice A: | Varian Halcyon |
| Choice B: | Accuray Tomotherapy |
| Choice C: | Accuray CyberKnife |
| Choice D: | Elekta Aqua |
| Choice E: | All of the above |
| Question 2: Who is ultimately responsible for accurate IT system functionality in radiation oncology, including software systems used to treat patients that are considered “black boxes†|
| Reference: | Siochi, R. and el., Information technology resource management in radiation oncology, JACMP, Volume 10, Number 4, Fall 2009 |
| Choice A: | IT directors |
| Choice B: | Administrators/CEO |
| Choice C: | Medical Physicists |
| Choice D: | Radiation Oncologists |
| Choice E: | Therapists |
| Question 3: What references do physicists currently have for testing “black box†systems in radiation oncology? |
| Reference: | AAPM TG 135: Quality assurance for robotic radiosurgery and AAPM TG 148: QA for helical tomotherapy: Report of the AAPM Task Group 148, IEC 60601-2-1, Particular requirements for the basic safety and essential performance of electron accelerators in the range of 1MeV to 50MeV. |
| Choice A: | AAPM Task Group Reports |
| Choice B: | IEC Standards |
| Choice C: | A only |
| Choice D: | A and B |
| Choice E: | None of the above |
| Question 4: What was the top failure mode of the Halcyon commissioning process in one recent study? |
| Reference: | Teo et al. Application of TG-100 risk analysis methods to the acceptance testing and commissioning process of a Halcyon linear accelerator. Med. Phys. 46 (3), March 2019. Table 2
The process step of setting the SSD at the start of beam profile measurements and comparison had the top failure mode of an error in determining the non-isocentric SSD. This failure mode has an occurrence scores of 6.0. The high occurrence score is associated with the frequent encounters of difficulty in setting up the SSD in the absence of a light field, ODI, and laser in the gantry bore. Potential failure pathways were: 1) hardware limitation, that is, the source and imager is only orthogonal to the water level at isocentric distance, and 2) scanning mechanism of tank blocks the view of chamber in lateral MV images. The effects of this failure mode were that the measured profiles differ from vendor recommended data and that more manpower required for reaching consensus on data. |
| Choice A: | Error in setup due to multiple options provided for reference dosimetry by the manufacturer |
| Choice B: | Error in determining non-isocentric SSD (e.g., for SSD = 90 cm) from lateral MV image |
| Choice C: | Machine temperature and water flow rate err |
| Choice D: | Error in locating beam scanning detector on MV images |
| Choice E: | Poor MV image quality |
| Question 5: What was the top failure mode of the Halcyon acceptance testing process in one recent study? |
| Reference: | Teo et al. Application of TG-100 risk analysis methods to the acceptance testing and commissioning process of a Halcyon linear accelerator. Med. Phys. 46 (3), March 2019. Table 1.
During acceptance testing, the process step of dosimetry verifications has the largest RPN value. The potential causes are: 1) human error (lack of awareness), 2) human error (insufficient experience in physics), and 3) unclear instructions; incomplete guidance from vendor. |
| Choice A: | Failure in dose reproducibility with gantry angles |
| Choice B: | Machine temperature and water flow rate error |
| Choice C: | Error in locating beam scanning detector on MV images |
| Choice D: | Failure in dose reproducibility with factory-calibrated MU |
| Choice E: | Error in determining SSD from MV images (e.g., inter and intra-observer error) |
| Question 6: Related to machine QA, what might Machine Learning algorithms provide in the future? |
| Reference: | Kalet et al. Quality assurance tasks and tools: The many roles of machine learning. Med. Phys. 2019 Feb 15. doi: 10.1002/mp.13445. [Epub ahead of print].
The use of machine performance and regular QA measurement logs to develop a model that would predi |
| Choice A: | Specification of which QA tests to perform for Black-box machines |
| Choice B: | Comparison of the machine uptime |
| Choice C: | Implementation strategies for Black-box machines |
| Choice D: | Design requirements for 3rd party QA tools |
| Choice E: | Prediction of machine performance issues |
| Question 7: 3rd party access to data from the Treatment Delivery System enables which of the following to be completed in an independent fashion? |
| Reference: | www.sunnuclear.com, www.iba-dosimetry.com, www.ptw.com, www.standardimaging.com, radimage.com, van Elmpt et al, Radiother Oncol. 2008, 88(3) 289-309; Eckhause et al, Med Phys 2015, 42(10): 6074-83 |
| Choice A: | Daily, Monthly, and Annual QA tasks |
| Choice B: | Pre-treatment patient QA |
| Choice C: | In Vivo Dosimetry |
| Choice D: | Research by clinicians |
| Choice E: | All of the above. |
| Question 8: What approximate percentage of a lack of independent checks was sited in an IAEA review of Radiotherapy accidents from 1974-2000? |
| Reference: | IAEA Safety Report Series No. 17, Lessons Learned from Accidental Exposures in Radiotherapy, IAEA, Vienna, 2000 |
| Choice A: | 25% |
| Choice B: | 55% |
| Choice C: | 75% |
| Choice D: | 95% |
| Choice E: | None of the above |
| Question 9: Since the Halcyon system only has unflattened beams, the typical definition of beam flatness for conventional linacs is not used. What is the method by which the flatness of the Halcyon system is characterized? |
| Reference: | For FFF beams, Fogliata et al.
TG-142 |
| Choice A: | IEC 60976 method for flatness of square x-ray fields |
| Choice B: | Ratio of max and min dose in the central 80% of a 10 cm x 10 cm field |
| Choice C: | Ratio of the dose at a specified off-axis distance to the central axis dose at the largest field size |
| Choice D: | Standard deviation of dose values sampled at 5 mm radial distances for a 40 cm x 40 cm field |
| Question 10: For reference dosimetry of the Halcyon treatment beam which one of the following statements is relevant? |
| Reference: | The reference to high dose per pulse affecting Pion is mentioned in McEwen but Kry et al measured the effect for the TrueBeam system from Varian Medical Systems and found that the recombination factor is not outside the bounds recommended by TG51 [5]. |
| Choice A: | Special care must be taken since the shape of the dose profile of the Halcyon system necessitates the use of very small ion chambers with high-Z electrodes. |
| Choice B: | The Pion recombination factor is significantly larger for Halcyon than that of conventional linacs due to the high dose per pulse associated with its FFF beam. |
| Choice C: | Because the ring gantry prevents the use of a water phantom, water-equivalent solid phantoms are recommended for absolute dosimetry. |
| Choice D: | Measurement of beam with or without lead (Pb) foil has a minimal (~0.1%) effect on the beam quality conversion factor. |
