Question 1: Small field is defined as: |
Reference: | Das IJ, Ding GX, Ahnesjö A. Small fields: Non-equilibrium radiation dosimetry. Med Phys 2008; 35:206-215 |
Choice A: | Any field smaller than 3x3 cm2. |
Choice B: | Field that is comparable to focal spot of the machine. |
Choice C: | Fields that are smaller than detector. |
Choice D: | Depends on beam energy due to lateral range of secondary electron. |
Choice E: | Where ratio of detector reading is equal to ratio of dose. |
Question 2: Microdetector is defined as: |
Reference: | Das IJ et al, TG-106 Med Phys 2008; 35:4186-4215. |
Choice A: | Any solid state detector. |
Choice B: | Only diode detector as size is small. |
Choice C: | Small volume ion chamber. |
Choice D: | Diamond detector. |
Choice E: | Detector with sensitive volume in order of micron. |
Question 3: Dosimetry of small field should be preferably performed with: |
Reference: | Azangwe et al, Med Phys 41, 072103 (2014); Benmakhlouf et al, Med Phys 41, 041711 (2014) |
Choice A: | Small water-equivalent detectors (MicroLion, MicroDiamond, Plastic Scintillators) |
Choice B: | Edge detector. |
Choice C: | Pinpoint. |
Choice D: | MicroMosfet. |
Choice E: | Any micro-detector. |
Question 4: Microdetectors are suited for dosimetry due to:
|
Reference: | Azangwe et al, Med Phys 41, 072103 (2014)
Das IJ et al, TG-106 Med Phys 2008; 35:4186-4215
Kamio & Bouchard; Phys Med Biol 2014;59:4973-5002
|
Choice A: | Pion, ion recombination effect is negligible. |
Choice B: | No dose perturbation. |
Choice C: | Extremely small volume. |
Choice D: | Large signal to noise ratio. |
Choice E: | Bragg-Gray cavity theory concept is valid. |
Question 5: What is correct bias (voltage) applied to microdetectors to collect reading?
|
Reference: | Das IJ et al, TG-106 Med Phys 2008; 35:4186-4215 |
Choice A: | 300 volts and higher. |
Choice B: | 150 Volts. |
Choice C: | 10 Volts. |
Choice D: | 0 volts. |
Choice E: | Depends on microdetector. |
Question 6: Correction factor k fclin, fmsr
Qclin, Qmsr
defined in IAEA protocol for small field accounts for:
|
Reference: | Alfonso et al, Med Phys 2008; 35:5179-5186. |
Choice A: | Photon fluence perturbation. |
Choice B: | Spectral changes (stopping power). |
Choice C: | Secondary electron perturbation. |
Choice D: | Combinations of stopping power and various perturbations. |
Choice E: | Unity for microdetector. |