1. Which of the following is true for low-level radioactive wastes, such as tubing, and swabs contaminated with Tc-99m?
ANSWER: D – They can be stored until reaching background levels and then disposed of with other medical trash.
2. A shielding design for a diagnostic or therapy installation (such as a Cyberknife), when there is no restriction on the beam direction, must:
ANSWER: A – Consider all walls as primary barriers.
3. Which of the following statements is true? A neutron _____.
ANSWER: E – Has a mass approximately equal to the proton mass.
4. Far which of the following particles can one observe a Bragg peak in the depth-dose curve?
ANSWER: B – Protons.
5. CT or Hounsfield numbers arc linearly related to:
ANSWER: C – Linear attenuation coefficient
6. A patient is treated with 6 MV photon fields of 15 and 30 cm height, respectively, at100 cm SSD. In order to match the fields at 5 cm depth, the gap on skin should be:
ANSWER: A – 1.1cm