MDCB exam questions with answers

MDCB exam questions with answers
|\ |\ |\ |\




(T/F) In SAD techniques, the beams are weighted at dmax
|\ |\ |\ |\ |\ |\ |\ |\ |\



point. - CORRECT ANSWERS ✔✔False
|\ |\ |\ |\ |\




(T/F) In SAD techniques, the beams are weighted at target
|\ |\ |\ |\ |\ |\ |\ |\ |\



center. - CORRECT ANSWERS ✔✔False
|\ |\ |\ |\ |\




(T/F) Isodose or PDD data can be used directly for a
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



patient, without any modification. - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\



✔✔False


(T/F) TAR concept is usually not used with accelerator
|\ |\ |\ |\ |\ |\ |\ |\ |\



photon beams because the dose in free air is not well
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



defined due to conceptual difficulties - CORRECT
|\ |\ |\ |\ |\ |\ |\



ANSWERS ✔✔True |\




(T/F) TAR can be measured directly or derived from the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



PDD data. - CORRECT ANSWERS ✔✔True
|\ |\ |\ |\ |\




(T/F) In general TAR increases with increase in depth. -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔False |\ |\

,(T/F) At orthovoltage beam quality's (>about 0.5 mm Cu
|\ |\ |\ |\ |\ |\ |\ |\ |\



HVL) BSF increases with an increase in energy. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\



ANSWERS ✔✔False
|\ |\




(T/F) TAR decreases with increase in field size. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



ANSWERS ✔✔False |\




(T/F) Exit dose calculated using the standard PDD tables
|\ |\ |\ |\ |\ |\ |\ |\ |\



would give the correct exit dose. - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\



✔✔False


(T/F) The off axis ratio is the dose at any point in a plane
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



perpendicular to the central axis to that of the dose on |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



the central axis in that plane. - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\



✔✔True


(T/F) At a phantom depth of 10 cm, on the central axis,
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



scatter contribution to the dose is more for an accelerator
|\ |\ |\ |\ |\ |\ |\ |\ |\



photon beam compared to a Co‐60 beam. - CORRECT
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



ANSWERS ✔✔False |\




(T/F) At any depth, the scatter contribution to total dose
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



decreases with increase in incident photon energy -
|\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔True |\ |\

,(T/F) Cross‐beam profile can give information regarding
|\ |\ |\ |\ |\ |\ |\



field size, physical penumbra, beam flatness, and
|\ |\ |\ |\ |\ |\ |\



symmetry. - CORRECT ANSWERS ✔✔True |\ |\ |\ |\




(T/F) A wedge in motion is known as a dynamic wedge. -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔False |\ |\




(T/F) The energy fluence of the photons falls according to
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



the inverse square law of distance with the source
|\ |\ |\ |\ |\ |\ |\ |\ |\



position as the origin. - CORRECT ANSWERS ✔✔True
|\ |\ |\ |\ |\ |\ |\




(T/F) Photon beams have a finite range in a patient. -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔False |\ |\




(T/F) In the AAPM TG‐51 protocol, the electron beam
|\ |\ |\ |\ |\ |\ |\ |\ |\



quality is specified by E0 , the mean energy of the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



electrons incident on the patient. - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\



✔✔False


(T/F) The field size dependence of the PDD of an
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



accelerator photon beam is very much influenced by the
|\ |\ |\ |\ |\ |\ |\ |\ |\



electron contamination of the beam - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\



✔✔True
|\

, (T/F) Scatter generally decreases PDD. - CORRECT
|\ |\ |\ |\ |\ |\ |\



ANSWERS ✔✔False |\




(T/F) Half blocked tangential breast treatments can be
|\ |\ |\ |\ |\ |\ |\ |\



easily accomplished with independent jaw movements. -
|\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔True |\ |\




(T/F) One of the advantages of a dynamic wedge over a
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



physical wedge for treatment is that there is no change in
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



beam quality across the field size. - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



✔✔True


(T/F) The tail of the electron beam depth dose distribution
|\ |\ |\ |\ |\ |\ |\ |\ |\



is due to some long‐range electrons in the beam. -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔False |\ |\




(T/F) Electron beams have a finite range in medium. -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔True |\ |\




(T/F) Low‐energy electrons are more easily scattered
|\ |\ |\ |\ |\ |\ |\



compared to high‐energy electrons. - CORRECT ANSWERS
|\ |\ |\ |\ |\ |\



✔✔True
|\




The beam output (cGy/min) measured in air for a Co‐60
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



unit increases with field size mainly due to:
|\ |\ |\ |\ |\ |\ |\