Module 2

Unit 4: Quiz

Instructions: Answer the multiple choice questions below, then click on the "Process Questions" button at the end of the quiz to see your score in the adjacent message box. The program will not reveal which questions you answered incorrectly, only how many points you have. Go back and change your answers until you get them all right. (At that point the page frame will change to pink.)

Points to note: (1) Questions with one or more possible answers give a point for each correct answer, but also subtract a point for each wrong answer! (2) The program will not attempt to score your efforts at all if you have not tried at least half of the questions. (3) This quiz is for your own use only. No record of your progress is kept or reported to anyone.

1. The isocentre of a LINAC is...
...the point of intersection between the beam central axis (CAX) and the gantry axis of              rotation. 
...a point which is always 100 cm vertical beneath the source. 
...a specified point on the surface of the treatment couch. 
2. What are the planning objectives in treatment planning?
To deliver as much dose as possible to the target. 
To achieve a target dose uniformity of +7% and -5% relative to the ICRU reference point. 
To keep the dose to healthy tissue below the tolerance dose. 
3. For which of the following cases may a treatment with a single beam be appropriate?
A curative treatment of a deep seated tumour at a depth >12 cm. 
A palliative treatment of a relatively superficial lesion at a depth of <5-10 cm. 
4. In the “Carpet 4, Carlos”-Phantom, which of the following beam arrangements can lead to a box (square)     shaped high dose region in a transversal plane?
A 3 beam arrangements without wedges. 
3-field technique: Two parallel opposed beams with wedges plus a beam perpendicular to         them. 
4-field technique: Two opposing pairs at right angles (“4-field brick”). 
5. Which of the following criteria are preferable in the search for beam angles?
Beam directions where the PTV is close to the beam entry surface. 
Beam directions where OARs traversed by the beam are close to the beam entry surface. 
Beam directions for which the volumes of OARs traversed by the beams are minimized. 
Beam arrangements with all beams lying close together (small angles between the beams). 
6. For a coplanar beam arrangement with 4 equidistant beams (see illustration below), which of the MLC         apertures shown below is most appropriate?


Figure 1: Beam arrangement



A


B


C

A, leaving no margin around the PTV. 
B, leaving a uniform margin around the PTV to allow for the penumbra of the beam. 
C, leaving a margin around the PTV to allow for the penumbra of the beam, with this margin     being greater in the directions where the field edges of all coplanar beams coincide.  

      Points out of 9:

Return to top.

This consummately cool, pedagogically compelling, self-correcting,
multiple-choice quiz was produced automatically from
a simple text file of questions using D.K. Jordan's
dubiously original, but publicly accessible
Think Again Quiz Maker
of October 6, 2008.

<< Previous Page
 Top of the Page
 Next Page >>