Brainlab RT/RS Hardware User's Manual page 93

QUALITY ASSURANCE
Steps
Hardware User Guide Rev. 4.9 RT / RS Stereotactic Hardware
Remove the Phantom Pointer tip and securely replace it with the ball pointer tip. The
tungsten sphere at the tip simulates the isocenter and should align with the lasers.
• Brainlab provides two different tungsten sphere tips of diameters 2.9 mm and 5 mm.
5. Brainlab recommends using a 7.5 mm collimator and the 5 mm ball pointer tip.
• The sphere generates a non-irradiated area on the film. This projection of the tung-
sten sphere must always be completely inside the exposed film area for every gantry
and table position.
Prepare a light-proof 8" x 4" strip of ready-pack film by marking off 8 areas, numbered
6. 1 to 8 on the envelope. This is for exposure of the film in 8 combinations of gantry and
couch angles (see Page 94).
Position the film for each exposure in the film holder with the area to be irradiated in
7.
the circular field.
8. Fasten the screw on the film holder to fixate the film during each exposure.
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