Mounting the Gantry Fixture on the Holder
Gantry Fixture for Elekta, 1: Gantry Fixture, 2: Advanced Holder, 3: Gantry Mount
(In this example, the Gantry Fixture for Elekta is used for illustration. However, this step is the same for
Siemens and Varian fixture.)
- Place the Gantry Fixture on top of the Holder.
- Attatch the legs of the Gantry Fixture to the Holder with the provided screws (4 screws per leg, 16 total). If any screws are missing, please contact IBA Dosimetry for replacements (see Section 9.1).
Note: The mounting parts (circled below) in the fixture can have two orientations. They can be interchanged by loosening the screws of the mounting parts and fix them in the other orientation.
Left: Orientation 1 (Top view); Right: Orientation 2 (Top view)
For myQA Patients applications, it is recommended to assemble the Gantry Fixture in Orientation 1. This
places the Y-axis of the detector in the inline direction.
Mounting the Gantry Mount on the gantry
Elekta
- Rotate the gantry to 180°.
- Locate the white plastic hole (i) and the accessory ring (ii) of the gantry.
- Hold the Gantry Fixture upside down and align the fixture bolt (f1) to the white plastic hole (i). Ensure that the 4 steel nuts (f2) are inside the gantry accessory ring (ii), and then place the gantry fixture down.
f1: Fixture bolt to be inserted into the white hole of the LINAC
f2: Steel nuts for positioning
f3: Fixation clamps for fixing the fixture to the LINAC accessory ring
Please note, there is little room for movement in the crossline direction as the fixture bolt fits snugly into the white plastic hole. However, there is noticeable room for movement in the inline direction. - Turn the two knobs to fix the two clamps (f3-a) far away from the fixture bolt simultaneously. Then fix the other two clamps simultaneously (f3-b). Check that all 4 clamps grip to the ring properly.
- Rotate the gantry to 0°.
Siemens and Varian
- Rotate the gantry to 0°.
- Insert the two rails of the fixture into the accessory mount of the LINAC until you hear a clicking sound. The light on the side of the accessory mount should turn to green if the mounted device is properly locked.
- Tighten the fixation clamps to fix to the LINAC accessory ring. See examples below:
Examples: SDD 100 cm Varian (1); Siemens (2)
Mounting the device in the Advance Holder
- Loosen the four side knobs (h1), move the clamps (1) so that there is enough space for the detector and the build-up plates to be inserted, and then lock the fixation knobs again.
Place the detector all the way into the holder. - Unlock the clamp on both sides by pulling out the red knobs and turn them to the unlock position (2).
- Slightly pull out the red knob and turn and push it into the locked position; the pin should be inside the device ventilation opening (see the drawing below)
3: Device ventilation opening, 4: Pin - Place the detector all the way into the holder.
- Fix (but not firmly) the two side screws (h3) to push the detector to the other side so that the detector is parallel to the inline axis.
h1: Side knobs for adjustment clamps, h2: Detector locking pins, h3: Side screws, h4: Bottom knobs, h5: Window, h6: Upper back clamps, h7: Lower back clamps.
Please note, the build-up plates are not mounted in this example.
CAUTION: ENSURE THE DEVICE IS LOCKED IN PLACE
Ensure that all safety clamps and the knobs are fastened, especially the four bottom knobs (h4). Otherwise, the device will fall out when the gantry is rotated.
Fix the four bottom knobs (h4) tightly to lift the device Only when the MatriXX is lifted to the upper surface of the frame, the distance of the device housing surface to the isocenter is exact 100 cm or 76.2 cm SDD. Confirm with the laser alignment to the side markers on the detector through the windows (h5) on left / right / back sides. Ensure the security pins (h2) are locked into place. - Rotate the gantry slowly to check if the detector is locked properly.
Mounting build-up plates
Up to 5 cm build-up is mounted on the top of the detector, which is fixed by the four clamps (h1) (The fixture is removed for better illustration).
- Loosen the two knobs (h6-a), removing safety clamps (h6-b), so that it is open wider for inserting the build-up plates.
- Loosen the four knobs (h1-a), moving safety clamps (h1-b) up so it is high enough that the build-up
plates can be placed under them. - Place the plates on the top of the MatriXX from the rear side of the holder, Lock the plates from above with the four clamps h1 by moving the safety clamps (h1-b) tightly on the plates and fixing them with the four knobs (h1-a).
- Place the safety clamps (h6-b) back so that the two clamps block the build-up plates from falling out from the backside. Fix (h6-b) by tightening (h6-a).
CAUTION: BUILD-UP PLATES FROM OTHER MANUFACTURERS
Build-up plates made of RW3 and PMMA from other manufacturers can be used if they fit into the holder and can be properly locked.
CAUTION: LOCK THE BUILD-UP PLATES PROPERLY
Ensure that all clamps h1 and h6 are tightened; otherwise, the plates may fall out when the gantry is rotated.
Aligning the XY Table
XY Table 1: XY table security clamps, 2: X-adjusting knob, 3: Y-adjusting knob, 4: X-Scale, 5: Y-Scale
- Loosen the four knobs of the XY table security clamps (1) before adjusting the XY Table.
- Adjust the X and Y directions by turning the X and Y-adjusting knobs (2 and 3), respectively. There are two printed scales (4 and 5) on each side of the table. The knobs are graded in 0.1 mm increments; one full turn is one millimeter. Maximum adjustable length is ± 10 mm.
If the knob becomes loose, insert a 2 mm hexagonal screwdriver into the hole on the side of a knob and tighten the screw. - Tighten the four knobs of the XY table security clamps.
CAUTION: DO NOT TURN THE XY ADJUSTING KNOBS WHEN THE FIXTURES ARE LOCKED.
Loosen the four additional fixtures before adjusting the XY Table. Otherwise, the adjustment mechanism of the XY Table may get damaged.
CAUTION: DO NOT DISASSAMBLE THE ADVANCED XY TABLE
Do not dismount the top part of the advanced XY Table. If so, a realignment of the mechanics is required to ensure the correct positioning with the required precision.
Remove the detector from the gantry
In general, the procedure to remove the detector from the gantry is the reverse order of the procedure to mount the detector and instead of tightening but loosening the screws:
- Remove the build-up plates from the holder.
- Remove the detector from the holder.
- Remove the Gantry Fixture together with the holder from the gantry.