Users Manual Part 6
Clinical User’s Guide
IBA | 49-3|
Volume 1 - Treatment Session
|Part XI
- Patient Positioning and Alignment Aligning a Patient in the GTR
|
If the remaining device(s) is (are) at the Setup position when the last device reaches
the Setup position the hand-pendant beeps two times.
Verifying Patient Alignment in Setup Position
When the equipment is at the Setup position, the RTT may use the lasers, X-ray
tubes, or other patient alignment aids to verify the position of the target site with
respect to the isocenter.
As set forth in the treatment center’s procedures, the RTT may choose to:
Use the lasers (refer to section "Working With Laser Devices” on page 12-9)
Take orthogonal X-ray images (using adaPTinsight), following the procedure
applicable in the TR type. For detailed information, refer to section "Setting up
for Orthogonal X-ray Images in a GTR” on page 12-13.
Note: The lasers and/or light field are less accurate than the X-ray tubes and are
therefore used for initial positioning of the patient only; use the X-ray tubes for
accurate patient alignment.
Lasers and/or light field have a precision of ~3 mm; the precision of the X-ray based
method: is <1 mm.
If you are using a gating system, follow the procedure described in Section
“Triggering Procedure” on page 48-16. Check the X-ray triggering display (see
Figure 48-2) to see that the correct gating system has been selected.
CAUTION The nozzle lasers have been calibrated at 270° only. Lasers therefore
should be used for rough alignment only.
WARNING As a Radiation Therapy Technologist (RTT), do evaluate the longest
acceptable exposure time considering that taking the X-ray image may
finish after the end of the triggering cycle.
WARNING As a Radiation Therapy Technologist (RTT), check the gating signal with
respect to the presence of the X-ray beam. In case a mismatch occurs,
do NOT use the resulting X-ray images for patient alignment.