A robust quality assurance prostate brachytherapy QA program is essential to
ensure accurate image-guidance and dosimetry calculations. The CIRS Model 04a,
used in conjunction with the CIRS Model 053G Ultrasound Prostate Phantom, offers
a complete solution for implementing a QA program specific to transrectal
ultrasound used for guidance of prostate brachytherapy as recommended by AAPM
Task Group 1281.
The Model 04a enables users to check key imaging parameters such as depth of
penetration, axial and lateral resolution, distance measurements, area
measurements, volume measurements and geometric consistency with the
treatment-planning computer.
When scanning towards the top of the phantom, a partial grid of wires
appears. This N-shaped pattern should align with the electronic grid that
appears on your screen to ensure correct vertical and horizontal distance
measurements. This target group can also be used to assess axial and lateral
resolution of the system. Five cross wires are embedded within the phantom to
determine if the probe is being retracted by the stepper system by the specified
distance.
Turn the probe 60 degrees to the right or left to visualize and measure the
volume of three different calibrated objects, one of which is non-spherical.