Implant Quality

Following the placement of radioactive sources inside the prostate gland, the patient will undergo an imaging procedure to evaluate implant quality. This is usually done within the first month following the procedure and will provide the most accurate picture of the radiation dose being delivered to the gland. This follow-up evaluation is done for two reasons:

1. To determine if there are any low dose or high dose regions in the gland. Low dose regions might suggest the need for additional treatment (a follow-up seed implant or external beam radiotherapy). High dose regions might signify that physicians should carefully watch for complications.
2. To evaluate the overall quality of the implant team’s technique. This analysis can lead to changes or improvements in the implant procedure. Learning from experience is what sets a top quality program apart.

CLICK TO ENLARGE 
 
Figure 1. Example of a post plan. Slices through the prostate from base (Z = 9) to apex (Z = 24) are shown. The urethra and rectum are also displayed. The colored lines show different radiation dose levels.

CLICK TO ENLARGE
 
Figure 2. Improvement of implants with continued experience. V80 is depicted for the first 130 implants.

 
Figure 3. This is an example of CT and MR fusion. The MR image shown below was used to determine prostate, urethra and rectum location (shown in yellow). The source locations (and the dose distribution) were extracted from a set of CT images, where the sources (shown in blue) are readily identified.

CLICK TO ENLARGE
 
Figure 4. Another example of image fusion, but this time the prostate borders, urethra, and rectum (shown in yellow) were determined from ultrasound and displayed on the CT image shown above. The CT image was used to locate the sources and create the dose pattern.

CLICK TO ENLARGE
 
Figure 5. This is a unique display of dose along the center of the urethra. Image slice numbers (in green, 9 to 33, base to apex) are shown at the top, distance along the urethra is shown at the bottom. Urethra dose is shown at the left.