 |
The ultrasound volume study: Cross-sectional ultrasound scans
taken at 5-mm intervals |
Ultrasound-guided Prostate Volume Study
The first technical step to performing the brachytherapy procedure is called the volume study. This is an ultrasound study done with the patient in the implant position. A series of prostate ultrasound pictures are made at 5mm intervals from top to bottom, encompassing the entire prostate volume, and each one of these captured in the brachytherapy-planning computer. The radiation oncologist then draws a contoured target volume around each ultrasound picture on the computer, with potential target coordinates appearing as a computer-generated dotted “grid” pattern over the ultrasound pictures, referenced by letters on the X-axis and numbers on the Y-axis (FIGURE 8).
After the contouring process has been completed, the computer then reconstructs the contours into a 3-dimensional prostate planning target volume, incorporating the targeting grid within that volume. The radiation oncologist and supporting physics staff then interact with the computer, to create a customized radioactive seed pattern that creates a customized radiation dose volume, which wraps tightly around the prostate target volume (FIGURE 9). The final plan is displayed 3-dimensionally for final review before it is approved (FIGURE 10). This information is then transferred to a “seed map” that is carried into the operating room to direct the radiation oncologist when the brachytherapy procedure is then done.
Immediately after the volume study session, the RMG nursing staff gives the patient his preparation instructions, and schedules the brachytherapy procedure, the pre-brachytherapy admitting examination, and the post-brachytherapy CT scan. In fact, one of our nurses typically spends up to an hour with the patient at this stage, to help them understand and navigate all of the logistics of the brachytherapy procedure. The nursing staff develops a relationship with the patient at this point that continues until well after the procedure, until the brachytherapy treatment-related side effects have settled. Prostate brachytherapy is a team effort, attended by a dedicated group of physicians, nursing and physics personnel.
<< BACK I NEXT >>
3D Conformal Radiotherapy (with IMRT)
High Dose Rate Prostate Brachytherapy
CyberKnife Radiosurgery for Prostate
|
