Improvement in dosimetry of ultrasound-guided prostate implants with the use of multiple stabilization needles.

The use of three stabilization needles for ultrasound-guided permanent prostate implants results in better dosimetric coverage of the prostate, all other variables being equal. This technique prevents rocking motion of the prostate when anterior needles are inserted and thus improves accuracy of seed placement and shortens the length of the procedure. On post-implant CT-based dosimetric evaluation, the three stabilization needles technique provides better coverage, with the prescription isodose line encompassing 95% of the target volume compared to 90% for the implant utilizing two stabilization needles. Further improvements in the technique are currently under investigation, with the goal of consistently achieving truly "conformal anatomical prostate brachyradiotherapy."