Brachytherapy--an example of a urological minimally invasive robotic procedure

A review of the application of urological robots to the prostate is given, together with an examination of the conventional brachytherapy procedure for insertion of radioactive seeds to treat prostate cancer. The specification and design of a robotic system is provided, which can position a series of needles and radioactive pellets in accordance with a pre-operative plan. The needles can be withdrawn automatically, leaving the seeds in position.A separate motorised system is used to position a trans-rectal ultrasound (U/S) probe, which can be used to continually monitor the seed placement. The robot program can be updated intra-operatively if the U/S image shows this to be necessary. The demonstrator system has been demonstrated in-vitro using a variety of gel and animal tissue phantoms. The resulting robot performance shows this to be a viable approach.