Prostate Cancer: IMRT or Seed Implant
I was in the OR last Friday for a prostate implant procedure. We (i.e. the physics group) prepared the seed, did the proper QA, and set them on the table–ready for implant. Everything was set. After a short while, a nurse brought the patient into the room. He looked somewhat scared and panicked, as many patients do when they are brought into the OR. He was wondering what we were going to do with him. He probably remembered the pain he went through when his PVA was done with an ultrasound probe while he was awake. Shortly thereafter, the radiation oncologists and urologists, while chatting it up with each other, arrived in the room. The nurse and the doctors helped to place the patient on the table. The anesthesiologists prepared to put him under for the implant procedure.
After the induction of anesthesia, the patient was placed in the lithotomy position with his legs stretched up as if he were delivering a baby. The scrotum was kept away from the perineum by holding it up to the abdominal wall with a clear plastic tape sheet. The poor guy! Then a urinary catheter with contrast was inserted inside the urethra through the penis (yet again, the poor guy!) to help visualization of the urethra and bladder neck on ultrasound imaging. After preparation of the ultrasound probe, it was inserted into the rectum (all together now–the poor guy!) and attached to the stepping unit. The urologists moved the probe and the step up and down, left and right until we saw the image of the prostate gland in the ultrasound monitor screen. Ideally, the imaging plans during the implant procedure should match those of the pre-planning images. The image did not look identical to the pre-planned image. We all helped out with moving the probe and the step, and finally we matched the images. If the patient was awake, I don’t know what he would thinking. He would probably say, what are you idiots doing to my ass!?! Finally, the MDs took over and implanted the seeds by inserting the needles through a template and the perineal into the patient’s prostate gland. The patient normally gets on average 20 needles and 80 seeds. The insertion of each needle seemed very painful (thank god for anesthesia). With the help of the physics team, the needle was moved until the seed positions matched with the pre-treatment plan. However, an uncertainty always exists since the relative position of the seed and prostate changes (i.e. the prostate moves with peristalsis). Also, the seed may not be positioned at exactly right position. As a QA program, a couple of weeks after the implant, a post-plan CT is done on the patient and a post-plan isotope distribution is generated to evaluate the implant precision. I, however, think post-plan results are subjective and depend both on how the contours around the gland are drawn and on assuming the seeds are in the right positions. In addition to everything else, being in compliance with NRC or State licensing regulations is such work for physicists (e.g. receiving the seeds, storing the seeds, handling the seeds and taking inventory of seeds).
With all this in mind, what choice would I make if I get early prostate cancer? I would choose IMRT over seed implant. And these are my reasons, in a nutshell:
1- No pain in my ass.
2- No uncertainty of my treatment plan.
3- No need for radiation precautions for my family when I go home.
4- No one sees my ass and my scrotum fastened up to my belly.
5- No need going through pre-OR preparation.
6- For the physicists: no source handling.
7- For the radiation oncologists: not having a boss (the urologist) in the OR.
For the reasons above, I would choose 40 to 45 treatments–one fraction each day–with IMRT rather than implant.
As a physicist, this was just my personal view and my own choice for treatment for early prostate cancer if one day I was diagnosed. I wonder if other physicists (given your own first-hand observation and experience with these two treatment modalities) feel the same way when it comes to IMRT versus seed implant? However, the choice is yours to make.
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