Prostate Cancer: IMRT or Seed Implant

April 25, 2009 · Written by ·

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.

Posted in: Op-Ed ·Tags: no tags


5 Responses to “Prostate Cancer: IMRT or Seed Implant”

  1. Harvey L. Kliman on July 24th, 2009 9:44 am

    Question: What are your thoughts on IMRT vs Cyberknife i.e. 43 more or less coplanar exposures vs 5 fully 3D exposures with a higher dose per exposure but less than 1/2 the total dose?

  2. medphysphd on July 24th, 2009 11:43 pm

    2- No uncertainty of my treatment plan.

    You must know something I don’t :) I’d say there is always plan/delivery uncertainty, maybe just not on the order of prostate brachy.

    Don’t forget (robotic) surgery and protons…

  3. on July 26th, 2009 9:05 pm

    Good question, Harvey–I was in fact discussing this very issue with a friend not too long ago. I posted a response to your comment as a new blog post (since it is a rather lengthy answer!). Please refer to the blog post titled “Prostate Seed Implant, IMRT or SBRT for Prostate Cancer Treatment?” on

    Medphysphd–you are right–I just meant the plan/delivery uncertainty is greater with Prostate Seed Implant than with IMRT.

  4. Aria HDR Implant Sullivan on October 27th, 2011 7:49 pm

    Thanks for posting. My husband has been considering an HDR implant to help with his prostate cancer. This has been very helpful. Thanks again!

  5. JK on June 23rd, 2012 8:32 am

    Great post

    1. The “pain in your ass” with any EBRT will be there, just much more slowly than an implant, and without anesthesia :-)
    2/3. taken care of with an HDR implant to some degree, if offered in the area.
    4. although your scrotum wont be fastened to your belly, let me assure you that your ass will be seen many a time on the MD side of things during/before/after EBRT
    5/6. no way around the Pre-OR prep or source handling, but again if HDR / prodecure done in department instead of OR that can make it slightly better
    7. Practice dependent – many places have a great relationship and having them in there often is good for patient care.

    Another thing to consider is cost, as we move into the era of healthcare reform (Billing vs actual costs of doing these things)

    Many patients who work / lead active lifestyles prefer implants to external beam, and because they have differing side effect profiles, individual patients should discuss this in depth with their physician.

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