IMRT vs IGRT- Which does SRT better?

James, the Greenville Clinic does both, and they convinced me that the IMRT was better suited for the prostate bed area. Again, all things PC, sure you will get a variety of answers.

That's interesting, 142. Even though they use both machines, I was told that they could be more precise with the IMRT Tomalis machine. Now I see why we all go nuts making decisions.

James, this article did some good explaining:

http://www.cancerinfotech.com/igrt.asp

Hi James,

IGRT and IMRT are the same treatment. IGRT stands for "Image Guided Radiation Therapy". IMRT stands for "Intensity Modulated Raditaition Therapy". The image guided part is the placement of the "fiduciaries" (gold seeds) using a sonograph to locate the prostate. The seeds are then mapped using a CT scan. The mapped seeds are then studied by the radiation oncologist for planning the proper angles of attack. During the planning the desired dose is also calculated.

Now comes the IMRT part. The radiation beam is shaped to fit the prostate seed locations. This will deliver a varying amount of radiation depending on the location with the higher dosage to the area between the seeds and lower doses to the extremeties. Sort of like triangulation using the seeds as beacons. This is to place most of the radiation on the affected area and less to the surrounding tissue. Thus intensity modulation. The seeds also play a part in fixing the target of the beam prior to each session.

You will also be given "tattoos" during the intial CT scan to locate the seeds. The alignment beam will use these to position the table prior to each session. Prior to the radiation the seed locations are checked and then the treatment begins after all is in alignment. (image guided/intensity modulated) In my case the machine used was the Varian. The head rotated 360 degrees around me while I layed still on the table. It stopped at seven station and delivered the radiation for a specified dose at each location. The reason for the sevne locations is to limit the exposure to surrounding tissue and to get a more complete treatment of the targeted area.

There is a new Varian called Rapid Arc that does not stop. And I think there is an upgrade to that as well that allows for higher doses and fewer treatment session. You can google the Varian website and get all the information you need. There are other machines out there as well and all are similar. I looked at cyberknife but wasn'e right for me.

Sorry for the long post.

Don

When I was looking at it, i went with IMRT using my own reasoning. They had both IGRT and IMRT available, but IGRT is a precise point and shoot. Since I had the positive margins and seminal vesicles, I felt that being too precise could miss the cancer. I probably was not fully understanding of the technology, but a wider area being hit was better in my thoughts. In three weeks, I have the Calypso manufacturer at our UsTOO meeting. They will go over everything Calypso.

I'll let you know if I feel anything differently.

Tony

Many cancers require a more precise beam. I am certain that the intent is to minimize side effects. Precise delivery of radiation is a better way to go to do that. The question is if you are not precisely sure where a cancer is, then is a wider area beam best? I bit on that logic, but looking back I have no idea if that is really true. But I can say this, I have had 38 IMRT treatments adjuvant to surgery and hormone therapy and I have no SE's and my cancer is currently under control...

Tony

I am presently going through IGRT. Don described it very well. I watch them line up my 4 gold seeds by imaging just prior to the treatment each day on a monitor.

I don't see the argument in favor of a wider, less accurate beam. I would think that you can get the same intended coverage more precisely with IGRT, and it might be possible to avoid nearby organs in the process if they are not likely to be affected. The way I understand it, the shape of the target area can be more precisely designed using a combination of computer graphics, and daily imaging. I just don't understand why "less precise" could be better.
Jeff

Good evening, gentlemen.

I have participated in other threads of this forum, but this seems fitting at this juncture.

First, a summary of my status:

60 years old
Health otherwise: Excellent
April 2013 PSA: 5.7
Traditional biopsy in May 2013: Results benign
Urologists suspected prostatitis and subscribed 30-day regimen of Cipro
October 2013: PSA 5.3; active surveillance begins
December 2013: PSA still 5.3; patient inists on MRi;
January 2013: 3D MRI at Massey Cancer Center in Richmond, VA, shows suspicious area in transitional zone
Mid-January 2013: Final pathology report concludes there is only one tumor, moderate in size, Stage 2, located in the transitional zone at the right apex; Gleason Score: 7 (3+4), favorable intermediate risk

I have ruled out surgery for various reasons, chief of which it is not necessary given the parameters of my diagnosis. But now I am frankly in angst as to whether to go with IGRT/IMRT or the Calypso method for radiation.

Your thoughts?

Thanks --

Windsor11

My sincere apologies for the double posting. I was unaware of the rule. Never again, I promise.

Tony's post was 3.5 years ago

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