Bear in mind that for the most part the real mechanical difference between IMRT and XRT is the detachable MLC or multi-leaf collimator, There does have to be some modifications and software updates to the LINAC. As Brian points out, it's not as simple as all that. Many regional treatment centers are boasting about adding IMRT to their bag of tricks but the RO's there may lack training and experience that will be found at a CCC (for the thousanth time - get an opinion from a CCC at the very least). Where and how to use it depends on the experience of the RO. My RO, for instance, irradiated many suspect areas besides just the tonsils. She is a world specialist in IMRT, even being recognized as such in the Castle book of the top 500 docs in the US. She was also one of the pioneers of IMRT usage and the CCC she teaches and practices at has been using it there for over 10 years. There are limitations for tolerance of rad or cGy levels passing through certain areas and these must be observed to obtain the full therapeutic effect balanced with tissue sparing as well. What Brian says is absolutely true about the long term studies. IMRT was first developed for prostate cancer (as well as many other H&N cancer treatments) so it's common use for H&N cancer is relatively new comparatively speaking. As far as the amount of radiation administered, I have to correct Brian here. Most everyone who receives radiation for H&N cancer gets the full lifetime dose regardless of whether it is IMRT or XRT. An analogy of the difference would be like repairing an electronic circuit. Some techs use a "shotgun" approach and replace all of the components in a bad circuit (or even an entire circuit board) and others find and replace the specific defective component. Sometimes no matter what a tech does to locate the specific component there is no choice but to replace all of the parts (or use the "shotgun" technique).
And it's not as simple as that. Even with XRT, they don't exactly just stick your head under a LINAC and zap it. They still have to define and use specific applicators, beam blocks and shadow trays for protective measures (i.e., minimizing exposure to the spinal cord).
I had to be my own advocate for getting IMRT as they had originally prescribed XRT even though I was a perfect candidate for it so yes I am passionate about telling persons to question the doctors about their treatment modality (whatever it is actually). As for whether or not IMRT is the best thing since sliced bread, personally knowing what I know now, I may have opted fot PBT instead (although it is SO accurate they typically supplement it with IMRT for prophylactic reasons (to insure safe margins) anyway - although probably not the full boatload of ionizing radiation). Last year MDACCC announced that they were committing 200M dollars to an entire new building for their PBT treatment center.
Those reading my posts about IMRT always have a disclaimer that "not all patients are candidates for it". The primary focus here, as Brian has said in so many words, is to survive the disease. Whether you have to carry a water bottle around, or other workarounds for zerostomia is a small price to pay for being on this side of the grass.
It would be nice to have 6-10 year long term efficacy studies for all of the emerging treatment modalities but it has to be balanced with state of the art (of course this includes chemotherapy as well). Probably this is why even the NCCN Oncology Practice Guidelines always recommend clinical trials wherever possible. We're all lab rats when you get down to it (but at least some of us are LIVE lab rats). It is a personal choice to make - use a treatment that is 10 years old or go for state of the art - is there REALLY a choice?!?!
Always push for the best institutions, doctors and treatments. You really don't get many chances with this disease. Mistakes, late and missed diagnosis are serious issues when it comes to cancer.
Another thing is what Glenn has pointed out in the past, there is a danger in stating absolutes here in regards to treatment. There is no "rubber stamp" treatment for this disease. All of us are different, respond differently and have much uniqueness in regards to our body chemistry, age, tumor type, location, staging and health habits. (sorry if it seems like I am paraphrasing you Brian)
