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Old 12-08-2008, 08:50 PM   #2
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Re: The Cyberknife? Has anyone used this form of treatment?

Originally Posted by Trace212 View Post
I was reading about it when I was at work today. What do you all know about it's effectiveness?

I just went to our friend PubMed, [url][/url], a site we can mention here because it is sponsored by the Government, and searched for " prostate cancer AND Cyberknife ".

I got 9 hits - not many for a prostate cancer option - as you would expect for a newly emerging kind of therapy, and the dates of the papers were interesting, showing that knowledge and interest is growing:

2003 - 1
2006 - 1
2007 - 3
2008 - 4

I looked at the abstract of only one paper because that looked the closest to what you were interested in. That 2008 paper gives early results for a Phase II clinical trial, and it's clear there are only a few years (about three) of followup results, which is a very short period. In other words, no one really knows how effective it will be in curing and controling cancer. However, the followup period does seem to me to be long enough to get a good feeling for side effect occurence and seriousness, and the early results look good. If you look over some of those abstracts, I'm sure we all would like to know your impressions.

Because CyberKnife is another form of IMRT, but with far more potential beaming aiming points (think aiming from any point in a sphere in contrast to aiming from any point in a circle), my hunch is that its long term results will be close to those from advanced IMRT.

CyberKnife is getting a big commercial push in my area. It competes, of course, with brachytherapy, IMRT, Tomo-therapy (and similar Trilogy), and proton beam. We are blessed with the curse of many options!

Here's something that puzzles me: external beam radiation, which includes CyberKnife, is divided up into sessions over time to give healthy cells a chance to recover, with the time periods being too short for recovery of cancer cells, which are more sensitive to radiation. Well, CyberKnife sharply reduces the number of sessions, with more radiation delivered in each, at least that's my impression. That isn't consistent with my notion of how the healthy cells tolerate the radiation (in other words, the healthy cells get a pretty hefty dose each session), but the early results for side effects look good, so apparently toleration is good. Maybe more aiming points is key. Anyone got that one figured out? I don't yet know much about CyberKnife.