Interesting Article on Cyberknife Accuracy

[PaulW]

An article showing end to end accuracy of the Cyberknife
0.45mm +/- .09mm

http://www.scribd.com/peerEmed/d/21807945-The-Targeting-Accuracy-of-the-CyberKnife-as-Measured-with-EBT2-film-inside-a-Ball-Cube-II-film-Cassette-and-Head-Phantom

[Richard_T]

Thanks for the article, Paul.  It certainly conflicts with some studies that suggest that CK and GK have a similar +- 1mm degree of accuracy.  According to this study CK is between 1/3 and less than 1/2 of 1mm deree of accuracy.  Of course, there may be differences between machines when dealing with such a high degree of accuracy.  Since I received CK at Stanford, I feel just that much better about the treatment.

[akaltz]

Interesting article thanks a lot for posting!

[neuroma_racer]

got a direct link?
i cant seem to get the article to appear
thanks
jesse

[producer]

Im not able to view it either.. i think you must register first?

chris

[nftwoed]

Hi;

  I see the site owner has the control set at private.
  Seems Elekta boasts accuracy of + or - .50 mm. of their Perfexion GK. W/o many moving parts, I'm unsure how one could expect accuracy greater than this with a Linear Accelerator.
  Seems the real differences would be in the Dr's experience and physics principles of the two Tx modalities?
  I can't see an advantage of one over the other.

[PaulW]

Found a new link here
http://documents.scribd.com.s3.amazonaws.com/docs/50n7nq0bsw1eoe45.pdf?t=1329551876

The Cyberknife is essentially an industrial car assembly robot. These robots are mechanically accurate to around +/- 0.05mm

The difference between Gammaknife and Cyberknife is the registration of the position of the tumour is only done once with Gammaknife, and then Gamma knife relies on the rigidity of the headframe, and the fixed nature of the Gamma Knife machine.

Cyberknife gets its accuracy from a feedback circuit, the xray cameras, the infrared scanner, and positional sensors on the robot are all used to locate where the robot is in space. The bony structures of the skull and are fed back into the robot. The robot adjusts on the fly as to where your skull is. Its the feed back mechanism that Gammaknife lacks that makes Cyberknife similarly accurate as Gammaknife.

Probably the best analogy is to look at the human body. Through feed back from our eyes, and through our bodies we know where our are fingers are in space and we can position them very accuratly too.. Yet there is nothing rigid about our body, yet we can position our fingers to within tenths of a millimetre too..