What is the difference between Linac/ Cyberknife , Gamma KNife, Novalis

[Cheryl]

I keep seeing all these different machine/ treatments....My doctor said they use Linac, but I don't see anyone refer to this,  has anyone had experience with this.  I understand it to be  a one time treatment of a higher dose of radiation.  YOu have the helmet type thing screwed to your head and all that...has anyone had this treatment??  thanks  Cheryl. 

[Mark]

Cheryl,

the variety of differently named machines and terminology certainly can be confusing. I will attach a link that I think you will find helpful as it differentiates the various radiosurgery systems

http://www.cksociety.org/PatientInfo/radiosurgery_stereotactic_technology_comparisons.asp

In answer to your specific question, there are principally two types of radiation used in all radiosurgical machines. Gamma Knife was the original machine and uses radioactive cobalt to generate the radiation it uses. all newer generation machines utlize a linear accelerator ( LINAC) where X rays are produced instead of gamma rays. My understanding is that there isn't any meaningful difference on either's effectiveness in killing the AN. LINAC is generally preferred because it is "cleaner" and doesn't require the disposal of radiaoctive cobalt by the hospital.

All systems need to secure the head in order to achieve the highest targeting accuracy. GK always requires a frame to be attached to the skull and can only do one dose treatments as a result. other machines utilize either a frame for one dose or some other head restraint to performed staged or fractionated treatments. Typically, these systems sacrifice some degree of accuracy in this process. CK differs in that in uses active imaging of the tumor during treatment and reacts to any changes in postion instantly. Thus it can do either one dose or FSR protocols using only a mask restraint and still achieve frame based system accuracy

Mark

[Cheryl]

Mark, thank you for your information and the link.  It was very helpful!  Cheryl

[rmaddal]

Hi Cheryl-I was going to try to go into the various procedures but I see Mark beat me to it. So I will just tell you briefly about my experience with the Novalis system. It needs the frame attached to the head, but it's not a big deal. For anyone going the frame route, just make sure that the local anesthetic has taken effect before letting the neurologist proceed. I've heard from people who didn't and, yes, it's very painful if the area is not numb.  After all, he's tightening down screws through the skin to the skull. I believe sometimes they think the local takes effect immediately. Once it does, all you feel is a little pressure. Kinda of feels like you're wearing a hat one size too small. They also gave me a sedative shot that had pain relieving properties, and that helped a LOT  . I thought I would be claustrophoic when they bolted my head to the table for the CT scan and for the procedure itself, but I just closed my eyes and it really was nothing. I would rather do the frame than the head mask as I have read and was told that with the frame the accuracy is within 1mm, but with the head mask it can be 1-2mm, more for an uncooperative patient. If you're coloring, a mm or two off is no big deal, but when they're shooting radiation into your head, I think that would make a difference. Besides, read through some of the posts here and you will see some people have had their own miserable experiences with the mask.