For diagnosed non bleed AVM survivors like myself at some point we need to make a decision on how or if we would like to treat it.
After reading Hanne's excellent post Photons vs Protons, Whats the difference? I decided to throw in my two dimes worth about how I made my decision on choosing Gamma-Knife vs Cyber-Knife.
For what it's worth I would like to add my opinion on Gamma-Knife vs Cyber-Knife (the differences of the technology) as these were the two SRS options that were considered to be a good fit for my "deep compact AVM" (1 square inch). If I were to put all 4 Neurosurgeon that I interviewed in the same room there would probably be a lengthy debate on which was best for me including embolization + craniotomy, but I chose Gamma-Knife based on the facts that made sense to me.
We don't know what the future will bring or whether the newer technology will overtake the old, but I had to make a decision for my case and this is what I came up with in two months that helped me chose.
Cyber-Knife:
Invented in the early 1990's less than 20 years in service with some good results. I could find only limited data due to the fairly new technology. The Cyber-Knife was designed to target lesions anywhere in the body. A newer technology allows a less invasive face mask vs the scalp fixed halo with the Gamma-Knife that fixes the head in a more ridged position. However the Cyber-Knife tracking system exposes the patient to multiple x-Ray's throughout the session each time the beam is repositioned to make sure the beam is on target. The Cyber-Knife has only one focused beam which must be fired from one angle at a time thus lengthen's the time of the session or may require more than one visit depending on size.
Gamma-knife:
Invented in 1968 with decades of great results and improvements in recent years. The Gamma-Knife has approximately 200 narrow focused beams that can target more of a lesion at one time than the Cyber-Knife. The Scalp fixed halo is not a pretty thought but to my understanding is more accurate vs the time delays in between the Cyber-Knife re-position x-Ray's. Multiple focused beams allows less time on the table and less likely to need multiple sessions to irradiate the entire lesion.
I'm not putting down the Cyber-Knife as I think it's an amazing machine which dose have a few advantages such as it can reach more angles than the Gamma-Knife can. It can also reach lesions anywhere in the body and amazingly track lesions in the lungs while the patent is breathing.
According to my research a typically Cyber-Knife has 150 to 250 angles per session. I understand that each of those beam's would have to be a slightly stronger to get the same dosage as what the Gamma-Knife delivers in one session. My Gamma-Knife treatment on 9/14/2010 lasted 1hr and the table moved about 6 times. Approximately 10 mins of 200 beams x 6, that's 1,200 angles I hope they got it all :) Time will tell if the Cyber-Knife will be the new Gamma-knife but as far as I'm concerned they are both awesome.