GK question for those who've used it

[theshawn65]

Hello, 48 yr old male recently diagnosed (Monday) with 2.4cm AN on my right side. Have seen local specialist in Cincy (Dr. Ravi Samy) but he's a surgeon so obviously he recommends surgery and says the tumor is too large and radiation would be risky. I'm obviously early in my research into the various options to deal with this but I have some questions.

A. Where are the best places to get GK and how did you go about getting opinions? I have the MRI CD I can send out to other doctors but what's the procedure for doing so?

B. Where to find best info on case histories, side effects etc. of this GK option?

C. Main differences between GK and CK?

Wife, Sis, friends want me to just get the surgery and get it out as soon as possible but that's easy for them to say when they aren't the ones whose head will be opened up. Plus my only symptoms are tinnitus and hearing loss the last 8-10yrs I've obviously had it. (Based on doctors estimate from when I first had hearing loss appear)

Thanks for any help you can provide.

Shawn

[nftwoed]

Hi;
   UPMC, University of Pittsburgh Medical Center ( Dr. Kondziolka ) has an excellent reputation, as do others. I would call and ask to speak to his secretary as to how to get a second interprative reading of the CD.
   For comparative procedural purposes of irradiation types: http://www.irsa.org/  It might be remembered this site may have a commercial interest, but nevertheless, good info.
   CK is delivered in fractions, usually 3 - 5 by a linear accelerator. However, the overall difference of outcomes between the two, is minimal. GK has a constant cobalt source of radiation and uses 201 intersecting beams of radiation to tumor target with a movable collander. IOWs, it's unlikely to miss, have cool spots, or warm spots.
   If your hearing loss is moderate to profound, I wouldn't expect to keep much whether surgery, or irradiation given that size AN.
   2.4 cm. is a pretty goodly size AN and I would be more concerned about maintaining good facial nerve function. I think radiation may give you an edge, that regard. GK is very accurate ( to .5 mm ) and doesn't have the added radiation of x-rays aligning the equipment to target.
   Please listen to your own heart and not relatives in choosing your Tx. Your own belief system and comfort level of your choice and Dr. likely improves the Tx outcome.
   Those who have had radiation are probably better able to tell you more and may have their own favorite Tx providers.

[theshawn65]

Thank you very much for your opinion. And don't worry, I'm not allowing anyone else to dictate my choice. I was a little annoyed with the Dr. I went to on Tuesday who basically proceeded as though I was just going to go along until I spoke up and said "if I choose this route" to which he backed up a bit and said "well yes, it's not urgent and I need to take time and decide."

They then showed me the MRI I brought in and the size, etc. Which I already knew to some degree because I looked at it myself and used a ruler to get a rough estimate, knowing the image was a bit magnified I guessed 2.5cm so I wasn't far off. When transferred to the woman who was in charge of insurance negotiations she had a "Authorization for Surgery" type form on her screen she wanted to start filling out (this annoyed me again) until I said I'm not making that decision one day after finding out I have this. She said "well I'm going to download your CD and mail it back to you then if that's OK". I said fine but after leaving felt I should have just waited for her to download it. I did transfer a copy to a thumbdrive as a backup though in case they or whoever I send it to "misplace" it.

My AN is larger than average for sure, but after researching the last couple days CK or GK certainly isn't out of the question as surgical neurologists would suggest. I'm a bit pissed at the doctor for shutting that option off when it's not his specialty and I bet where he in the same situation he would seriously consider GK or CK himself. I'd put money on it.

I'm not scared of the tumor itself or the thought of it remaining in me doesn't bother me as long as it doesn't grow larger and create more health issues. I have tinnitus and hearing loss, that's it, and they both have their positives at times lol. So if that's the worst it will probably get going with GK or CK vs. opening my head up and the risks that involves I'm leaning towards it at the moment. But less than 1 week into diagnosis I'm in no hurry to decide by next week.

Anyway, thanks for your input it's appreciated.

[rupert]

This link will get you started on info for UPMC.

http://www.neurosurgery.pitt.edu/centers-excellence/center-image-guided-neurosurgery/gamma-knife

Once they get the CD it's usually about 2 weeks for an opinion from them.

[PaulW]

Both CK and GK are highly accurate.
The New Cyberknife M6 has the ability to shape the beam creating a very homogeonous dose
Gamma Knife cannot shape the beam and creates hot spots.

Most GK treatments are to the 50% isodose line which typically means the maximum dose is double the margin dose.
So if you got 13 Gy at the 50% isodose line, some of the tumour got 26 Gy.
This may have consequences for your hearing or facial nerve if they happen to pass through the middle of a hot spot.
So far this is unproven and fortunately nerves tend to run along the edge and not right in the middle.

With CK a single dose at 13 Gy to the 80% isodose line meaning the maximum dose is 16.25 Gy

The higher maximum dose of radiation to the tumour for AN's with GK may result in a different clinical outcome than CK.
CK's ability to treat reducing hot spots may have an advantage.

CK can also fractionate which may be an advantage.

Some studies suggest that hearing preservation appears to be related to the amount of radiation received by the cochlear and is not related to tumour size.

Results to date between CK and GK are very similar. One you dont need a head frame, and the other you do.
The new Cyberknife M6 is certainly a better machine than the older CK. Will it provide better results than the latest GK Perfexion?
Worth asking!

[robinb]

See link to my treatment journal below.

Dr. Kondziolka left UPMC almost a year ago for NYU Langone. UPMC GK program still run by his mentor; Dr. Lunsford.
Links below.

http://neurosurgery.med.nyu.edu/patients/our-divisions/gamma-knife%C2%AE-center/what-gamma-knife%C2%AE?CSRT=15203179362838974050

http://www.neurosurgery.pitt.edu/centers-excellence/center-image-guided-neurosurgery/gamma-knife

For CK, Dr. Chang at Stanford will do the same.

http://med.stanford.edu/profiles/neurosurgery/faculty/Steven_Chang/

You can send your MRI to both and they will review it at no charge. Info in their web sites or PM me if you'd like more info about my experience.

[luttman]

I had GK in February 2012 by Dr. Kondziolka. I just had a followup MRI and hearing test etc. Tumor has shrunk from 1.8 X 1.6 to 1 X 0.8. My hearing is stable and I have virtually no balance issues. Some tinnitus that seems to be stable. I have no regrets and was very pleased with everyone at UPMC. I am with Dr. Niranjan now. I think he is taking most of Dr. Kondziolka's former patients.

[phantagrae]

I'm having fractionated treatments and from what I understand, it's a version of GK, not CK.
When my ENT first suggested FSR, I assumed it was CK, but the neurosurgeon I saw as part of the consultation process told me that it was not CK.   

At any rate, I'm having 30 lower dose treatments, wearing a full mask that holds my head in place, and they do use an x-ray to aid in positioning before the machine starts irradiating me.  The machine is a big sort of disk that rotates into different positions and angles, and the bed turns as well.

My doctor and I decided on the 30 fractions specifically to try to protect my hearing and minimize side effects.

[nftwoed]

Hi;
  GK, even fractionated, does not use a face mask. The treatment then, must employ a linear accelerator. 30 Txs and a face mask, sounds like FSR. You'll receive a total, higher dosage in the hearing sparing attempt; Say, maybe 50 gy?
   Best wishes in this. It seems worth a try in hearing preservation.

I'm having fractionated treatments and from what I understand, it's a version of GK, not CK.
When my ENT first suggested FSR, I assumed it was CK, but the neurosurgeon I saw as part of the consultation process told me that it was not CK.   

At any rate, I'm having 30 lower dose treatments, wearing a full mask that holds my head in place, and they do use an x-ray to aid in positioning before the machine starts irradiating me.  The machine is a big sort of disk that rotates into different positions and angles, and the bed turns as well.

My doctor and I decided on the 30 fractions specifically to try to protect my hearing and minimize side effects.

[Jim Scott]

Phantagrae ~

I also believe that you are receiving FSR which is what I underwent back in 2006.  The mask is confining but one adjusts and the 'sessions' were relatively short.  I experienced no 'side effects' whatsoever and according to subsequent MRI scans, the FSR (following debulking surgery on a 4.5 cm AN) was very successful. 

It is a conservative approach that worked to good effect for me, as I hope it does for you.

Jim

[Echo]

Definitely take some time to review all your options and definitely get more than 1 or 2 opinions. 

At 2.5cm your tumor is not larger than average but it is at a point where if it continues to grow your options change a bit.   My tumor was 1.8cm one year ago when diagnosed - flash forward one year and it is now 2.4cm.  I took the entire past year to research and make a decision while monitoring things very carefully. I honestly did not expect the tumor to grow the way it did.  I have some hearing loss and tinnitus with headaches and balance issues becoming a problem.  My neurosurgeon told me at 2.4cm I could still have Gamma Knife (single session).  If the tumor became larger than 2.5cm then Fractionated Radiation is recommended. I opted for Gamma rather than surgery primarily because of the overall risks I would face with surgery.   I've had problems in the past with anesthetic during a 2 hour surgery, so facing an 8 hour Retrosigmoid surgery was not appealing. Obviously there were other factors I considered in making my decision and I can tell you it wasn't easy.  My Gamma treatment will be in 5 weeks, so the next phase of this process will start for me. 

There is a wealth of information here and some wonderful people to share experiences with.  Good luck!

Cathie

[theshawn65]

Thanks for all the info everyone! Very much appreciated.

Having never been under or opened up in any way surgically I'd prefer not to unless absolutely necessary.

It seems the Dr. Samy I consulted with in Cincinnati last Tuesday spoke at the last ANA Symposium in 2011 held there so I'm assuming he is well versed in AN should I choose surgery as an option. When I asked how many AN surgeries he had done he said 300-400 and he's also a F.A.C.S surgeon which I believe is a good thing. Then again assuming can cause problems. I'm not opposed to traveling elsewhere, but if someone 30-45minutes from my home is just as good (at least in my mind) as someone 5 hours away I'll choose the closer option most likely.

Just went through the 2011 ANA presentation on radiation and how they kill brain tumors which was interesting. If it can just stop any future growth that would be enough for me, I could care less if it's there the rest of my life, just don't grow!

[theshawn65]

After seeing another 2011 ANA presentation by a Dr. Ronald Warnick on radiation and how it kills tumors I just placed a call to his office to schedule an appt. Anxious to learn if GK or CK is an option for me because if it is I'm pretty sure I'm going to go this route. My wife won't like it if I choose this option but....hopefully after sitting with me consulting with an expert in this field she may change her mind.

I'll keep posting my thoughts and decisions.

Thanks ANA for this site! Time for a donation I think.

[nftwoed]

Hi;
   I believe max to the cochlea is not to exceed 3.8 gy. Beyond that, ciliary damage can occur. Who could know?

Both CK and GK are highly accurate.
The New Cyberknife M6 has the ability to shape the beam creating a very homogeonous dose
Gamma Knife cannot shape the beam and creates hot spots.

Most GK treatments are to the 50% isodose line which typically means the maximum dose is double the margin dose.
So if you got 13 Gy at the 50% isodose line, some of the tumour got 26 Gy.
This may have consequences for your hearing or facial nerve if they happen to pass through the middle of a hot spot.
So far this is unproven and fortunately nerves tend to run along the edge and not right in the middle.

With CK a single dose at 13 Gy to the 80% isodose line meaning the maximum dose is 16.25 Gy

The higher maximum dose of radiation to the tumour for AN's with GK may result in a different clinical outcome than CK.
CK's ability to treat reducing hot spots may have an advantage.

CK can also fractionate which may be an advantage.

Some studies suggest that hearing preservation appears to be related to the amount of radiation received by the cochlear and is not related to tumour size.

Results to date between CK and GK are very similar. One you dont need a head frame, and the other you do.
The new Cyberknife M6 is certainly a better machine than the older CK. Will it provide better results than the latest GK Perfexion?
Worth asking!

[Cheryl R]

Dr Samy did his fellowship at Univ of Iowa which was way back with my first AN surgery in 2001.     He did the open and shut of the surgery and Dr Gantz did the tumor.    I went on over time to have NF2 and more surgeries and know more Fellows.           I have come across him at 3 AN symposiums also.     He is  one that yes would recommend surgery since he does surgery.           Anyway if you do choose surgery then he would be fine to stay on with.      One does have to remember that many do fine past surgery and are on here not for long and leave past recovery.   More with issues post op do stay and can make it look like everyone has severe issues post op.      Everyones recovery is different so is hard to know ahead how it will go.         
                              I wish you well!              Cheryl R