ANA Discussion Forum

Treatment Options => Radiation / Radiosurgery => Topic started by: rodneyd on July 19, 2017, 09:56:30 am

Title: Cyberknife vs Gammaknife
Post by: rodneyd on July 19, 2017, 09:56:30 am
I have been on W & W for three years.  Getting ready for my annual MRI this morning.  But my balance has worsened since my last MRI and I am seriously considering radiosurgery. 

The Hospital I am going to has both Cyberknife and Gammaknife machines.  I am wondering if anyone could recommend one over the other, and maybe the reason why?  I fully understand this is my decision, but I was hoping for some thoughts from other AN patients who have been faced with this decision. 

Thank you,

Title: Re: Cyberknife vs Gammaknife
Post by: ANSydney on July 19, 2017, 05:06:01 pm
Between Gamma Knife and Cyber Knife I would go for Gamma Knife. It's specifically designed for head treatment (Cyber Knife can treat any part of the body). Also, Gamma Knife has more studies in relation to ANs and has been around longer than Cyber Knife . Just my opinion.

Beyond that, would you consider going another 6 months to see if the latest disturbance is permanent or temporary? Right down symptoms weekly, don't rely on memory!

Let us know your MRI results.
Title: Re: Cyberknife vs Gammaknife
Post by: rodneyd on July 20, 2017, 10:06:58 am
Very happy with the MRI results, my AN has barely grown, if at all.  The last MRI was 13 months ago, so this is a good sign.

I was prepared to go for the radiosurgery, but now I am waffling.  I can still hear out of the affected ear (although much less than the other ear).  My tumor appears to be growing very slowly, and as I am now 74 I am hoping to not have to deal with it.

My biggest symptom has been, and continues to be, balance issues.  I have started a walking program to see if that will help my overall stamina, but too soon to tell on that.  I have had success with balance therapy in the past, and will resume these exercises shortly. 

I am also concerned about potential impact to my facial nerve.  My left eye seems to be giving me some difficulty, not seeing as well, difficulty with my eyelid control.  No tingling or numbness, so not sure if it is related to my AN or just something else.

I will investigate the Gammaknife more fully after your suggestion. 

Thank you for your response,

Title: Re: Cyberknife vs Gammaknife
Post by: ANSydney on July 20, 2017, 05:20:03 pm
As you've alluded, vestibular therapy looks better for you than radiosurgery. Your eye problem may be related to your vestibular system. When your head moves, it's up to your vestibular system to detect this and provide information for eye tracking purposes. If you find that your vision becomes poor with head movements, such as walking or running, it's vestibular related. Eyelid control is a concern as that looks like facial nerve related.
Title: Re: Cyberknife vs Gammaknife
Post by: PaulW on July 23, 2017, 02:56:52 pm
There is very little difference between the machines and it's more a personal choice.
With CK you do not need a headframe so it is more comfortable.
CK verifies the the tumour location before shooting a beam of radiation.
So the chance of getting it wrong are reduced as this human element is removed.
GK does create radiation hotspots, which means the centre of the tumour receives around 24-26 GY while the perimeter receives 12-13.
With CK the centre of the tumour receives 15-16.25GY and the perimeter receives 12-13GY
This reduced radiation dose may lead to better nerve outcomes, but remains unproven.
On the other hand CK does spread a little more low dose radiation around than GK.
Which might cause other issues. There are advantages and disadvantages of both machines.. neither is showing statistically an advantage over the other
Title: Re: Cyberknife vs Gammaknife
Post by: rodneyd on July 24, 2017, 01:41:57 pm
Thank you to all of the responses to my question. 

I do have an update based on a phone call to my neuterologist (sp?) today.  Amazingly, after 13 months, my tumor has actually decreased!  And fairly significantly as well.

In June, 2016, the tumor was 9.6 x 10.7 x 8 mm.

In July, 2017 the tumor was  8.2 x 8.6 x 8 mm. 

I am not 100% sure about this, but the volume of the  tumor has decreased by 256 mm3 so I think this is about a 31% decrease.  Can anyone confirm that this is the right way to measure it?

Needless to say, I am thrilled with the result, and the only thing I can attribute the decrease to is the 81 mg of baby aspirin I take on a daily basis.  That and the prayers of a lot of good people! 

I started the baby aspirin regimen about two years ago in response to a study done by the ANA that showed that this amount of aspirin tends to retard tumor growth.  But in my case, it looks like it not only retarded it, but it is beginning to shrink it.

I still am concerned about the eyelid involvement, and the neuterologist said the tumor is only about 1 mm from the facial nerve, but she recommended I wait for another year and have another MRI.  In the meantime, I am going to continue to take the 81 mg of aspirin and keep on praying!

Title: Re: Cyberknife vs Gammaknife
Post by: ANSydney on July 24, 2017, 05:10:00 pm
Rod, congratulations on your shrinkage. You're now the third person on the forum that have had shrinkage. (LisaM and Derek are the other two. I hope to join the shrinkage club one day!)).

I wonder how many have observed for a coupe of years to see if there was shrinkage? That would tell us the chance of shrinkage.

You are correct that by volume, your tumor has shrunk 31%. However, it has not decreased by 256 mm3, but rather 135 mm3. The 256 mm3 would only be the case if your tumor was a rectangular prism.

For an ellipsoid, the volume is 4/3*PI*r1*r2*r3. So, converting to cm, in your case, the volume has gone from 0.430 cm3 (small) to 0.295 cm3 (even smaller).

Aspirin is an interesting subject. I'm also on a quarter tablet of aspiring per day regime (75 mg, which is effectively the same as 81 mg). I think I'll start a thread to prospective register those on aspirin therapy and see over the years what the outcome is.

I'm looking forward to your June 2018 MRI results. Congratulations once again.

Title: Re: Cyberknife vs Gammaknife
Post by: Citiview on July 25, 2017, 05:31:34 am
We were diagnosed around the same time. I read somewhere that the average period of time on WW is four years. I think sometimes it takes that amount of time to determine if there is actually growth and if so how much. I think that the measurements do vary so it's hard to tell.
I think the good news for you is it seems stable and even may have decreased. There is some research about the aspirin regimen.
Given your age and the stable nature of the tumor I would feel good if I were you.
Title: Re: Cyberknife vs Gammaknife
Post by: ANSydney on July 25, 2017, 05:05:18 pm
I don't think W&W is for just four years. It's a life long process of observation. Sure, after four years you can decrease the frequency of MRI to as much as every 5 years, but I wouldn't stop MRIs after four years of no growth.
Title: Re: Cyberknife vs Gammaknife
Post by: rodneyd on July 25, 2017, 10:24:33 pm
Hi all,

I had posted information about the aspirin treatment regimen three years ago, but I think it is worth repeating.

The Information is in the June, 2014 Edition of the Acoustic Neuroma Notes newsletter.  Page 4.  It was about a study conducted by Mass Eye and Ear, Harvard Medical School, MIT, and Mass General Hospital.  The study demonstrated that one 81 mg aspirin "correlates with halted growth of vestibular Schwannomas (AN's)".

"Our results suggest a potential therapeutic role of aspirin in inhibiting vestibular schwannoma growth" stated Dr. Stankovic, the study's author.  It is true across all ages and genders as well.   

The ANA consulted with their Medical Advisory Board about the potential use of a daily baby aspirin related to acoustic neuroma growth mentioned in the article.  It was the Medical Advisory Board's opinion that this is an option to consider in inhibiting the growth of AN's.  They do recommend consulting with a physician before starting the aspirin regimen, and to keep track of the growth of the tumor via regular MRI's.

I have been taking the 81 mg of aspirin on a daily basis for the last three years.  Whether this is what caused my tumor reduction is anyone's guess.  But I figured it couldn't hurt, plus aspirin has beneficial effects for heart and stroke issues, so I just thought it was worth the small cost of the aspirin. 

For what it is worth, even though my AN has decreased in size, I haven't noticed any change in my symptoms.  In fact, my wife thought I was getting slightly worse.  I am pinching myself and wondering if the measurements are really true, but I was assured that the best radiologist (or whatever they call themselves when they read MRI's) on staff had looked at the MRI's and made the measurements.  So I am just going to be happy for a few days or weeks!  Yea!

Title: Re: Cyberknife vs Gammaknife
Post by: ANSydney on August 08, 2017, 04:43:23 am
Rod, how are your balance issues going? Also, have you had a hearing test recently?
Title: Re: Cyberknife vs Gammaknife
Post by: rodneyd on August 08, 2017, 04:12:22 pm
Hi ANSydney,

My balance issues remain.  It is so hard to tell whether they are worse or the same or better.  It is probably more like the same, which I would expect given the length of time the AN has had to damage my balance nerves in the affected area.  About a month ago, I started walking 1 - 1 1/2 miles per day to improve my stamina and I feel better just for that. 

I should have had a hearing test done at the same time.  I do still have hearing in the affected ear, one of the reasons I chose to go to W & W. 

I have no idea if any of these new symptoms are related to my AN, but in June, on a plane flight home, I experienced severe shooting pains in my forehead on the AN side.  I have flown a lot and have never had anything even remotely like this pain.  Eventually, it stopped but in the last few days I have noticed a very slight recurrence of the pain, in the same area.   I attributed this to maybe a sinus infection that I was unaware of, but could it be related to my AN?  Who knows.

My left eye still seems to be bothering me. Scratchy and irritated.  I visited the eye doctor and he told me about some over the counter drops that did help, but did not end the painfulness.     Not content with the good news about the shrinkage of the AN, I am now worrying that my facial nerve is involved.  The Radiologist told me that my tumor was only 1 mm from the facial nerve, so it may irritate it occasionally.  Again, who knows?

We just broke a record in the Seattle area for the number of days without rain.  52 and counting.  This comes after one of the wettest winter/springs on record. 

Title: Re: Cyberknife vs Gammaknife
Post by: ANSydney on August 08, 2017, 05:42:22 pm
Rod, hard to have an AN not 1 mm away from the facial nerve. The cochleovestibular nerve and the facial nerve both travel through the internal auditory canal and are close to each other. If you're interested in learning more, take a look at

The reason I ask about balance and hearing is because, as you've observed, an "improving" balance nerve from shrinkage can introduce balance issues. This is a good sign. However, you also need to look at hearing loss, in particular PTA (pure tone average) to get the complete picture. To me, a squeezed cochlear nerve will degrade hearing. The degree of hearing loss is related to the amount of squeezing. (Note, you can still have hearing loss that is not due to mass effect.) The vestibular nerve on the other hand will cause imbalance if your tumor is growing or shrinking. Therefore loss of balance is not necessarily a sign of a growing tumor, but rather a tumor that is changing in size.

As we now, one way to improve balance is to cut the vestibular nerve. Things get much worse first up since you've lost a sensor, but eventually central compensation takes over and your balance is better. Here's one example, of where a stable vestibular nerve (zero information) improves balance.

In summary, a hearing test with significantly deteriorating PTA is probably a sign of a growing tumor, but balance issues is probably a sign of a changing tumor.

Walking is a good idea. So is looking around. Give your brain lots of varied input and it will learn. It will feel terrible at first, but things will get better (without the need for surgery!).
Title: Re: Cyberknife vs Gammaknife
Post by: Freelander on November 01, 2017, 10:24:05 am
This is an interesting conversation.  I am 68 and was diagnosed two+ years ago with an AN on the left side that was 6mm x 6mm.  As of May 17, it was 10mm x 6mm.  Been taking aspirin at 325-650 mg/day for years.  My neurotologist is at MA Eye and Ear, and he supervises the author of the study on the effects of anti inflammatories on AN growth, and had encouraged me to continue taking the aspirin.  I had been taking it all along due to a cardio condition.   Just want to add that while we have been w&w for over 2years, the lesion has grown despite taking aspirin (we are all different) and that while my symptoms had been the usual suspects: hearing loss, tinnitus, facial tingling, with mild balance issues, the symptoms have worsened over the past 6 months, especially the balance and tingling. Hearing has steadily declined, though somewhat still functional.   For the first time I am considering an intervention.  My doc, he is the only one I have seen about this, is suggesting SRS and i have an appt with an MGH radiation oncologist next week.
If anyone has suggestions about radiation v surgery, or a specific radiation approach over another, e.g. GK, CK, proton therapy, intensive modulated radiotherapy, etc. I would be grateful to hear from you. I would also like to know of places and physicians who are known to be among the best in treating AN.  MA Eye and Ear and MGH are highly regarded, yet I know I need to talk to others before finally deciding.   I am willing to travel.  BTW, thanks for the insights that the tumor changing size either larger or smaller can affect balance.   I am an avid outdoorsy type and for the past 11 years found a deep passion for endurance cycling that I really need to continue.