Gamma Knife Treatment

[Joseph]

Hi All,    I have a question about Gamma Knife Treatment, is it true that there is a restriction in the size of the tumor for this procedure?

[GM]

I have heard two different opinions....one based on age and the other on size.   

I have heard that in younger patients (under 50) they really don't want to treat tumors that are 3 cm and over...and if the patient is over 50 they will consider it because of the recovery time with surgery.

I have also also heard that there has been some success with treating tumors that are 3.0 - 3.5....

All depends on the doctor...(radiologist).

GM

[ppearl214]

Hi Joseph,

There is an approx average of 3cm for radio treatments.  Some drs have been known to treat AN's larger than that but its very rare. Typically, 3cm is the cut off point.

Hope that helps.
Phyl

[leapyrtwins]

Just want to reinforce what Phyl said.  Most docs will not radiate an acoustic neuroma of 3 cm or larger.

Jan

[Vivian B.]

Hi there,

Just want to let you know that I also agree that most doctors will not go over 3cm. That's the first thing I was told when I was put on Watch and Wait.

Vivian

[Jim Scott]

Joseph ~

My "2¢" - The 3 cm limit for Gamma Knife treatment is based on the risk of the Gamma Knife treatment inducing temporary swelling of a large tumor that may result in hydrocephalus not present earlier.  Post-radiation swelling can also impact the trigeminal nerve ('5th nerve')  and cause problems you don't want.  However, I've read about AN patients with 3+ cm tumors receiving Gamma Knife treatment successfully.  Still, employing GK on a 3+ cm AN remains a relatively rare procedure due to the inherent risks involved that, in this litigious age, scare off doctors who might otherwise attempt to utilize GK on larger tumors.  So, for the present, most radiation techniques maintain a 3 cm limit on the size of the tumor they address.  Individual cases require individual judgment and in some cases, a doctor may attempt using the Gamma Knife treatment on a tumor larger than 3 cm, but, bottom line: most will not.

Jim

[Joseph]

Thanks everyone, for your comments.
Pretty much the same comments I received from you all were the same diagnosis I received from my surgeon. (Which is a good thing)
He is a good surgeon, but after two attempts to remove my tumor by surgery he was not successfull. He stated the tumor was connected to my brainstem and both times I had some severe swelling issues which caused them to abort early each time.
Now awaiting the third surgery as the surgeon refers to it as "the more aggressive approach" I am really sweating. See last time around the translabrynthe approach left me a mess which took eight months of healing and lots of pain medication before things started getting better. Now I still take pain medication daily...

[GM]

Joseph, sorry to hear about your difficult surgical past...sometimes doctors will radiate a tumor that has been partially removed...you may want to talk to them about that.

[opp2]

I spoke to Dr. Guha and he told me I was within the threshold for Gamma. My tumor is 2.9 in length but the 'bulb' is 1.9-2.0 cubed.

Are they measuring the mass of the tumour? Dr. Guha did. Told me it was 2.0 and mentioned that they don't include the tail.

Is this the general consensus?

[mk]

When evaluating the size for radiation treatment, the relevant dimension is the diameter of the spherical portion inside the CPA. The tail that extends inside the internal auditory canal does not count, since it contributes minimally to the volume.
Radiation oncologists evaluate the volume, which for a perfect sphere would be equal to pi*diameter^3/6. Since most of the times an AN looks like an ellipsoid, they will use the formula pi*(diameter1*diameter2*diameter3)/6.
Based on the size of your AN Nikki you should be within the limits acceptable for radiation.
In the medical literature there are quite a few cases of ANs larger than 3cm being treated, but these reports come mostly from Japanese groups. As everyone else has mentioned here in North America generally the cut off is 3 cm, since beyond that the potential for detrimental side-effects due to swelling increases dramatically. The absolute cut-off I have seen in the literature in terms of volume is about 30 cm cubed, which corresponds to a size of about 3.5 cm in diameter.

Joseph, your situation seems very tricky. I am sorry you already had to endure two difficult surgeries. I remember of one or two more people on the forum with unsuccessful surgeries that had to be repeated. It seems to me that for such a difficult case you may want to seek the most expert surgeons available.

Marianna

[yardtick]

Just a FYI for the Canadians on this forum.  Hamilton's Juravinski Centre is getting a Gamma Knife machine.  It was featured on the local news. 

Anne Marie

[Vivian B.]

Hi Anne Marie,

Just to add on treatment in the Canadian System. I heard that Cyberknife is coming to Ottawa in a few months.

Joseph,

I am sorry for your experiences. Everyday there is new advances for these type of tumours and the Specialists are aware that cases are very individual. You may want to get different opinions just to be more at ease. Hope everything goes well. My prayers are with you.

Vivian

[opp2]

Well I'm off for my consult tomorrow at TW. I'm feeling kind of nervous actually. Don't know why. Too much waiting maybe.

I hope to  know by January 20 on my flight home what I'm going to do. I've been relatively sidetracked in thinking about myself lately which is good, but the distraction is my husband who just found out he needs gall bladder surgery. Soon. He's at the docs right now.

I hope he gets the surgery soon, as he's been in a tremendous amount of pain. Poor man.

[mk]

Nikki,

good luck with your consult. Go armed with questions and insist (I have noted that depending who you see there, sometimes they tend to be kind of vague). Let us know how it goes.

Marianna 

[varun_bansal90]

Hello Sir

Please review my Acoustic Neuroma case as below and advice if Gamma Knife or CyberKnife will work in this case. Summary of the MRI Report :

Right CP Angle Cystic Schwannoma (Acoustic Neuroma)
Size : 33x30x23 mm
Patient Age : 24 Years
15-20% Hearing Left in Right Ear (Wants to be preserved if possible)

I have read much about Gamma Knife and Cyber Knife which have proved to be of excellence and minimal failure rate and damage to facial nerve. How can I be 100% sure to go for this radio treatment instead of the complicated surgery. Also as per the report is it advisable ?