MED BIZ | Gamma Knife Kills Neuroma (Updated May 1, 2017)

Note pressure of the
titanium frame on head.
You get used to it.
Selfie by JT Marlin.

I lost hearing in my left ear a decade ago. The ear doctor said there was a 5 percent chance it was an acoustic neuroma a.k.a. a vestibular Schwannoma. I had an MRI and sure enough, that is what it was. It was small, 4 mm., but in a bad place, the vestibular ear canal.

Having already lost most of my hearing in the left ear, I decided to wait before doing anything about the neuroma.

Executive Summary

Nurse feeds me water through a
titanium cage. Photos by Alice
Tepper Marlin.

The decision to go yesterday for the Gamma Knife op was based on deterioration in my sense of balance.

The neuroma had grown to 8 mm. The vestibular ear canal controls balance. As a doctor told me: "When you hear the sound of hoofs outside the window in the USA, do you assume a zebra or a horse?" The horse is this case would be the neuroma's interfering with my balance. Anything to do with my balance should be assumed to relate to the neuroma.

So yesterday morning I had the Gamma Knife procedure. I am informed it successfully killed the neuroma (although the process of its dying may take weeks or months), so unless you want to know more, that is the end of the story. My balance sense is improved.

More Detail

A neuroma or schwannoma (also known as a "Schwann cell tumor" or a "neurinoma,"or "neurolemoma") is a benign nerve sheath tumor composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral nerves. The tumor cells can be thought of as feeding on a nerve, but they stay outside the nerve. The tumor causes trouble by pushing the nerve aside and/or up against a bony structure. Schwannomas are relatively slow-growing and are almost always benign, so they don't spread.

Dr. Wang sets up the Perfexion machine. 

A neuroma can be removed via microsurgery as well as radiation. Microsurgery requires cutting a hole in the scalp and (I understand) feeding a tiny pair of scissors up through the ear canal. I didn't like the risk associated with that, especially when the seventh and eighth nerves are intertwined and a frequent enough byproduct of the surgery is some loss of control over facial nerves on that side of the face. Think Phantom of the Opera.

The "Gamma Knife" radiation procedure  avoids having to cut through the skull or physically cut out the tumor. Instead, it bombards the neuroma with gamma rays from dozens of different directions. After enough of this the neuroma cries "Uncle" and goes into a funk that ends with its death.

"The neuroma is a weakling among tumors and is ready to give up the ghost with a little bombardment," is how I remember Dr. Michael Sisti summing up the situation.  The downside is less worrisome than the hole-in-the-scalp and mini-scissors strategy for the surgery.

The Gamma Knife is an advanced radiation treatment for adults and children with small to medium-sized brain tumors and diseases such as abnormal blood vessel formations called arteriovenous malformations, epilepsy, and trigeminal neuralgia (a nerve condition that causes chronic pain) and other neurological conditions.

That takes care of what I know of the medical science. You can stop here or review what happened during the 9-10 hours that were occupied by the surgery.

The Surgery Narrative

Getting ready to open the machine.

For those contemplating or just curious about the Gamma Knife procedure, here's how my day went  yesterday:

4:30 a.m. Shower and dress in clothing with no metal anywhere (even metallic snaps are verboten). I wore a polo shirt and jogging pants.

5:30 a.m. Taxi with Alice to the basement of the New York Presbyterian Hospital Children's Hospital, where the Gamma Knife center is located. That Hospital is where my eldest sister, Olga E. Marlin, was born in 1934. Fortunately all six of us siblings are still living, aged 71-81.

Dr. Wang watches the Perfexion machine,
with data at his left. 

6:30 a.m. I am checked in. Alice gets a visitor's pass, I get two bracelets, one indicating my name and doctor and various numeric IDs, and the other listing allergies. I also get a hospital bathrobe. We are introduced to half a dozen people who have different responsibilities during the procedure.

The first task was to put the
titanium frame on me. The metal is unusual because it isn't affected by the magnets in the MRI machine. This is one of the two most unpleasant parts of the procedure because it must be absolutely, positively tight on my head.

7:30 a.m. I was given 0.5 mg. of valium to help face the placement of the helmet and the tight MRI that followed. The frame was tightened in four places on my head and they all bled. Discomfort occurred during this difficult process, involving three or four people – one of whom was injecting a numbing fluid, something like Novocaine (generic name procaine). Alice said that a woman in the next treatment room had been in tears briefly during this step (I couldn't hear it).  Alice had to stay outside while this was done and was concerned, but she said she heard me cracking jokes after a while and all the attendants were laughing, so she was relieved. After five minutes I got used to the frame and the three of us who were waiting for the procedure paraded, or were wheeled, around like aliens from Star Trek or The Empire Strikes Back.

Nurse puts on ice to reduce
swelling at pressure points.

8:00 a.m. A clear-plastic thing that looks like a transparent hair dryer and was mysteriously called a "halo" was put on me. Dr. Tony Wang used it to take measurements of my skull. This information was presumably fed into the computer to help it decide where to target the gamma rays.

10:00 a.m. I went in for the brain MRI of the brain, with the titanium frame on. This was the second step that the valium helped me deal with. The MRI ensures that the location of the neuroma would be entirely up to date. I have always used the Dove Open MRI, because it doesn't make me feel like I am being buried in the catacombs. The hospitals don't like the Open MRI so much because the more-open machines sacrifice some detail.  For Gamma Knife purposes, it has to be the closed MRI, so I felt as though I was stuffed into the capsule space like a sausage (the photo is of the Perfexion machine, which provides a lot more space than the MRI). Luckily, the small amount of valium was enough to prevent any panic. I was given ear plugs, which was a good thing, because the noise seemed to be considerably louder than in the Dove machine.

12:00 noon. After Dr. Sisti and Dr. Wang conferred on a strategy, I was brought in to the "Perfexion" Gamma Knife machine and by this time it was programmed with measurements and the irradiation plan. It was almost an anti-climax. The zapping of the brain is quiet. No noise, just an occasional hello from Dr. Wang and Alice. And then I was out of there.

Data from Perfexion machine.

1:00 p.m. Dr. Sisti says they got all of it but it might take six months before the neuroma was completely dead. Meanwhile, he said, "play tennis". Apparently it helps with the sense of balance.

1:30 p.m. Headed home with a bandage on my head.

I am grateful to Drs. Sisti and Wang, to all the attendants, to Alice for accompanying me, to all those who said they prayed for me, and to the divine being(s) who respond to prayer. And now... back to work.

Update, May 1, 2017

Today I brought in the MRI taken after six months. Dr. Sisti was happy with the outcome and said that, unusually, the Gamma Knife had cut a hole in the neuroma so that it now had a doughnut-like shape. I am to come back after another brain scan in July 2018, and then he expects to be able to say with some finality that the neuroma is dead.