Author Topic: Has anyone's AN shrunk along the oblique transverse axis?  (Read 2202 times)

Tumbleweed

  • Hero Member
  • *****
  • Posts: 1052
Has anyone's AN shrunk along the oblique transverse axis?
« on: June 21, 2009, 02:31:12 pm »
Hi, everyone:

I'm wondering if anyone has had their tumor shrink along the oblique transverse axis after receiving radiosurgery/radiotherapy (CK, GK or other FSR). The oblique transverse axis is typically the first-quoted and largest of the 2 or 3 measurements reported in an MRI report. (That is, when quoted to be "x" by "y" x "z" mm in size, the oblique transverse measurement is usually the "x" figure.) My AN has shrunk dramatically along the other two axes, but not along the oblique transverse.

The oblique transverse axis roughly follows the course of the vestibular nerve as it traverses the IAC and CPA, on its way to its nerve-root entry zone of the brainstem. I wonder if my AN hasn't shrunk along this axis simply because tumor scar tissue is adhering to my vestibular nerve along its entire length. If so, it may never retract.

All technical jargon aside and in plain English: has anyone ever seen the largest of the 3 measurements of their AN get smaller on followup MRI reports after radiosurgery/radiotherapy?

Thanks,
TW
L. AN 18x12x9 mm @ diagnosis, 11/07
21x13x11 mm @ CK treatment 7/11/08 (Drs. Chang & Gibbs, Stanford)
21x15x13 mm in 12/08 (5 months post-CK), widespread necrosis, swelling
12x9x6 mm, Nov. 2017; shrank ~78% since treatment!
W&W on stable 6mm hypoglossal tumor found 12/08

sgerrard

  • Hero Member
  • *****
  • Posts: 3475
Re: Has anyone's AN shrunk along the oblique transverse axis?
« Reply #1 on: June 22, 2009, 08:52:27 am »
Hi Tumbleweed,

I saw your other update post as well. Congratulations on the shrinkage! I lost a little more hearing after CK as well. I attribute that to the last dying throes of the AN, rather than the CK treatment itself. If it was the CK, I think it would be a more dramatic reduction.

I noticed your odd before and after dimensions, even before seeing this post. My impression, without necessarily finding real data to support it, is that usually shrinkage occurs in all three dimensions. I don't recall seeing one that was still 2 cm long while the other dimensions were 1 cm or less.

Your theory of adhesion to the nerve is reasonable, but who can really say. I don't know what the dynamics of tumor shrinkage really are. The main thing is that it getting smaller. As it fills in with scar tissue, it may very well stop shrinking and become permanently dormant, which is just fine.

Good news on the HG tumor as well. I hope that one stays in watch and wait forever. :)

Steve
8 mm left AN June 2007,  CK at Stanford Sept 2007.
Hearing lasted a while, but left side is deaf now.
Right side is weak too. Life is quiet.

mk

  • Hero Member
  • *****
  • Posts: 968
Re: Has anyone's AN shrunk along the oblique transverse axis?
« Reply #2 on: June 22, 2009, 10:04:50 am »
Hmmm,

if ANs stop shrinking when they fill with scar tissue, then how  come most observations of shrinkage come after years, and not months?

TW, the dimensions of your AN do seem "out of the ordinary", in that it seems to have more of an oval shape, rather than a spherical one. Your observation that most ANs grow more along the transverse axis along the vestibular nerve seems to be correct, as it is almost always the largest measurement (it certainly is for mine!). But I am not sure why your shrinkage isn't uniform, could it have something to do with the way the radiation is delivered to the tumor (I am thinking isodose lines which applies for GK, but maybe there is something similar in CK).

Marianna
GK on April 23rd 2008 for 2.9 cm AN at Toronto Western Hospital. Subsequent MRIs showed darkening initially, then growth. Retrosigmoid surgery on April 26th, 2011 with Drs. Akagami and Westerberg at Vancouver General Hospital. Graduallly lost hearing after GK and now SSD but no other issues.

Tumbleweed

  • Hero Member
  • *****
  • Posts: 1052
Re: Has anyone's AN shrunk along the oblique transverse axis?
« Reply #3 on: June 22, 2009, 12:32:28 pm »
It's doubtful that it has anything to do with how the radiation is delivered to the tumor, as CK is quite homogeneous in that regard: The center of the tumor only receives 15% more radiation than the periphery. Marianna, I love your observation about how shrinking happens years after scar tissue is formed. That gives me hope that I can get the bugger to shrink even more! I'm continuing to take large doses of vitamin E with the goal of eliminating any scar tissue. It's a shot in the dark, for sure, as there's no data to support that works in the brain area.

Steve, I wonder if most people see shrinkage along the transverse axis when the tumor is large before treatment, thus extending medially beyond the nerve-root entry zone to the brainstem. Has anyone seen a small or medium-size tumor shrink along this axis? I sure hope mine does. That's the component that's still pushing (albeit only slightly) on my brainstem. I'd love to lose a few mm of tumor there.

Best wishes,
TW

L. AN 18x12x9 mm @ diagnosis, 11/07
21x13x11 mm @ CK treatment 7/11/08 (Drs. Chang & Gibbs, Stanford)
21x15x13 mm in 12/08 (5 months post-CK), widespread necrosis, swelling
12x9x6 mm, Nov. 2017; shrank ~78% since treatment!
W&W on stable 6mm hypoglossal tumor found 12/08

ppearl214

  • Administrator
  • Hero Member
  • *****
  • Posts: 7451
  • ANA Forum Policewoman - PBW Cursed Cruise Director
Re: Has anyone's AN shrunk along the oblique transverse axis?
« Reply #4 on: June 22, 2009, 12:41:55 pm »
Hey TW :)

Well, I'm not exactly sure of the current measurements of my AN, over 3-yrs Post CK.... but, at my last appt this past Feb.... they did notice a considerable shrinkage in mine... .but, can't elaborate more since the doc and I were celebrating with smiles when I was told. 

Continued wellness wishes your way!
Phyl
"Gentlemen, I wash my hands of this weirdness", Capt Jack Sparrow - Davy Jones Locker, "Pirates of the Carribbean - At World's End"