size of tumor?

[nanramone]

It's interesting to me that we learn that these tumors are generally slow growing. I had my first MRI on 2-28-2010. The tumor size was reported to be 1.9cm x 1.3 cm.

On 5-18, I had GK. The MRI performed that morning showed the size to be "at least" 2.3cm x 1.7cm. Whereas the first report showed no brainstem compression, the second showed mild compression.

So did it really grow that fast in 3 months time, or is one report inaccurate? I guess it doesn't matter, but this just shows that while we certainly need to be informed and comfortable with our decision, it's important not to sit around waiting forever to make a decision. Though still of moderate size, this tumor could have conceivably grown too large for GK had I decided to wait another 6 months to have it treated....yikes!

Does anyone have any thoughts about this?

[CHD63]

If I've learned anything on this forum in the time I have been active, it is that no two ANs are alike ..... in size, in shape, in exact location in the auditory canal, in growth rate, etc. etc.  The statistics are only that ...... just numbers and averages.  They do not always refer to the range of each stat when making reports.  On the average, ANs are slow growing, but there are several of us now on the forum who experienced rapid growth.  This is why we stress to newly diagnosed friends, to be very watchful for changes in symptoms, which short of another MRI, is the best way to determine significant tumor growth.  Do not ignore changes in symptoms, check with your physician, and insist on an earlier MRI, if needed.

Glad you had treatment when you did.

Clarice

[Jim Scott]

Nancy ~

I believe that in many AN patients, the tumor does grow at a glacial pace.  However, at some point, it can experience a 'growth spurt' that will usually be manifested in the symptoms we all know too well; imbalance, hearing loss, vertigo, facial pain, etc. and these symptoms will usually force us to see a doctor, get an MRI and confront the reality of having an acoustic neuroma that has to be addressed.  However, up until the time the symptoms awaken us to the realization that 'something is wrong', the AN can sit dormant or near-dormant for years.   My very AN-experienced neurosurgeon guessed that my AN had been growing for 10 to 15 years.  The pre-surgery MRI showed it as 4.5 cm and pressing hard on my brainstem but, according to the doctor, the tumor was actually closer to 5 cm when he operated on it.  That leads me to believe that even a high-quality MRI with contrast can be less than perfectly accurate in depicting the actual size of a tumor.  As you inferred, human error is also a factor that is always has to be considered.  Obviously, gauging the size of an AN accurately when the option of radiation is in play is critical but the reality is that even the best MRI and gimlet-eyed doctor can be slightly wrong in gauging tumor size.  That being the case, for those who tumors are deemed small enough to be treated with radiation, I would suggest they not postpone scheduling the treatment once the MRI shows the AN growing much beyond 2.5 cm - if they have that option.  Of course, some AN patients, (Jim slowly raises his hand) don't find out they have an acoustic neuroma until it's quite large and far too big for radiation. However, that's a separate issue and, as in my case, debulking surgery followed by radiation is an option.  Well, my doctors thought that it was.  I agreed and the debulking/radiation process rendered a good result. 

The takeaway from all this is that, yes, being vigilant with scheduling MRI scans and not waiting too long to undergo radiation once the tumor is anywhere close to 3 cm would be the prudent course.

Jim

[Doc]

I just read with amazement how very similar Jim's AN experience and mine were. Right down to the size and course of treatment our Doctor's deemed appropriate. The only real difference being my surgeon suggested my Tumor had been growing at a "glacial pace" for what he thought was nearly four decades.

Wow Jim...we should write a book - Twin AN's - Stories of Survival

Take Care!
  
Doc

[mk]

Interesting, I was actually thinking of starting my own thread about this, as I have been thinking a lot about it, after reviewing my old MRI scans, including the diagnostic one.

Having an engineering background, I find it hard to believe that the typically reported growth rate of 1-2 mm/year can be applicable for ANs of all sizes. If you think about it, a 1 mm growth would represent a 10% increase in a 10 mm tumor. However a 1 mm growth will only represent a 3% growth on a 30 mm  (3 cm) tumor. If we actually consider volumes (which would be more accurate), that difference is even more pronounced.

I have been gathering (very informal) statistics from the stories I have read on this forum, and it seems to me that larger tumors (mine included) have shown much more significant rates of growth than the 1-2 mm/year (or otherwise in growth spurts, like Jim mentioned). I am inclined to believe therefore that quoting a standard rate is probably an oversimplification.

OK so now maybe I should consider polling people about their growth rates and then writing a scientific publication about this  . In the meantime, I totally agree with Jim that especially when considering radiation, one shouldn't wait much longer when they reach a 2.5 cm size.

Marianna

[moe]

 my surgeon suggested my Tumor had been growing at a "glacial pace" for what he thought was nearly four decades.

Wow, Doc, that is glacial! Mine was probably doing the same over a mere 2 decades.
I went through 3 pregnancies, so that apparently did not increase the growth rate.
No 2 AN's are alike. Kind of like a fingerprint! (almost, not really)
Hijack-Doc how's your neck doing since your little stumble?
Moe

[Doc]

Hey Moe,

The Neck is still a "sore spot!" I hyper extended it according to the x-rays and my Neurosurgeon. I was going to do some physical therapy but the place I went to for my Vestibular Retraining was dumped by my insurance company. I haven't found another provider close by that can accommodate my schedule; I was going in at 6 a.m. on Monday's and Friday's at the old place so it wouldn't interfere with my work schedule.  As it turns out, I also have a touch of Arthritis in my neck; so the Doctor says. I'll probably just continue the exercises I found online and forego therapy; Google is a wonderful thing! On a side note, we're not pursuing any further legal action against the hotel either; the lawyer had a change of heart and so far, their insurance company has paid all incurred expenses.

Thanks for asking.

Take Care!
 
Doc

[leapyrtwins]

My sense of things is there are a lot of inaccurate MRI measurements out there.

My diagnostic MRI showed my AN to be 1.5 cms.  I had my surgery approximately 6 weeks later and both my neurotologist and my neurosurgeon agreed that my AN was much larger.  Neurosurgeon said it had doubled; neurotologist said it was definitely a lot bigger than 1.5 cms, but he wasn't willing to use the word "doubled".  As I recall he said it "almost doubled".

Jan

[nanramone]

Hi all - I found a local radiation oncologist in my town to oversee my future care. Among other things, I asked her why this thing appeared to have grown so rapidly in a few months after the first MRI...

She said it did not grow. It appears larger on the second MRI report because Pittsburgh has a better MRI machine than they have here! The Pittsburgh reported it as being "at least 2.3cm" at the largest dimension. However, the first MRI I had here (which reported that same dimension to be 1.9cm) will be used as the baseline when comparing my next scan, which will be done on the same machine.

So - at least that answered my original question about the apparently rapid growth. There was none! I guess none of this matters, but it seems in our search for info this is all very interesting to us.

Nancy

[Stephanie]

My tumor was also a different size from the first MRI. I was diagnosed with a 1.7cm and when I had my surgery 6 mo. later it was aprox. 3 cm. My husband has a theory... He says maybe the first MRI they are just looking for something, anything, and the MRI isn't as specific as it could be. Then once they find what they are looking for they are more specific with the MRI's they request.
My theory however is the radiation boosts the growth which is probably wrong but I was the one with the tumor so I trump his theory in my mind. Ha Ha : )
Stephanie

[Tod]

Measurement of most anything is a tricky business. If one thinks about the definitions used at the National Institutes of Standards and Technology, it is very easy to see how complex a business it is to measure something you can see and hold. Just defining the length of a meter, and thereby the length of a millimeter, centimeter, etc. is nothing to taken lightly (http://www.nist.gov/mel/ped/museum-timeline.cfm).

I've had six MRIs in the last eight months and change. I know for a fact that at least four of them were on different machines, three of those within the same hospital. The other scans I was unconscious and my seventh is scheduled for a week from tomorrow. The results all differ slightly, both the two presurgery and the four post. Even with these differences, I'm amazed at how consistent they are in mapping an image of tissue deep within my skull, and this without even accounting for the unavoidable variances in the position of my skull.

What I am not clear on is this: when people talk about the range of accuracy of an MRI being typically 1-2 mm, is that positional or or measurement acuracy? For example, is the boundary of a tumor within 1 to 2mm in either direction, or is that the measurement of between two boundaries is within to 1 to 2mm? If it is the positional accuracy, that difference alone can account for tremendous swings in the size of estimate of nearly half a centimeter, which really suggests one be cautious about overreacting to any difference between only two MRIs and that if you want at least 3 MRIs showing growth if the difference between the first two are less than that half-centimeter?

Does that make sense? Are there standards for how much measured change is required before going to treatment?

[Tumbleweed]

Marianna, what you said makes perfect sense. That's really great insight, thanks.

***
Some of the factors that can cause an MRI to be measured differently:
1. The "slices" of film that the MRI takes are roughly 2mm apart (or at least that's my understanding). Two of the images may land right on opposite borders of a tumor, resulting in an accurate measurement along that axis. But one or both of the images may instead land quite a bit inside the borders (and the next slices to the outside will therefore land outside the borders, missing them), resulting in some tumor tissue exactly on the borders not getting imaged and therefore making the tumor look smaller along that axis of measurement. Each time you have an MRI series taken, the image slices are taken through slightly different parts of the tumor. The same-size tumor may look smaller or bigger along any one axis of measurement by as much as 2mm in different series taken at different times (because your head is not exactly in the same orientation as for the other series).

2. ANs are measured along three oblique axes (this I'm positive of). That is, the measurements are made at an angle across the greatest span of the tumor. The angle of measurement is totally up to the reading radiologist to decide; there is no standard. Therefore, two people may look at the same tumor and measure it differently, even though the image they see is exactly the same.

3. Some facilities have superior imaging equipment compared to others. My MRI at diagnosis of my AN (not taken at Stanford) also showed a blurry image of a small hypoglossal tumor that was overlooked. When an MRI was taken at Stanford (which had superior equipment), the image of the hypoglossal tumor showed up much more clearly and the reading radiologist noted it in his report. Which makes the point: if the border of an AN is blurry, where should the measurement to its edge end? The difference in what two people call the edge of a blurry image can easily amount to a millimeter or more.

4. Not all doctors are equally meticulous. My last MRI report was obviously not even developed from my own MRIs! The idiot who filled out the report misstated my age, date of treatment and tumor size (by a huge amount), making it apparent that he was reading the wrong films (for another patient) when he filled out my report.

Human error, interpretation, equipment and limits of the technology all conspire to create different reports for the same MRIs.

That said, ANs can have genuine growing spurts. Before treatment, mine grew at about 5x the "average rate" of 2mm/year, over a five-month period.

Best wishes to all,
TW

[Joef]

4. Not all doctors are equally meticulous. My last MRI report was obviously not even developed from my own MRIs! The idiot who filled out the report misstated my age, date of treatment and tumor size (by a huge amount), making it apparent that he was reading the wrong films (for another patient) when he filled out my report.

this means that some poor soul got a bad report about an AN ...and they might not really have one !!!

[QRM]

Now that you mention this, I never asked for a second MRI to confirm the original DX, lets just say there was a mix up, nobody would know until I was on the slab with half my skull ground away before anyone figured out the error, Scary thought.

My local Doc spent all of 3 seconds looking at my post op scan and confirmed that all was OK.

[Tumbleweed]

Now that you mention this, I never asked for a second MRI to confirm the original DX, lets just say there was a mix up, nobody would know until I was on the slab with half my skull ground away before anyone figured out the error, Scary thought.

This is why I taught myself to read the copy of my scans that I requested. I wanted to see the thing myself. It really isn't that difficult to learn. I have no medical background and it took me only a couple hours or so to learn the software and how to measure my AN, all by trial and error and by comparing my observations to the MRI report. It is empowering to learn all you can about your condition and not trust blindly that the medical establishment will be 100% error-proof all the time.

Best wishes,
TW