Repeat GK after 5 years?

[dadburnett]

I had GK in 2006 followed by frequent MRIs. The last MRI in Nov 2011 seemed to indicate (for the first time) a 2mm growth in both dimensions (from 28mm to 30mm lateral). I've read elsewhere that 2mm might be within the "margin of error" for AN MRIs. I'm being pushed by my doctors to do something quickly - either GK or surgery.
I question the wisdom of proceeding on the basis of "one MRI." My only option for a second opinion is to go out of state. Any suggestions or insights will be appreciated.

[Jim Scott]

I had GK in 2006 followed by frequent MRIs. The last MRI in Nov 2011 seemed to indicate (for the first time) a 2mm growth in both dimensions (from 28mm to 30mm lateral). I've read elsewhere that 2mm might be within the "margin of error" for AN MRIs. I'm being pushed by my doctors to do something quickly - either GK or surgery.
I question the wisdom of proceeding on the basis of "one MRI." My only option for a second opinion is to go out of state. Any suggestions or insights will be appreciated.

I agree that rushing into surgery on the basis of a 2mm difference on one MRI (assuming you have no new AN symptoms) seems to be premature and possibly, unwise.  I would suggest having another MRI scan in 3 months (so that any possible growth doesn't get ahead of you) and to be certain to use the same apparatus for each MRI because the machines will differ in size presentations.  If your doctors insist on pushing surgery, I would make the effort to go out of state for a consultation.  Remember, it's ultimately your decision, not theirs - and you have to live with the consequences, not them.  Be cautious (but sensible).

Jim

[mindyandy]

Hi there. I agree with Jim. I wouldn't freak out just yet. I can honestly say I'm in somewhat of a similar situation. I would send my scans out to various doctors to get their opinion. I sent mine to Dr. Haines in Minnesota and Dr. Friedman at House Oh and also Dr. Medberry (can't forget my buddy). All gave me their opinions. I have been having symptoms that accompanied my 2mm growth so I've reached the point where I just want it out. This is just me.
Please keep us posted on your decisions.

Mindy

[leapyrtwins]

I'm no doctor, but I think you are right to consider margin of error.

If it were me I think I'd have another MRI in 3 - 6 months and go from there.

Just my two cents,

Jan

[PaulW]

While it is true 1-2mm is within Margin of error, as tumours get bigger measurement gets more accurate.
Moden MRI's are accurate to about 0.1mm, but the operator adds another 0.1 mm. and because you are measuring 2 edges of the tumour the error is doubled.
The slicing of the MRI is the greatest source of error, and can easily add or take a mm on small tumours.

Think of the MRI as an Egg slicer.
The MRI cuts the tumour up into multiple slices, just like an egg slicer custs up an egg. What you see on the MRI film is the face of one slice of egg.. I mean tumour..

If you are cutting up something the size of an egg with your egg slicer, and you measure the diameter of the slice of egg at the face, of the slice, where the wire has cut it, the two largest diameter slices will be very similar in diameter. If you are cutting up something small like a pea, the diameters can change a lot depending on where the egg slicer cuts the pea.

So little tumours are subject to larger measurement errors, due to where the MRI slices the tumour, if it slices straight through the middle, the measurement will be bigger. If it misses the middle the diameter will be smaller.

As your tumour is quite large, measurement errors caused by the slicing are reduced. Your tumour has also increased in size in two diameters, you have 5 years of imaging history, and the radiosurgeons would not soley rely on the Radiologists report, but would look at the MRI's themselves. I can see why they could be concerned that regrowth is occurring.

A second opinion of course cannot hurt, hope it all turns out well.

[ppearl214]

I'm no doctor, but I think you are right to consider margin of error.

If it were me I think I'd have another MRI in 3 - 6 months and go from there.

Just my two cents,

Jan

I'll take Jan's two cents and raise it by another two cents

Total agree and in line with what Paul has shared.  Also, different docs read films different.  That 2mm "margin of error" also is due in part to how they measure. Each one may use different "edges" of the growth to measure.  I have 2 docs on the same treating team. Neither measures the same.  One will read my films and tell me "Phyl, your AN is approx (insert measurement here)".... then, the other will say "Oh, Phyl, if you insist on knowing the measurement of your AN, it is approx (insert measurement here)".... and neither is the same as the other, so I have to do an approx between the 2.

Also, different technologies may come into play.  I have had prior MRI's on closed magnets... then, MRI center offers up the "open" magnet for my comfort.  My docs (or their radiologist) do a comparison between the 2 (older on closed..... newer on open) and then, the "margin of error" comes into play again.

What others have noted here are spot on.....

I'll take what Jan noted... give it 6 mos in between the 2 MRI's... and then see.  My last MRI (done at my 5 yr post-CK) noted a slight 1mm growth.  I had to sit back, remind myself of the margin of error, realize (in my case) that for AN radio patients, is it very rare (can happen but VERY rare) to have growth after the 3-4 yrs post treat and try not to panic for 1mm growth noted on report.  My docs looked at the films and when we saw it's shape (or lack thereof... basically, doing nothing)..... it's color (looking total lackluster! ), etc....... helped put my mind at ease.

Hang in there!
Phyl

[mk]

The problem as I see it when trying to assess growth is the following: 1-2 mm is within the margin of error of the instruments, and so is the average rate of growth of an AN. So whenever you get a report showing a change in size, you can never know if it is within the statistical error margin, or it there has been indeed growth. I kept getting reports every 6 months that the changes where "within the margin of error". However one of the radiologists looked back through many consecutive MRIs, and a clear pattern of growth emerged. So is best to have an expert review your MRIs since your initial GK treatment (including the planning treatment), to assess if there is a definite growth trend.
Obviously your doctors are getting nervous, because you are approaching the 3 cm cut-off limit. Having said that, I am not sure that second GK treatments are commonly practiced, especially for tumors of this size (although I know that Pittsburgh sometimes recommends them). If you decide to treat this with surgery, then waiting for another 6 months to get a more definitive answer may be a good idea, if your doctors agree that it is safe.

Marianna