6 month interval change in tumor size: Is this significant?

[terry]

Hi,  I am new to this forum and would appreciate any insight into my situation.  Approximately 2 years ago, I was seen by a muscular skeletal physician for pain radiating down the front of my right thigh.  this pain NEVER went below my knee.  He looked at my x-rays [and probably considered my age:  63 years] and decided that I had degenerative disc disease. He prescribed Neurotin to help with the pain.  Neurotin was pretty effective in controlling the pain.  However, I kept needing higher and higher doses of this drug .   Nine months ago, a lumbar MRI was obtained and revealed the presence of a tumor at L2-L3.  The radiologist thought it was likely to be a schwannoma.  For reasons that are not clear to me [given the location of my pain:  the front of my right thigh], it was decided by the muscular skeletal doctor AND a neurologist that the radiating pain was probably NOT caused by the tumor.  Since they decided that this tumor was not causing symptoms, they took a wait and see approach [given those assumptions, OK].  So, here's my question:   the size of the tumor was measured in July of 2015 and then again in early February 2016.  This was the change in size of the tumor:  July 2015:  19mm [length] x 10mm x 24mm   and this was the size of the tumor in February 2015:  43mm [length] x 13mm x 23 mm.   It was concluded by the radiologist that:  ". . .no significant interval change since 07/14/2015".   It seems to me that a tumor that MORE than doubles in size in 6 months IS a significant change, right?  Could there be that much measurement error in this measurement technique that this conclusion could be justified or was this radiologist simply asleep at the switch?  Thank you for your help!  Terry

[terry]

So here's the answer to this question: yes, a doubling of the size of this tumor [as this APPEARS to be] would be significant BUT this is NOT a significant finding because the first radiologist likely did not capture the full size of the tumor to begin with. In effect the tumor was probably always around 43 mm in length. So, the Neurologist is sticking with the conclusion in Feb of 2016: the tumor is stable. In the scheme of things, I can hardly complain.

[dmdgood]

Dear Terry. It's a good thing that you found this out. I don't know much about schwannomas (I have some kind of an intramedullary tumor, probably an ependymoma), however, doubling would also seem significant to me for any lesion. I haven't yet been able to find out how much 'growth' is potentially measurement error and how much is actual growth (e.g. is up to 5mm significant or is it still considered measurement error?). This has baffled me. But what baffles me more is that the lesion would have been growing for a time, yet it is from the point it is discovered that growth becomes a big issue. Don't you find that strange? Imagine yours had doubled since the previous scan. Would they still recommend surgery even though your symptoms are the same?

[terry]

Hi dmdgood, I agree with your observation: what if the tumor doubled in size just before it was detected but now has stopped rapidly growing. Maybe it is only growing a little now but not enough to trigger the: we need to do something. It sounds to me like SCT can have a very un-even growth rate: sometimes they just sit there not doing much but then takes off and grow. I think that this is a very grey area and you will probably see a lot of different opinions on when to do something based on a change in tumor size. The problem is that if suddenly a SCT justs takes off and grows, it can cause some permanent damage. My doctors are now offering me Cyber Knife surgery. I may take them up on this offer because I think I have pain originating from this tumor AND I don't like the idea of it just sitting there waiting to suddenly grow.

[dmdgood]

I hope you didn't interpret my email as being encouraging of surgery or radiation Terry. That has to be an individual decision. I am 'watching and waiting' as they call it myself with my tumor. It's up high in the cervical area, and peeking into the brainstem. It's quite large - more than 3cm in length. Now we're watching every mm of growth, yet at some point the thing grew to 3 cm. I wonder if I was diagnosed earlier whether the doctors would have been calling for surgery earlier. I am symptomatic but weirdly no where near as I should be according to my neurosurgeon given the size and location of the tumor. So, it is just something that continues to baffle me. I guess it's a combination of growth and symptoms that they make a call on. Who knows.

[terry]

No worries, dmdgood: I understand fully that we make our own decisions. What I heard today [from a radiation oncologist] is that these type of tumors might grow about 1 mm/year. Doesn't seem like much but when you figure that they are growing in "expensive real estate" it does catch your attention.

[markalan]

Hi Terry

We have a lot in common since I also had an L2/L3 schwannoma removed about 15 yrs ago. My comments

(1) pain on the front of the thigh is almost certainly associated with the L3 nerve root.
(2) it would bother me a lot that the first radiologist made a "mistake" in under reporting the size. By all means send your entire MRI collection to one of the top neurosurgeons for an independent look. I recommend Columbia University in NYC. Of course there are many other good places.
(3) Cyberkife is not necessarily the best choice, especially if you have never had surgery. The location of your lesion may not be all that difficult for the right surgeon
(4) as you say, the "real estate" available is defined by the transverse dimension of the lesion. What matters is the percentage of the spinal canal that is filled with the tumor.
(5). Yes, schwannoma as you said can grow in a very nonlinear way.

Again, get a second or third opinion before taking any action.

[terry]

Hi Markalan,

Thank you for your response and I agree, a second opinion is essential. It was valuable to hear that the L3 nerve root was almost certainly associated with pain on the front of the thigh.

Did you have pain associated with your schwannoma? Did any of that pain resolve when they removed it? Thank, again!