Author Topic: Large AN: radio-short term hearing preservation, surgery-long term tumor control  (Read 14744 times)

caryawilson

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Thanks Bomberman. Great analysis.  When I looked at the statistical data, I always questioned the validity of the data due to the sample size.  I guess I need to spend more time looking at the data, my own personal experience may be skewing my analysis.  In summary:
* Large AN, 4.5 cm
* the location of my tumor was stressing cranial nerves 5-12.  Nerves 7 and 8 were removed and the I have issues with 5, 9, 10, 12. 
* by the time of my surgery I had lost the ability to produce tears in the eye on the side of my AN.  Hence, it was clear my Facial Nerve had significant damage.
* vascularity.  My tumor was highly vascular, and my surgeon made the conscious decision to remove my facial nerve in order to remove more of the tumor.
* location: 

Hence, in my case, the key factors were: size, location, damage to existing nerves, tumor characteristics. 
4.5 cm, 17.5 hour modified retro surgery
John Hopkins: Lim / Carey
Complete Facial Paralysis
Facial Plastic Surgeon (amazing): Dr. Boahene

ANSydney

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Hi Bomberman,

You mentioned, "Facial function preservation I see at 146 instead of 142 on page 5 of the PDF. Where did you see 142?". I got the 142 from the abstract. I don't have access to the PDF.

You mentioned, "For your number 55.8, you didn't include the chance that there is tumor regrowth." Tumor regrowth is low at about 3%, so even multiplying 55.8 * 0.97 gives 54.1, an essentially unchanged number.

Bomberman

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Thanks Bomberman. Great analysis.  When I looked at the statistical data, I always questioned the validity of the data due to the sample size.  I guess I need to spend more time looking at the data, my own personal experience may be skewing my analysis.  In summary:
* Large AN, 4.5 cm
* the location of my tumor was stressing cranial nerves 5-12.  Nerves 7 and 8 were removed and the I have issues with 5, 9, 10, 12. 
* by the time of my surgery I had lost the ability to produce tears in the eye on the side of my AN.  Hence, it was clear my Facial Nerve had significant damage.
* vascularity.  My tumor was highly vascular, and my surgeon made the conscious decision to remove my facial nerve in order to remove more of the tumor.
* location: 

Hence, in my case, the key factors were: size, location, damage to existing nerves, tumor characteristics.

Hi Cary, I'm sorry to hear of your situation. You have already had an op I assume? In that case, these numbers should not apply to you anymore.
« Last Edit: November 21, 2016, 03:48:05 pm by Bomberman »

Bomberman

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Hi Bomberman,

You mentioned, "Facial function preservation I see at 146 instead of 142 on page 5 of the PDF. Where did you see 142?". I got the 142 from the abstract. I don't have access to the PDF.

You mentioned, "For your number 55.8, you didn't include the chance that there is tumor regrowth." Tumor regrowth is low at about 3%, so even multiplying 55.8 * 0.97 gives 54.1, an essentially unchanged number.

https://www.ncbi.nlm.nih.gov/pubmed/25065850 shows that 142 people have facial function after failed surgery and after GK salvage therapy. Non-failed surgeries have higher numbers.

Tumor regrowth is 8% after radio. Not 3% and that is considerable. Especially as the number increases as time goes on and the larger the tumor size. See https://www.ncbi.nlm.nih.gov/pubmed/26508404, supported by https://www.ncbi.nlm.nih.gov/pubmed/22921979, and https://www.ncbi.nlm.nih.gov/pubmed/21353158

I think you really have to read the articles carefully. Taking numbers that suit your preferences isn't going to do you any good.
« Last Edit: November 21, 2016, 10:53:18 am by Bomberman »

ANSydney

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Hi Bomberman,

Good to have a continuing discussion.

Tumor regrowth is 8% after radio. Not 3% and that is considerable. Especially as the number increases as time goes on and the larger the tumor size. See https://www.ncbi.nlm.nih.gov/pubmed/26508404, supported by https://www.ncbi.nlm.nih.gov/pubmed/22921979, and https://www.ncbi.nlm.nih.gov/pubmed/21353158

The mention of tumor regrowth was only to provide a multiplier for the 55.8% figure. I was trying to demonstrate that with the regrowth rates being low, the 55.8% figure did not change by much.

However, let's move onto the topic of regrowth since it is of significance to people with our problem. Here are the three sources you mentioned plus a couple of others and their quotes control rates.

https://www.ncbi.nlm.nih.gov/pubmed/26508404 ........ 92 - 100%
https://www.ncbi.nlm.nih.gov/pubmed/22921979 ........ 90%
https://www.ncbi.nlm.nih.gov/pubmed/21353158 ........ 91 - 100%

https://www.ncbi.nlm.nih.gov/labs/articles/25434946 .......... 97.1%
https://www.ncbi.nlm.nih.gov/pubmed/11483338 ........ >=97%

If we average the ranges and average the 5 papers, we get 95.4%. Happy to have other paper's results incorporated into this conclusion.

I think you really have to read the articles carefully. Taking numbers that suit your preferences isn't going to do you any good.

Acoustic neuroma treatment analysis is an information minefield. If we work together, clarity may be improved. Your enthusiasms for the statistics is just what is needed. However, if you attack the player rather than the ball, we will not get the benefit if navigating the information minefield in a meaningful manner.
« Last Edit: November 21, 2016, 05:09:43 pm by ANSydney »

Bomberman

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https://www.ncbi.nlm.nih.gov/labs/articles/25434946 .......... 97.1%
https://www.ncbi.nlm.nih.gov/pubmed/11483338 ........ >=97%

Hi ANSydney, so you found 2 articles that mention 3% regrowth rates. I think the first link mentions followup of about  5-6 years. But one question is, what is the rate if it's a longer follow up time? Why is there a discrepancy between your 2 articles and the 3 articles I found? Could your articles be only treatment of smaller tumors which are easier to take care of?

ANSydney

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There are five articles cited. (Please, if others know of another reference, please add it to the list.)

They are:
https://www.ncbi.nlm.nih.gov/pubmed/26508404 ........ 92 - 100%
https://www.ncbi.nlm.nih.gov/pubmed/22921979 ........ 90%
https://www.ncbi.nlm.nih.gov/pubmed/21353158 ........ 91 - 100%

https://www.ncbi.nlm.nih.gov/labs/articles/25434946 .......... 97.1%
https://www.ncbi.nlm.nih.gov/pubmed/11483338 ........ >=97%

Remember, the first and third have a range. The first article has a radiosurgery control rate of 92 - 100% which, in the absence of any other information, we would use the average, which is 96%. The third article has a control rate of 91 - 100% which, in the absence of any other information, we would use the average, which is 95.5%. (My personal opinion is that if there is a range of 92 - 100%, that the applicable value is closer to 100% than 92% because it is possible to have a control better than 100%, which is shrinkage. This makes the applicable average on higher than the simple average.)

So, the articles are in general agreement with each other (96 +/- 1.5%) except for article 2. It's the odd man out.

ANSydney

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Bomberman,

I looked at your symptoms and diagnosis date and we are remarkably alike.

You have a 29 mm tumor with slight hearing loss and some face/lip numbness.

I have a 27 mm tumor with slight hearing loss and one side of the tongue has altered taste sensation.

A surgeon's bias is to operate. A radiosurgeon's bias is to radiate. They rarely agree, so they both can't be right for the optimal solution. Yours and my bias is to get the best outcome for ourselves.

You may be interested in reading, if you haven't already, "What intervention is best practice for vestibular schwannomas? A systematic review of controlled studies" at http://bmjopen.bmj.com/content/3/2/e001345.full.pdf [2013]. The conclusion is "The available evidence indicates radiosurgery to be the best practice for solitary vestibular schwannomas up to 30 mm in cisternal diameter". That's us!

There are also some articles that go beyond the 30 mm criteria:

"Gamma Knife radiosurgery for larger-volume vestibular schwannomas"   http://thejns.org/doi/pdf/10.3171/2010.8.JNS10674%40sup.2013.119.issue-suppl [2011]
"Gamma Knife Radiosurgery as Primary Treatment for Large Vestibular Schwannomas: Clinical Results at Long-Term Follow-Up in a Series of 59 Patients" http://www.worldneurosurgery.org/article/S1878-8750(16)30666-0/abstract  [25 mm plus tumor control = 98.3%]
"Long-term tumor control and cranial nerve outcomes following γ knife surgery for larger-volume vestibular schwannomas" https://www.ncbi.nlm.nih.gov/pubmed/22175724 [2011] [25mm plus tumor control = 91%?]

The first article's conclusion is "Although microsurgical resection remains the primary management choice in patients with low comorbidities, most vestibular schwannomas with a maximum diameter less than 4 cm and without significant mass effect can be managed satisfactorily with Gamma Knife radiosurgery"

The second article's conclusion is "Surgical resection remains the primary approach for large VS with symptomatic brainstem compression. GKRS can be considered a safe and effective option in particular in patients who are not good candidates for surgery."

The third article's conclusion is "Single-session radiosurgery is a successful treatment for the majority of patients with larger VSs. Although tumor control rates are lower than those for smaller VSs managed with GKS, the cranial nerve morbidity of GKS is significantly lower than that typically achieved via resection of larger VSs"

I've included these articles since we still fall under the 3 cm criteria, just to let you know there is a buffer. I have another one at home that I can include in the list.

From what I can gather, if you have no symptoms of brainstem compression, which includes both of us, there's some room to move.

You are lucky to be in the US since you can talk to one of the authors directly (Dr Lunsford) and can also talk to Dr Chan who I know has done radiosurgery at 3.2 cm.

ANSydney

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I've done a google search for "gamma knife control rate vestibular schwannoma" for entries over the past year and these were the first 5 papers that came up:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4831944/ ........ 93% control rate after 5 years
https://www.ncbi.nlm.nih.gov/pubmed/26606668 .................. 92% control rate after 10 years (tumor size of ≥4 cm)
http://beating-gbm.org/wp-content/uploads/2016/01/LippitzEvidenceUpdate2015.pdf ........ 97%, 97%, 91.1%, 90.44%, 96.8%, 93%, 79%, 92%
https://www.lgksociety.com/fileadmin/groups/1/Documents/LGKS_2016_-_Slides_PDF/Tuesday/Mathieu_-_Gamma_Knife_radiosurgery_for_Koos_grade_4_VS_BT19.pdf ...... 92% after 10 years (≥ 4 cc)
https://www.scholars.northwestern.edu/en/publications/low-dose-gamma-knife-radiosurgery-for-vestibular-schwannomas-tumo ....... 91% after 5 years.

The last paper shows that it's important to make a distinction between progression free survival based on freedom from persistent growth was 91% at 5 years and progression free survival based on freedom from surgery was 100% at 5 years. Different papers have different criteria for control, with some papers using no growth and some papers consider control to be no further treatment required.

Can we summarize that growth is between 90 to 95% and no need for further treatment is between 95 to 100%. In any case, in the vast majority of cases, control is achieved. Failing that, how about control is somewhere between 90% and 100%.

We need to move on, because the real question is, which is the best treatment option?


Blw

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With the noted exceptions of size and location, my feeling is that radiosurgery will be vastly more frequent in a few years--I think it is somewhat less now. It has great outcomes, but the ease and cost compared to surgery are significantly better. More importantly, outside of working or not working, there is very little else that goes wrong with radiation. Surgery, in addition to working or not working, can have a huge number of complications that go beyond major surgery (infection, anesthesia, etc), and are specific to schwannomas (leaks, severing nerves, etc). Worse, I can't imagine having a second surgery in the event of a failure, and it also seems to be frequent to leave some tumor behind to preserve the nerve, which almost contradicts the need for surgery.
« Last Edit: November 23, 2016, 11:55:40 pm by Blw »

ANSydney

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Blw, I think you've said it in a nutshell. Nicely worded. I see cranioctomy moving towards debulking, if needed, only. Time will tell. Of course a valid pharmacological solution would change the equation yet again.

Bomberman

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So, I've completed my treatment. I did surgery with Dr. Sisti on 11/18. Everything seemed to be fully recovered 4 weeks out. There was about 1% remaining left. Dr. Sisti was even able to get some that was inside of the IAC which would be extremely helpful with swelling. I am able to still hear in that ear, and this Saturday I am going for a hearing test to see how much of it remained. But I've totally gotten used to it now. I was told that Dr. Sisti was flying blind with the high and low abr bands, but was lucky to still have the mid band to guide him with making sure my hearing was still there. So I think I am really lucky. I don't have to worry about the mass anymore as anything leftover could be zapped if it misbehaved. My numbness and tongue symptoms are totally gone. I also do have a very slight balance issue, but it's so slight, that I can run and move fine. I can do all activities I did before.

I'm glad that the main part of the ordeal is over and done with. And whatever you decide, I hope you will also have a great outcome.
« Last Edit: January 18, 2017, 09:36:22 pm by Bomberman »

Citiview

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Congratulations on a great outcome!
I have read lots of nice things about Dr. Sisti.

Jet747

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Bomberman,

Great to hear you had such a wonderful outcome!

Keep us posted in the years to come.

Best to you, your family and friends!!!

Jet
RS Surgery May 2015

GK Radiation October 2015

https://www.anausa.org/smf/index.php?topic=21969.0

Bomberman

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Here are my hearing results 3 months post op: http://imgur.com/a/7dj4r
About 20% loss. (considered mild hearing loss)