Cystic degeneration after Gamma Knife

[ales]

Hi everyone.  I had a small 1cm solid AN treated by Gamma Knife.  The tumor had shrunk at 1.5 year MRI follow-up.  At the 2.5 year MRI follow-up, it had undergone cystic degeneration, and grown to 2.5cm (mostly cystic component), and now pushing on the cerebellum.  I still have good hearing on the affected side and am fairly non-symptomatic (only minor facial twitch occasionally and very minor imbalance on rare occasions, not affecting my work or life).  Has anyone had a similar course?  The options given to me are surgical resection, or watch for symptom development (and then have surgery).  Sharing any similar experiences would be greatly appreciated! Thank you!

[extropy]

Found these two interesting papers about **cystic** AN and GK.

https://www.ncbi.nlm.nih.gov/pubmed/28368501

https://academic.oup.com/neurosurgery/article/62/5/E1164/2558440

--Serafino (Rome, Italy)

[augustin]

Hello Ales,

I have read your message and I have worried. I was treated with Gamma Knife of a 16.1 mm AN in 2015. The following two years its size was reduced to 13.2 mm but the following two years the diameter increased to 16.4 mm. In this last report, the radiosurgeon who has been treating me mentions for the first time that the tumor has cystic degeneration, but then adds that this data improves the prognosis regarding the progressive reduction of the tumor.

Your history has left me worried because it seems that cystic degeneration is bad news and that it involves the growth of the tumor and leads us to a surgical resection of the tumor.

Below I transcribe part of my last report:

"The tumor volume is 0.4 cubic centimeters, it has been reduced by 50% with respect to the treatment volume (0.8 cubic centimeters), in the lower part of the lesion a cystic degeneration is evident and the facial nerve is distinguished in all its extension and with a normal signal. The lesion partially occupies the cistern of the right cerebellopontine angle and is not accompanied by changes in the peripheral parenchyma or other lesions. "

Regarding hearing loss (from 30 to 60 dB at frequencies from 2000 Hz to 8000 Hz), the report says that "this fact is usually observed in injuries such as this one that are presenting cystic degeneration. This reinforces a good prognosis regarding the progressive reduction of the tumor. "

If anyone can shed some light on this case I would greatly appreciate it.

( Originally written in Spanish and tranlated into English by Google Translate )