Cognitive effects of SRT?

[SallyGT]

Thanks to everyone who responded to our recent post regarding SRT. We have a virtual consultation with the radiation oncology team at NC State veterinary scheduled in early August (their earliest availability).

We have one more question we'd like to pose: Because the brain tissue surrounding the pituitary tumor is inevitably irradiated (to a much lesser extent than the tumor), has anyone whose cat has undergone SRT noticed any personality/behavioral changes in their cat post-procedure? We read Amanda's very sad and difficult account of her and Schmee's experience with this following pituitary gland removal. We understand that SRT is much less invasive, with lesser risk of disturbing healthy brain tissue, but we're wondering whether it still can happen with SRT.

We found a study on human patients undergoing radiation therapy for brain tumors, which found that 50-90% of patients experienced significant cognitive effects post-procedure (link below). We're wondering whether it's possible that this is also a common effect in cats--but that it goes unnoticed since higher brain functions aren't really assessed in feline patients. Any thoughts?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5805381/

 

[Wendy&Neko]

I've never seen or heard of anyone here noticing cognitive side effects, other than very short term, like maybe a few days. Neko was a little out of it the night after her first SRT session (1 of 3), but was fine the next morning and for the ones after that. By "out of it", I mean less social more hiding. She was also in a hotel room she wasn't used to.

The SRT planning software they use is very thorough, with the idea that no tissue surrounding the pituitary gets much radiation. The idea behind SRT is that they shoot from 7 different directions to avoid high doses in any one direction, except where the doses overlap at the end in the pituitary. The cat is fixed in position, and the device delivering the radiation is on a gantry, and swivels around the cat. We got an extensive tour of the place afterwards, including a demo of the software they use. Both DH and I are software folks, so took it all in. Regular radiation therapy for acros, has a much higher chance of side effects as it's a higher beam of radiation in one direction. And this is one of the main reasons SRT is so much better than regular linear radiation therapy.