? Titan and an IAA number

A question for the members, talked To Titans vet today about his IAA numbers after I got the IGF number confirming his acro. My vet chatted with an endocrinologist at UofMinnesota who didn't think the IAA number was too important because it would not change the treatment plan. So I did not get an IAA number. My question is after reading so many posts and threads here and all are asking for both numbers, what does a high or low IAA number tell me about the antibodies and what would I do different if I knew? Maybe a silly question but trying to arm myself with knowledge. Plus my vet talked about a consultation with the UofM to see if we wanted a CT scan and possible radiation therapy. Is that the same as SRT ? Thanks Ed

 

It's Michigan State University that runs the tests for IAA, the same labs that do the IGF-1. It's a lot cheaper to do both tests at once. Greater than 20% IAA is considered positive. Most vets do dismiss it as unimportant, but most vets also don't do see a lot of home testing. The action of the antibodoes can change our dosing strategies. You need to be more aggressive with dosing, if positive for IAA, and similarly, you have to be very conservative if the IAA break. IAA is supposed to be self limiting after around a year and dosing needs can change dramatically when it happens.

Given Titan's IGF-1 number, I would save money and not do the CT scan, unless you were planning on following up with radiation therapy. Depends on what type of radiation equipment UofM has as to whether it's the same as SRT. There is conventional radiation therapy too, which is much harder on the cats. SRT can be completed in 2-4 days. The first day is a CT scan to confirm the tumour and map it for radiation purposes. The following 1-3 days are the radiation therapy. The SRT equipment is more expensive, which is why there are a limited number of locations that have it. But the corresponding good part about SRT is that they can be much more focussed on the tumour, and radiate very little tissue outside the tumour boundaries. Which means less side effects or damage to non tumour tissue. Which is why SRT is very good for brain tumours, which is what the benign pituitary essentially is. Note that radiation just neuters the tumour cells, it can still take up to two years to take full effect. Cyberknife is another option that possibly even better than SRT. But only available in a few places in the US for pets.

Other possible treatments for acromegaly, which your vet may or may not know about, is hypophysectomy (surgical removal of the pituitary) or some medical treatments (paseriotide and cabergoline). There are few places in the US that have experience with hypophysectomy for acromegaly, Washington State University and in LA. Ideally you don't want to be a vet surgeons first patient in this tricky surgery. The Royal Veterinary College in London are the most experienced and it is the gold standard (and most expensive) treatment option - most kitties are cured. The medical treatments are still being researched. Pasireotide (Signifor) is effective but very expensive - the long acting version Signifor LAR is best as it's just once a month injections. Cabergoline is in the research phase, again under the Royal Veterinary College, and a much cheaper option. Most kitties in the trial had their insulin needs greatly reduced, but so far only one, Marvin (on FDMB) has gone off of insulin.

Side note: looks like it's time for another increase with Titan.

 

Wendy did a great job covering the options. If you consider SRT, consider it now. Theresa and I wish we had diagnosed Leo and treated him earlier.

 

Thanks a ton Wendy, our vet said the radiation from UofM would be ten days so I guess it's not the SRT. Plus it comes with a$7700 price tag. I'll check again to see if the vet also ran an IAA test thru Michagan State but I doubt it. Plus this morn Titan gave us an AMPS of 717, ouch! Started 3 units 2x a day also this morn. He's eating well and negative for ketones but for how long??? Peace, Ed

 

Holy smokes AMPS = 717. That is off the radar. Poor kitteh.

In general - good that you are taking care of Titan. I humbly suggest you start ramping up the dose until you achieve some 120-150 nadirs. Those 400s and 500s are really, really bad for Titan. He will have neuropathy in no time at that level. And he will have trouble maintaining weight. As the pituitary tumor grows, the insulin demand will increase.

I looked at UofM and found their oncology site:
https://www.vmc.umn.edu/about-us/specialties-services/oncology.

Their radiation therapy is "linear radiation". There's nothing wrong with it. It just takes more treatments to achieve the same as SRT. The SRT machine uses two large arms and a very focused radiation dose. Both types of machines are quite impressive really.

 

Thanks Jeff fir checking out the UofM oncology dept.ndidnt even occur to me . We are increasing his dosage every 6 cycles by .5 unit each shot. Initially we zoomed to 4 units 2x a day but thought bouncing or Symogyi might be in play. Went slowly back down to 1 unit 2x to see if a change and/or start over. Then did a IGF test. Positive at 255 o now with an AcroCat we are climbing the scale to see where we land. Thanks again for the link. He's already a 10,000 dollar puddy cat with his previous issues but he's ours!

 

That sounds great! How very dedicated you are - to your sweet kitteh. I'm familiar with high vet bills too.

I read your signature. How very unfortunate that someone shot Titan in the face. I can't believe the lowlifes that are part of our society.

 

I briefly thought about getting linear radiation therapy for Leo. Then I saw how many anesthesias it would be. Just in itself, those anesthesias are tough on a kitten (or a human even). So I ruled linear radiation out pretty early in the evaluation process.

 

I think we are going to wait on the decision until we get him better under control. Patiently waiting for pink/yellow/greens