What are other chemo options if CAPTEM becomes resistant?

I'm so sorry captem isn't working for you. I know how disappointing that must be for you.
My first question is are you seeing a net specialist? Mayo and many other facilities have doctors who specialize in nets. This is important because nets are in many ways more complex than "standard" more common cancers.
As to your cancer, while captem is an oral form of chemo, it is one of the very few that are effective against nets. "Chemotherapy drugs" are more effective against more traditional cancers that are typically fast growing. Nets are usually slow growing, therefore, most chemo drugs aren't effective against it. But there are several other types of therapies that are effective. The most widely used is PRRT whichbis an IV treatment using radiation-type particles..
There are also other oral meds such as everolimus, cabozantinib, sutent, etc.
You can learn alot about the different therapies from sites such as http://www.carcinoid.org and http://www.netrf.org.
If you're not currently seeing a net specialist both of those sites have directories of specialists nationwide.

@lindabees Thanks so much for the reply and useful information. I had PRRT done two years ago, and a year later I was told that my PRRT response has been no longer sensitive for the second round treatment. I would talk to my oncologist and see what other medicines are good for me.