In general terms it seems the slower your cancer grows, the less effective chemo would be. Therefore, many NETs patients grade 1 or 2 are not candidates for chemotherapy.

I believe you can have a completely clear PET scan and still have Neuroendocrine cancer. Dividing cancer cells are very small. There is no known cure for NETs. My Oncologist made a great point when he said " I don't use terms like cancer free, that's not real". On a positive note, it can be very slow growing and there are drug treatments that are affective in stalling this cancer for many.

Found this info on the net about using chemo at http://www.everydayhealth.com

Chemotherapy Chemotherapy uses drugs to kill cancer cells. It isn’t generally used for tumors that are grade 1 or 2, says Kim, but for the more aggressive grade 3 tumors. According to a study, more research needs to be done on chemotherapy’s effectiveness in grade 3 tumors, particularly new chemo combinations or chemotherapy combined with other treatments. Among the many chemo drugs used to treat GEP-NETs are streptozocin (Zanosar), doxorubicin (Adriamycin), etoposide (Vepesid), dacarbazine (DTIC-Dome), fluorouracil (Adrucil), and cisplatin (Platinol). Some of these drugs are given in combination.