There is no certification program for alcohol injection of a thyroid cyst.
If you are referring to ECNU - this certification is reassuring (however is relatively new so many of my very experienced colleagues have not had time to certify). ECNU certification does not include PEI.
As long as the doctor has experience with it and is doing frequent ultrasound guided FNA procedures, it should be fine.
Thank you very much Dr Lupo for replying to my inquiry.