Sounds like your PET/CT is being sourced out as not every hospital has a PET/CT machine or the staff to Interpret them. Having been in treatment of several facilities, the one where the ENT or person taking charge of your care, may want to do the imaging there or their affiliation, so I would keep the appointment, besides their probably going to do a physical/visual exam, scope, reviewing the pathology of the biopsy, and you can ask questions, and some prefer a CT, even an MRI, depending on location of cancer, and type.

A PET/ CT requires advanced preparation, such as low or no carbs for 24hrs, some just say 8, no exercise for 2 days as these can alter the PET scan results. A CT requires no advanced preparation, can be pretty much done anywhere, and easily read compared to a PET, and is cheaper. I think that's where the wait time can be is with insurance approval or pre approval, so wait times can vary, and yes, I've waited two weeks, sometimes less depending on the Doctor and association with the radiology center or department, and my insurance.

I hope this helps, and good luck tomorrow.