CTX availability?

After 20+ years on Evista, I switched from my PCP to an endocrinologist at a major medical center 4 years ago when my osteopenia drifted into osteoporosis territory. There was improvement following the first 2 Reclast infusions which nudged my DEXA scan scores slightly back into the realm of osteopenia. The final 2 infusions provided very little to no improvement. My endocrinologist recommends either continuing with Reclast or taking a holiday and then proceeding with one of the stronger OP meds.
I asked about CTX or any other tests but was told by my endocrinologist and the DEXA scan technician that nothing else was available at this and associated facilities. I would be happy to have feedback from others.