Persistent lower extremity edema

I have a new patient sent to me from oncology for persistent LLE edema without DVT or cellulitis despite multiple tests. She's been treated with abt and has had every imaging order known to man. Oncology has no ideas. Left hip pain started roughly 3 months post her last radiation tx for colon cancer and then morphed into edema and neuropathy over the last 8 months. Labs and imaging normal aside from a new lesion to R kidney, which I've referred for. I suspect LLE CRPS II from radiation. What am I missing here?