Have you encountered severe truncal and bilateral lower-extremity edema after pelvic radiation for a rectal neuroendocrine tumor?

I have seen something similar after radiation to the lower retroperitoneal nodal chain, where there was likely progressive fibrosis that obliterated the lower IVC to the point that nothing could be done. Also, it is possible, albeit very unlikely, that rectal NETs produce serotonin in sufficient quantities to result in tissue fibrosis. I would be curious to know the dose delivered and the field size. I think this is not related to the NET itself, but rather to the RT and resultant nodal/lymphatic damage, but I would want to hear from radiation oncology colleagues about that... @Dr. First Last and @Dr. First Last - any thoughts?