Would you consider radiotherapy for an unresectable 4 cm functional adrenal pheochromocytoma that is growing slowly but is not metastatic?

Yes, ablative dose 50 Gy in 5# radiation with DIBH soft tissue IGRT motion management. This area is typically not near luminal structures, but 67.5 Gy in 15 # would be preferred. These doses result in excellent control; lower doses may not. The tumor will typically not remain functional.

I would consider SBRT, Gonzalez et al., PMID 33552774, radiofrequency ablation, radiopharmaceutical therapy, hypofractionation, Vogel et al., IJRO 2012, Breen et al., PMID 29556576, and ask interventional radiology about tumor embolization. Keep in mind that while the gross tumor might not change in...