On conventional diagnostic imaging, the features of radiation necrosis (RN) are similar to those of local recurrence (LR) of brain metastases (BM). 11C–methionine positron emission tomography (MET-PET) is reportedly useful for making a differential diagnosis between LR and RN. | Prospective study of 11C methionine PET for distinguishing between recurrent brain metastases and radiation necrosis Limitations of diagnostic accuracy and long-term results of salvage treatment