Comparison of Amino Acid PET to Advanced and Emerging MRI Techniques for Neurooncology Imaging: A Systematic Review of the Recent Studies

Figure 3

FET PET combined with DWI to detect radiation necrosis (histologically confirmed) after glioma treatment. Contrast-enhanced MRI, ADC map obtained from DWI, and FET PET of a 69-year-old female patient with anaplastic oligodendroglioma. Twenty-nine months after fractionated external beam radiotherapy, brachytherapy, and adjuvant temozolomide chemotherapy, contrast-enhanced MRI suggested tumor progression. In spatial correspondence to the contrast enhancement, the ADC map revealed a substantial decrease of diffusivity in the area of contrast enhancement (arrowheads on the enlarged image; ADC below ), suggesting tumor progression. In contrast, FET PET showed no increased metabolic activity and a steadily increasing time-activity curve, indicating treatment-related changes. Histological findings obtained following stereotactic biopsy were consistent with radiation necrosis (hematoxylin and eosin staining: original magnification, ×200; scale bar, 50 μm). For a follow-up time of 6 years, the patient was in a stable clinical condition. Reproduced with permission from Figure 1 of Werner et al. [50].