NI-09 Amide Proton Transfer (APT) image is useful for diagnostic imaging of glioma

Introduction: APT image(APT),which images the concentration of amide groups that increases in tumors, is expected to be applied clinically in diagnostic imaging of glioma. Purpose: APT was compared with MET-PET based on the pathological diagnosis results, and it was retrospectively verified that APT was useful for diagnostic imaging of glioma. Methods: A total of 46cases with glioma (WHO 2016 Grade: GII/III/IV) and Pseudoprogression were included. APT measured the APT measurement value by placing the region of interest in the tumor part. MET-PET was administered with 370MBq and the accumulation ratio(TNR) between the tumor part and the normal part was measured. Results: The APT measurement value in all cases was 2.22±1.01 and the TNR was 2.58±1.50,and a correlation was observed between the APT measurement value and the TNR(r=0.6, p<0.001).When the accuracy of discrimination between GII/III/IV (32cases) and Pseudoprogression(14cases) by APT measurement was verified, the sensitivity was 91% and the specificity was 100% at the threshold of 1.81. In the verification of malignancy diagnosis, the measured APT value of GII (6cases) was 2.18±0.43,the measured APT value of GIII (11cases) was 2.67±0.69,and the measured APT value of GIV (15cases) was 2.99±0.61.The measured value showed a significant difference. The measured APT value in the oligodendroglioma group (GII/III:10cases) was 2.37±0.66,the TNR was 3.52±1.41,and the measured APT value in the astrocytoma group (GII/III: 7cases)Was 2.67±0.45 and TNR was 2.41±0.87.In the oligodendroglioma group, the measured APT value was lower and the TNR was higher than in the astrocytoma group. Conclusion: It was suggested that APT may have the same diagnostic ability as MET-PET in diagnosing malignant tumors and distinguishing between recurrence and Pseudoprogression. Patients with an actual APT of 1.81 or higher should consider treatment strategies, and follow-up may be an option for patients with an APT of <1.81.APT,which is not affected by the blood-brain barrier, has little variation in measured values and is considered to be useful for diagnostic imaging of glioma.