Amide proton transfer imaging to evaluate the grading of squamous cell carcinoma of the cervix: A comparative study using 18F FDG PET: Amide Proton Transfer Imaging in Cervix Uteri

BACKGROUND: Amide proton transfer (APT) imaging has shown great potential value in the diagnosis of cancer, but has yet not been applied in cervical carcinoma patients. PURPOSE: To investigate the utility of APT imaging in estimating histologic grades of squamous cell carcinoma of the cervix (SCCC), compared with the standardized uptake value (SUV). STUDY TYPE: Prospective. POPULATION: Thirty-one patients with SCCC (median age 51 years) were included. FIELD STRENGTH/SEQUENCE: Ingenia 3.0 T CX, Axial T1 -weighted imaging (T1 WI), Axial T2 WI, 3D turbo spin echo sequence for APT imaging. ASSESSMENT: Patient pathology was confirmed by surgery and the patients were divided into three groups based on histologic grades: Grade 1 (n = 9), Grade 2 (n = 12), and Grade 3 (n = 10). The APT signal intensity (APT SI), maximum SUV (SUVmax ) and mean SUV (SUVmean ) for each grade were assessed by experienced radiologists in a blinded manner. STATISTICAL TESTS: The obtained parameters were compared by one-way analysis of variance with Tukey honest significant difference post-hoc test. The correlations between the parameters and histologic grades were analyzed by Spearman's correlation coefficient. The Pearson correlation coefficients of the APT SI with the SUVmax and SUVmean were also calculated. RESULTS: The APT SIs for the three grades were significantly different (P = 0.0002). The APT SIs of Grade 2 and Grade 3 had significant differences (P = 0.009). The Spearman correlation coefficients for the correlations between the parameters and histological grade were as follows: APT SI: 0.684 (P = 0.00002), SUVmax : 0.318 (P = 0.082), and SUVmean : 0.261 (P = 0.157). The Pearson correlation coefficients of the APT SI with the SUVmax and SUVmean were 0.108 (P = 0.564) and 0.178 (P = 0.337), respectively. DATA CONCLUSION: The APT SI was positively correlated with the SCCC grades. APT imaging maybe a promising method for predicting SCCC histologic grades. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:261-268.