Takeshi Yoshikawa

Background Amide proton transfer (APT) weighted chemical exchange saturation transfer CEST (APTw/CEST) magnetic resonance imaging (MRI) has been suggested as having the potential for assessing the therapeutic effect of brain tumors or rectal cancer. Moreover, diffusion‐weighted imaging (DWI) and positron emission tomography fused with computed tomography by means of 2‐[fluorine‐18]‐fluoro‐2‐deoxy‐D‐glucose (FDG‐PET/CT) have been suggested as useful in same setting. Purpose To compare the capability of APTw/CEST imaging, DWI, and FDG‐PET/CT for predicting therapeutic effect of chemoradiotherapy (CRT) on stage III non‐small cell lung cancer (NSCLC) patients. Study Type Prospective. Population Eighty‐four consecutive patients with Stage III NSCLC, 45 men (age range, 62–75 years; mean age, 71 years) and 39 women (age range, 57–75 years; mean age, 70 years). All patients were then divided into two groups (Response Evaluation Criteria in Solid Tumors [RECIST] responders, consisting of the complete response and partial response groups, and RECIST non‐responders, consisting of the stable disease and progressive disease groups). Field Strength/Sequence 3 T, echo planar imaging or fast advanced spin‐echo (FASE) sequences for DWI and 2D half Fourier FASE sequences with magnetization transfer pulses for CEST imaging. Assessment Magnetization transfer ratio asymmetry (MTR asym ) at 3.5 ppm, apparent diffusion coefficient (ADC), and maximum standard uptake value (SUV max, ) on PET/CT were assessed by means of region of interest (ROI) measurements at primary tumor. Statistical Tests Kaplan–Meier method followed by log‐rank test and Cox proportional hazards regression analysis with multivariate analysis. A P value <0.05 was considered statistically significant. Results Progression‐free survival (PFS) and overall survival (OS) had significant difference between two groups. MTR asym at 3.5 ppm (hazard ratio [HR] = 0.70) and SUV max (HR = 1.41) were identified as significant predictors for PFS. Tumor staging (HR = 0.57) was also significant predictors for OS. Data Conclusion APTw/CEST imaging showed potential performance as DWI and FDG‐PET/CT for predicting the therapeutic effect of CRT on stage III NSCLC patients. Level of Evidence 2 Technical Efficacy Stage 1