Amide Proton Transfer-Weighted Imaging and Multiple Models Intravoxel Incoherent Motion-Based ¹⁸F-FDG PET/MRI for Predicting Progression-Free Survival in Non-Small Cell Lung Cancer

Background: Amide proton transfer-weighted imaging (APTWI) and multiple models intravoxel incoherent motion (IVIM) based F-18-FDG PET/MR could reflect the microscopic information of the tumor from multiple perspectives. However, its value in the prognostic assessment of non-small cell lung cancer (NSCLC) still needs to be further explored. Purpose: To determine whether pretreatment APTWI, mono-, bi-, and stretched-exponential model IVIM, and F-18-FDG PET-derived parameters of the primary lesion may be associated with progression-free survival (PFS) in NSCLC. Study Type: Prospective. Population: Seventy-seven patients (mean age, 62years, range, 20-81years) with 37 men and 40 women were included. Field Strength/Sequence: 3.0T F-18-FDG PET/MRI, single shot echo planar imaging sequences for IVIM and fast spin-echo sequences with magnetization transfer pulses for APTWI. Assessment: Patient clinical characteristics (age, sex, smoke, subtype, TNM stage, and surgery), PFS (chest CT every 3months, median follow-up was 18months, range, 4-27months), and APTWI (MTRasym(3.5ppm)), IVIM (ADC(stand), D, D*, f, DDC, and alpha), and F-18-FDG PET (SUVmax, MTV, and TLG) parameters were recorded. Statistical Tests: Proportional hazards model, concordance index, calibration curve, decision curve analysis (DCA), and Log-rank test. A P value <0.05 was considered statistically significant. Results: Histological subtype, TNM stage, MTV, D*, and MTRasym(3.5ppm) were all independent predictors of PFS. A prediction model based on these predictors was developed with a C-index of 0.895 (95% CI: 0.839-0.951), which was significantly superior to each of the above predictors alone (C-index=0.629, 0.707, 0.692, 0.678, and 0.558, respectively). The calibration curve and DCA indicated good consistency and clinical utility of the prediction model, respectively. Log-rank test results showed a significant difference in PFS between the high- and low-risk groups. Data Conclusion: APTWI and multiple models IVIM based F-18-FDG PET/MRI can be used for PFS assessment in NSCLC.