Revolution APEX CT: preliminary assessment of its application value in pancreatic cancer T staging

To evaluate the diagnostic value of Revolution APEX energy spectrum CT imaging and quantitative parameters in T staging of pancreatic cancer (PCa). Energy spectrum CT of 105 patients diagnosed with PCa confirmed by pathologic biopsy and 72 controls from June 2022 to January 2025 were retrospectively obtained. Patients were pathologically confirmed as PCa (15 patients with T1 stage, 23 patients with T2 stage, 46 patients with T3 stage, and 21 patients with T4 stage). Energy spectrum CT captured 40 keV, 70 keV, and 120 kVp-like images (Equivalent to conventional CT images at approximately 120 kVp), which were analyzed for contrast-to-noise ratio (CNR), noise, signal-to-noise ratio (SNR), and subjective scores. Normalized iodine concentration (NICtumor), energy spectrum slope (k), attenuation coefficient, and normalized CT value were quantitatively assessed, and the diagnostic efficacy was analyzed by ROC curve and area under the curve (AUC). The control group and each T-staging subgroup did not differ significantly in age, gender, and BMI, although tumor diameter significantly increased with advancing T-staging (P < 0.001). The 70 keV images outperformed the control group in noise control, SNR, and subjective scores, despite having a significantly lower CNR in the tumor group (P < 0.001). Energy spectrum parameters changed significantly with T staging, including NICtumor (T1: 38.7% to T4: 64.0%), k value (T1: 1.3 to T4: 2.6 HU/keV), and attenuation coefficient (T1: 0.9 to T4: 1.6 HU/keV) (all P < 0.001). The AUC for NICtumor and k combined was 93.40% (sensitivity: 94.03%, specificity: 81.50%) in differentiating early from late stages, significantly surpassing the performance of a single parameter (P < 0.001). This preliminary study suggests that the 70 keV images from Revolution APEX spectral CT, combined with a multiparametric model based on standardized iodine concentration and spectral slope, demonstrate potential value in distinguishing pancreatic cancer T staging. This approach may provide additional quantitative radiographic reference information for preoperative assessment.