Spectral CT-derived quantitative imaging parameters combined with inflammatory markers for exploratory preoperative...

Pathological grade and muscular invasion determine bladder cancer treatment and prognosis. Conventional CT lacks quantitative tumor characterization, while gemstone spectral imaging CT (GSI-CT) provides perfusion-related quantitative metrics; systemic inflammatory markers also correlate with tumor aggressiveness.

To explore whether combined GSI-CT parameters and inflammatory markers improve preoperative bladder cancer grading, and analyze their association with muscular invasion.

This single-center retrospective study enrolled 61 pathologically confirmed bladder cancer patients (26 low-grade, 35 high-grade) with preoperative GSI-CT. Venous-phase iodine concentration (IC), spectral slope λHU, effective atomic number (Zeff) and four inflammatory indices were measured. Between-group comparisons, logistic regression and DeLong ROC comparison were performed using SPSS 25.0 and R 4.3.3 (α = 0.05).

Venous-phase IC, λHU and Zeff were significantly elevated in high-grade lesions, while lymphocyte-to-monocyte ratio (LMR) was markedly lower (all P < 0.05). The λHU + LMR combined model yielded an AUC of 0.877 versus LMR alone (AUC = 0.835), with no statistically significant diagnostic improvement (P = 0.061) by DeLong test. After adjusting for tumor diameter, both λHU and LMR remained independent grading predictors. A post-hoc inflammation-free subgroup analysis suggested λHU may partially offset the confounding effect of systemic inflammation on LMR performance, though this result is exploratory and requires further validation.

Combined GSI-CT and LMR jointly reflect tumor angiogenesis and host immunity, yet the dual-parameter model offered no statistically meaningful incremental grading value over LMR in this NMIBC-dominated single-center cohort. The auxiliary value of λHU needs large multi-center prospective verification.