Evaluation of kidney stone-related renal infection status by 18F-FDG PET/CT in lung cancer patients with concomitant nephrolithiasis: a multicenter study.

INTRODUCTION

Positron emission tomography/computed tomography (PET/CT) has demonstrated significant clinical utility in the localization of infectious foci, yet its application in nephrolithiasis-associated renal infections remains underexplored.

METHODS

This retrospective cohort study assessed the diagnostic efficacy of 18F-FDG PET/CT in 120 lung cancer patients with radiologically confirmed nephrolithiasis across multiple centers. Quantitative analyses included calculation of diagnostic accuracy parameters, Pearson correlation between standardized uptake values (SUVmax), calculi burden, and serum cytokine profiles. Complementary experimental validation was performed using a murine calcium oxalate (CaOx) nephrocalcinosis model, utilizing micro-CT to analyze crystal deposition and inflammatory activity.

RESULTS

Clinically, PET/CT detected focal FDG uptake in 77 patients (64.2%), demonstrating 85.7% sensitivity and 76.7% specificity for infection identification. SUVmax positively correlated with stone burden and proinflammatory cytokines. The larger the size of the stone, the more severe the kidney infection, which in turn further aggravated the development of the stone. Furthermore, preclinical micro-PET/CT in CaOx mice revealed spatial concordance between crystal deposition and metabolic activity, paralleling human cytokine trends.

DISCUSSION: In lung cancer patients with concomitant nephrolithiasis, 18F-FDG PET/CT demonstrates high diagnostic yield for detecting renal infection foci and may serve as a valuable tool for preoperative risk assessment. These findings provide a foundation for future studies in broader nephrolithiasis populations.