# Association between FDG accumulation in interstitial lesions and acute exacerbation risk in lung cancer: multicenter analysis

## TL;DR

This study examines whether FDG accumulation in interstitial lesions is linked to acute exacerbation risk in lung cancer patients with interstitial pneumonia.

## Contribution

The study is one of the few to investigate FDG accumulation in interstitial lesions as a potential predictor of acute exacerbation in lung cancer patients with interstitial pneumonia.

## Key findings

- No significant association was found between FDG accumulation in interstitial lesions and acute exacerbation risk.
- Patient characteristics and imaging patterns did not differ significantly between those who experienced AE and those who did not.
- FDG accumulation levels in interstitial lesions were not predictive of AE development.

## Abstract

Interstitial pneumonia (IP) is associated with poor prognosis in lung cancer and increases the risk of acute exacerbation (AE). Few studies analyzed the relationship between fluorodeoxyglucose (FDG) accumulation in IP with lung cancer complicated with IP and the incidence of AE. This study investigates the association between FDG accumulation in the interstitial lesions and the AE incidence in patients with lung cancer complicated with IP.

This multicenter, retrospective study included patients with lung cancer complicated with IP who received chemotherapy. All CTs at baseline and the onset of AE were centrally adjudicated. The SUVpeak and FDGscore for interstitial lesions were calculated from FDG positron emission tomography images before chemotherapy, and these values were corrected using reference uptake. To determine the association with AE risk, clinical characteristics and imaging findings were compared between patients who developed AE and those who did not. Subsequently, logistic regression analysis was performed to identify risk factors for the development of AE.

One hundred and thirteen patients who met the eligibility criteria were enrolled from three centers. However, 9 patients with a clinical diagnosis of collagen-related interstitial pneumonia were excluded due to predominant FDG accumulation in the interstitial lesions, and 104 patients were analyzed. Of those patients, 31.7% (33/104) developed all grade AE and 18.3% (19/104) developed grade 3 or higher. There were no significant differences in patient characteristics and imaging patterns between those with and without AE. SUVpeak in the ipsilateral and contralateral interstitial lesions to the tumor and the FDGscore did not differ between those with or without AE.

No association was observed between FDG accumulation in interstitial lesions and AE in patients with lung cancer complicated with IP. We may have to remain cautious about the risk of AE in lung cancer complicated with IP, even when FDG accumulation in interstitial lesions is high or low.

The online version contains supplementary material available at 10.1007/s11604-025-01869-4.