Clinical significance of visual cardiac 18F-FDG uptake in advanced non-small cell lung cancer.

Background: Two-deoxy-2-[fluorine-18]-fluoro-d-glucose (¹⁸F-FDG) positron emission tomography (PET) is useful for detecting malignant lesions; however, the clinical significance of cardiac ¹⁸F-FDG uptake in patients with cancer remains unclear. This preliminary study explored the relationship between cardiac ¹⁸F-FDG uptake and advanced diseases such as cancer cachexia in non-small cell lung cancer (NSCLC).

Methods: Forty-three patients with advanced NSCLC who underwent ¹⁸F-FDG PET and complained of weight loss before the first-line systemic therapy were retrospectively included in this study. Visual assessment using a 5-point scale based on ¹⁸F-FDG uptake was performed; a cut-off score of 3 was determined, a low score was 1, 2, or 3, and a high score was 4 or 5).

Results: High and low visual cardiac ¹⁸F-FDG uptakes were observed in 27 (62.8%) and 16 (37.2%) patients, respectively. Of the 43 patients, 17 (39.5%) definitely had cachexia, and 26 (60.5%) did not. A low visual score and standardized uptake value_max for cardiac ¹⁸F-FDG uptake were significantly associated with high metabolic tumor activity (p = 0.009, and p = 0.009, respectively) and a high neutrophil-to-lymphocyte ratio (p = 0.016, and p = 0.047, respectively), whereas a low visual score for cardiac ¹⁸F-FDG uptake and high metabolic tumor activity were significantly associated with cachexia (p = 0.004). The amount of cardiac ¹⁸F-FDG accumulation depicted a close relationship with body mass index, low weight loss, and inflammation. The combination of cachexia and low visual cardiac ¹⁸F-FDG uptake was identified as a significant predictor for poor overall survival (OS) (p = 0.034).

Conclusion: Decreased visual cardiac ¹⁸F-FDG uptake was associated with poor nutritional status and OS, and cachexia in patients with advanced NSCLC.