[18F]AlF-NOTA-QHY-04 uptake in spleen before anti-tumor therapy may predict degree of myelosuppression for patients with small cell lung cancer.

BACKGROUND: The aim of this study was to assess the value of C-X-C motif chemokine receptor 4 (CXCR4) targeted positron emission tomography/computed tomography ([18F]AlF-NOTA-QHY-04 PET/CT) imaging in spleen for prediction of degree of myelosuppression in patients with small cell lung cancer (SCLC) before therapy. METHODS: 59 patients with SCLC underwent [18F]AlF-NOTA-QHY-04 PET/CT scanning before treatment. The maximum, mean, and peak standard uptake value (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV) and total lesion CXCR4 expression (TLC) of spleen at baseline were acquired. Chemotherapy-based treatment was administered for limited-stage and extensive-stage SCLC. The most severe degree of myelosuppression during the treatment was recorded. Patients were identified as mild and severe myelosuppression. Potential predictors were identified and validated through intergroup difference analysiis, ROC curve assessment, and ordinal regression analysis. RESULTS: Patients with severe myelosuppression exhibited significantly higher splenic uptake values (SUVmax, SUVmean, SUVpeak and TLC) compared to those with mild myelosuppression (all p < 0.05). Regions of interest (ROI) curve analysis identified that higher metabolic parameters, including SUVmax (AUC = 0.853, p < 0.0001), SUVmean (AUC = 0.885, p < 0.0001), SUVpeak (AUC = 0.821, p < 0.0001), TLC (AUC = 0.753, p = 0.0016), were significantly associated with more severe myelosuppression. Multivariate analysis identified SUVmax (p = 0.007) and age (p = 0.005) as significant independent predictors of treatment-related myelosuppression severity. CONCLUSIONS: Our findings suggest that baseline splenic [18F]AlF-NOTA-QHY-04 PET/CT parameters, particularly SUVmax, may help identify patients with small cell lung cancer who are at high risk of severe treatment-related myelosuppression, with older age serving as an additional clinical risk factor.