Prognostic significance of ¹⁸F-fluorodeoxyglucose uptake of bone marrow measured on positron emission tomography in patients with small cell lung cancer

Objectives: We investigated whether ¹⁸F-fluorodeoxyglucse (FDG) uptake of bone marrow (BM) on positron emission tomography/computed tomography (PET/CT) has implications for predicting clinical outcomes in patients with small cell lung cancer (SCLC).

Methods: We retrospectively enrolled 70 SCLC patients who underwent FDG PET/CT prior to treatment. On PET/CT, maximum FDG uptake of all tumor lesions (Tmax), coefficient of variation (COV) of FDG uptake of primary tumor, and mean FDG uptake of BM (BM SUV) were measured. The relationships of BM SUV with PET/CT parameters of SCLC and serum markers were evaluated. Univariate and multivariate analyses were performed to assess the significance of BM SUV for predicting progression-free survival (PFS) and overall survival (OS).

Results: BM SUV had significant positive correlations with Tmax, COV of primary tumor, white blood cell count, and serum C-reactive protein level (p < .05). On univariate analysis, BM SUV showed significant association with only PFS (p = .006). On multivariate analysis, Veterans Administration Lung Cancer Study Group (VALSG) stage, N stage, M stage, Tmax, and BM SUV were independent prognostic factors for PFS (p < .05) and, for OS, VALSG stage and M stage were independent prognostic factors (p < .05). Among patients with limited disease, patients with high FDG uptake of BM had significantly worse PFS than did those with low FDG uptake of BM (p < .05), but, there was no significant difference in PFS between patients with extensive disease and patients with limited disease and high FDG uptake of BM (p > .05).

Conclusion: FDG uptake of BM was an independent predictor of disease progression in SCLC patients. Patients with limited disease and high FDG uptake of BM had similar PFS to those with extensive disease.