Objective We analyzed the correlation of ¹⁸F-fluorodeoxyglucose (FDG) uptake into primary tumors using the maximum standardized uptake value (SUV_max) and clinicopathological factors of disease. The impact of the pretreatment SUV_max of the primary tumor on survival was investigated.

Materials and Methods The records of 149 patients with biopsy-proven cervical cancer treated with definitive chemoradiotherapy (ChRT) were reviewed. All patients underwent pretreatment FDG positron emission tomography with computed tomography, and posttherapy FDG positron emission tomography with computed tomography was performed within a median interval of 4.2 months (range, 3.0–11.2 months) after the completion of chemoradiotherapy.

Results The mean SUV_max in patients with lymph node metastasis was significantly higher than that in patients without metastasis (19.7 ± 8.2 vs 16.4 ± 8.2, respectively; P = 0.01). A significant difference existed between tumor size (<4 vs ≥4 cm) and the primary tumor SUV_max (14.7 ± 6.6 vs 18.7 ± 8.5, respectively; P = 0.02). The primary tumor pretreatment SUV_max for patients with complete remission was significantly lower than that of patients with partial response or progressive disease (15.6 ± 5.7 vs 28.0 ± 9.9, respectively; P < 0.001). The relationship between primary tumor FDG uptake and survival was evaluated by the cutoff value determined by receiver operating characteristic curve analysis. The area under the curve was 0.901 (P < 0.001; 95% confidence interval, 0.848–0.954), and 15.6 was determined as the SUV_max cutoff value. The 4-year actuarial overall survival (OS) and disease-free survival for SUV_max of less than 15.6 compared with SUV_max of 15.6 or greater were 85% vs 34% (P < 0.001) and 80% vs 29%, respectively (P < 0.001). In multivariate analysis, age, SUV_max of 15.6 or greater, and lymph node metastasis were independent prognostic factors of OS, and International Federation of Gynecology and Obstetrics stage IIB or higher, SUV_max of 15.6 or greater, and lymph node metastasis were significant factors for disease-free survival.

Conclusion The primary tumor pretreatment SUV_max is correlated with increased tumor size and lymph node involvement at diagnosis, how well the primary tumor responds to treatment, the likelihood of disease recurrence, and OS.