Survival effect of pre-RT PET-CT on cervical cancer: Image-guided intensity-modulated radiation therapy era.

CONDENSED ABSTRACT: No large-scale, well-designed randomized study with a long-term follow-up has evaluated the survival effect of pretreatment 18-fluorodeoxyglucose positron emission tomography-computed tomography (18 FDG-PET-CT) on patients with stage IB-IVA cervical cancer receiving image-guided intensity-modulated radiation therapy (IG-IMRT). This is the first head-to-head propensity score-matched, nationwide population-based cohort study evaluating this survival effect. The results revealed that pretreatment 18 FDG-PET-CT might be associated with longer survival in patients with stage IB-IVA cervical cancer receiving radiotherapy or concurrent chemoradiotherapy, especially in the IG-IMRT era.

PURPOSE: No large-scale, well-designed randomized study with a long-term follow-up has evaluated the survival effect of pretreatment 18-fluorodeoxyglucose positron emission tomography-computed tomography (18 FDG-PET-CT) on patients with stage IB-IVA cervical cancer receiving image-guided intensity-modulated radiation therapy (IG-IMRT). Therefore, in this propensity score-matched, population-based cohort study, we investigated these survival effects.

PATIENTS AND METHODS: We included 4167 patients with stage IB-IVA cervical cancer receiving radiotherapy (RT) or concurrent chemoradiotherapy (CCRT) through the IG-IMRT technique. The patients were categorized into two 1:2 propensity score-matched groups depending on whether they underwent pretreatment 18 FDG-PET-CT, and their outcomes were compared.

RESULTS: We included 2778 and 1389 patients with cervical cancer in the nonpretreatment and pretreatment PET-CT groups, respectively. Univariable and multivariable analyses revealed an association between pretreatment PET-CT and improved survival in the patients (in the adjusted model, the adjusted hazard ratio [aHR] was 0.88; 95% confidence interval [CI], 0.80-0.97: P = 0.010). Regardless of the cancer stage (early or advanced), pretreatment PET-CT was significantly superior to nonpretreatment PET-CT in terms of all-cause death (aHR, 0.78; 95% CI, 0.60-0.92; P = 0.013 and aHR, 0.90; 95% CI, 0.81-0.99; P = 0.039 for the early [IB-IIA] and advanced stages [IIB-IVA], respectively).

CONCLUSIONS: Pretreatment 18 FDG-PET-CT might be associated with longer survival in patients with stage IB-IVA cervical cancer receiving RT or CCRT, especially in the era of IG-IMRT.