Objective To explore the value of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT metabolic parameters in predicting the efficacy of concurrent chemoradiotherapy (CCRT) in metastatic lymph nodes of intermediate–advanced cervical squamous cell carcinoma.

Methods The clinical data of 50 patients with intermediate–advanced cervical squamous cell carcinoma (stage ⅢC, 22 cases; stage ⅣA, 4 cases; and stage ⅣB, 24 cases) who underwent CCRT in the Affiliated Hospital of North Sichuan Medical College from December 2016 to December 2020 were analyzed retrospectively. The patients aged (50.7±8.6) years. In accordance with the changes in metastatic lymph nodes before and after CCRT, the patients were divided into effective group (36 cases) and ineffective group (14 cases). The ¹⁸F-FDG PET/CT metabolic parameters maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and other related clinical features, such as age and clinical stage, were analyzed to predict the efficacy of CCRT in metastatic lymph nodes of intermediate-advanced cervical squamous cell carcinoma. In accordance with normal distribution, the measurement data were expressed by \bar x\pm s , and comparison between groups was conducted by two independent sample t-test (uniform variance). The measurement data that did not conform to the normal distribution were represented by M(Q₁, Q₃), and Mann-Whitney U test was used for comparison between groups. The classification variables were expressed as an cases (%), and χ² test or Fisher's exact test was used for comparison between groups. In accordance with the receiver operating characteristic (ROC) curves, the best critical value of ¹⁸F-FDG PET/CT metabolic parameters for predicting the efficacy of CCRT in metastatic lymph nodes was obtained, and the classified variables were classified on the basis of the optimal critical value. Univariate Logistic regression analysis was used to determine the potential independent predictors and predictive efficacy of CCRT in metastatic lymph nodes of intermediate-advanced cervical squamous cell carcinoma.

Results No significant difference was found in the age, clinical stage, and SUV_max between the two groups (t=0.464, Fisher's exact test, Z=0.864; all P>0.05). Significant differences were found in the MTV and TLG between the two groups (Z=3.457, 3.630; both P<0.05). The univariate Logistic regression analysis showed that MTV and TLG were correlated with the efficacy of CCRT in metastatic lymph nodes of intermediate-advanced cervical squamous cell carcinoma (OR=7.333, 15.600; both P<0.05). The multivariate Logistic regression analysis showed that TLG<26.265 g (OR=8.335, 95%CI: 1.040–66.817, χ²=3.987; P=0.046) was a potential independent predictor of CCRT efficacy in metastatic lymph nodes of intermediate-advanced cervical squamous cell carcinoma. The ROC curves to evaluate the efficacy of TLG in the CCRT treatment of metastatic lymph nodes showed that the area under curve was 0.833 (95%CI: 0.718–0.949, P<0.001).

Conclusions Correlation exists among MTV, TLG, and the efficacy of CCRT in the metastatic lymph nodes of intermediate–advanced cervical squamous cell carcinoma, and TLG<26.265 g was found to be the highest predictive value.