The treatment response evaluation through the combination of contrast-enhanced ultrasound and squamous cell carcinoma antigen in cervical cancer.

Background: The evaluation of the treatment response after concurrent chemotherapy and radiotherapy (CCRT) for locally advanced cervical cancer is closely related to the formulation of treatment strategies. Magnetic resonance imaging (MRI) is a recommended method for efficacy evaluation; however, a unified consensus has not yet been reached on its use, and it has its limitations. This study aimed to evaluate the diagnostic value of a combination of contrast-enhanced ultrasound (CEUS) parameters and the squamous cell carcinoma antigen (SCC-Ag) to establish another efficient and feasible examination method.

Methods: The data of 94 patients with cervical cancer who underwent transvaginal contrast-enhanced ultrasound (TV-CEUS) from October 2020 to March 2023 were retrospectively collected. Based on the inclusion and exclusion criteria, 70 patients diagnosed with cervical squamous cell carcinoma (SCC) who underwent CCRT were selected for inclusion in the study. The patients were divided into the residual disease (RD) group (comprising 26 patients) and the complete response (CR) group (comprising 44 patients) according to the diagnostic standard. Data on the grayscale echogenicity, color Doppler flow imaging (CDFI), CEUS parameters, and the SCC-Ag of all the patients were collected by two experienced radiologists. Inter-observer reliability was assessed using the intraclass correlation coefficient (ICC). Receiver operating characteristic (ROC) curves were created based on the non-parametric U-test or t-test results for the two groups. Delong's test was used to compare the area under the curve (AUC) between different ROC curves. A subgroup analysis was conducted based on the patient's age, tumor diameter, and disease stage.

Results: The ICCs between the two observers ranged from 0.915 and 0.947. Hypervascular hyper-enhancement in the arterial phase, hypo-enhancement in the venous phase, and the SCC-Ag differed significantly between the RD and CR groups (P<0.05). The AUC of the ROC curve combining these indicators was 0.890 [95% confidence interval (CI): 0.792-0.989], which was higher than the AUC of any indicator alone (P<0.05). The subgroup analysis showed that the AUCs of the patients aged ≥53 and <53 years were 0.922 (95% CI: 0.816-1.00) and 0.896 (95% CI: 0.782-1.00), respectively, those of the patients with stage II, III, and IV were 0.881 (95% CI: 0.732-1.00), 0.955 (95% CI: 0.894-1.00), and 1.000 (95% CI: 1.00-1.00), respectively, and those of the patients with a tumor diameter ≤10 mm, 10 mm < tumor diameter (post) <20 mm, and tumor diameter (post) ≥20 mm were 0.976 (95% CI: 0.910-1.00), 0.883 (95% CI: 0.763-1.00), and 1.00 (95% CI: 1.00-1.00) respectively.

Conclusions: Transvaginal ultrasound (TVUS), TV-CEUS, and the SCC-Ag can be used in combination to evaluate the patient response to CCRT in locally advanced cervical SCC. This integrated approach enhanced the accuracy of the diagnosis of residual lesions and may be helpful in treatment plan optimization.