The Role of Ultrasound in the Evaluation of Inguinal Lymph Nodes in Patients with Vulvar Cancer: A Systematic Review and Meta-Analysis

Simple Summary Currently, around 30% of vulvar cancer cases at first diagnosis are spread to the inguinal lymph nodes. Preoperative staging of patients affected by vulvar carcinoma is still a hot topic. To date, MRI has shown a great diagnostic accuracy on defining disease extension to soft tissue and deep organs. At present, regarding the study of inguinal nodes, the PET/CT scan has shown a high negative predictive value, although in the presence of a suspicious/positive report it should be taken with caution. We report the results of a study aimed to investigate the role of groin ultrasound in the assessment of lymph nodal status in vulvar cancer. Furthermore, this review represents the most accurate collection of papers available in the literature. This work demonstrates that groin ultrasound can be considered a valuable tool for risk assessment of the presence of groin lymph node metastases. Achieving a high diagnostic accuracy would allow tailored surgical planning with access to minimally invasive surgery techniques for an increasing number of patients. Objective. To determine the efficacy of ultrasound in assessing the inguinal lymph nodes in patients with vulvar cancer. Methods. A systematic review of published research up to October 2020 that compares the results of ultrasound to determine groin node status with histology was conducted. All study types that reported primary data on the role of ultrasound in the evaluation of groin lymph nodes in vulvar cancer were included in the systematic review. Data retrieved from the included studies were pooled in random-effects meta-analyses. Results. After the screening and selection process, eight articles were deemed pertinent for inclusion in the systematic review and meta-analysis. The random-effects model showed a pooled Se of 0.85 (95% CI: 0.81-0.89), Sp of 0.86 (95% CI: 0.81-0.91), PPV of 0.65 (95% CI: 0.54-0.79) and NPV of 0.92 (95% CI: 0.91-0.94). There was a pooled LR+ and LR- of 6.44 (95% CI: 3.72-11.4) and 0.20 (95% CI: 0.14-0.27), respectively. The pooled accuracy was 0.85 (95% CI: 0.80-0.91). Conclusions. Although the studies had small sample sizes, this review represents the best summary of the data so far. Ultrasound has revealed high sensitivity and high negative predictive value in the assessment of nodal status in vulvar cancer.