The Role of Pelvic Ultrasound in Monitoring and Predicting Therapeutic Efficacy of <scp>GnRHa</scp> for Central Precocious Puberty

PURPOSE: To investigate the role of pelvic ultrasound in monitoring therapeutic response and predicting long-term outcomes in girls with central precocious puberty (CPP) undergoing gonadotropin-releasing hormone agonist (GnRHa) therapy. METHODS: In this retrospective study, 219 girls aged 6-8 years (69 with CPP and 150 age-matched controls) were enrolled between February 2018 and September 2021 at Wuzhong People's Hospital of Suzhou. Pelvic ultrasound was used to measure uterine and bilateral ovarian volume, follicle number ≥ 4 mm, and maximum follicle diameter. A total of 69 girls with precocious puberty were treated with GnRHa and followed up. The data of pelvic ultrasound, breast ultrasound, and bone age index were collected for 3, 6, and 12 months after treatment, and carry on the contrast analysis. A total of 252 girls, aged 6-8 years, who were diagnosed as CPP and treated with GnRHa at the same hospital, were randomly divided into two groups: Modeling Group (N = 176) and validation group (N = 76). According to the change of growth rate after 1 year treatment and other evaluation indexes, the patients were divided into two groups: the group with significant therapeutic effect and the group without significant therapeutic effect, to collect the related data of ultrasound measurement of uterus and ovary and to construct the prediction model of curative effect. The model was validated by validation group. RESULTS: The ultrasonic parameters of pelvic cavity in the treatment group were significantly different from those in the control group (p < 0.05). In the treatment group, there were significant differences in every stage before and after treatment except for 3 months (p < 0.05). To analyze the related data of pelvic ultrasound examination in the significant-response group and the group with no significant therapeutic effect, the established joint prediction equation of pelvic ultrasound related parameters: Logit (p) = 7.8696-0.4435 × (maximum follicle diameter)-0.2640 × (number of follicles ≥ 4 mm)-0.4425 × age. The joint prediction model equation yielded an AUC of 0.747 (95% CI: 0.672, 0.822). The results of the validation group were similar to those of the modeling group, with an AUC of 0.730 (95% CI: 0.610, 0.851). CONCLUSION: Ultrasound can dynamically evaluate the efficacy of GnRHa in the treatment of central precocious puberty. Pelvic ultrasound has significant predictive value in evaluating the efficacy of GnRHa therapy at the early diagnosis of central precocious puberty.