Nomogram for Predicting the Recurrence Rate in Selective Radiofrequency Thermocoagulation of the Trigeminal Nerve Based on Regression via Least Absolute Shrinkage and Selection Operator.

Background: Computed tomography-guided percutaneous selective radiofrequency thermocoagulation (RFT) of the trigeminal nerve is a novel, minimally invasive technique for the treatment of trigeminal neuralgia, but the high recurrence rate after surgery might pose a serious problem.

Objectives: The purpose of this study was to explore the risk factors affecting the recurrence rate after RFT and to predict the recurrence rate and provide evidence for the early prediction.

Study Design: A single-center retrospective study.

Setting: This study was carried out in the Affiliated Hospital of Jiaxing University in China.

Methods: One hundred thirty-nine patients were included in this study. The cumulative survival rates according to temperature and type of pain were estimated by the Kaplan-Meier analysis. The least absolute shrinkage and selection operator Cox regression model was used to build the nomogram. Time-independent receiver operating characteristic curve analysis confirmed the signature's predictive capacity. A calibration curve was generated to judge the accuracy of absolute risk predictions, and Brier scores were used to quantitatively evaluate the calibration. Decision curve analysis was applied to comprehensively evaluate the clinical effectiveness of the model. A multiparameter nomogram was used to analyze the scores and predict the risk of relapse.

Results: Three predictors were screened by multivariate Cox regression analysis. Pain grade (refit hazard ratio [HR]: 1.6807; 95% confidence interval [CI]: 1.1963-2.3613) and type of pain (HR: 6.2802; 95% CI: 3.3705-11.7021) were considered to be risk factors affecting the recurrence rate after RFT, while temperature (HR: 0.5203; 95% CI: 0.2859-0.9468) was identified as a protective factor. The recurrence rate within 2 years in 85°C group was 51.09%, while that in 95°C group was 29.79%. The nomogram exhibited good discrimination and calibration. Compared with the preoperative period, all of the patients' postoperative Numeric Rating Scale scores (NRS-11)decreased significantly (P < 0.05). The main postoperative complication was numbness, with a gradual decrease in the Barrow Neurological Institute score over time. Autonomic symptoms and decrease of masticatory muscle function were the secondary postoperative complications, and no other adverse events were observed. Overall patient satisfaction at 2 years postoperatively was 7.83 ± 1.93.

Limitations: This study contains a small sample size from a single center and the conclusion of randomized controlled trials will be more convincing.

Conclusions: Increasing temperature can effectively reduce the recurrence rate after RF, and the combination of atypical pain and higher NRS-11s could be a risk factor increasing the recurrence rate. The novel nomogram exhibited favorable survival stratification accuracy and shown a great potential for screening high-risk groups and evaluating the risk of recurrence rate.