Evaluation of risk factors for difficult-to-control pain (VAS score > 3) at two months after late-stage non-small cell lung cancer treatment with iodine-125 radioactive particle implantation combined with chemotherapy

Purpose:
This study aimed to explore the risk factors associated with difficult-to-control pain (visual analog scale [VAS] score > 3) experienced by patients with advanced non-small cell lung cancer (NSCLC) assessed at two months after receiving iodine-125 (¹²⁵I) radioactive seed implantation combined with chemotherapy, in order to improve pain management and enhance patient quality of life.

Material and methods:
A total of 87 patients diagnosed with advanced NSCLC were included in the study, all of whom underwent treatment using ¹²⁵I radioactive seed radiotherapy and chemotherapy. Through univariate and multivariate analyses, the risk factors affecting pain control at two months post-treatment were identified. Predictive and survival analyses were done using ROC curves and Kaplan-Meier survival curves.

Results:
The results indicated that minimal pleural distance, smoking history, and pleural effusion were independent risk factors influencing the control of pain shown in VAS scores. Moreover, a non-linear relationship between minimal pleural distance and difficulty of pain control was observed, indicating that the risk of uncontrolled pain decreases when the minimal pleural distance reaches ≥ 10.84 millimeters. ROC curve analysis demonstrated that the predictive capability of minimal pleural distance was the highest.

Conclusions:
Minimal pleural distance, smoking history, and pleural effusion are significant factors in predicting the difficulty of pain control in patients with advanced NSCLC receiving ¹²⁵I radioactive seed implantation combined with chemotherapy at two months post-treatment. Patients with a minimal pleural distance of less than 10.84 millimeters are more likely to experience uncontrolled pain after treatment. Therefore, developing predictive models may assist clinicians in more accurately evaluating treatment efficacy and patients’ pain management needs.