Radioactive seed brachytherapy for malignant tumors with navigation system and 3D-printing template: a propensity score-matched analysis

To compare accuracy and efficacy between Image Navigation System (INS, an optical tracking system for real-time needle guidance) combined with 3D printing template (3DPT) versus 3DPT alone in radioactive I-125 seed brachytherapy for malignant tumors. 157 patients who underwent CT-guided brachytherapy from July 2020 to June 2023 were included. 27 cases using INS+3DPT were matched 1:1 with cases using 3DPT alone based on propensity score-matching. Needle path error, dose accuracy, and clinical outcomes were compared. Results: Mean needle errors were comparable between INS+3DPT and 3DPT groups: angle error (0.5° vs. 0.5°), depth error (3.5 mm vs. 4.4 mm), and tip error (3.1 mm vs. 2.9 mm). No significant differences were found in dosimetric parameters (D90, V100, V150, V200, CI, EI, HI) or clinical outcomes. The 2-year local control rates were 35.6% and 49.2%, while 2-year overall survival rates were 45.1% and 34.8% for INS+3DPT and 3DPT groups respectively (p > 0.05). Conclusion: INS+3DPT showed no significant advantages over 3DPT alone. The use of 3DPT without INS can achieve satisfactory therapeutic quality in current clinical practice.