ABSTRACT
Objective:To investigate the safety and dose of 4D template (real-time adjustable angle template) in the treatment of advanced malignant tumors with 125I seeds. Methods:98 patients with advanced malignant tumors admitted to Department of Thoracic Surgery of Shaanxi Provincial Tumor Hospital were treated with 4D template-navigated radioactive 125I seed implantation from June 2018 to December 2019. Preoperative TPS plan, intraoperative optimization, postoperative verification of immediate dose and postoperative evaluation of implantation dose were performed. The treatment results were observed. Results:All 98 patients completed the seed implantation. The implantation dose of GTV of implantation site receiving external irradiation was (12 489±414) cGy and the dose of no external irradiation was (15 036±514) cGy. V 100% was 84.7%-94.1%, and 88.2%-93.7%. The implantation dose of CTV was (7 450±621) cGy, and (9 080±761) cGy. The quality of dose implantation was evaluated as: excellent in 89 cases (91%, 89/98), good in 7 cases (7%, 7/98), fair in 2 cases (2%, 2/98), and poor in 0 case, respectively. The symptom relief rate of patients with pain was 92%(36/39). The 1-and 2-year local control rates were 61%, 36% and 82%, 54% in patients treated with and without external irradiation, respectively. The difference was statistically significant ( P=0.02). The incidence rates of pneumothorax and hemoptysis were 19%(9/48) and 10%(5/48). No corresponding complications were observed in other parts of the patients. Conclusion:4D template-assisted 125I seed therapy is safe and effective for malignant tumors, and intraoperative adjustment of needle angle and dose optimization can realize the precise control of implantation dose.