Objective To investigate the safety and clinical efficacy of permanent implantation of ¹²⁵I radioactive particle in the surgery of malignancies such as brain tumors, liver cancer, cholangiocarcinoma, lung cancer, prostate cancer and malignant teratoma.

Methods Thirty eight patients proved by puncture biopsy, his-tology or cytology were retrospectively analyzed.Three-D images of the tumor were reconstructed using treat-ment planning system(TPS), the number and the dose rate distribution of ¹²⁵I seeds were calculated.The matched peripheral dose of ¹²⁵I seeds implantation was 60~120Gy, the number of ¹²⁵I seeds implanted ranged from 6~40 per lesion, and the median amount of implanted ¹²⁵I seeds were 23.

Results Twelve months followup after the therapy showed 9 cases of complete relief, 24 cases of partial relief and 5 cases of no change.The overall effective rate(complete relief+partial relief)of 12 months was 86.8%.

Conclusion Permanent implantation of ¹²⁵Iradioactive particle in the surgery of malignancies treatment is a safe, effective treatment fortumors.