0.05 ). The total effective rate was 89.29 % and 62.50 % in Group A and Group B respectively, the differences being significant ( P

BACKGROUND: As a new radiotherapy for malignant tumor, brachytherapy of radioactive seed implantation enables the inter-tissue implantation of radioactive seeds to be applied further with the appearance of seed implantation treatment planning system (TPS), and the gradual consummation of ultrasound and CT-guided precise positioning system.OBJECTIVE: To evaluate the methods, feasibility, safety and efficacy of CT-guided iodine-125 (125I) implantation for malignant tumors.DESIGN: A controlled observation before and after implantation.SETTING: The First People's Hospital of Hefei City.PARTICIPANTS: Twenty-one patients with malignant tumors, who were not suitable for surgical treatments of operation,were selected from the First People's Hospital of Hefei City from January 2004 to March 2005. There were 26 lesions, including 9 lesions of primary unresectable carcinoma and 17 lesions of metastasis tumors.METHODS: Under CT guidance, 125I seeds were implanted into malignant tumor according to TPS, the radioactivity quantum were 22, 26, 30 and 33 MBq per granule. Larger radiation 125I wes suitable for the implantation in the center of a lesion and smaller ones were for the margin of the lesion and the peripheral region of some important organisms such as vessels and nerves. The interval between larger seeds was about 1.5 cm whereas the interval between smaller ones was about 1.0 cm.MAIN OUTCOME MEASURES: The seed distribution, existence of complication and changes of the size of lesion after implantation were observed.RESULTS: ① The seeds were implanted successfully in all the 21 cases. No complication was observed. The practical distribution of the implanted seeds was basically the same as the scheduled scheme before implantation. All the 21 patients were involved in the analysis of results. ② The number of seeds implanted in one lesion was 5 to 40 (mean 14).Pain relief was obtained in all 10 cases of malignant tumors of bone after implantation. Follow-up CT reexamination demonstrated that 18 lesions were obviously diminished, necrosis was found in 4 lesions and remaining 4 lesions had no significant changes in size. ③ The average sizes of 14 lesions in 11 patients at 5-7 months after implantation were obviously smaller than those before implantation (1.84 cm vs 3.41 cm, t =5.7237, P ＜ 0.001). The average sizes of 12 lesions in 10 patients at 8-10 months after implantation were also obviously smaller than those before implantation (1.96 cm vs 3.43 cm, t =5.577 8, P ＜ 0.002).CONCLUSION: CT-guided 125I implantation is a safe, effective and feasible method for the treatment of malignant tumor.

Objective To evaluate the role and technical advantages of CT in 125Ⅰseed implantation in the treatment of tumors. Methods CT-guided 125Ⅰ seed implantation in 45 cases of cancer patients treated 57 times in 51 lesions,CT were used to evaluate the progress of lesions after 125Ⅰ seed implantation 1,2,6 months. Results All procedures were once successful and the total effective rate was 74.5% without any serious complications. Fifty CT examinations immediately after implantation showed satisfactorily seeds distribution but seven cases less satisfactorily that include particles overlap,the location is too close to the lesion edge,the larger the radiation cold spots,etc. Follow-up CT reexamination in 1,2 and 6 months demonstrated that CT examinations showed satisfactorily seeds distribution but accurate seeds number,which could be solved by combined with MPR images and the positioning piece. Conclusions CT-guided 125Ⅰ seed implantation treatment of tumors was a safe,reliable and effective minimally invasive treatment. CT in the preoperative treatment of seed implants planning,precise intraoperative guidance,quality assurance and efficacy of postoperative assessment had a greater role and application advantages.