CT-guided 125I seed implantation in the treatment of malignant pulmonary metastases

Objective To evaluate the clinical outcomes and the prognostic factors in patients with pulmonary metastases treated with CT-guided radioactive 125I seed implantation(CTRISI).Methods A total of 50 patients were treated with implantation of 125I radioactive seeds under computed tomography (CT)guidance or combined with surgical resection.There were 10(20％)patients with colorectal cancer,8(16％)patients with malignant fibrous histiocytoma,5(10％)patients with sarcoma,22 (44％)patients with other cancer,respectively.CTRISI was the only treatment in 45 patients(90％)and combined with surgical resection in 5(10％).The local control rate,the survival rate and the factor associated with overall survival were evaluated.Results The D90％ was(112.3 ± 12.2)Gy,the V90 was 91.3％ ± 8.2％,and the postoperative matched peripheral dose(MPD)was 106.2 Gy.The local control rate for 1-,2-,3-,4-,5-year were 95.8％,86.5％,56.6％,42.4％,31.1％,respectively.At a mean follow-up of 26 months(7-74 months),6 patients were alive.The median survival time was 27.1 months.The survival rate for 1-,2-,3-,4-,5-year were 83.4％,52.3％,38.7％,20.3％,13.7％,respectively.Lesion size ≤ 4 cm or ＞ 4 cm was an important prognostic factor associated with overall survival(x2=4.621,P＜0.05)and disease-free survival(x2=7.548,P＜0.05).Conclusions CTRISI is safe in these patients with pulmonary metastases,with promising results.Surgical resection remains the standard for resectable patients,while CTRISI alone or combined with surgery might offer an alternative in selected patients. Key words: Pulmonary metastases; Radioactive 125I seeds; Surgical resection