Objective To evaluate the clinical efficacy and safety of CT-guided percutaneous osteoplasty(POP)in the treatment of osteolytic metastases of the pelvis.Methods The clinical data of a total of 40 patients with pelvic osteolytic metastases,who received CT-guided POP at the Affiliated Zhongda Hospital of Southeast University between October 2011 and December 2021,were collected.Visual analogue scale(VAS)score was used to evaluate the clinical pain relief degree at one week,one month,3 months,6 months and 12 months after POP,and the joint function and the used dose of analgesic drugs were recorded.The preoperative and the postoperative 3-month,6-month and 12-month extents of the pelvic tumor destruction were compared.Based on the progression of local lesions within 12 months of follow-up,the patients were divided into controlled group and progression group.The proportion of using systemic anti-tumor therapy,the size of lesion,the amount of bone cement injected,and the cement filling ratio were compared between the two groups.Results Successful surgical procedure was accomplished for 57 lesions in 40 patients.The mean amount of bone cement injected was(4.56±2.25)mUpoint.In the 40 patients,the preoperative and the postoperative one-week,one-month and 3-month VAS score were(8.00±0.85)points,(2.05±0.96)points,(2.08±0.94)points and(2.18±0.84)points respectively,the difference in VAS score between preoperative value and postoperative one-week value was statistically significant(P＜0.01).In 37 patients,the postoperative 6-month VAS score was(2.35±0.54)points;and in 28 patients,the postoperative 12-month VAS score was(2.43±0.79)points.The differences in VAS score between postoperative one-week value and postoperative one-month,3-month,6-month,and 12-month values were not statistically significant(all P＞0.05),while the differences in VAS score between preoperative value and postoperative values were statistically significant(F=316.3,P＜0.01).The postoperative 3-month,6-month,and 12-month local control rates were 96.49％,85.19％,and 78.12％respectively,the differences between each other among the above three values were statistically significant(P=0.026).No statistically significant differences in the proportion of using systemic anti-tumor therapy,the lesion size and the amount of bone cement injected existed between the controlled group and the progression group(all P＞0.05).The cement filling ratio in the controlled group and the progression group was(81.26±9.17)％and(68.40±12.98)％respectively,and the difference between the two groups was statistically significant(P＜0.01).Conclusion For the treatment of pelvic metastases,CT-guided POP is clinically safe and effective.The injected bone cement can control the progression of local lesions for a longer time.(J Intervent Radiol,2023,32:1197-1201)