CT guided ~(125)Ⅰseed brachytherapy for recurrent rectum cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the technological feasibility,efficacy and morbidity of cr guided ~(125)Ⅰseed implantation for recurrent rectum cancer.Methods Twenty-three patients with recurrent rectum cancer were treated with cr guided interstitial ~(125)Ⅰseed brachytherapy.In 20 patients the procedure was performed under epidural anesthesia and 3 patients under local anesthesia.Treatment planning system was used to calculate the number of seeds,the space distribution and the introduction of the seeding needles.Matched peripheral dose (MPD) of ~(125)Ⅰseed implantation ranged from 90-120 Gy for patients who had had external radiotherapy,and 140- 160Gy for those who had not.The planning target volume(PTV)was clinical target volume(CTV)plus 1 cm margin.The range of radioactivity of the ~(125)Ⅰseeds was 18.5-25.9 MBq.All these 23 patients had CT scan at 5 mm intervals after implantation for quality evaluation,together with routine chest,pelvic X-ray films within 24-48 hours after seed implantation.Three patients received three-dimensioual conformal radiation therapy(3DCRT) to a total dose of45-50 Gy,with 2-3 Gy/f.Follow-up time was from 3 to 28 months.Results All patients was able to tolerate seed implantation well.Complete pain relief was observed in 12/15,and partial relief in 2/15 and no response in 1/15,with a response rate of 93%.The local control rate was 87%.The 1-and 2-year survival rate was 93% and 50% respectively.Two of four patients have died of dissemination to the lung after 8 and 12 months. One seed has migrated into the pelvis without causing any untoward morbidity.Conclusion CT guided ~(125)Ⅰseed implantation for recurrent rectum cancer is safe,minimally invasive,causing only mild morbidity.It possesses a high efficacy,yet it should be given in combination with external beam radiation and chemotherapy,should distant metastasis be observed.