单管球囊腔内治疗和组织间插植治疗早期乳腺癌的剂量和临床比较

Doshnetric and clinical comparison between MammoSite and interstitial EIDR brachytherapy in treatment of early stage breast cancer after conserving surgery

目的比较单管球囊腔内治疗（MammoSite）和组织间插植两种高剂量率（HDR）后装技术行早期乳腺癌保乳术后局部乳腺加速照射的剂量学优缺点、早晚期毒副作用及美容评估。方法自2004年1月至12月，10例乳腺癌在肿瘤局部扩大切除后使用了高剂量率^192Ir加速照射（APBI），其中组织间插植6例、MammoSite4例。全部息者均在手术中植入施源器，组织间插植组瘤腔距皮肤〉0．5～0．7cm，MammoSite中1例瘤腔距皮肤0．65cm，其余3例均大于1cm。治疗靶区组织间插植组为瘤腔外2cm（皮肤和胸壁方向根据实际情况略小），MammoSite组为球囊外1cm。组织间插植组中位剂量均匀指数（DHI）为0．77，MammoSite组中位DHI为0．73。结果全部患者随诊12～24个月，中位随诊18个月，随诊率为100％。治疗期间两组无一例发生Ⅲ级以上急性反应，仅发生红斑、水肿、乳腺触痛和感染，均为1～2级。晚期毒性（皮肤纤维化、乳腺触痛、脂肪坏死）组织间插植组较MammoSite组略高。美容效果达到极好和良好的在治疗结束时为100％，随诊12个月时组织间插植组患者和医生评估分别是100％和83％，MammoSite组均为100％。无一例局部复发。结论组织间插植剂量分布较MammoSite均匀而且治疗体积大；MammoSite重复性好、操作简单，早晚期毒副作用及美容效果相同。

Objective To comparatively study dosimetric evaluation, side effects in early and late stage, and cosmetic outcome between MammoSite and interstitial using high-dose-rate （HDR） brachytherapy accelerated partial breast irradiation （APBI） in early stage breast cancer patient after conserving surgery. Methods From January 2004 to December 2004, 10 breast cancer cases were treated with HDR ^192Ir APBI after Lumpectomy surgery, 6 cases with interstitial hrachytherapy, 4 cases with MammoSite. Sources were placed during the operation in all patients, distance from cavity to skin 〉 5-7 mm in interstitial brachytherapy group, one case is 6.5 mm, 3 cases 〉 10 mm in MammoSite group. Treatment Target area is 20 mm away from cavity in interstitial brachytherapy group with DHI 0.77, 10 mm away from Balloon margin in MammoSite with DHI 0.73. Results Follow up 12-24 months while median follow-up was 18 months for the whole group （100%）. During the treatment, grade Ⅲ acute reactions were not seen in both group, grade Ⅰ or Ⅱ were seen including： erythema, edema, tenderness and infection. More late toxicity reaction including skin fibrosis, breast tenderness and fat necrosis were observed in interstitial brachytherapy group than that of MammoSite group. Cosmetic outcome evaluation were excellent in 12 months 100 % （patient） and 83 % （ doctor ） in interstitial brachytherapy, 100 % in MammoSite group, respectively, none recurrence. Conclusions Interstitial brachytherapy shows more uniformity in dose distribution as well as larger treatment volume, while MammoSite tends to be stable in repeatability and easy in use. Both groups show excellent cosmetic results, with same acute and late reactions.