Chin Christine, Hirji Sitara, Onishi Maika, Ha Richard, Taback Bret, Horowitz David P, Connolly Eileen P
Department of Radiation Oncology, New York Presbyterian Hospital, Columbia University Medical Center, New York, New York.
Medical Oncology, Sutter Health Network, Palo Alto Foundation Medical Group, Sunnyvale, California.
Adv Radiat Oncol. 2018 Nov 20;4(2):253-260. doi: 10.1016/j.adro.2018.11.004. eCollection 2019 Apr-Jun.
Intraoperative radiation therapy (IORT) as a form of accelerated partial breast irradiation (APBI) is controversial given the limited evidence to support its efficacy. However, it remains an attractive option for low-risk patients with ductal carcinoma in situ (DCIS), who derive a small absolute benefit in local control with standard whole breast irradiation (WBI). We examine how the American Society for Therapeutic Radiation Oncology (ASTRO) APBI consensus guidelines (CG) may be applied to the preoperative selection of patients with DCIS for IORT and determine treatment outcomes by CG group.
We identified patients with biopsy-proven pure DCIS enrolled in an institutional prospective registry IORT database using the Zeiss Intrabeam device between September 2013 and February 2017. Based on available preoperative clinicopathologic information, patients were deemed suitable, cautionary, or unsuitable for IORT according to the ASTRO CG. Change in CG group based on final pathologic diagnosis was determined, and additional therapy was recommended for unsuitable patients. Outcome in terms of ipsilateral breast tumor recurrence was determined.
A total of 61 DCIS lesions in 60 patients were treated with IORT. Preoperatively, 21 patients (35%) were suitable and 36 (59%) were cautionary. Four (6%) were unsuitable because of lesion size but declined WBI. Final pathologic diagnosis changed the CG grouping of 10 patients (16%) because of either occult high-grade disease in 2 (3%) or close/positive margins in 8 (13%). Ultimately 12 patients total were considered unsuitable, of whom 8 (66%) accepted additional WBI after IORT. At a median follow-up of 2.2 years, ipsilateral breast tumor recurrence was identified among 2 suitable, 1 cautionary, and no unsuitable patients.
Further investigation is necessary to refine selection of patients with DCIS who may be optimally treated with IORT alone. High acceptance of additional therapy among unsuitable patients resulted in excellent outcomes. The use of biomarkers in addition to traditional clinical and pathologic factors may help to better select patients for IORT.
术中放疗（IORT）作为加速部分乳腺照射（APBI）的一种形式，鉴于支持其疗效的证据有限，存在争议。然而，对于原位导管癌（DCIS）的低风险患者，它仍是一个有吸引力的选择，这些患者通过标准全乳照射（WBI）在局部控制方面获得的绝对益处较小。我们研究了美国放射肿瘤学会（ASTRO）的APBI共识指南（CG）如何应用于DCIS患者IORT的术前选择，并按CG组确定治疗结果。
我们确定了2013年9月至2017年2月期间使用蔡司 Intrabeam 设备纳入机构前瞻性注册IORT数据库的经活检证实为纯DCIS的患者。根据术前可用的临床病理信息，根据ASTRO CG将患者视为适合、谨慎或不适合IORT。根据最终病理诊断确定CG组的变化，并为不适合的患者推荐额外的治疗。确定同侧乳腺肿瘤复发的结果。
60例患者中的61个DCIS病变接受了IORT治疗。术前，21例患者（35%）适合，36例（59%）为谨慎型。4例（6%）因病变大小不适合，但拒绝了WBI。最终病理诊断因2例（3%）隐匿性高级别疾病或8例（13%）切缘接近/阳性改变了10例患者（16%）的CG分组。最终共有12例患者被认为不适合，其中8例（66%）在IORT后接受了额外的WBI。在中位随访2.2年时，2例适合、1例谨慎型患者中发现同侧乳腺肿瘤复发，无不适合患者复发。
有必要进一步研究以优化DCIS患者的选择，这些患者可能仅用IORT就能得到最佳治疗。不适合的患者对额外治疗的高接受率带来了良好的结果。除了传统的临床和病理因素外，使用生物标志物可能有助于更好地选择IORT患者。
