Accelerated partial breast irradiation:advances and controversies

The management of localized breast cancer has changed dramatically over the past three to four decades.Breastconserving therapy,which involved lumpectomy followed by adjuvant irradiation,is now widely considered the standard of care in women with early-stage breast cancer.Accelerated partial breast irradiation(APBI),which involves focal irradiation of the lumpectomy cavity over a short period of time,has developed over the past two decades as an alternative to whole breast irradiation(WBI).Multiple APBI modalities have been developed including brachytherapy,external beam irradiation,and intraoperative irradiation.These new technigues have provided early-stage breast cancer patients with shorter treatment duration and more focused irradiation,delivering very high biological doses to the region at a high risk of failures over a much shorter treatment course as compared with conventional radiotherapy.However,the advantages of APBI over conventional radiotherapy are controversial,including a higher risk of complications reported in retrospective literature and shorter follow-up duration in the intraoperative APBI trials.Nevertheless,APBI presents a valuable alternative to WBI for a selected population of women with early-stage breast cancer.

Intraoperative Open-Cavity Implant for Accelerated Partial Breast Irradiation Using High-Dose Rate Multicatheter Brachytherapy in Japanese Breast Cancer Patients: A Single-Institution Registry Study

Background: Previous research has compared the efficacies of accelerated partial breast irradiation (APBI) and wholebreast irradiation (WBI). APBI immediately after surgery may provide more benefit after intraoperative insertion of catheters. Although balloon catheter-based APBI is available in the US, it is difficult in Japanese women, who have relatively small breasts. With the applicators being implanted during tumor removal, APBI can be started immediately after surgery. The aim of this study was to assess the safety and efficacy of APBI using the intraoperative open-cavity implant technique. Method: Patients (age≥40 years) with invasive breast cancer (diameter≤3 cm) were enrolled. Before lumpectomy, the insertion of applicators and delivery doses were simulated by computed tomography (CT). After confirmation of free margins and negative sentinel nodes (SNs) using frozen section analysis, applicators were inserted. Postoperative CT-based dose distribution analysis was performed using dose-volume histograms. APBI was started on the day of surgery, delivering 32 Gy in 8 fractions over the following 5-6 days, and it covered a distance of 2 cm from tumor margins. This observational study was approved by the institutional review board of our hospital. Results: From October 2008 to July 2012, 157 women (160 lesions) were enrolled (age 55.0 years, <40:9, SN+: 25, for patients’ request). The mean number of applicators used was 6.4 (2-15) and mean planning target volume was 35.8 cm3 (6.5-137.1 cm3). All radiotherapy-related toxicities were mild. However, 12 patients (7.5%) experienced wound breakdown because of surgical site infection. Two patients developed ipsilateral breast tumor recurrence (1 marginal, 1 at a distant site). Conclusions: Despite the small number of participants and a short follow-up period, our results suggest that this technique could be helpful in establishing clinical safety and efficacy.

Accelerated partial breast irradiation: Past, present, and future

Accelerated partial breast irradiation(APBI) focuses higher doses of radiation during a shorter interval to the lumpectomy cavity, in the setting of breast conserving therapy for early stage breast cancer. The utilization of APBI has increased in the past decade because of the shorter treatment schedule and a growing body of outcome data showing positive cosmetic outcomes and high local control rates in selected patients undergoing breast conserving therapy. Technological advances in various APBI modalities, including intracavitary and interstitial brachytherapy, intraoperative radiation therapy, and external beam radiation therapy, have made APBI more accessible in the community. Results of early APBI trials served as the basis for the current consensus guidelines, and multiple prospective randomized clinical trials are currently ongoing. The pending long term results of these trials will help us identify optimal candidates that can benefit from ABPI. Here we provide an overview of the clinical and cosmetic outcomes of various APBI techniques and review the current guidelines for selecting suitable breast cancer patients. We also discuss the impact of APBI on the economics of cancer care and patient reported quality of life.

Sentinel-Node-Driven Personalized Radiation Techniques Ranging from Partial Breast Irradiation to Regional Nodal Radiation after Breast-Conserving Surgery

Background: Breast-conserving surgery (BCS) followed by whole breast irradiation (WBI) has become the standard of care for treating patients with early-stage breast cancer. Recently, various radiation techniques followed by BCS have been reported. We have been investigating “personalized radiotherapy after BCS” ranging from accelerated partial breast irradiation (APBI) to WBI with regional nodal irradiation (RNI) based on the axillary node status. In this study, we compared different cohorts that received personalized radiotherapy. Method: Of 317 consecutive patients who underwent BCS followed by radiotherapy since November 2007, 187 who received APBI and 122 who received WBI were analyzed. Results: The local-only recurrence rate was 1.1% in the APBI group and 3.3% in the WBI group, and the regional-only recurrence rate was 1.1% for APBI and 0.8% for WBI. Conclusions: The clinical efficacy of APBI for local control after BCS was comparable to that of WBI ± RNI. Although this study was based on a small number of patients with a short follow-up period, the feasibility of breast-conserving therapy using multicatheter brachytherapy to achieve acceptable clinical outcomes was demonstrated.

Mammographic Findings Associated with Accelerated Partial Breast Irradiation Using Single Fraction Intraoperative Radiotherapy

Purpose: To evaluate the mammographic findings of women treated with accelerated partial breast irradiation (APBI) using single-fraction intraoperative radiotherapy (IORT). Materials/Methods: Women ≥ 40 years of age with unifocal invasive or intraductal carcinoma ≤ 2.5 cm on physical examination, mammography, and ultrasound were enrolled on an APBI trial using single fraction IORT. Post-treatment mammographic imaging was obtained at 6 months, 1 year, and then annually. Results: Between 12/02 and 6/04, 17 women underwent IORT at the time of lumpectomy (median age = 60 years;range = 40 - 83). The initial post-IORT mammogram showed increased density at the lumpectomy site in 11 patients (65%), while six patients (35%) had architectural distortion in the area of the irradiated tissue. Fifteen patients (88%) had numerous punctate, benign-appearing calcifications corresponding to the irradiated region. There was focal skin thickening near the incision in 13 patients (76%). At a median of 67 months, architectural distortion had stabilized and the benign-appearing calcifications remained stable in number and character. Eight patients (47%) had mammographic findings consistent with fat necrosis, ranging in size from 0.5 - 4 cm. Conclusions: After lumpectomy and IORT, mammographic changes include increased density and benign appearing calcifications in the irradiated region with focal skin thickening. These changes appear to stabilize over time and are consistent with post-treatment changes. These changes are important to identify in order to characterize benign changes from recurrent tumor.

Accelerated partial breast irradiation:Current evidence and future developments

Whole breast irradiation after breast-conserving surgery for early breast cancer has become one of the standard treatment modes for breast cancer and yields the same effect as radical surgery.Accelerated partial breast irradiation(APBI)as a substitute for whole breast irradiation for patients with early breast cancer is a hot spot in clinical research.APBI is characterised by simple high-dose local irradiation of the tumour bed in a short time,thus improving convenience for patients and saving costs.The implementation methods of APBI mainly include brachytherapy,external beam radiation therapy,and intraoperative radiotherapy.This review provides an overview of the clinical effects and adverse reactions of the main technologies of APBI and discusses the prospects for the future development of APBI.

Hypofractioned Radiation Therapy in the Treatment of Partial Breast: 30 Gy in Five Consecutive Fractions

Background and Purpose: Recent prospective studies have explored the partial breast irradiation (PBI) for patients with early-stage breast cancer using different technical approaches. The purpose of this study is to explore feasibility, tumor control and acute and late toxicity of a specific hypo-fractionated 3D-CRT when treating postmenopausal patients with early breast cancer with partial breast irradiation, using five fractions in five consecutive days. Materials and Methods: Ten patients, aged ≥ 70 underwent breast conservative surgery for invasive breast carcinoma with a complete microscopic resection;no lymphovascular invasion was found and negative axillary node status was assessed. Metal clips were positioned in the surgical bed at the time of surgery. All of the patients provided an informed consent for breast irradiation. Seven patients received Tamoxifen. Of the ten patients, five were treated for left breast disease, and five for right breast disease. The dose fractionation schedule was 3000 cGy delivered to the isocenter in 5 fractions (600 cGy/fr) using 6 MV photons. According to the linear quadratic model and an α/β ratio of 4 Gy this prescription is equivalent to 50 Gy in a standard 2-Gy fractionation schedule. Patients were treated in the supine position. A comercial breast board was used as immobilization device in order to keep the arms of the patient raised. The clinical target volume (CTV) was drawn with a uniform 1-cm three-dimensional margin around the surgical clips. The CTV was limited to 3 mm from the skin surface and 3 mm from the lung-chest wall interface. A three-dimensional margin was added to the CTV to obtain the planning target volume (PTV). The ipsilateral and controlateral breast, the ipsilateral and controlateral lung, heart and spinal cord were contoured as organs at risk (OAR). The treatment was developed using Precise Plan Treatment Planning System and four no-coplanar fields. The constraints used have been: uninvolved breast (ipsilateral breast-PTV): V15 ≤ 50%;heart: V3 ≤ 10%;ipsilateral lung: V10 ≤ 20%;controlateral lung: V5 ≤ 10% and controlateral breast: maximum dose ≤ 1 Gy. We required PTV coverage of ≥ 90%. Patient set-up was verified every day before treatment using portal images. No tumour bed boost was delivered. Clinical assessments of early normal tissue reaction were carried out every day during radiotherapy and 10 days after the end of the treatment. After radiotherapy, we visited all patients every 3 months during the first 2 years and every six month thereafter. Frontal and lateral pictures of the breast were taken on the first day of treatment (baseline), at the end of treatment, 10 days after the end of treatment and at the first follow-up. Any change in breast appearance compared with the baseline picture was scored on a four-point RTOG for acute and late radiation morbidity scoring scale. Results: No local or distant recurrences was observed and then confirmed by mammograms performed every year and breast ultrasound performed every six months. For acute and late toxicity, only 2 patients developed acute effects at the end of the treatment. Conclusion: The clinical outcomes observed in ten patients demonstrate a good feasibility of the schedule adopted both in terms of tumour control and acute and late toxicity, with good cosmetics results. Long term follow-up and a large number of patients will be needed for full evaluation.

Feasibility and acute toxicity of 3-dimensional conformal external-beam accelerated partial-breast irradiation for early-stage breast cancer after breast-conserving surgery in Chinese female patients

Background A growing number of studies worldwide have advocated the replacement of whole-breast irradiation with accelerated partial breast irradiation using three-dimensional conformal external-beam radiation （APBI-3DCRr） for early-stage breast cancer. But APBI can be only used in selected population of patients with early-staged breast cancer. It is not replacing the whole breast radiotherapy. This study aimed to examine the feasibility and acute normal tissue toxicity of the APBI-3DCRT technique in Chinese female patients who generally have smaller breasts compared to their Western counterparts.Methods From May 2006 to December 2009, a total of 48 Chinese female patients （with early-stage breast cancer who met the inclusion criteria） received APBI-3DCRT after breast-conserving surgery at Sun Yat-sen University Cancer Center. The total dosage from APBI-3DCRT was 34 Gy, delivered in 3.4 Gy per fractions, twice per day at intervals of at least six hours. The radiation dose, volume of the target area and volume of irradiated normal tissues were calculated.Acute toxicity was evaluated according to the Common Toxicity Criteria （CTC） 3.0.Results Among the 48 patients, the planning target volume for evaluation （PTVE） was （90.42±9.26） cm3, the ipsilateral breast volume （IBV） was （421.74±28.53） cm3, and the ratio between the two was （20.74±5.86）%. Evaluation of the dosimetric characteristics of the PTVE revealed excellent dosimetric results in 14 patients and acceptable results in 34 patients. The dose delivered to the PTVE ranged from 93% to 110% of the prescribed dose. The average ratio of the volume of PTVE receiving 95% of the prescription dose （V95） was （99.26±0.37）%. The habituation index （HI） and the conformity index （CI） were 1.08±0.01 and 0.72±0.02, respectively, suggesting good homogeneity and conformity of the dose delivered to the target field. The radiation dose to normal tissues and organs was within the dose limitation.Subjects experienced mild acute toxicity. The main manifestations were breast edema in 22 patients, breast pain in 7,skin erythema in 25, general malaise in 22 and cytopenia in 8. No acute radiological cardiac or pulmonary injury was found.Conclusions The results of our short-term follow-up showed that it is feasible to perform APBI-3DCRT for early-stage breast cancer after breast-conserving surgery in Chinese female patients with smaller breasts. However, further studies are required to elucidate its efficacy and long-term side effects.

乳腺癌保乳术后采用APBI-IMRT的效果

目的:探讨乳腺癌保乳术后采用加速部分乳腺调强放疗(accelerated partial breast irradiation with intensitymodulated radiation therapy,APBI-IMRT)的效果。方法:选择2018年6月—2022年9月南京大学医学院附属苏州医院收治的82例行乳腺癌保乳术患者作为研究对象,以随机数表法将患者分为对照组与研究组,各41例。对照组应用常规放疗,研究组应用APBI-IMRT,比较两组肿瘤标志物、危险器官剂量、心功能指标。结果:治疗前,两组肿瘤标志物、心功能指标比较,差异无统计学意义(P>0.05);治疗后,两组癌胚抗原(carcinoembryonic antigen,CEA)、β_(2)-微球蛋白(β_(2)-Microglobulin,β_(2)-MG)、细胞角蛋白19片段(cytokeratin 19 fragment,CYFRA21-1)、甲胎蛋白(alpha fetoprotein,AFP)水平、左房收缩末期内径(left atrial end-systolic diameter,LADs)、左室舒张末期内径(left ventricular end diastolic dimension,LVDD)、射血分数(ejection fraction,EF)、左心室短轴缩短率(fraction shortening,FS)较治疗前降低,且研究组肿瘤标志物低于对照组,但心功能指标高于对照组,差异有统计学意义(P<0.05)。研究组危险器官剂量低于对照组,差异有统计学意义(P<0.05)。结论:APBI-IMRT在乳腺癌保乳术后应用可增强治疗效果,降低对心肺功能的损伤。

Current role of modern radiotherapy techniques in the management of breast cancer

Breast cancer is the most common type of malignancy in females. Advances in systemic therapies and radiotherapy(RT) provided long survival rates in breast cancer patients. RT has a major role in the management of breast cancer. During the past 15 years several developments took place in the field of imaging and irradiation techniques, intensity modulated RT, hypofractionation and partial-breast irradiation. Currently, improvements in the RT technology allow us a subsequent decrease in the treatment-related complications such as fibrosis and long-term cardiac toxicity while improving the loco-regional control rates and cosmetic results. Thus, it is crucial that modern radiotherapy techniques should be carried out with maximum care and efficiency. Several randomized trials provided evidence for the feasibility of modern radiotherapy techniques in the management of breast cancer. However, the role of modern radiotherapy techniques in the management of breast cancer will continue to be defined by the mature results of randomized trials. Current review will provide an up-to-date evidence based data on the role of modern radiotherapy techniques in the management of breast cancer.

多导管组织间插植近距离放射治疗在乳腺癌治疗中的应用

乳腺癌是全球女性发病率最高的癌症。术后放射治疗(以下简称“放疗”)可以降低局部复发率和远处转移率,延长患者的生存期。近年来,多导管组织间插植近距离放疗(multicatheter interstitial brachytherapy,MIB)成为乳腺癌近距离放疗最常用的技术,常应用于保乳术后的加速部分乳房照射、保乳术后瘤床补量及同侧乳房复发的加速部分乳腺再照射方面。与外照射放疗及其他近距离放疗技术相比,MIB对于乳腺癌患者具有良好的局部控制率和美容效果、较低的3级以上的不良事件发生率,患者的远期预后良好。虽然其为侵入性、高度专业性技术,但综合来看,MIB因其明确的临床疗效及剂量学优势而有望成为乳腺癌放疗的主要手段。

乳腺癌保乳术后加速部分乳腺照射研究进展

保乳手术加术后全乳腺放疗(whole breast irradiation,WBI)已成为早期乳腺癌的标准治疗模式之一,但是传统的WBI照射范围大,疗程长。近年来,缩小照射范围、缩短总疗程的加速部分乳腺照射(accelerated partial breast irradiation,APBI)作为保乳术后WBI的替代治疗方法,得到了广泛的认同。APBI常用的治疗方式有术中放疗、外照射和近距离放疗三种。术中放疗为保乳手术中给予一次性照射,照射范围准确,但是对设备的要求较高。外照射由专业的放疗科医师和物理师执行,相对容易实现,而且可以通过治疗计划系统使靶区剂量均匀分布。近距离治疗目前常用的有组织间插植和mammosite球囊治疗,mammosite设备技术简单、实施容易,目前应用较广泛。然而,由于APBI技术应用时间尚短、临床随访数据有限,应用时必须进行严格的病例筛选以及合理的计划,以降低局部复发的风险。

放射治疗在早期乳腺癌中的应用

目前保乳治疗已经成为早期乳腺癌的标准治疗方案,而放射治疗在保乳治疗中的作用也日益得到体现由于传统的全乳放射治疗存在着诸多的劣势,所以近些年来,部分乳腺放疗逐渐为人们所重视相对于传统全乳腺照射,部分乳腺放疗可使患者的保乳治疗更快捷,且降低了远期并发症的风险但是部分乳腺放疗研究的长期结果尚缺乏,而且病例选择及放疗实施也存在很多不确定性部分乳腺放疗是有前途的方法。

早期乳腺癌患者保乳术后体外部分乳腺加速照射的循证治疗

目的应用循证医学方法为1例行保乳术后的早期乳腺癌患者确定放疗方案。方法计算机检索Pub Med、Cochrane图书馆、CNKI、Wanfang和VIP数据库,纳入所有关于乳腺癌外照射部分乳腺加速放疗的随机对照试验,放疗技术不限。检索时限均为从建库至2015年10月31日。结果检索到3项随机对照试验。与全乳腺放疗相比,外照射加速部分乳腺放疗能够显著缩短放疗时间、不增加局部复发的风险,但提高美容效果、延长生存时间的作用有限。结论外照射加速部分乳腺放疗实现部分早期乳腺癌术后辅助放疗是可行的,但其疗效与远期生存结果仍需随机对照试验进一步研究。

乳腺癌保乳术后加速部分乳腺照射的研究进展

传统的乳腺癌保乳术后放疗是对全乳腺进行5周-6周的放疗。随着放射治疗技术的发展,加速部分乳腺照射可能会成为另一选择。该文就加速部分乳腺照射在乳腺癌治疗中的研究进展作一综述。

乳腺癌保乳手术加术中放疗32例临床观察

目的临床观察早期乳腺癌保乳手术加术中足量电子线放疗（intraoperative radiotherapy，IORT）的可行性和近期疗效。方法2007年10月至2009年10月我科32例早期乳腺癌（肿瘤直径不超过2．5厘米）患者接受了保乳手术及术中9～12MeV电子线照射，剂量为21Gy。术后对切口愈合状况、并发症、乳房外观及肿瘤复发等进行临床观察，并随访至今。结果切口愈合天数为14--22天，平均17天，全组未出现术后切口感染或血肿。手术切口愈合后、术后半年、1年、2年对乳房外观评价，评价为优的分别为43．8％、51．7％、70％及80％；评价为良的分别为37．5％、31％、20％及20％；评价为一般的分别为18．8％、17．2％、10％及0．0％。仅出现照射区域的轻至中度纤维化，未出现其他放疗并发症。未发生局部复发，远处转移。结论对于低危的早期乳腺癌患者，采用术中电子线行部分乳腺照射是可行的。但病例选择标准、远期美容效果、局部肿瘤控制及远期生存率有待进一步探讨和观察。

2019 SABCS乳腺肿瘤外科治疗进展

第42届圣安东尼奥乳腺癌研讨会(SABCS)对乳腺癌治疗和预后相关的新临床热点和争议问题进行了讨论。大会充分展现了乳腺外科未来的“减法”趋势:对于前哨淋巴结阳性患者,前哨淋巴结活检联合腋窝放疗可能替代腋窝淋巴结清扫成为新的治疗手段;残余肿瘤负荷作为新辅助化疗后的新的疗效评估指标;新辅助化疗患者后续是否可以豁免手术;早期乳腺癌保乳术后应用部分乳腺加速放疗替代全乳放疗等。作者对SABCS大会中外科治疗部分的最新进展进行了介绍和解读。

部分乳腺加速照射近距离治疗技术设备进展

组织间插植是目前随访时间最长的部分乳腺加速照射(APBI)近距离技术,但其技术实施复杂。球囊设备是简化的APBI设备。MammoSite是第一个APBI球囊近距离设备,其技术设备简单,很受医生和患者青睐。Xoft Axxent Electron-ic Brachytherapy是改进的基于电子射线源的球囊设备,SenoRx Contura相对MammoSite增加了4个放射源通道,可以更好地根据靶区调整剂量分布。Strut adjusted volume implant和ClearPath是组织间插植与球囊结合的设备,结合了球囊设备单点插入的优点和组织间插植的剂量学优势。AccuBoost是基于乳腺X线摄影机的无创近距离设备,无需外科插入导管,对瘤腔形状的依赖性小,且无感染风险。

Ⅰ期乳腺癌保乳术后乳腺三维适形加速外照射的临床研究

目的探讨Ⅰ期乳腺癌保乳术后乳腺三维适形加速外照射(APBI-3DCRT)治疗的近期疗效。方法选择2003年2月至2006年3月在湖北省肿瘤医院行Ⅰ期乳腺癌保乳术后患者89例,自愿接受APBI-3DCRT治疗的患者57例为APBI-3DCRT组,全乳腺照射(WBI)治疗的患者32例为WBI组。使用8 MV光子线进行APBI-3DCRT和WBI计划设计,设定4～5个照射野,处方剂量为每次3.4 Gy,每天2次,间隔6 h,总剂量34 Gy。观察两组患者的生存率、复发率、急性放射性损伤发生率和乳房美容效果。结果 APBI-3DCRT组急性放射性皮肤反应发生率和肺损伤发生率(10.53%和5.26%)较WBI组(28.13%和18.75%)低(P<0.05)。APBI-3DCRT组乳房美容优良率(92.98%)较WBI组(75.00%)高(P<0.05)。结论Ⅰ期乳腺癌保乳术后APBI-3DCRT治疗近期疗效好。

乳腺癌保乳术后大分割放疗的临床研究进展

乳腺癌保乳术后行全乳腺放疗在降低局部肿瘤复发同时也可改善患者生存情况。虽然全乳腺标准放疗可以实现良好的肿瘤控制及美容效果,且具有不良反应轻的特点,但5～7周的治疗时间对患者相对较长,甚至可能造成医疗资源浪费,因此临床上越来越倾向大分割放疗和加速部分乳腺照射的短疗程放疗。短疗程放疗与常规分割放疗均为安全有效的治疗模式,具有与常规放疗相似的生存和局部肿瘤控制效果,不良反应可以耐受。相较于常规分割放疗,短疗程放疗具有缩短治疗总时间,减少治疗费用,节约医疗资源,改善患者生存质量的显著优势。