Ductal carcinoma in situ of the breast treated with accelerated partial breast irradiation using balloon-based brachytherapy

Minimally invasive tumor bed implant (MITBI) and peri-operative high-dose-rate brachytherapy (PHDRBT) for accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost) in breast-conserving surgery for ductal carcinoma in situ

Purpose

To evaluate our institutional experience of minimally invasive tumor bed implantation (MITBI) during breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) to deliver peri-operative high-dose-rate brachytherapy (PHDRBT) as accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost).

Material and methods

Patients older than 40, with clinical and radiological unifocal DCIS < 3 cm were considered potential candidates for accelerated partial breast irradiation (APBI) and were implanted during BCS using MITBI-technique. Patients who in final pathology reports showed free margins and no other microscopic tumor foci, received AMBI with PHDRBT (3.4 Gy BID in 5 days). Patients with adverse features received A-PHDRBT-boost with post-operative external beam radiotherapy (EBRT).

Results

Forty-one patients were implanted, and 36 were treated and analyzed. According to final pathology, 24 (67%) patients were suitable for AMBI and 12 (33%) were qualified for A-PHDRBT-boost. Reoperation rate for those with clear margins was 16.6% (6/36); this rate increased to 33% (4/12) for G3 histology, and 66% (4/6) were rescued using AMBI. Early complications were documented in 5 patients (14%). With a median follow-up of 97 (range, 42-138) months, 5-year rates of local, elsewhere, locoregional, and distant control were all 97.2%. 5-year ipsilateral breast tumor recurrence rates (IBTR) were 5.6% (2/36), 8.3% (2/24) for AMBI, and 0% (0/12) for A-PHDRBT-boost patients. Both instances of IBTR were confirmed G3 tumors in pre-operative biopsies; no IBTR was documented in G1-2 tumors. Cosmetic outcomes were excellent/good in 96% of AMBI vs. 67% in A-PHDRBT-boost (p = 0.034).

Conclusions

The MITBI-PHDRBT program allows selection of patients with excellent prognoses (G1-2 DCIS with negative margins and no multifocality), for whom AMBI could be a good alternative with low recurrence rate, decrease of unnecessary radiation, treatment logistics improvement, and over-treatment reduction. Patients whose pre-operative biopsy showed G3 tumor, presents with inferior local control and more risk of reoperation due to positive margins.

Management of ductal carcinoma in situ with accelerated partial breast irradiation brachytherapy: Implications for guideline expansion

PURPOSE

Accelerated partial breast irradiation (APBI) for patients with ductal carcinoma in situ (DCIS) is controversial, and the suitability criteria from the American Brachytherapy Society (ABS), American Society of Therapeutic Radiology and Oncology (ASTRO), and the European Society for Radiotherapy and Oncology (GEC-ESTRO) have important differences.

METHODS AND MATERIALS

This is a single-institution retrospective review of 169 consecutive patients with DCIS who underwent lumpectomy followed by APBI intracavitary brachytherapy from 2003 to 2018. Outcomes, including overall survival, recurrence-free survival (RFS), ipsilateral breast tumor recurrence, and distant metastasis, were estimated with the Kaplan-Meier method.

RESULTS

The median followup time was 62.5 months. Median age was 66 years (47-89 years). The majority of patients had estrogen receptor-positive disease (89%). Fifty patients (30%) had Grade 3 disease. Of the 142 patients with adequate pathology interpretation, 91 and 108 cases had margins ≥ 3 mm and ≥2 mm, respectively. Most patients (72%) were prescribed and started endocrine therapy. Of the patients evaluable for ABS criteria (N = 130), 97 met the suitability criteria. Of the patients evaluable for ASTRO criteria (N = 129), 42 were deemed cautionary and 33 were deemed unsuitable. Of the patients evaluable for GEC-ESTRO criteria (N = 143), 141 cases were at intermediate risk and two were at high risk. Five-year ipsilateral breast tumor recurrence, RFS, and overall survival were 0.6%, 97.7%, and 97.2%, respectively. The ABS, ASTRO, and GEC-ESTRO criteria failed to significantly predict for RFS.

CONCLUSIONS

These results, although limited by short-term followup, indicate that expansion of the eligibility criteria of APBI for patients with DCIS should be considered.

External accelerated partial breast irradiation for ductal carcinoma in situ: long-term follow-up from a phase 3 randomized trial

Introduction:

For a long time, accelerated partial breast irradiation (APBI) effectiveness for ductal carcinoma in situ (DCIS) has been debated, due to conflicting published results. Recent encouraging data from phase 3 trials reopened new perspectives for this radiation approach. The aim of the present study was to analyze the long-term efficacy and safety results of the series of patients with DCIS enrolled in the APBI arm of the APBI-IMRT-Florence phase 3 trial (NCT02104895).

Methods:

Patients were treated in a phase 3 randomized trial comparing whole breast irradiation (50 Gy in 25 fractions to the whole breast, plus 10 Gy in 5 fractions to the tumor bed) to APBI (30 Gy in 5 nonconsecutive fractions) using the intensity-modulated radiotherapy technique.

Results:

Overall, 22 patients were treated in the APBI arm. Median age was 62 years (mean 59; range 42–75 years). At a median follow-up of 9.2 years (mean 8.8; range 3.8–12.1 years), no contralateral invasive/DCIS occurrence, distant metastasis, or breast cancer–related death were recorded. The 5- and 10-year local recurrence, distant metastasis–free survival, and breast cancer–specific survival were 100%. The 10-year overall survival rate was 90.9%. No late toxicity at 5 and 10 years was recorded.

Conclusions:

Waiting for pending studies and mature follow-up, we confirmed the efficacy and safety of APBI for low-risk DCIS.

Ductal Carcinoma In Situ

Ductal carcinoma in situ has been stable in incidence for a decade and has an excellent prognosis. Breast conservation therapy is safe and effective for most patients. Adjuvant whole breast radiation therapy is recommended to reduce the risk of local recurrence. Accelerated partial breast irradiation is a promising alternative to decrease toxicity and improve cosmetic results. Adjuvant hormonal therapy can reduce local recurrence, but should be used cautiously. Future directions in management include developing predictive tools for guidance for use of adjuvant therapy and selecting low-risk patients with ductal carcinoma in situ in whom surgery may be safely omitted.

Adjuvant therapy in patients with ductal carcinoma in situ of the breast: The Pandora's box

Most patients with ductal carcinoma in situ of the breast (DCIS) are eligible for breast conservation treatment. The key management decision is whether to add radiotherapy and/or endocrine therapy to minimize the risk of a subsequent recurrence. Recent analyses indicating a lack of benefit in terms of breast cancer-associated mortality have suggested that more conservative approaches, omitting adjuvant therapy or even surgery, may be advisable in selected patients. These mortality observations are directly influenced by widespread use of mammographic screening which has opened a Pandora's box of subclinical DCIS and early invasive lesions. Confusion as to how aggressively such possibly indolent lesions should be treated has led to misunderstandings among patients and medical professionals. While awaiting further prospective evidence from clinical trials, we endorse an active treatment of DCIS as the standard of care. Our rationale is twofold: invasive recurrences are associated with an increase in breast cancer mortality, which is not the only relevant endpoint for DCIS. The benefit of complete surgical excision, adjuvant radiotherapy and endocrine treatment in preventing recurrence and invasive progression has been demonstrated in DCIS. The challenge now is how to identify DCIS patients who will not progress to invasive carcinoma even without complete excision and, at the other extreme, those patients at the highest risk who require mastectomy for local control. The current controversies over whether and which adjuvant therapy should be implemented can at least in part be addressed by developing effective doctor-patient communications that enable mutual understanding about the management of this biologically heterogeneous disease.

A Single-Site Retrospective, Nonrandomized Study of Accelerated Partial Breast Irradiation Brachytherapy for Early-Stage Breast Cancer Treatment to Evaluate Local Tumor Control, Cosmetic Outcome, and Toxicities

Purpose:

To evaluate the efficacy and safety of the accelerated partial breast irradiation brachytherapy with a combination of applicators at a community hospital cancer center.

Methods and Materials:

Between 2005 and 2009, 120 patients with early-stage breast cancer were being followed after treatment with accelerated partial breast irradiation brachytherapy using MammoSite, single or multilumen balloon, or Contura multilumen balloon. After their lumpectomy surgery, each patient was treated with Ir-192 high-dose rate unit following radiation therapy oncology group 0413 guidelines. The patients had multiple follow-ups at 6 months, 1 year, 2 years, 3 years, or more.

Results:

Based on the Harvard Breast Cosmesis Scale, 95.00% of patients described their cosmetic evaluation as the treated breast essentially the same as the opposite side (excellent) or minimal but identifiable effects were noticed from radiation (good). After a median follow-up of 36 months, the local recurrence rate was 1.66% and a disease-free survival is 98.3%. Forty-two patients reported 85 adverse events, which were fibrosis: 24.70%, hyperpigmentation: 20.00%, radiation skin reaction: 7.05%, seroma: 7.05%, breast pain: 7.05%, erythema: 5.88%, and other events were less than 5.00%. Of all the adverse events recorded, grade 1 to 3 events are 95.29% (n = 81), 2.35% (n = 2), and 2.35% (n = 2). There was no grade 4 or 5 events recorded.

Conclusions:

Our study has shown promising results for delivering radiation with MammoSite, single or multilumen balloon, or Contura multilumen balloon and has been successful in achieving local control in patients with early-stage breast cancer.

Targeted Intraoperative Radiotherapy for the Management of Ductal Carcinoma In Situ of the Breast

Multiple long-term studies have demonstrated a propensity for breast cancer recurrences to develop near the site of the original breast cancer. Recognition of this local recurrence pattern laid the foundation for the development of accelerated partial breast irradiation (APBI) approaches designed to limit the radiation treatment field to the site of the malignancy. However, there is a paucity of data regarding the efficacy of APBI in general, and intraoperative radiotherapy (IORT), in particular, for the management of ductal carcinoma in situ (DCIS). As a result, use of APBI, remains controversial. A prospective nonrandomized trial was designed to determine if patients with pure DCIS considered eligible for concurrent IORT based on preoperative mammography and contrast-enhanced magnetic resonance imaging (CE-MRI) could be successfully treated using IORT with minimal need for additional therapy due to inadequate surgical margins or excessive tumor size. Between November 2007 and June 2014, 35 women underwent bilateral digital mammography and bilateral breast CE-MRI prior to selection for IORT. Patients were deemed eligible for IORT if their lesion was ≤4 cm in maximal diameter on both digital mammography and CE-MRI, pure DCIS on minimally invasive breast biopsy or wide local excision, and considered resectable with clear surgical margins using breast-conserving surgery (BCS). Postoperatively, the DCIS lesion size determined by imaging was compared with lesion size and surgical margin status obtained from the surgical pathology specimen. Thirty-five patients completed IORT. Median patient age was 57 years (range 42-79 years) and median histologic lesion size was 15.6 mm (2-40 mm). No invasive cancer was identified. In more than half of the patients in our study (57.1%), MRI failed to detect a corresponding lesion. Nonetheless, 30 patients met criteria for negative margins (i.e., margins ≥2 mm) whereas five patients had positive margins (<2 mm). Two of the five patients with positive margins underwent mastectomy due to extensive imaging-occult DCIS. Three of the five patients with positive margins underwent successful re-excision at a subsequent operation prior to subsequent whole breast irradiation. A total of 14.3% (5/35) of patients required some form of additional therapy. At 36 months median follow-up (range of 2-83 months, average 42 months), only two patients experienced local recurrences of cancer (DCIS only), yielding a 5.7% local recurrence rate. No deaths or distant recurrences were observed. Imaging-occult DCIS is a challenge for IORT, as it is for all forms of breast-conserving therapy. Nonetheless, 91.4% of patients with DCIS were successfully managed with BCS and IORT alone, with relatively few patients requiring additional therapy.

Ductal carcinoma in situ: recent advances and future prospects

Introduction. This article reviews current management strategies for DCIS in the context of recent randomised trials, including the role of sentinel lymph node biopsy (SLNB), adjuvant radiotherapy (RT) and endocrine treatment. Methods. Literature review facilitated by Medline, PubMed, Embase and Cochrane databases. Results. DCIS should be managed in the context of a multidisciplinary team. Local control depends upon clear surgical margins (at least 2 mm is generally acceptable). SLNB is not routine, but can be considered in patients undergoing mastectomy (Mx) with risk factors for occult invasion. RT following BCS significantly reduces local recurrence (LR), particularly in those at high-risk. There remains a lack of level-1 evidence supporting omission of adjuvant RT in selected low-risk cases. Large, multi-centric or recurrent lesions should be treated by Mx and immediate reconstruction should be discussed. Adjuvant hormonal treatment may reduce the risk of LR in selected cases with hormone sensitive disease. Conclusion. Further research is required to determine the role of new RT regimes and endocrine therapies. Biological profiling and molecular analysis represent an opportunity to improve our understanding of tumour biology in DCIS to rationalise treatment. Reliable identification of low-risk lesions could allow treatment to be less radical.

Ductal carcinoma in situ, and the influence of the mode of detection, population characteristics, and other risk factors

Approximately 25% of breast cancers in the United States are diagnosed as ductal carcinoma in situ (DCIS). Rates of DCIS have risen from 5.8 per 100,000 women in the 1970s to 32.5 per 100,000 in 2004. This pattern is generally attributed to increased use of screening mammography. DCIS is a major risk factor for invasive breast cancer, and considerable controversy remains about whether DCIS should be considered a direct precursor of invasive breast cancer. There is, however, a general consensus that DCIS represents an intermediate step between normal breast tissue and invasive breast cancer. Although the majority of major risk factors are similar for DCIS and invasive breast cancer, prognostic factors including estrogen and progesterone receptor status and HER2 positivity are less well studied but look to have similar value in both cases. The use of postdiagnostic MRI, sentinel lymph node biopsy, surgery, radiation, and endocrine therapy are all evolving as evidence from randomized and observational studies continues to accumulate. Treatment of DCIS requires a balance between risk of overtreatment and undertreatment. Ongoing studies are focusing on whether partial-breast irradiation is as effective as whole-breast irradiation and whether treatment with endocrine therapies can reduce the likelihood of either invasive breast cancer or DCIS recurrence. In general, treatment decisions should take into account the likelihood that an apparent case of DCIS could harbor foci of invasive disease.

Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer

PURPOSE

An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning.

METHODS

The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff = [D(max) Man - D (max)DVH]) and relative (Rediff[%] = 100 x ([D(max)Man-D(max)DVH])/D(max)DVH) maximal skin and rib dose differences between the manual selection method (D(max)Man) and the objective method (D(max)DVH) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients.

RESULTS

The average +/- standard deviation of maximal dose difference was 1.67% +/- 1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value < 0.0001) was observed in maximal rib dose difference compared with maximal skin dose difference for both Abdiff (2.30% +/- 1.71% vs 1.05% +/- 1.43%) and Rediff[%] (2.32% +/- 1.79% vs 1.21% +/- 1.41%). In general, rib has a more irregular contour and it is more proximally located to the balloon for 50 HDR patients. Due to the inverse square law factor, more dose difference was observed in higher dose range (D(max) > 90%) compared with lower dose range (D(max) < 90%): 2.16% +/- 1.93% vs 1.19% +/- 1.25% with p value of 0.0049. However, the Rediff[%] analysis eliminated the inverse square factor and there was no statistically significant difference (p value = 0.8931) between high and low dose ranges.

CONCLUSIONS

The objective method using volumetric information of skin and rib can determine the planner-independent maximal dose compared with the manual selection method. However, the difference was < 2% of PD, on average, if appropriate attention is paid to selecting a manual dose point in 3D planning CT images.

Ductal carcinoma in-situ: an update for clinical practice

INTRODUCTION

Ductal carcinoma in-situ (DCIS) is a heterogeneous entity with an elusive natural history. The objective of radiological, histological and molecular characterisation remains to reliably predict the biological behaviour and optimise clinical management strategies. Increases in diagnostic frequency have followed the introduction of mammographic screening and increased utility of magnetic resonance imaging. However, progress remains limited in distinguishing non-progressive incidental lesions from their progressive and clinically relevant counterparts. This article reviews current management strategies for DCIS in the context of recent randomized trials, including the role of sentinel lymph node biopsy (SLNB), adjuvant radiotherapy (RT) and endocrine treatment.

METHODS

Literature review facilitated by Medline, PubMed, Embase and Cochrane databases.

RESULTS

DCIS should be managed in the context of a multidisciplinary team. Local control depends upon adequate surgical clearance with margins of at least 2 mm. SLNB is not routinely indicated and should be reserved for those with concurrent or recurrent invasive disease. SLNB can be considered in patients undergoing mastectomy (MX) and those with risk factors for invasion such as palpability, comedo morphology, necrosis or recurrent disease. RT following BCS significantly reduces local recurrence (LR), particularly in those at high-risk. There remains a lack of level-1 evidence supporting the omission of adjuvant RT in selected low-risk cases. Large, multi-centric or recurrent lesions (particularly in cases of prior RT) should be treated by MX with the opportunity for immediate reconstruction. Adjuvant Tamoxifen may reduce the risk of LR in selected cases with hormone sensitive disease.

CONCLUSION

Further research is required to determine the role of contemporary RT regimes and endocrine therapies. Biological profiling and molecular analysis represent an opportunity to improve our understanding of the tumour biology of this condition and rationalise its treatment. Reliable identification of low-risk lesions could allow treatment to be less radical or safely omitted.

Post-surgical treatment of early-stage breast cancer with electronic brachytherapy: an intersociety, multicenter brachytherapy trial

INTRODUCTION

Electronic brachytherapy (EBT) was developed to allow accelerated partial breast irradiation to be performed in a patient procedure room with minimal shielding. This observational, nonrandomized, multicenter study evaluated EBT as a post-surgical adjuvant radiation therapy for early stage breast cancer.

METHODS

This study included women aged 50 years or more with invasive carcinoma or ductal carcinoma in situ, tumor size ≤3 cm, negative lymph node status, and negative surgical margins. The endpoints were skin and subcutaneous toxicities, efficacy outcomes, cosmetic outcomes, and device performance. In this interim report, 1-month, 6-month, and 1-year follow-up data are available on 68, 59, and 37 patients, respectively.

RESULTS

The EBT device performed consistently, delivering the prescribed 34 Gy to all 69 patients (10 fractions/patient). Most adverse events were Grade 1 and included firmness, erythema, breast tenderness, hyperpigmentation, pruritis, field contracture, seroma, rash/desquamation, palpable mass, breast edema, hypopigmentation, telangiectasia, and blistering, which were anticipated. Breast infection occurred in two (2.9%) patients. No tumor recurrences were reported. Cosmetic outcomes were excellent or good in 83.9%-100% of evaluable patients at 1 month, 6 months, and 1 year.

CONCLUSION

This observational, nonrandomized, multicenter study demonstrates that this EBT device was reliable and well tolerated as an adjuvant radiation therapy for early stage breast cancer.