Analysis of Treatment Efficacy, Cosmesis, and Toxicity Using the MammoSite Breast Brachytherapy Catheter to Deliver Accelerated Partial-Breast Irradiation: The William Beaumont Hospital Experience

The evolution of the locoregional therapy of breast cancer

Breast-conserving therapy (BCT) and mastectomy have equal survival outcomes. Rates of local recurrence after BCT have declined steadily, largely as a result of the widespread use of systemic therapy. Sentinel node biopsy has replaced axillary dissection for staging the axilla, and in women undergoing BCT with whole-breast irradiation (WBI), axillary dissection is not needed for local control or survival in those with fewer than three involved sentinel nodes. Alternatives to 6 weeks of WBI have been shown to be safe and effective for subsets of breast cancer patients, and the use of preoperative chemotherapy allows BCT in some women who require mastectomy if surgery is the initial step in treatment. The combination of the smaller cancers detected with screening and the routine use of multimodality therapy has resulted in a decrease in the morbidity of local therapy and improved cancer treatment outcomes.

Electronic brachytherapy as adjuvant therapy for early stage breast cancer: a retrospective analysis

PURPOSE

This multicenter, retrospective study evaluated treatment and clinical outcomes of patients with early stage breast cancer who received adjuvant high-dose rate (HDR) electronic brachytherapy (EBT) treatment post-lumpectomy using the Axxent(®) EBT system. Dosimetric data from the EBT treatment plans were compared with those based on iridium-192 HDR brachytherapy.

MATERIAL AND METHODS

Medical records of 63 patients with early stage breast cancer (Tis, T1a, T1b, T1c, and T2) who were treated post-lumpectomy with EBT alone or in combination with external beam radiation therapy were reviewed. The prescribed EBT dose was 34 Gy (10 fractions over 5 days, 3.4 Gy each) to 1 cm from the balloon surface. Dosimetry data from 12 patients were compared with these of treatment plans using an iridium-192 source prepared for the same 12 patients.

RESULTS

The majority of patients (90.5%) were older than 50 years and had one or more risk factors for breast cancer (80.6%). Tumor sizes were 0.1 cm to 3.5 cm (mean 1.3 cm). Median follow-up was 7 months (1 to 18 months) post-EBT. Balloon applicators were implanted 0 to 85 days (mean 13.4 days) post-lumpectomy/re-excision. The most common adverse events were erythema, rash dermatitis, and pain or breast tenderness. No recurrences were reported. Dosimetric analyses demonstrated comparable target coverage, increased high-dose regions, and a significantly reduced dose to the ipsilateral breast and lungs as well as the heart with EBT as compared with the iridium-192 treatment plans.

CONCLUSION

This retrospective, multicenter study showed that postsurgical adjuvant radiation therapy for early stage breast cancer can be administered using the EBT system with similar toxicity outcomes to those reported with iridium-192 brachytherapy. EBT offers a convenient, portable, nonisotope alternative to HDR brachytherapy using iridium-192.

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.

Five-year outcome of patients classified in the "unsuitable" category using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus Panel guidelines for the application of accelerated partial breast irradiation: an analysis of patients treated on the American Society of Breast Surgeons MammoSite® Registry trial

PURPOSE

We applied the ASTRO Consensus Panel (CP) guidelines for the application of accelerated partial breast irradiation (APBI) to patients treated with this technique on the ASBS MammoSite® registry trial to determine potential differences in outcome of patients classified in the "unsuitable" category.

METHODS

Of 1,449 cases treated with APBI on the registry trial, 176 fit the criteria for the unsuitable category: 130 cases were <50 years of age, 13 had positive margins, 38 had positive nodes, 6 had tumors >3 cm, and 9 had an EIC >3 cm. Rates of ipsilateral breast tumor recurrence (IBTR) and regional nodal failure (RNF) were assessed. Median follow-up was 53.6 months.

RESULTS

The 5-year actuarial rate of IBTR for unsuitable cases was 5.25% (RNF rate was 0.63%). By comparison, the 5-year actuarial IBTR rates for various subsets of patients were: all 1,449 cases, 3.89% (p = 0.2365); all 1,449 cases excluding unsuitable cases [n =1,273] (3.6%, p =0.1683); invasive only cases [n = 1,255] (3.86%, p = 0.2464); and invasive only cases excluding unsuitable invasive cases [n =1,105] (3.89%, p = 0.2396). On univariate analysis for variables potentially associated with IBTR in all 1,255 cases with invasive cancer (including age, tumor size, nodal status, overall stage, margin status, ER status, presence of an EIC, and ASTRO unsuitable category), only negative ER (-) status was associated with the 5-year rate of IBTR (p = 0002). No other variable (including unsuitable CP designation) was associated with IBTR.

CONCLUSIONS

The ASTRO CP guideline designation of unsuitable did not differentiate a subset of patients with a significantly worse rate of IBTR when treated with the MammoSite® breast brachytherapy catheter to deliver APBI.

Experience with an electronic brachytherapy technique for intracavitary accelerated partial breast irradiation

OBJECTIVES

Phase IV study evaluated the safety and device performance of an electronic brachytherapy system (Axxent Electronic Brachytherapy System) as adjuvant therapy for early-stage breast cancer.

METHODS

Patients were > or =50 years of age and had completely resected invasive ductal carcinoma or ductal carcinoma in situ (<2.0 cm), with N0 M0 and negative microscopic margins of > or =1 mm. The balloon applicator was placed in a closed cavity with a balloon surface to skin distance of > or =7 mm. The prescribed dose was 3.4 Gy/fraction prescribed to 1 cm beyond the balloon surface twice daily (BID) for 10 fractions.

RESULTS

Of 65 patients consented, 21 (32%) were not eligible for treatment, and 44 (68%) were treated, with 6-months follow-up in 43 and 1-year follow-up in 36. The prescribed radiation treatment was successfully delivered in 42/44 (95.4%) patients; one was unsuccessful due to a controller issue and the other declined the final fraction following a balloon deflation. Side effects were as anticipated and generally manageable. Four CTCAE v3 grade 3 toxicities were reported: blistering (1), breast tenderness (1), and moist desquamation (2); all have resolved. The most common grade 2 toxicity was erythema. There were no device-related serious adverse events.

CONCLUSIONS

Early experience demonstrates that the electronic brachytherapy system performed as expected. Electronic brachytherapy has similar acute toxicity profiles to other high dose rate approaches for accelerated partial breast irradiation and offers the convenience of having the treatment in an unshielded room.

Accelerated Partial Breast Irradiation: Potential Roles following Breast-Conserving Surgery

Background

Multiple randomized trials comparing mastectomy to lumpectomy and whole breast irradiation (WBI) have shown equivalent survival outcomes in early-stage breast cancer. WBI requires a treatment course of several weeks, which has resulted in limited access to breast-conserving therapy in certain populations. A shorter accelerated course of partial breast irradiation (APBI) has been investigated recently.

Methods

This article reviews the current medical literature, including randomized trials and prospective institutional studies of APBI and the current recommendations regarding the use of this emerging technique.

Results

Several APBI techniques have been developed, including brachytherapy and external beam methods. The longest follow-up data are available for multicatheter interstitial brachytherapy, a technique that is not commonly used. Other methods, including balloon brachytherapy and external beam three-dimensional conformal techniques, have limited follow-up that shows similar local control rates to whole breast irradiation in highly selected patients. Guidelines for the appropriate use of APBI have been published.

Conclusions

While APBI may increase access to breast conservation therapy for some women with early-stage breast cancer, follow-up data demonstrating the efficacy of this relatively new treatment approach are limited. Therefore, strict evidence-based selection criteria should be applied when evaluating patients who may be appropriate for APBI.

Shaping the breast in aesthetic and reconstructive breast surgery: an easy three-step principle. Part III--reconstruction following breast conservative treatment

SUMMARY

Of the relatively few studies that exist regarding the cosmetic satisfaction of patients following breast conservation therapy, several indicate significant dissatisfaction in many patients. Breast conservation often results in some of the most challenging and complex reconstructive problems. Indeed, even defining the problem or analyzing the defect can be difficult for the junior surgeon. For the more seasoned reconstructive surgeon, analyzing the problem and applying solutions may be less difficult, but clearly communicating the defects typically seen after an aggressive lumpectomy and radiotherapy can be difficult, especially with trainees or junior surgeons. The goal of this article, the third in a four-part series, is to provide a template for the analysis and surgical reconstruction of defects resulting from breast conservation therapy utilizing a systematic three-step method. Part I of this series described the three main anatomical features of the breast--the footprint, the conus of the breast, and the skin envelope--and how they interact. By systematically analyzing the breast with this three-step method, a "problem list" based in specific anatomic traits of the breast can be generated, allowing the surgeon to then generate an appropriate surgical plan for reconstruction. Surgical approaches based on the percentage of breast parenchyma resected are suggested, with a focus on glandular rearrangement, breast reduction techniques, and locoregional flaps. The three-step method of breast analysis, evaluating the anatomical deformation of the breast footprint, conus, and skin envelope, remains the fundamental "fall-back" principle of this approach.

Five-year analysis of treatment efficacy and cosmesis by the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation

PURPOSE

To present 5-year data on treatment efficacy, cosmetic results, and toxicities for patients enrolled on the American Society of Breast Surgeons MammoSite breast brachytherapy registry trial.

METHODS AND MATERIALS

A total of 1440 patients (1449 cases) with early-stage breast cancer receiving breast-conserving therapy were treated with the MammoSite device to deliver accelerated partial-breast irradiation (APBI) (34 Gy in 3.4-Gy fractions). Of 1449 cases, 1255 (87%) had invasive breast cancer (IBC) (median size, 10 mm) and 194 (13%) had ductal carcinoma in situ (DCIS) (median size, 8 mm). Median follow-up was 54 months.

RESULTS

Thirty-seven cases (2.6%) developed an ipsilateral breast tumor recurrence (IBTR), for a 5-year actuarial rate of 3.80% (3.86% for IBC and 3.39% for DCIS). Negative estrogen receptor status (p=0.0011) was the only clinical, pathologic, or treatment-related variable associated with IBTR for patients with IBC and young age (<50 years; p=0.0096) and positive margin status (p=0.0126) in those with DCIS. The percentage of breasts with good/excellent cosmetic results at 60 months (n=371) was 90.6%. Symptomatic breast seromas were reported in 13.0% of cases, and 2.3% developed fat necrosis. A subset analysis of the first 400 consecutive cases enrolled was performed (352 with IBC, 48 DCIS). With a median follow-up of 60.5 months, the 5-year actuarial rate of IBTR was 3.04%.

CONCLUSION

Treatment efficacy, cosmesis, and toxicity 5 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI with similar follow-up.

Cosmetic outcomes for accelerated partial breast irradiation before surgical excision of early-stage breast cancer using single-dose intraoperative radiotherapy

PURPOSE

Determine cosmetic outcome and toxicity profile of intraoperative radiation delivered before tumor excision for patients with early-stage breast cancer.

METHODS AND MATERIALS

Patients age 48 or older with ultrasound-visible invasive ductal cancers <3 cm and clinically negative lymph nodes were eligible for treatment on this institutional review board-approved Phase II clinical trial. Treatment planning ultrasound was used to select an electron energy and cone size sufficient to cover the tumor plus a 1.5- to 2.0-cm circumferential margin laterally and a 1-cm-deep margin with the 90% isodose line. The dose was prescribed to a nominal 15 Gy and delivered using a Mobetron electron irradiator before tumor excision by segmental mastectomy. Physician- and patient-assessed cosmetic outcome and patient satisfaction were determined by questionnaire.

RESULTS

From March 2003 to July 2007, 71 patients were treated with intraoperative radiation therapy. Of those, 56 patients were evaluable, with a median follow-up of 3.1 years (minimum 1 year). Physician and patient assessment of cosmesis was "good or excellent" (Radiation Therapy Oncology Group cosmesis scale) in 45/56 (80%) and 32/42 (76%) of all patients, respectively. Eleven patients who received additional whole breast radiation had similar rates of good or excellent cosmesis: 40/48 (83%) and 29/36 (81%), respectively). Grade 1 or 2 acute toxicities were seen in 4/71 (6%) patients. No Grade 3 or 4 toxicities or serious adverse events have been seen.

CONCLUSION

Intraoperative radiotherapy delivered to an in situ tumor is feasible with acceptable acute tolerance. Patient and physician assessment of the cosmetic outcome is good to excellent.

Partial breast irradiation: a review of techniques and indications

The addition of whole-breast external beam radiotherapy (EBRT) to breast-conserving surgery results in a significant reduction in the risk of death due to breast cancer, but this may be offset by an increase in deaths from other causes and toxicity to surrounding organs. Because of this, and with a view to patterns of local recurrence, irradiation of the tumour bed has been explored in selected patients with early breast cancer using a variety of radiotherapeutic modalities. This review article explores the treatment options for partial breast irradiation and examines their role within the field of breast cancer treatment.

Dosimetric Improvements in Balloon Based Brachytherapy Using the Contura® Multi-Lumen Balloon (MLB) Catheter to Deliver Accelerated Partial Breast Irradiation

Purpose

Preliminary dosimetric findings in patients managed with the Contura^® Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) on a multi-institutional phase IV registry trial were reviewed.

Material and methods

CT-based 3D planning with dose optimization was performed for all patients. For the study, new ideal dosimetric goals were developed: 1) ≥ 95% of the prescribed dose (PD) covering ≥ 90% of the target volume (TV), 2) a maximum skin dose ≤ 125% of the PD, 3) maximum rib dose ≤ 145% of the PD, and 4) the V150 ≤ 50 cc and V200 ≤ 10 cc. The frequency of concurrently achieving these dosimetric goals using the Contura^® MLB was investigated.

Results

194 cases were evaluable. Employing the MLB, all ideal dosimetric criteria were achieved in 76% of cases. Evaluating dosimetric criteria separately, 90% and 89% of cases met the new ideal skin and rib dose criteria, respectively. In 96%, ideal TV coverage goals were achieved and in 96%, dose homogeneity criteria (V150 and V200) were met. For skin spacing ≥ 5-7 mm, the median skin dose was 121% of the PD and when < 5 mm, the median skin dose was 124.4%. For rib distancees < 5 mm, the median rib dose was reduced to 136.4% of the PD. For skin spacing < 7 mm and distance to rib < 5 mm, the median skin and rib doses were concurrently limited to 121% and 142.8% of the PD, respectively.

Conclusions

The Contura^® MLB catheter provides potential improvements in dosimetric capabilities (i.e., reduced skin and rib doses and improved TV coverage) in many clinical scenarios.

Dosimetric effects of air pocket sizes in MammoSite treatment as accelerated partial breast irradiation for early breast cancer

MammoSite brachytherapy system has been used as one of the accelerated partial breast irradiation (APBI) techniques since 2002. The clinical results from several clinical institutions had shown comparable treatment efficacy, cosmesis, and toxicity to other APBI techniques. During MammoSite treatment, air cavities had been one of the primary issues causing treatment cancellation or delay. With the tolerance of the air volume less than 10% of the total Planning Target Volume (PTV) set, there is still no data available to show the actual dose delivered to the breast tissue with the existence of the air pocket. In this paper, Monte Carlo N‐Particle version 5 (MCNP5) was used to model a hypothesis MammoSite phantom with different sizes of air pockets, and compared to the calculation results from the treatment planning system (TPS) without heterogeneous corrections. It was found that without heterogeneous corrections, the difference between the TPS and MCNP5 calculations in the air cavity surface doses and PTV point doses can be up to 2.02% and 3.61%, respectively, using the balloon and air pocket size combinations calculated in this paper. Based on the distance from the point of interest to the balloon surface, an approximate dose can be calculated using the linear relationship found in this study. These equations provide a quick and simple way to predict the actual dose delivered to the breast soft tissue located within the PTV. With the equation applied to the dose from the TPS, the dose error caused by the air pocket during MammoSite treatment can be reduced to a minimum.

PACS number: 87.53.Jw

Initial surgical experience evaluating early tolerance and toxicities in patients undergoing accelerated partial breast irradiation using the Contura Multi Lumen Balloon breast brachytherapy catheter

We reviewed our surgical experience with the Contura Multi Lumen Balloon breast brachytherapy catheter used to deliver accelerated partial breast irradiation and determined short-term treatment efficacy, cosmesis, and toxicity. Forty-six patients undergoing breast conserving therapy, including the use of Contura catheter, were analyzed. Thirty-four Gray were delivered in 10 fractions. Fourteen patients had stage 0, 24 had stage I, and 8 had stage II breast cancer. Catheters were placed with a closed cavity technique. Median minimum skin spacing was 10 mm (range, 2-18 mm). Median maximum skin doses were 99.7 per cent of the prescription dose. Nine patients were treated with a skin spacing < or = 5 mm (2 patients with 2 mm skin spacing). The percentage of patients with excellent/good cosmesis at 6 (n = 26) and 12 (n = 13) months was 100 per cent, respectively. Patient tolerance was assessed on a scale of 0-10 (0 = no pain, 10 = requiring narcotic analgesics). Pain was graded < or = 3 in 98 per cent of patients at catheter insertion and 84 per cent at catheter removal. Four breast infections (8.8%) and one symptomatic seroma developed. Adjuvant accelerated partial breast irradiation using the Contura Multi Lumen Balloon exhibited similar toxicities to standard single lumen, single dwell balloon brachytherapy with improvements in dosimetric capabilities allowing the treatment of patients with skin spacing < or = 5 mm.

Local recurrence of invasive micropapillary breast cancer after MammoSite brachytherapy: a case report and literature review

Controversy exists over the optimal patient selection criteria for accelerated partial-breast irradiation (APBI), which has been introduced as an alternative to whole-breast irradiation. The goal is to select patients with the lowest risk for tumor spread outside of the original lumpectomy bed targeted by the local internal radiation dose. Therefore, patients with more aggressive types of breast cancer might not be ideal candidates for partial breast irradiation. We discuss the case of a 67-year-old woman who presented with local recurrence of invasive micropapillary breast cancer, a rare aggressive tumor type, 5 years after MammoSite brachytherapy. The patient's primary tumor possessed all favorable indicators except for the histology of invasive micropapillary carcinoma. This is the first report of invasive micropapillary carcinoma recurring after APBI. Although this is a single case, it supports the hypothesis that more aggressive types of breast cancer have a higher risk of local recurrence after APBI. We propose that invasive micropapillary carcinoma be considered a potential exclusion criterion until it can be validated in prospective clinical trials. More aggressive treatment approaches including whole-breast irradiation and/or chemotherapy might be needed to reduce the risk of local recurrence for invasive micropapillary breast cancer.

Phase I/II study evaluating early tolerance in breast cancer patients undergoing accelerated partial breast irradiation treated with the mammosite balloon breast brachytherapy catheter using a 2-day dose schedule

PURPOSE

Initial Phase I/II results using balloon brachytherapy to deliver accelerated partial breast irradiation (APBI) in 2 days in patients with early-stage breast cancer are presented.

MATERIALS AND METHODS

Between March 2004 and August 2007, 45 patients received adjuvant radiation therapy after lumpectomy with balloon brachytherapy in a Phase I/II trial delivering 2800 cGy in four fractions of 700 cGy. Toxicities were evaluated using the National Cancer Institute Common Toxicity Criteria for Adverse Events v3.0 scale and cosmesis was documented at >or=6 months.

RESULTS

The median age was 66 years (range, 48-83) and median skin spacing was 12 mm (range, 8-24). The median follow-up was 11.4 months (5.4-48 months) with 21 patients (47%) followed >or=1 year, 11 (24%) >or=2 years, and 7 (16%) >or=3 years. At <6 months (n = 45), Grade II toxicity rates were 9% radiation dermatitis, 13% breast pain, 2% edema, and 2% hyperpigmentation. Grade III breast pain was reported in 13% (n = 6). At >or=6 months (n = 43), Grade II toxicity rates were: 2% radiation dermatitis, 2% induration, and 2% hypopigmentation. Grade III breast pain was reported in 2%. Infection was 13% (n = 6) at <6 months and 5% (n = 2) at >or=6 months. Persistent seroma >or=6 months was 30% (n = 13). Fat necrosis developed in 4 cases (2 symptomatic). Rib fractures were seen in 4% (n = 2). Cosmesis was good/excellent in 96% of cases.

CONCLUSIONS

Treatment with balloon brachytherapy using a 2-day dose schedule resulted acceptable rates of Grade II/III chronic toxicity rates and similar cosmetic results observed with a standard 5-day accelerated partial breast irradiation schedule.

Current surgery for breast cancer

Surgeons retain the central role in the multidisciplinary care of the breast cancer patient. While technical details of the operations for these patients remain important, effective evidence-based decision making may be even more so. Advances in the methods of breast cancer diagnosis, localization techniques and surgical therapies, as well as the expanded role of the surgeon in breast cancer prevention, radiation therapy and the treatment of distant disease, requires surgeons to stay up to date with the available evidence. Herein, we present a review of the current surgical therapy of invasive breast cancer.

Accelerated partial breast irradiation consensus statement from the American Society for Radiation Oncology (ASTRO)

PURPOSE

To present guidance for patients and physicians regarding the use of accelerated partial-breast irradiation (APBI), based on current published evidence complemented by expert opinion.

METHODS AND MATERIALS

A systematic search of the National Library of Medicine's PubMed database yielded 645 candidate original research articles potentially applicable to APBI. Of these, 4 randomized trials and 38 prospective single-arm studies were identified. A Task Force composed of all authors synthesized the published evidence and, through a series of meetings, reached consensus regarding the recommendations contained herein.

RESULTS

The Task Force proposed three patient groups: (1) a "suitable" group, for whom APBI outside of a clinical trial is acceptable, (2) a "cautionary" group, for whom caution and concern should be applied when considering APBI outside of a clinical trial, and (3) an "unsuitable" group, for whom APBI outside of a clinical trial is not generally considered warranted. Patients who choose treatment with APBI should be informed that whole-breast irradiation (WBI) is an established treatment with a much longer track record that has documented long-term effectiveness and safety.

CONCLUSION

Accelerated partial-breast irradiation is a new technology that may ultimately demonstrate long-term effectiveness and safety comparable to that of WBI for selected patients with early breast cancer. This consensus statement is intended to provide guidance regarding the use of APBI outside of a clinical trial and to serve as a framework to promote additional clinical investigations into the optimal role of APBI in the treatment of breast cancer.

Review of MammoSite brachytherapy: advantages, disadvantages and clinical outcomes

BACKGROUND

The MammoSite radiotherapy system is an alternative treatment option for patients with early-stage breast cancer to overcome the longer schedules associated with external beam radiation therapy. The device is placed inside the breast surgical cavity and inflated with a combination of saline and radiographic contrast to completely fill the cavity. The treatment schedule for the MammoSite monotherapy is 34 Gy delivered in 10 fractions at 1.0 cm from the balloon surface with a minimum of 6 hours between fractions on the same day.

MATERIAL AND METHODS

This review article presents the advantages, disadvantages, uncertainties and clinical outcomes associated with the MammoSite brachytherapy (MSB).

RESULTS

Potential advantages of MSB are: high localised dose with rapid falloff for normal tissue sparing, minimum delay between surgery and RT, catheter moves with breast, improved local control, no exposure to staff, likely side-effects reduction and potential cost/time saving (e.g. for country patients). The optimal cosmetic results depend on the balloon-to-skin distance. Good-to-excellent cosmetic results are achieved for patients with balloon-skin spacing of > or =7 mm. There have been very few published data regarding the long term tumour control and cosmesis associated with the MSB. The available data on the local control achieved with the MSB were comparable with other accelerated partial breast irradiation techniques. The contrast medium inside the balloon causes dose reduction at the prescription point. Current brachytherapy treatment planning systems (BTPS) do not take into account the increased photon attenuation due to high Z of contrast. Some BTPS predicted up to 10% higher dose near the balloon surface compared with Monte Carlo calculations using various contrast concentrations (5-25%).

CONCLUSION

Initial clinical results have shown that the MammoSite device could be used as a sole radiation treatment for selected patients with early stage breast cancer providing good local control, minimal complication rate and excellent cosmesis.

Radiation recall reaction with docetaxel administration after accelerated partial breast irradiation with electronic brachytherapy

PURPOSE

Accelerated partial breast irradiation (APBI) offers several advantages over whole breast irradiation. Electronic brachytherapy may further reduce barriers to breast conserving therapy by making APBI more available. However, its toxicity profile is not well characterized.

METHODS AND MATERIALS

A 60-year-old woman was treated with APBI using Axxent (Xoft, Sunnyvale, CA) electronic brachytherapy. One month after APBI, a cycle of docetaxel and cyclophosphamide was given. Within 3 weeks, the patient developed an ulcerative radiation recall reaction in the skin overlying the lumpectomy cavity. To investigate this toxicity, the skin dose from electronic brachytherapy was compared with the dose that would have been delivered by an iridium-192 ((192)Ir) source. Additionally, a dose equivalent was estimated by adjusting for the increased relative biologic effectiveness (RBE) of low energy photons generated by the electronic source.

RESULTS

Using electronic brachytherapy, the skin dose was 537cGy per fraction compared with 470cGy for an (192)Ir source. Given an RBE for a 40kV source of 1.28 compared with (192)Ir, the equivalent dose at the skin for an electronic source was 687cGy-equivalents, a 46% increase.

CONCLUSIONS

We present a case of an ulcerative radiation recall reaction in a patient receiving APBI with electronic brachytherapy followed by chemotherapy. Our analysis shows that the use of electronic brachytherapy resulted in the deposition of significantly higher equivalent dose at the skin compared with (192)Ir. These findings suggest that standard guidelines (e.g., surface-to-skin distance) that apply to (192)Ir-based balloon brachytherapy may not be applicable to electronic brachytherapy.

Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

PURPOSE

To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite applicator and compare to those produced by whole breast external beam radiotherapy (WBRT).

MATERIALS AND METHODS

Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10) and the dose received by 20 cc of the structure (D20), were calculated as well as the maximum and mean doses received.

RESULTS

Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925-1380 cc. Cardiac volumes ranged from 337-551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction.

CONCLUSION

This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets.

Skin necrosis in smoking patients receiving partial breast irradiation: two case reports

Partial breast irradiation has become an increasingly popular mode of treatment after excisional biopsy to treat early stage invasive breast cancer. Its main advantage is that treatment can be delivered in five days rather than 30, as is standard for whole breast irradiation. Early reports suggest good to excellent cosmesis in the vast majority of subjects. Herein we report two cases of skin necrosis in women with Stage 1 breast cancer who smoked before and after partial breast irradiation.

Accelerated partial breast irradiation as part of breast conserving therapy of early breast carcinoma: a systematic review

New strategies for adjuvant radiotherapy of early breast cancer are being investigated in several phase III randomised trials at the present time. Accelerated partial breast irradiation (APBI) is a way to offer an early breast cancer patient, who has had breast conservative surgery, an adjuvant radiotherapy of short duration aimed at the tumour bed with a certain margin. The rationale of this strategy is that most local recurrences appear close to the tumorectomy cavity and a wish to spare the patient late radiation morbidity. This review discusses the background for APBI, the different techniques, and we highlight possible pitfalls using these techniques. A systematic overview of all phase I and II studies is provided. Patient selection for this therapy is pivotal and based on evidence from previous studies on patient/tumour characteristics and pattern of local recurrences we propose inclusion criteria for patients in APBI protocols.

Multicatheter hybrid breast brachytherapy: a potential alternative for patients with inadequate skin distance

PURPOSE

The purpose of this study was to determine whether the ClearPath (CP) multicatheter hybrid device was able to achieve acceptable dosimetry in patients in whom the proximity of the breast surgical cavity to the skin precluded treatment with intracavitary MammoSite (MS) brachytherapy.

METHODS AND MATERIALS

The study consisted of 11 patients who had the MS catheter placed and who were subsequently not treated due to inadequate skin distance. A phantom scan of the CP multicatheter hybrid device was superimposed on the MS CT scan and a dosimetric comparison was performed.

RESULTS

The median MS balloon size, diameter, and minimum skin distance were 40 cc, 4.1cm, and 5mm, respectively. The D(90), V(100), V(150), and V(200) with MS vs. CP were 95.29% vs. 97.06%, 88.8% vs. 91.3%, 35.7% vs. 38.0%, and 9.4% vs. 9.6%, respectively. The median maximum skin dose was 5.5 Gy vs. 3.9 Gy (p <.0001). The median dose homogeneity index (DHI) was 0.60 vs. 0.59 (p=.09). The median maximum rib, heart, and lung dose were 2.17 Gy vs. 2.18 Gy, 2.17 Gy vs. 2.18 Gy, and 0.50 Gy vs. 0.56 Gy, respectively.

CONCLUSION

The hybrid CP catheter reduced the skin dose significantly without compromising the planning target volume coverage, DHI, or dose to other critical organs. The use of this device has the potential to increase the applicability of accelerated partial breast brachytherapy (APBI) in patients with a surgical cavity close to skin compared with balloon brachytherapy.