Breast conservation therapy with tumor bed irradiation alone in a selected group of patients with stage I breast cancer

Breast Cancer and Mediastinal Hodgkin's Lymphomas: Multidisciplinary Discussion

Treatment for Hodgkin's lymphoma (HL) has evolved, with modern treatments combining less toxic chemotherapy and radiation, leading to improved long-term disease-free survival. However, there is a higher chance of second cancer, especially breast cancer, following effective HL treatment. The impact of reduced radiation doses and volumes, as well as the use of advanced irradiation techniques, on the risk of second malignancy is not clear. According to medical organizations, the history of chest irradiation is a relative contraindication to breast preservation therapy for women with initial breast cancer, leading to a paradigm of mastectomy. This article proposes a discussion between radiation oncologists and surgeons to review major trials and recent developments on the prevalence of breast cancer following HL therapy, the risk of contralateral cancer, the feasibility of breast conserving surgery (BCS), as well as breast reconstruction modalities.

A prospective feasibility study of MammoSite accelerated partial breast irradiation for early breast Cancer

BACKGROUND

Accelerated partial breast irradiation is a potential alternative to standard whole breast irradiation, following breast-conserving surgery, in the management of breast cancer. The MammoSite applicator-based technique allows for the delivery of a higher dose of radiation to the tumour bed and adjacent area, over a shorter treatment period.

AIMS

To investigate the long-term feasibility of the MammoSite technique in early stage breast cancer in an Irish cohort.

METHODS

Sixty-two patients with early stage breast cancer were enrolled in this prospective study between November 2005 and October 2012 at the University Hospital Galway. A single-entry MammoSite applicator was inserted post-operatively. A CT scan was performed to assess the balloon to skin distance, the conformance of target tissue to balloon surface and balloon symmetry. A total dose of 34 Gy was delivered over 10 fractions twice daily.

RESULTS

Median follow-up was 10 years. 91.9% (57/62) completed the full course of MammoSite treatment. Technical issues with the MammoSite balloon precluded three patients from completing the full course of treatment. On last follow-up, 6.4% (4/62) of patients had developed an ipsilateral breast recurrence. Half of these recurrences occurred more than 10 years after the initial breast cancer treatment. The most common toxicities observed were fibrosis (67.7%), pain (61.3%) and skin erythema (35.5%).

CONCLUSION

The use of the MammoSite technique, as an alternative to standard whole breast irradiation, is feasible in a typical Irish clinical setting with integrated multidisciplinary team input.

Intraoperative Radiotherapy during Breast Conserving Surgery in Patients Previously Treated with Radiotherapy for Hodgkin's Disease

Aims and background

Women who have received radiotherapy for Hodgkin's disease have an increased risk of developing breast cancer. Breast-conserving surgery followed by breast irradiation is generally considered to be contraindicated in such patients owing to the high cumulative radiation dose to the breast. Mastectomy is therefore recommended as the preferred treatment option in these women.

Methods

We report 3 patients affected by breast cancer who had previously been treated with mantle radiation for Hodgkin's disease and on whom breast-conserving surgery and full-dose intraoperative radiotherapy with electrons (ELIOT) were performed.

Results

A total dose of 17 Gy (prescribed at 100% isodose) in one case and 21 Gy (at the 90% isodose) in two cases was delivered directly to the mammary gland without acute complications and with good cosmetic results.

Conclusions

In women previously irradiated for Hodgkin's disease, ELIOT could avoid repeat irradiation of the whole breast, thereby permitting conservative surgical treatment.

Adjuvant Photothermal Therapy Inhibits Local Recurrences after Breast-Conserving Surgery with Little Skin Damage

Adjuvant treatments following breast-conserving surgery (BCS) are essential to reduce the risk of local recurrences in patients with breast cancer. However, current adjuvant treatments are based on ionizing radiation, which brings radiation-induced damage and amplifies the risk of death. Here we explore the feasibility of using non-ionizing light to induce photothermal therapy as an adjuvant treatment to BCS. In an orthotopic breast cancer mice model, we demonstrate that adjuvant photothermal therapy (aPTT) decreases the incidence of local recurrences after BCS with no expense of cosmetic outcome. In comparison with conventional photothermal therapy, the technique used in aPTT provides more uniformly distributed light energy and less risk of skin burns and local recurrences. Overall, this work represents a departure from the traditional concept of using PTT as an alternative to surgery and reveals the potential of using PTT as an alternative to adjuvant radiation therapy, which is valuable especially for patients susceptible to radiation damage.

American Brachytherapy Society consensus report for accelerated partial breast irradiation using interstitial multicatheter brachytherapy

PURPOSE

To develop a consensus report for the quality practice of accelerated partial breast irradiation (APBI) using interstitial multicatheter brachytherapy (IMB).

METHODS AND MATERIALS

The American Brachytherapy Society Board appointed an expert panel with clinical and research experience with breast brachytherapy to provide guidance for the current practice of IMB. This report is based on a comprehensive literature review with emphasis on randomized data and expertise of the panel.

RESULTS

Randomized trials have demonstrated equivalent efficacy of APBI using IMB compared with whole breast irradiation for select patients with early-stage breast cancer. Several techniques for placement of interstitial catheters are described, and importance of three-dimensional planning with appropriate optimization is reviewed. Optimal target definition is outlined. Commonly used dosing schemas include 50 Gy delivered in pulses of 0.6-0.8 Gy/h using pulsed-dose-rate technique and 34 Gy in 10 fractions, 32 Gy in eight fractions, or 30 Gy in seven fractions using high-dose-rate technique. Potential toxicities and strategies for toxicity avoidance are described in detail. Dosimetric constraints include limiting whole breast volume that receives ≥50% of prescription dose to <60%, skin dose to ≤100% of prescription dose (≤60-70% preferred), chest wall dose to ≤125% of prescription dose, Dose Homogeneity Index to >0.75 (>0.85 preferred), V₁₅₀ < 45 cc, and V₂₀₀ < 14 cc. Using an optimal implant technique coupled with optimal planning and appropriate dose constraints, a low rate of toxicity and a good-to-excellent cosmetic outcome of ≥90% is expected.

CONCLUSIONS

IMB is an effective technique to deliver APBI for appropriately selected women with early-stage breast cancer. This consensus report has been created to assist clinicians in the appropriate practice of APBI using IMB.

Accelerated partial breast irradiation with brachytherapy: patient selection and technique considerations

Accelerated partial breast irradiation (APBI) through breast brachytherapy is a relatively recent development in breast radiotherapy that has gained international favor because of its reduction in treatment duration and normal tissue irradiation while maintaining favorable cancer-specific and cosmetic outcomes. Despite the fact that several large national trials have not reported final results yet, many providers are currently offering APBI to select patients and APBI is listed as a treatment option for selecting patients in the National Comprehensive Cancer Network guidelines. Multiple consensus guidelines exist in selecting patients for APBI, some with conflicting recommendations. In this review, the existing patient selection guidelines are reported, compared, and critiqued, grouping them in helpful subcategories. Unique patient and technical selection factors for APBI with brachytherapy are explored.

Progress and controversies: radiation therapy for invasive breast cancer

Radiation therapy is a critical component of the multidisciplinary management of invasive breast cancer. In appropriately selected patients, radiation not only improves local control, sparing patients the morbidity and distress of local recurrence, but it also improves survival by preventing seeding and reseeding of distant metastases from persistent reservoirs of locoregional disease. In recent years, considerable progress has been made toward improving our ability to select patients most likely to benefit from radiotherapy and to administer treatment in ways that maximize clinical benefit while minimizing toxicity and burden. This article reviews the role of radiation therapy in invasive breast cancer management, both after breast-conserving surgery and after mastectomy. It focuses particularly on emerging evidence that helps to define the clinical situations in which radiotherapy is indicated, the appropriate targets of treatment, and optimal approaches for minimizing both the toxicity and the burden of treatment, all in the context of the evolving surgical and systemic management of this common disease. It includes a discussion of new approaches in breast cancer radiotherapy, including hypofractionation and intensity modulation, as well as a discussion of promising avenues for future research.

MammoSite®

MammoSite is a novel brachytherapy applicator for breast irradiation as a component of breast conservation therapy in the management of early stage breast carcinoma. Early stage breast cancer accounts for over two-thirds of newly diagnosed cases. Breast conservation therapy is an option for most women for local therapy. The standard treatment of partial mastectomy and whole-breast irradiation is being challenged. Physicians and patients are searching for alternatives to a 6- to 7-week course of external beam radiation therapy. The direct application of radioactive materials (brachytherapy) in this setting has been employed for over 10 years. MammoSite has been developed as an easier, more quality assured applicator to allow broader acceptance and wider availability of partial breast irradiation techniques. The background leading to the device will be examined, current clinical results will be reviewed and alternative technologies will be discussed.

The American Brachytherapy Society consensus statement for accelerated partial breast irradiation

PURPOSE

To develop clinical guidelines for the quality practice of accelerated partial breast irradiation (APBI) as part of breast-conserving therapy for women with early-stage breast cancer.

METHODS AND MATERIALS

Members of the American Brachytherapy Society with expertise in breast cancer and breast brachytherapy in particular devised updated guidelines for appropriate patient evaluation and selection based on an extensive literature search and clinical experience.

RESULTS

Increasing numbers of randomized and single and multi-institution series have been published documenting the efficacy of various APBI modalities. With more than 10-year followup, multiple series have documented excellent clinical outcomes with interstitial APBI. Patient selection for APBI should be based on a review of clinical and pathologic factors by the clinician with particular attention paid to age (≥50 years old), tumor size (≤3cm), histology (all invasive subtypes and ductal carcinoma in situ), surgical margins (negative), lymphovascular space invasion (not present), and nodal status (negative). Consistent dosimetric guidelines should be used to improve target coverage and limit potential for toxicity following treatment.

CONCLUSIONS

These guidelines have been created to provide clinicians with appropriate patient selection criteria to allow clinicians to use APBI in a manner that will optimize clinical outcomes and patient satisfaction. These guidelines will continue to be evaluated and revised as future publications further stratify optimal patient selection.

Impact of interfraction seroma collection on breast brachytherapy dosimetry - a mathematical model

Purpose

Balloon brachytherapy is a widely accepted modality for delivery of accelerated partial breast irradiation (APBI). Our hypothesis was that inter-fraction seroma collection around the balloon surface would have an adverse effect on dosimetry of the target.

Material and methods

This is a dosimetric re-planning study using two volumetric models (30 cc and 45 cc) in a Contura^® multi-lumen balloon (MLB) catheter. In a previously treated patient, two customized baseline plans were generated using multiple channels of the Contura^® catheter prescribed to the Planning Target Volume Evaluation (PTV_Eval). Symmetric expansions of 1.0 mm (0-9 mm) increments around the balloon surface were performed to simulate a “Virtual Seroma” (VS) accumulation for both balloon volumes and plans were obtained for each expansion using Eclipse Brachyvision™. An analysis of these plans was then performed to evaluate the effect of seroma accumulation on dosimetric parameters of V100 and V90.

Results

20 plans were generated and analyzed (10 plans for each balloon volume), representing VS of 6.0-66.0 cc. There was a commensurate decrease in the dose delivered to the PTV_Eval V100 and V90 (as defined by the original treatment plan) with increasing VS accumulation leading to a sub-optimal coverage of the PTV_Eval. For 30 cc MLB catheter, V100 decreased by 1.4% and V90 decreased by 0.9% for every 1 cc of VS. For 45cc MLB catheter, V100 decreased by 1.3% and V90 decreased by 1.15% for every 1.0 cc accumulation of VS.

Conclusions

Balloon catheter-tissue adherence ensures daily dose delivery to the planned PTV_Eval. Accumulation of seroma, hematoma or air between HDR fractions can significantly impact PTV_Eval dosimetry. Vacuum-port aspiration prior to delivery of each fraction, if available, should be considered to minimize the risk of geographic under dosing.

Brachytherapy in accelerated partial breast irradiation (APBI) - review of treatment methods

Breast conserving surgery (BCS) with following radiotherapy (EBRT) of the conserved breast became widely accepted in the last decades as the treatment of early invasive breast cancer. In an early stage of breast cancer, research has shown that the area requiring radiation treatment to prevent cancer from local recurrence is the breast tissue that surrounds the area where the initial cancer was removed. Accelerated partial breast irradiation (APBI) is an approach that treats only the lumpectomy bed with 1-2 cm margin, rather than the whole breast and as a result allows accelerated delivery of the radiation dose in four to five days. Published results of APBI are very promising. It is evident that APBI will play a role in the management of a selected group of early breast cancer. We discuss current status, indications, technical aspects and recently published results of APBI using different brachytherapy techniques.

Brachytherapy for Accelerated Partial-Breast Irradiation: A Rapidly Emerging Technology in Breast Cancer Care

Purpose

Brachytherapy is a method for delivering partial-breast irradiation after breast-conserving surgery (BCS). It is currently used in the community setting, although its efficacy has yet to be validated in prospective comparative trials. Frequency and factors influencing use have not been previously identified.

Methods

In a nationwide database of 6,882 Medicare beneficiaries (age ≥ 65 years) with private supplemental insurance (MarketScan Medicare Supplemental), claims codes identified patients treated with brachytherapy versus external-beam radiation after BCS for incident breast cancer (diagnosed from 2001 to 2006). Logistic regression modeled predictors of brachytherapy use.

Results

Frequency of brachytherapy use as an alternative to external-beam radiation after BCS increased over time (< 1% in 2001, 2% in 2002, 3% in 2003, 5% in 2004, 8% in 2005, 10% in 2006; P < .001). Increased use correlated temporally with US Food and Drug Administration approval and Medicare reimbursement of brachytherapy technology. Brachytherapy use was more likely in women with lymph node–negative disease (odds ratio [OR], 2.19; 95% CI, 1.17 to 4.11) or axillary surgery (OR, 1.74; 95% CI, 1.23 to 2.44). Brachytherapy use was also more likely in women with non–health maintenance organization insurance (OR, 1.81; 95% CI, 1.24 to 2.64) and in areas with higher median income (OR, 1.58; 95% CI, 1.05 to 2.38), lower density of radiation oncologists (OR, 1.78; 95% CI, 1.11 to 2.86), or higher density of surgeons (OR, 1.57; 95% CI, 1.07 to 2.31).

Conclusion

Despite ongoing questions regarding efficacy, breast brachytherapy was rapidly incorporated into the care of older, insured patients. In our era of frequently emerging novel technologies yet growing demands to optimize costs and outcomes, results provide insight into how clinical, policy, and socioeconomic factors influence new technology diffusion into conventional care.

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.

Patient selection for accelerated partial-breast irradiation (APBI) after breast-conserving surgery: recommendations of the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) breast cancer working group based on clinical evidence (2009)

PURPOSE

To give recommendations on patient selection criteria for the use of accelerated partial-breast irradiation (APBI) based on available clinical evidence complemented by expert opinion.

METHODS AND MATERIALS

Overall, 340 articles were identified by a systematic search of the PubMed database using the keywords "partial-breast irradiation" and "APBI". This search was complemented by searches of reference lists of articles and handsearching of relevant conference abstracts and book chapters. Of these, 3 randomized and 19 prospective non-randomized studies with a minimum median follow-up time of 4 years were identified. The authors reviewed the published clinical evidence on APBI, complemented by relevant clinical and pathological studies of standard breast-conserving therapy and, through a series of personal communications, formulated the recommendations presented in this article.

RESULTS

The GEC-ESTRO Breast Cancer Working Group recommends three categories guiding patient selection for APBI: (1) a low-risk group for whom APBI outside the context of a clinical trial is an acceptable treatment option; including patients ageing at least 50 years with unicentric, unifocal, pT1-2 (<or=30 mm) pN0, non-lobular invasive breast cancer without the presence of an extensive intraductal component (EIC) and lympho-vascular invasion (LVI) and with negative surgical margins of at least 2mm, (2) a high-risk group, for whom APBI is considered contraindicated; including patients ageing <or=40 years; having positive margins, and/or multicentric or large (>30 mm) tumours, and/or EIC positive or LVI positive tumours, and/or 4 or more positive lymph nodes or unknown axillary status (pNx), and (3) an intermediate-risk group, for whom APBI is considered acceptable only in the context of prospective clinical trials.

CONCLUSIONS

These recommendations will provide a clinical guidance regarding the use of APBI outside the context of a clinical trial before large-scale randomized clinical trial outcome data become available. Furthermore they should promote further clinical research focusing on controversial issues in the treatment of early-stage breast carcinoma.

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.

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.

Partial breast irradiation as sole therapy for low risk breast carcinoma: early toxicity, cosmesis and quality of life results of a MammoSite brachytherapy phase II study

PURPOSE

The MammoSite is a device that was developed with the goal of making breast-conserving surgery (BCT) more widely available. Our objective was to evaluate the MammoSite device performances after an open cavity placement procedure and quality of life in highly selected patients with early-stage breast cancer.

METHODS AND MATERIALS

From March 2003 to March 2005, 43 patients with T1 breast cancer were enrolled in a phase II study. The median age was 72 years. Twenty-five (58%) patients were treated with high-dose rate brachytherapy using the MammoSite applicator to deliver 34Gy in 10 fractions. The main disqualifying factor was pathologic sentinel node involvement (10/43; 23%). There were no device malfunctions, migration or rupture of the balloon.

RESULTS

After a median follow-up of 13 months, there were no local recurrences and one contralateral lobular carcinoma. Seventeen (68%), 13 (52%), 8 (32%), 5 (20%) and 2 (8%) patients had erythema, seroma, inflammation, hematoma and sever infection, respectively. Only 2 patients developed telangiectasia. At 1 year the rate of "good to excellent" cosmetic results was 84%. Significant changes in QoL were observed for emotional and social well-being between 3 and 12 months. At 24 months, only emotional well-being subscore changes were statistically significant (p=0.015).

CONCLUSIONS

Our data in patients older than 60 years support the previously published data. Histologic features were the main disqualifying criteria. With higher skin spacing levels we observed very low incidence of telangiectasia. QoL evaluation indicates that baseline scores were satisfactory. Changes concerned emotional and social well-being.

Evaluation of coplanar partial left breast irradiation using tomotherapy-based topotherapy

PURPOSE

To investigate the use of topotherapy for accelerated partial breast irradiation through field-design optimization and dosimetric comparison to linear accelerator-based three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT).

METHODS AND MATERIALS

Hypothetical 3-cm lumpectomy sites were contoured in each quadrant of a left breast by using dosimetric guidelines from the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 protocol. Coplanar intensity-modulated topotherapy treatment plans were optimized by using two-, three-, four-, five-, and seven-field arrangements for delivery by the tomotherapy unit with fixed gantry angles. Optimized noncoplanar five-field 3D-CRT and IMRT were compared with corresponding topotherapy plans.

RESULTS

On average, 99.5% +/- 0.5% of the target received 100% of the prescribed dose for all topotherapy plans. Average equivalent uniform doses ranged from 1.20-2.06, 0.79-1.76, and 0.10-0.29 Gy for heart, ipsilateral lung, and contralateral lung, respectively. Average volume of normal breast exceeding 90% of the prescription and average area of skin exceeding 35 Gy were lowest for five-field plans. Average uniformity indexes for five-field plans using 3D-CRT, IMRT, and topotherapy were 1.047, 1.050, and 1.040, respectively. Dose-volume histograms and calculated equivalent uniform doses of all three techniques illustrate clinically equivalent doses to ipsilateral breast, lung, and heart.

CONCLUSIONS

This dosimetric evaluation for a single patient shows that coplanar partial breast topotherapy provides good target coverage with exceptionally low dose to organs at risk. Use of more than five fields provided no additional dosimetric advantage. A comparison of five-field topotherapy to 3D-CRT and IMRT for accelerated partial breast irradiation illustrates equivalent target conformality and uniformity.

New trends in radiotherapy for breast cancer

PURPOSE OF REVIEW

New radiotherapy techniques are under development to improve tumor control and to decrease the long-term side effects of breast cancer. These include accelerated partial breast irradiation, intensity modulated and image guided radiotherapy.

RECENT FINDINGS

Follow-up data of multicatheter brachytherapy accelerated partial breast irradiation and intraoperative electron beam radiotherapy confirm excellent 5-year local control rates in well selected patients. Early side effects seem to be improved, but recent data show increasing skin toxicity in multicatheter and intracavitary balloon brachytherapy. Intraoperative radiotherapy, proton beam partial breast irradiation, intensity modulated and image guided radiotherapy improve dose homogeneity and decrease normal tissue complication probability. For breast-only treatment, two tangential fields with different segments provide an attractive and feasible alternative to the conventional technique. The proposed intensity modulated radiotherapy techniques for comprehensive locoregional radiotherapy, however, result in increased doses to the contralateral lung and breast.

SUMMARY

Input from long-term clinical data on new radiotherapy techniques is needed. Consensus on target volume contouring and dose volume constraints for nontarget tissue has not yet been reached. Further research on skin toxicity with multicatheter or intracavitary brachytherapy is needed to improve the results.

[Accelerated partial breast irradiation: a concept to individualize treatment in breast cancer]

Whole breast irradiation delivering an equivalent dose of 50 Gy in 5 weeks, followed by a 10 to 16 Gy-boost to the tumor bed is the standard of care after breast-conserving surgery for early-breast cancer. Accelerated partial breast irradiation (APBI) is currently under investigations in large multi-institutional, prospective, randomized trials to objectively address the critical endpoints of treatment efficacy, toxicity and cosmesis. Patient's selection for this new approach is crucial to individualise treatments and define the subgroups of patients who will really benefit from APBI in terms of quality of life without decreasing long-term results of the disease control and cosmesis. In this review, we will discuss the patients' profiles selection for APBI regarding their general and tumor criteria. The differences between APBI techniques either performed intra or post operatively will be also discussed.

Virtual planning of multicatheter brachytherapy implants for accelerated partial breast irradiation

Over the last decade, increasing numbers of breast cancer patients are being treated using interstitial radioactive implants (brachytherapy). Multiple catheters are placed in the breast using a free-hand or template-guided approach. The configuration of the catheters and their relation to the tumor target volume are crucial to effective treatment. Catheter insertion requires a high level of experience to produce an implant of excellent quality. Construction of optimal catheter configuration prior to the procedure (virtual planning) would reduce the dependence of implant quality on the skill of the physician. Currently available commercial planning systems do not allow for virtual planning. We have developed software which inputs the target anatomy for a prospective patient and matches it to a previously-delivered catheter configuration from an institutional implant library. The archived catheter arrangement is then customized to fit the new target volume. The user can actually explore the implications of variations in catheter number and spatial arrangement. This may significantly improve the quality of implants that would otherwise be designed strictly based on a physician's prior experience. In an academic environment, this new resource could lead to better, faster results in the treatment of breast cancer.

Breast-conserving treatment with partial or whole breast irradiation for low-risk invasive breast carcinoma--5-year results of a randomized trial

PURPOSE

To report the 5-year results of a randomized study comparing the survival and cosmetic results of breast-conserving treatment with partial breast irradiation (PBI) or conventional whole breast irradiation (WBI).

METHODS AND MATERIALS

Between 1998 and 2004, 258 selected patients with T1 N0-1mi, Grade 1-2, nonlobular breast cancer without presence of extensive intraductal component and resected with negative margins were randomized after breast-conserving surgery to receive 50 Gy/25 fractions WBI (n = 130) or PBI (n = 128). The latter consisted of either 7 x 5.2 Gy high-dose-rate (HDR) multicatheter brachytherapy (BT; n = 88) or 50 Gy/25 fractions electron beam (EB) irradiation (n = 40).

RESULTS

At a median follow-up of 66 months, the 5-year actuarial rate of local recurrence was 4.7% and 3.4% in the PBI and WBI arms, respectively (p = 0.50). There was no significant difference in the 5-year probability of overall survival (94.6% vs. 91.8%), cancer-specific survival (98.3% vs. 96.0%), and disease-free survival (88.3% vs. 90.3%). The rate of excellent to good cosmetic result was 77.6% in the PBI group (81.2% after HDR BT; 70.0% after EB) and 62.9% in the control group (52.2% after telecobalt; 65.6% after 6-9-MV photons; p(WBI/PBI) = 0.009).

CONCLUSIONS

Partial breast irradiation using interstitial HDR implants or EB to deliver radiation to the tumor bed alone for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI. Significantly better cosmetic outcome can be achieved with carefully designed HDR multicatheter implants compared with the outcome after WBI.

Prospective Trial of Accelerated Partial Breast Intensity-Modulated Radiotherapy

PURPOSE

To examine the feasibility and acute toxicities of an accelerated, partial breast, intensity-modulated radiotherapy (IMRT) protocol.

METHODS AND MATERIALS

Between February 2004 and August 2005, 55 patients with Stage I breast cancer and initial follow-up were enrolled at four facilities on a HealthONE and Western institutional review board-approved accelerated partial breast IMRT protocol. All patients were treated in 10 equal fractions delivered twice daily within 5 consecutive days. The first 7 patients were treated to 34 Gy, and the remaining 48 patients were treated to 38.5 Gy.

RESULTS

The median follow-up after IMRT was 10 months (range, <1-19) and after diagnosis was 11.5 months (range, 2-21). No local or distant recurrences developed. The T stage distribution was as follows: T1a in 11 patients, T1b in 24, and T1c in 20. The median tumor size was 9 mm (range, 1-20 mm). Breast cosmesis was judged by the patient as poor by 2, good by 12, and excellent by 40 (1 patient was legally blind) and by the physician as poor for 1, good for 10, and excellent for 44 patients. Breast pain, as judged by patient, was none in 34, mild in 19, moderate in 2, and severe in 0 patients. There was a single report of telangiectasia but no incidents of significant edema. Compared with historic controls for whom three-dimensional treatment planning techniques were used, IMRT provided similar dose delivery to the target while reducing the volume of normal breast included in the 100%, 75%, and 50% isodose lines.

CONCLUSION

This initial report prospectively explored the feasibility of accelerated partial breast IMRT. After short-term follow-up, the dose delivery and clinical outcomes were very acceptable. We believe this regimen deserves additional investigation under institutional review board guidance.

A Technique of Partial Breast Irradiation Utilizing Proton Beam Radiotherapy: Comparison with Conformal X-Ray Therapy

PURPOSE

To develop a breast immobilization system and clinical technique to deliver partial breast irradiation with a proton beam and compare dose distributions using proton therapy and conformal x-rays.

METHODS

A clinical technique to provide reproducible breast immobilization was developed. Breast immobilization begins by fitting each patient with a treatment brassiere. Patients are placed prone in a cylindrical polyvinyl chloride shell with the upper and lower body being supported and immobilized with Vac-Lok foam bead cushions. The upper chest and breast areas are immobilized with two-part expandable foam. After a treatment planning computed tomography scan, the lumpectomy cavity is outlined, and a clinical target volume is generated by adding 1cm in all dimensions. A three-dimensional treatment plan is developed with treatment typically given with 2 to 4 separate proton beams. The dose administered is 40 cobalt Gray equivalents (CGE) delivered in 10 daily fractions of 4 CGE with multiple fields treated each day. Proton and conformal x-ray plans were compared using dose-volume histogram analysis to determine volumes of normal breast tissue and skin treated with each technique.

RESULTS

An institutional review board-approved clinical trial was developed using this technique, and 20 patients have completed treatment. All subjects were able to undergo the immobilization procedure and daily treatments without significant discomfort, and no treatment interruptions were encountered. There was no evidence of respiratory motion identified on treatment planning CT images or on daily set-up radiographs. Acute toxicity has been limited to occasional radiation dermatitis (Radiation Therapy Oncology Group grade 1-2). Proton plans were compared with 2 methods of photon partial breast irradiation, including reduced tangential fields and five-field conformal techniques. Ten treatment plans with dose-volume histogram analysis revealed that the use of proton beams provided a significant reduction in doses to the ipsilateral breast and skin while eliminating doses to the heart and lung tissues.

CONCLUSIONS

A simple immobilization procedure provides accurate and reproducible breast positioning while simultaneously eliminating respiratory motion. The procedure has been well tolerated by the first 20 patients. Protons can provide substantial normal tissue protection compared with the use of conformal x-rays when used for partial breast treatment. We plan to continue enrollment and analyze long-term toxicity, local control, and survival.

Feasibility study on the MammoSite in early-stage breast cancer: Initial experience

The aims of this study were to evaluate the feasibility, practicality, efficacy and safety of the delivery of accelerated partial breast irradiation using the MammoSite for the boost phase. Six patients aged 53-69 years with stage T1N0, T2N0, Grade I-II invasive ductal carcinoma received 9-10 Gy prescribed at 1 cm from the MammoSite balloon surface in two fractions of 4.5-5 Gy 6 h apart. The MammoSite was inserted 20-37 days postoperatively. External beam radiation therapy to the whole breast commenced 1-5 days after accelerated partial breast irradiation. The maximum skin dose ranged from 3 to 9 Gy. The skin-cavity distance ranged from 7 to 19 mm. Local discomfort resolved as the scar healed spontaneously within 3-5 days. No Grade III or higher acute toxicity or local infection was recorded. The ease of insertion and accuracy of dosimetry makes the MammoSite suitable for use in properly selected women with early-stage breast cancer in a trial setting.

Accelerated partial breast irradiation

BACKGROUND

Breast-conserving surgery followed by whole-breast radiotherapy (WBRT) has become the standard treatment for the majority of patients with early breast cancer. Whereas the indications for systemic adjuvant treatment have continuously expanded, there is a tendency to restrict postoperative radiotherapy to accelerated partial breast irradiation (APBI) instead of WBRT.

METHODS

The different techniques of APBI are described and their respective advantages or potential drawbacks outlined. Moreover, the results described in the literature are briefly reviewed as a basis for the consensus statements and recommendations of the German Society of Radiation Oncology, the German Society of Senology, and the Working Group for Gynecological Oncology of the German Cancer Society.

RESULTS

The methods mainly used for APBI are: interstitial radiotherapy with multicatheter technique, intraoperative radiotherapy (IORT) using either electrons produced by linear accelerators or 50 kV x-rays (Intrabeam), the balloon-catheter technique (MammoSite), or 3D conformal external beam radiotherapy. These techniques have marked differences in dose distribution and homogeneity. The published range of local recurrence rates varies between 0% to 37%, the median follow-up from 8 to 72 months.

CONCLUSIONS

To date, follow-up times mostly do not yet permit a definite judgment concerning the long-term effectiveness and side effects of APBI. The relevant societies in Germany support randomized clinical studies comparing APBI with WBRT in a well-defined subset of low-risk patients. However, the authors expressly discourage the routine use of APBI outside clinical trials. Until definite results show that APBI neither impairs therapeutic outcome nor cosmetic results, WBRT remains the gold standard in the treatment of early breast cancer.