Irradiation of the tumor bed alone after lumpectomy in selected patients with early-stage breast cancer treated with breast conserving therapy

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.

Contemporary Issues in Breast Cancer Radiotherapy

A series of landmark studies have increasingly emphasized the role of adjuvant radiotherapy for the definitive management of breast cancer. Although regional nodal irradiation, including the internal mammary nodes, was typically reserved for high-risk patients, there is now evidence of benefit to this approach even for those with a limited nodal disease burden. Similarly, low-risk disease has historically been treated with whole-breast tangents, although contemporary studies now support accelerated partial breast irradiation or the omission of radiotherapy in select cases. This article presents recent data informing these contemporary developments in the radiotherapeutic management of breast cancer.

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: a review and evaluation of indications for treatment

Accelerated partial breast irradiation (APBI) represents a well-studied treatment modality for the delivery of adjuvant radiation therapy following breast-conserving surgery. Interstitial APBI represents the APBI technique with the longest follow-up to date; data from randomized trials and matched pair analyses demonstrate equivalent local control to traditional whole-breast irradiation with comparable rates of toxicity and improved cosmesis. While less mature, prospective data support the efficacy and safety of applicator-based brachytherapy with new multilumen applicators offering the potential for improved outcomes. External beam APBI represents a noninvasive technique; however, concerns regarding toxicity with this technique have emerged though newer techniques may mitigate these concerns. Multiple guidelines have been published based on traditional clinical and pathologic criteria to help physicians offer APBI to appropriately selected patients.

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.

Brachytherapy in breast cancer: an effective alternative

Breast conserving surgery (BCS) with following external beam radiation therapy (EBRT) of the conserved breast has become widely accepted in the last decades for the treatment of early invasive breast cancer. The standard technique of EBRT after BCS is to treat the whole breast up to a total dose of 42.5 to 50 Gy. An additional dose is given to treated volume as a boost to a portion of the breast. In the early stage of breast cancer, research has shown that the area requiring radiation treatment to prevent the 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 plus a 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. There has been a growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy (3D-EBRT) and intra-operative radiation therapy (IORT). Balloon-based brachytherapy approaches include MammoSite, Axxent electronic brachytherapy, Contura, hybrid brachytherapy devices. Another indication for breast brachytherapy is reirradiation of local recurrence after mastectomy. Published results of brachytherapy are very promising. We discuss the current status, indications, and technical aspects of breast cancer brachytherapy.

Interoperative radiotherapy of seventy-two cases of early breast cancer patients during breast-conserving surgery

OBJECTIVE

To evaluate interoperative radiotherapy after breast conservative surgery in early breast cancer patients in terms of postoperative complications, cosmetic outcome and recurrence events.

METHODS

From June 2007 to Dec 2011, 143 early breast cancer patients received breast conservative surgery. Seventy-two (study group) received interoperative radiotherapy, compared with 71 patients (control group) given routine radiotherapy. Postoperative complications were evaluated 1 month after surgery; cosmetic outcome was evaluated 1 year postoperatively; recurrence and death events were followed up.

RESULTS

The average wound healing time was 13~22 d in the study group and 9~14 d in the control group. In the study group, 2 patients developed lyponecrosis, 16 patients showed wound edema while no such side effects were found in the control group. No infection or hematomas were found in either group. In the study group (59 cases), overall cosmetic outcome in 53 patients was graded as excellent or good, and in 6 as fair or poor. Meanwhile in the control group (56 cases), 42 patients were graded as excellent or good, and 14 as fair or poor (P=0.032). After a follow-up from 3 to 54 months (median: 32 months), two patients (2.78%) in study group developed local relapses, one of them (1.39%) died, 2 patients (2.78%) developed bone metastases. In control group, one patient (1.41%) developed local relapse, 2 patients (2.82%) developed bone metastases, and no one died.

CONCLUSION

Intraoperative radiotherapy is safe and reliable with good cosmetic outcome.

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.

Early-stage breast cancer conservative treatment: high-dose-rate brachytherapy boost in a single fraction of 700 cGy to the tumour bed

BACKGROUND AND PURPOSE

Conservative treatment represents the current therapy for early-stage breast cancer. When risk factors for local relapse exist, a tumour bed boost is required. Retrospectively, we evaluated the prognostic factors influencing local recurrence (LR), overall survival (OS) and disease-free survival (DFS).

MATERIAL AND METHODS

After conservative treatment, 210 patients received a single-dose HDR brachytherapy (HDRBT) boost between June 1996 and December 2005. Mean age was 57 years; 75% had invasive ductal carcinoma. The most frequent surgery was lumpectomy (55.7%); 39.4% were G3, 18.6% intraductal component >25% and only 22% had negative margins.

RESULTS

With a mean follow-up of 85 months, at 5 and 10 years the OS was 93% and 88%, DFS 92% and 89%, and LR 3.6% and 5.3%, respectively. For LR, the risk factors were carcinoma in situ, N+ and involved margins, whereas for metastasis, the risk factors were T2 tumours, stage III, N+ and the presence of local recurrence.

CONCLUSIONS

HDR-BT boost in one fraction is an effective, simple and safe method for reducing LR. The outpatient setting and shorter treatment duration represent undeniable advantages.

Consequences of dose heterogeneity on the biological efficiency of ¹⁰³Pd permanent breast seed implants

Brachytherapy is associated with highly heterogeneous spatial dose distributions. This heterogeneity is usually ignored when estimating the biological effective dose (BED). In addition, the heterogeneities of the medium including the tissue heterogeneity (TH) and the interseed attenuation (ISA) are also contributing to the heterogeneity of the dose distribution, but they are both ignored in Task Group 43 (TG43)-based protocols. This study investigates the effect of dose heterogeneity, TH and ISA on metrics that are commonly used to quantify biological efficiency in brachytherapy. The special case of 29 breast cancer patients treated with permanent (103)Pd seed implant is considered here. BED is compared to equivalent uniform BED (EUBED) capable of considering the spatial heterogeneity of the dose distribution. The effects of TH and ISA on biological efficiency of treatments are taken into account by comparing TG43 with Monte Carlo (MC) dose calculations for each patient. The effect of clonogenic repopulation is also considered. The analysis is performed for different sets of (α/β, α) ratios of (2, 0.3), (4, 0.27) and (10, 0.3) [Gy, Gy(-1)] covering the whole range of reported α/β values in the literature. BED is sometimes larger and sometimes smaller than EUBED(TG43) indicating that the effect of the dose heterogeneity is not similar among patients. The effect of the dose heterogeneity can be characterized by using the D(99) dose metric. For each set of the radiobiological parameters considered, a D(99) threshold is found over which dose heterogeneity will cause an overestimation of the biological efficiencies while the inverse happens for smaller D(99) values. EUBED(MC) is always larger than EUBED(TG43) indicating that by neglecting TH and ISA in TG43-based dosimetry algorithms, the biological efficiencies may be underestimated by about 10 Gy. Overall, by going from BED to the more accurate EUBED(MC) there is a gain of about 9.6 to 13 Gy on the biological efficiency. The efficiency gain is about 10.8 to 14 Gy when the repopulation is considered. Dose heterogeneity does not have a constant impact on the biological efficiencies and may under- or overestimate the efficacy in different patients. However, the combined effect of neglecting dose heterogeneity, TH and ISA results in underestimation of the biological efficiencies in permanent breast seed implants.

Partial breast irradiation techniques in early breast cancer

Whole breast irradiation represents an integral part of combined breast-conserving treatment of early breast cancer. A new concept includes replacing traditionally fractionated whole breast postoperative radiotherapy by accelerated partial breast irradiation. The latter involves a variety of techniques and may be applied intraoperatively or shortly after the surgery. The intraoperative techniques include photon or electron external beam irradiation and interstitial high dose rate (HDR) brachytherapy, whereas the postoperative techniques comprise interstitial brachytherapy, be it HDR, pulse dose rate (PDR) or low dose rate (LDR), intracavitary brachytherapy and external beam radiotherapy using electrons, photons or protons. This article presents accelerated partial breast irradiation techniques, ongoing phase III trials evaluating their value and recommendations for clinical practice.

Accelerated partial breast irradiation with IMRT: new technical approach and interim analysis of acute toxicity in a phase III randomized clinical trial

PURPOSE

To evaluate with a randomized clinical trial the possibility of treating the index quadrant with external intensity-modulated radiotherapy (IMRT) in a selected group of patients with early-stage breast cancer and to analyze the acute toxicity.

METHODS AND MATERIALS

From September 2005, a randomized Phase III clinical trial has been conducted to compare conventional (tangential field) fractionated whole breast treatment (Arm A) with accelerated partial breast irradiation plus intensity-modulated radiotherapy (Arm B). For intensity-modulated radiotherapy, the clinical target volume was drawn with a uniform 1-cm margin around the surgical clips in three dimensions. The ipsilateral and contralateral breast, ipsilateral and contralateral lung, heart, and spinal cord were contoured as organs at risk. All the regions of interest were contoured according to the International Commission on Radiation Units and Measurements reports 50 and 62 recommendations.

RESULTS

In September 2008, 259 patients were randomized and treated. The mean clinical target volume in Arm B was 44 cm(3) and the mean planning target volume was 123 cm(3). The mean value of the ratio between the planning target volume and the ipsilateral breast volume was 21%. The rate of Grade 1 and Grade 2 acute skin toxicity was 22% and 19% in Arm A (Radiation Therapy Oncology Group scale), respectively. The tolerance in Arm B was excellent with only 5% Grade 1 and 0.8% Grade 2 acute skin toxicity. The planning constraints were fully satisfied in most patients. In a very few cases, this was not possible because of very unfavorable anatomy. Quality assurance procedures were performed according to our internal quality assurance protocol, with excellent results.

CONCLUSION

In the present preliminary analysis, we have demonstrated that accelerated partial breast irradiation is feasible, with very low acute toxicity.

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.

Concepts and techniques of intraoperative radiotherapy (IORT) for breast cancer

The standard treatment for early breast cancer comprises wide local excision, sentinel lymph node biopsy or axillary lymph node dissection, adjuvant medical treatment and radiotherapy to the whole breast. Many studies suggest that local control plays a crucial role in overall survival. The local recurrence rate is estimated to be 1% per year and varies between 4 and 7% after 5 years and up to 10 to 20% in the long-term follow up. On the basis of low local recurrence rates the concept of whole breast irradiation comes up for discussion, and partial breast irradiation (PBI) is increasingly under consideration. Intraoperative radiotherapy (IORT) is referred to as the delivery of a single high dose of irradiation directly to the tumor bed (confined target) during surgery. PBI (limited field radiation therapy, accelerated partial breast irradiation APBI) is the irradiation exclusively confined to a breast volume, the tumor surrounding tissue (tumor bed) either during surgery or after surgery without whole breast irradiation. Various methods and techniques for IORT or PBI are under investigation. The advantage of a very short radiation time or the integration of the complete radiation treatment into the surgical procedure convinces at a first glance. The promising short-term results of those studies must not fail to mention that local recurrence rates could probably increase and furthermore give rise to distant metastases and a reduction in overall survival. The combination of IORT in boost modality and whole breast irradiation has the ability to reduce local recurrence rates. The EBCTCG overview approves that differences in local treatment that substantially affect local recurrence rates would avoid about one breast cancer death over the next 15 years for every four local recurrences avoided, and should reduce 15-year overall mortality.

Long-term efficacy and patterns of failure after accelerated partial breast irradiation: a molecular assay-based clonality evaluation

PURPOSE

To determine the long-term efficacy and cosmetic results of accelerated partial breast irradiation (APBI) by reviewing our institution's experience.

METHODS AND MATERIALS

A total of 199 patients with early-stage breast cancer were treated prospectively with adjuvant APBI after lumpectomy using interstitial brachytherapy. All patients had negative margins, 82% had Stage I disease, median tumor size was 1.1 cm, and 12% had positive lymph nodes. The median follow-up for surviving patients was 8.6 years. Fifty-three patients (27%) have been followed for >or=10 years.

RESULTS

Six ipsilateral breast tumor recurrences (IBTRs) were observed, for a 5-year and 10-year actuarial rate of 1.6% and 3.8%, respectively. A total of three regional nodal failures were observed, for a 10-year actuarial rate of 1.6%. Five contralateral breast cancers developed, for a 5- and 10-year actuarial rate of 2.2% and 5.2%, respectively. The type of IBTR (clonally related vs. clonally distinct) was analyzed using a polymerase chain reaction-based loss of heterozygosity assay. Eighty-three percent of IBTRs (n = 5) were classified as clonally related. Multiple clinical, pathologic, and treatment-related factors were analyzed for an association with the development of an IBTR, regional nodal failure, or contralateral breast cancer. On multivariate analysis, no variable was associated with any of these events. Cosmetic results were rated as excellent/good in 99% of patients.

CONCLUSIONS

Long-term results with APBI using interstitial brachytherapy continue to demonstrate excellent long-term local and regional control rates and cosmetic results. According to a polymerase chain reaction-based loss of heterozygosity assay, 83% of recurrences were classified as clonally related.

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.

Radiation Options for Early Stage Breast Cancer

OBJECTIVE

To explore the current radiation therapy options for early stage breast cancer.

DATA SOURCES

Research literature and review articles.

CONCLUSION

With 20 years of clinical data supporting the efficacy of whole breast radiotherapy after lumpectomy for early stage breast cancer, the attention has shifted to an even more conservative approach, namely partial breast irradiation following lumpectomy. A number of large clinical trials in North America and Europe are currently enrolling patients for the evaluation of several different techniques, including interstitial brachytherapy, the Mammosite device, 3-dimensional conformal external radiation therapy, and intraoperative radiotherapy.

IMPLICATIONS FOR NURSING PRACTICE

Radiation oncology nurses can significantly impact the coordination of services and the education of patients who enroll in these important clinical trials.

MammoSite balloon brachytherapy: errors, pitfalls, and technical issues for a practicing surgeon

This article describes the technical aspects of insertion of the MammoSite radiation therapy system for patients with T1-2 disease. Practicing breast surgeons should be aware of the errors and pitfalls, the importance of cosmetic issues, and patient selection procedures.

Partial irradiation of the breast: Old challenges, new solutions

Breast-conserving treatment, characteristically consisting of surgical removal of the tumor and post-operative whole breast irradiation, is nowadays considered as the standard therapeutic approach for most women with stage I/II, invasive breast cancer. Recently, a number of institutions started investigating the feasibility and safety of novel approaches in radiotherapy, modulating concomitantly treatment time and irradiation volume. Whilst this strategy is still under investigation, recent clinical studies on accelerated partial breast irradiation with intra-operative radiotherapy or high conformality irradiation strongly suggest that the way patients with early breast cancer are irradiated should be revisited.

Long-term cosmetic results and toxicity after accelerated partial-breast irradiation: a method of radiation delivery by interstitial brachytherapy for the treatment of early-stage breast carcinoma

BACKGROUND

The objective of this study was to assess the cosmesis and toxicities in patients with early-stage breast carcinoma who received treatment with accelerated partial breast irradiation (APBI) using interstitial brachytherapy.

METHODS

From April 1993 to December 2001, 199 patients with Stage I-II breast carcinoma received breast-conserving therapy with APBI to the tumor bed alone through a low-dose-rate (LDR) or high-dose-rate (HDR) implant. A template guide was used. The LDR dose was 50 Gray (Gy) over 96 hours; the outpatient HDR implant delivered 32 Gy in 8-Gy or 34 Gy in 10-Gy twice-daily fractions. Cosmesis (Harvard criteria) and toxicities (Radiation Therapy Oncology Group guidelines) were assessed at < or = 6 months, 2 years, and 5 years.

RESULTS

The median follow up was 6.4 years. Breast pain, edema, erythema, and hyperpigmentation all diminished over time. Breast fibrosis and hypopigmentation increased until the 2-year mark and then stabilized. Fat necrosis and telangiectasia increased over time, with a fat necrosis rate of 11% at 5 years. Nearly all telangiectasias (34% at 5 yrs) were Grade 1 (< 2 mm). The remaining toxicities were Grade 1 at all follow-up intervals. Infections (11%) occurred predominantly within the first month after treatment. Good-to-excellent cosmetic outcomes were noted in 95-99% of patients over time; cosmetic results stabilized at 2 years with excellent results increased out to 5 years.

CONCLUSIONS

APBI with interstitial brachytherapy resulted in mild chronic toxicities, the majority of which diminished or reached a plateau over time. Long-term cosmesis was good to excellent in 95-99% of patients and stabilized at 2 years.

The MammoSite® breast brachytherapy device: targeted delivery of breast brachytherapy

The MammoSite® breast brachytherapy device was designed to overcome the logistic difficulties presented by external beam radiation therapy and the technical difficulties of multicatheter-based interstitial brachytherapy. The device consists of a silicone balloon connected to a catheter which contains an inflation channel and a port for passage of a high-dose-rate brachytherapy source. The American Brachytherapy Society and American Society of Breast Surgeons have published partial breast irradiation patient selection guidelines. Initial reports have shown a favorable cosmetic outcome in the majority of patients. The MammoSite applicator has also been associated with minimal side effects. The NSABP B-39/RTOG 0413 trial will randomize patients to either whole breast irradiation or partial-breast irradiation consisting of interstitial brachytherapy, MammoSite brachytherapy, or 3D conformal radiation. This national randomized trial has the potential to provide a definitive answer regarding the benefits of partial-breast irradiation, and therefore lead to more women undergoing breast conserving therapy.

The MammoSite breast brachytherapy applicator: a review of technique and outcomes

The MammoSite breast brachytherapy device was designed to overcome the potential scheduling problems associated with external beam radiotherapy (EBRT) and the technical difficulties of multi-catheter-based interstitial brachytherapy. The device consists of a silicone balloon connected to a catheter which contains an inflation channel and a port for passage of a high-dose-rate brachytherapy source. The American Brachytherapy Society and American Society of Breast Surgeons have published partial breast irradiation (PBI) patient selection guidelines. The MammoSite applicator has been shown in two dosimetric studies to treat a comparable volume to multicatheter-based interstitial implants. The MammoSite catheter can be placed at the time of lumpectomy or in a separate procedure using ultrasound guidance. Four optimization methods have been described: the single point method, the six prescription point method (RUSH Technique), the University of Southern California Norris Cancer Center Method, and the Surface Optimization Technique. An excellent or good cosmetic outcome has been reported in 80% to 93% of patients at 1 year in most studies. Cosmetic results appear highly related to skin spacing. The MammoSite applicator has been associated with early side effects comparable with traditional breast conserving therapy. A NSABP trial will randomize patients to either whole breast irradiation or PBI consisting of interstitial brachytherapy, MammoSite brachytherapy, or 3D conformal radiation.

Accelerated partial breast irradiation: a dosimetric comparison of three different techniques

PURPOSE

We report the first single-institutional dosimetric comparison of patients treated with three forms of accelerated partial breast irradiation: interstitial HDR brachytherapy, the MammoSite balloon apparatus, and 3D conformal external beam quadrant irradiation (3D-CRT).

METHODS

A retrospective dosimetric comparison of interstitial HDR brachytherapy, MammoSite balloon brachytherapy, and 3D-CRT was performed. Thirty patients including 10 from each treatment technique were included for a dosimetric comparison of the dose received by the ipsilateral breast, PTV, heart, and ipsilateral lung. Interstitial patients were treated with 4 Gy in 8 fractions to 32 Gy, and the MammoSite patients were treated with 3.4 Gy in 10 fractions to 34 Gy. 3D-CRT patients were treated with 3.85 Gy in 10 fractions to 38.5 Gy using multiple isocentric beams. The CT images from simulation or implant evaluation were transferred into our 3D treatment planning software. The lumpectomy cavities were outlined for every patient, except the MammoSite patients, where the cavity was defined by the balloon edge. The PTV was constructed as a uniform expansion of 1.5 cm for all interstitial HDR patients, 1.0 cm for the MammoSite patients, and a 1.0 cm expansion in addition to the CTV expansion of 1.0 cm (n=2), and 1.5 cm (n=8) for the 3D-CRT patients. The CTV expansion for 3D-CRT and the PTV expansion for the brachytherapy patients were limited to the chest wall and skin. Normal structures including both ipsilateral lung and breast and heart for left-sided lesions were outlined. The lumpectomy cavity was subtracted from the PTV and normal breast tissue for evaluation. To evaluate dose to the ipsilateral breast and lung, PTV, and heart, a dose-volume histogram (DVH) analysis was performed. All histograms were normalized to the volume of the structure (i.e., expressed as percent volume).

RESULTS

The average percentage of the breast receiving 100% and 50% of the prescribed dose (PD) was higher in the 3D-CRT group (24% and 48%, respectively) compared with the MammoSite (5% and 18%, respectively) and interstitial patients (10% and 26%, respectively). Improved coverage of the PTV was noted in the 3D-CRT plans compared with the MammoSite and interstitial HDR plans. With the interstitial HDR technique, 58% of the PTV received 100% of the PD compared with 76% with MammoSite and 100% with 3D-CRT techniques. The percentage of the PTV receiving 90% of the PD was 68%, 91%, and 100% for the interstitial HDR, MammoSite, and 3D-CRT patients, respectively. The ipsilateral lung V20 was slightly higher for 3D-CRT at 5% compared with 0% for both brachytherapy techniques.

CONCLUSION

In those treated with 3D-CRT, coverage of the PTV was better with 3D-CRT but varied with the definition used. At the coverage at 90% of the PD, no difference was observed between 3D-CRT and MammoSite (which were both better than interstitial). 3D-CRT resulted in better coverage of the PTV compared with MammoSite or interstitial brachytherapy techniques. Better PTV coverage with 3D-CRT came at the cost of a higher integral dose to the remaining normal breast. Dosimetrically, the best partial breast irradiation technique appears to depend on the clinical situation. Of the brachytherapy techniques, MammoSite appears to be superior in PTV coverage. When comparing MammoSite vs. 3D-CRT PTV coverage at 90% of the PD, the difference was not significantly different.

Cosmetic Outcome and Incidence of Infection with the MammoSite Breast Brachytherapy Applicator

We present our results regarding the cosmetic outcome achieved and the rate of infection using the MammoSite breast brachytherapy applicator to treat patients with partial breast irradiation. In addition, factors associated with cosmetic outcome and infection are analyzed. The study population consisted of 30 patients with early stage breast cancer treated using the MammoSite device from October 28, 2002, to February 13, 2004. Cosmetic outcome was analyzed for its association with the following parameters: volume of the balloon, balloon-to-skin distance, maximal skin point dose per fraction, V100 (percent of volume that received 100% of the prescription dose), V150 (percent of volume that received 150% of the prescription dose), and V200 (percent of volume that received 200% of the prescription dose). The occurrence of infection at the time of treatment and during follow-up was also recorded. At a median follow-up of 13 months (range 1-16 months), 53.3% of the patients (16/30) were reported to have an excellent cosmetic outcome and 40.0% (12/30) had a good cosmetic outcome. Excellent cosmetic outcome was associated with a greater mean balloon-to-skin distance compared to those who achieved a good cosmetic outcome (1.5 cm versus 1.2 cm) (p = 0.164). The mean V100, V150, and V200 of those in the excellent cosmetic outcome group were 92.1%, 34.5%, and 7.6% versus 93.0%, 34.7%, and 7.6% in the good cosmetic outcome group (p = 0.642, 0.926, and 0.853), The mean balloon volumes were 47.7 cm3 and 56.9 cm3, respectively (p = 0.063) in the excellent and good outcome groups. The mean maximal skin doses per fraction in the excellent and good outcome groups were 354.8 cGy and 422.3 cGy (p = 0.286), respectively. Infection occurred in 13.3% of the patients (4/30). An excellent or good cosmetic outcome was achieved in 93.3% of patients and infection occurred in 13.3% of patients treated with the MammoSite breast brachytherapy applicator. Excellent cosmetic outcome was associated with a greater balloon-to-skin distance, lower maximal skin dose per fraction, and smaller mean balloon volume; however, the results did not reach statistical significance.

A new option for early breast cancer patients previously irradiated for Hodgkin's disease: intraoperative radiotherapy with electrons (ELIOT)

Introduction

Patients who have undergone mantle radiotherapy for Hodgkin's disease (HD) are at increased risk of developing breast cancer. In such patients, breast conserving surgery (BCS) followed by breast irradiation is generally considered contraindicated owing to the high cumulative radiation dose. Mastectomy is therefore recommended as the first option treatment in these women.

Methods

Six patients affected by early breast cancer previously treated with mantle radiation for HD underwent BCS associated with full-dose intraoperative radiotherapy with electrons (ELIOT).

Results

A total dose of 21 Gy (prescribed at 90% isodose) in five cases and 17 Gy (at 100% isodose) in one case were delivered directly to the mammary gland without acute complications and with good cosmetic results. After an average of 30.8 months of follow up, no late sequelae were observed and the patients are free of disease.

Conclusion

In patients previously irradiated for HD, ELIOT can avoid repeat irradiation of the whole breast, permit BCS and decrease the number of avoidable mastectomies.

A permanent breast seed implant as partial breast radiation therapy for early-stage patients: a comparison of palladium-103 and iodine-125 isotopes based on radiation safety considerations

PURPOSE

A permanent breast seed implant (PBSI) technique has been developed as a new form of partial adjuvant radiation therapy for early-stage breast cancer. This study compares iodine-125 ((125)I) and palladium-103 ((103)Pd) isotopes by examining the exposure and effective dose (ED) to a patient's partner.

METHODS AND MATERIALS

A low-energy survey meter was used to measure exposure rates as a function of bolus thickness placed over (103)Pd or (125)I seeds. A general mathematical expression for the initial exposure rate at 1 m (x(o,1m)) from the skin surface as a function of the implant size, R, and the distance between the skin surface and the implant, d, was derived. Also, a second general equation is proposed to calculate the ED to the patient's partner.

RESULTS

The initial exposure rate at 1 meter and the ED are calculated as follows: x(o,1m) = 3alpha2R(3) ; ;beta(3) [e(-beta(2R+d))(betaR + 1) + e(-betad)(betaR - 1)], and ED = aR(b) [e(-c(2R+d)) (cR + 1) + e(-cd) (cR - 1)]. For (125)I, the parameters are: alpha = 0.154409, beta = 0.388460, a = 197, b = -0.95, and c = 0.38846. For (103)Pd, they are: alpha = 0.06877, beta = 0.421098, a = 18.6, b = -0.78, and c = 0.421098. For implant diameters varying from 2 to 6 cm and skin-to-implant distances varying from 0.7 to 4 cm, the ED is consistently below 2.6 mSv using the (103)Pd isotope, but more than 5 mSv in many instances and possibly up to 20 mSv using (125)I.

CONCLUSIONS

PBSI using (103)Pd seeds appears safe because the patient's partner ED is consistently below 5 mSv. The(125)I isotope is not recommended for PBSI.

Surface optimization technique for MammoSite breast brachytherapy applicator

PURPOSE

We present a technique to optimize the dwell times and positions of a high-dose-rate (192)Ir source using the MammoSite breast brachytherapy applicator. The surface optimization method used multiple dwell positions and optimization points to conform the 100% isodose line to the surface of the planning target volume (PTV).

METHODS AND MATERIALS

The study population consisted of 20 patients treated using the MammoSite device between October 2002 and February 2004. Treatment was delivered in 10 fractions of 3.4 Gy/fraction, twice daily, with a minimum of 6 h between fractions. The treatment of each patient was planned using three optimization techniques. The dosimetric characteristics of the single-point, six-point, and surface optimization techniques were compared.

RESULTS

The surface optimization technique increased the PTV coverage compared with the single- and six-point methods (mean percentage of PTV receiving 100% of the prescription dose was 94%, 85%, and 91%, respectively). The surface method, single-point, and six-point method had a mean dose homogeneity index of 0.62, 0.68, and 0.63 and a mean full width at half maximum value of 189, 190, and 192 cGy/fraction, respectively.

CONCLUSION

The surface technique provided greater coverage of the PTV than did the single- and six-point methods. Using the FWHM method, the surface, single-, and six-point techniques resulted in equivalent dose homogeneity.

The MammoSite balloon brachytherapy catheter for accelerated partial breast irradiation

Whole-breast irradiation after lumpectomy for early-stage breast cancer appears to prevent relapse only at the site of initial involvement, and therefore it is likely that radiation can safely be limited to tissues immediately surrounding the excision cavity. Accelerated partial-breast irradiation (APBI) with the MammoSite catheter (Proxima Therapeutics, Alpharetta, GA) has been proposed as a means through which APBI can be offered to a wide range of patients. Although sufficient follow-up is not yet available regarding local control, survival, late toxicity, and long-term cosmetic results, early results are promising. This article reviews the current literature reflecting treatment, dose optimization, outcomes, and toxicity of APBI with the MammoSite brachytherapy catheter.

Irradiation with standard tangential breast fields in patients treated with conservative surgery and sentinel node biopsy: using a three-dimensional tool to evaluate the first level coverage of the axillary nodes

Recent data show that axillary coverage can be obtained, but only through a selective CT-based treatment planning, as standard tangential fields are inadequate to deliver therapeutic doses. Currently, the replacement of axillary dissection with new techniques, such as sentinel node (SN) biopsy, makes it necessary to re-address the question about the real role of axillary irradiation, complicated by the differences in the anatomy of dissected and undissected axillary regions. The purpose of this paper is the dosimetric analysis of first axillary level coverage in standard irradiation of 15 breast-cancer patients treated with quadrantectomy and SN biopsy (negative finding). During surgery a clip on the site of the SN was positioned, marking the caudal margin of first axillary level. After the breast treatment plan was completed, the first axillary level was contoured on CT scans, from the site of the surgical clip up to the sternal manubrium, for coverage analysis with dose-volume histograms (DVHs) and three-dimensional isodose visualization. The maximum dose mean ranged from 5% to 80% of the prescribed dose (mean value 48.7%). The mean total dose received by the volume of interest was lower than 40 Gy in all but one patient. No patient had total irradiation of first nodal level; only one patient had 35% of the volume enclosed in the 100% isodose. Our analysis lead to the conclusion that therapeutic doses are not really delivered to first level axillary level nodes by a standard tangential field technique, and that specific treatment planning and beam arrangement are required when adequate coverage is necessary.

Recurrent abscess after MammoSite brachytherapy

Recently a new catheter was introduced to facilitate brachytherapy in a lumpectomy cavity. Data are limited on the side effects of high-dose brachytherapy to the lumpectomy cavity with the MammoSite catheter. We present a case of recurrent abscesses over a 7-month period in the lumpectomy cavity after MammoSite brachytherapy.

Biologic comparison of partial breast irradiation protocols

PURPOSE

To analyze the dose/fractionation schedules currently used in ongoing clinical trials of partial breast irradiation (PBI) by comparing their biologically effective dose (BED) values to those of three standard whole breast protocols commonly used after segmental mastectomy in the treatment of breast cancer.

METHODS AND MATERIALS

The BED equation derived from the linear-quadratic model for radiation-induced cell killing was used to calculate the BEDs for three commonly used whole breast radiotherapy regimens, in addition to a variety of external beam radiotherapy, as well as high-dose-rate and low-dose-rate brachytherapy, PBI protocols.

RESULTS

The BED values of most PBI protocols resulted in tumor control BEDs roughly equivalent to a 50-Gy standard treatment, but consistently lower than the BEDs for regimens in which the tumor bed receives a total dose of either 60 Gy or 66 Gy. The BED values calculated for the acute radiation responses of erythema and desquamation were nearly all lower for the PBI schedules, and the late-response BEDs for most PBI regimens were in a similar range to the BEDs for the standard treatments.

CONCLUSION

Biologically effective dose modeling raises the concern that inadequate doses might be delivered by PBI to ensure optimal in-field tumor control.

Prospective trial of intraoperative radiation treatment for breast cancer

BACKGROUND

A new device, Intrabeam, is available for intraoperative radiotherapy. We have prospectively examined its feasibility and tolerability in delivering adjuvant breast cancer treatment.

METHODS

Thirty-five patients undergoing breast-conserving surgery received targeted tumour bed irradiation consisting of 5 Gy (at 10 mm) in a single fraction. This single intraoperative treatment was used to replace the external beam radiotherapy "boost" that would usually be given in 10 daily treatments following 5 weeks of whole breast irradiation. Patients later completed external beam radiotherapy as usual. Potential toxicities were prospectively assessed fortnightly prior to external beam radiotherapy, weekly during it, and 3 monthly subsequently.

RESULTS

The intraoperative radiotherapy was able to be delivered without difficulty, either at time of initial cancer surgery or as a second procedure. When performed as a separate procedure the median operating time was 56 min. The treatment was well tolerated, with only one patient experiencing any grade 3 or 4 toxicities--this was acute grade three itch. There was an overall early breast infection rate of 17%. No unexpected toxicities were seen.

CONCLUSIONS

This simple and well-tolerated treatment delivers a useful radiation dose to the area of highest risk of tumour recurrence. The early infection rate is similar to that reported in the literature, for treatments without intraoperative radiotherapy. Whether such a treatment may adequately replace the entire adjuvant radiation therapy treatment for low-risk patients is now being studied in a randomized trial.

Prone accelerated partial breast irradiation after breast-conserving surgery: preliminary clinical results and dose-volume histogram analysis

PURPOSE

To report the clinical and dose-volume histogram results of the first 47 patients accrued to a protocol of accelerated partial breast irradiation. Patients were treated in the prone position with three-dimensional conformal radiotherapy after breast-conserving surgery.

METHODS AND MATERIALS

Postmenopausal women with Stage T1N0 breast cancer were eligible only after they had first refused to undergo 6 weeks of standard radiotherapy. Planning CT in the prone position was performed on a dedicated table. The postoperative cavity was defined as the clinical target volume, with a 1.5-cm margin added to determine the planning target volume. A total dose of 30 Gy at 6 Gy/fraction was delivered in five fractions within 10 days.

RESULTS

The median age of the patients was 67.5 years (range, 51-88 years). The median tumor diameter was 9 mm (range, 1.3-19 mm). In all patients, the prescribed dose encompassed the planning target volume. The mean volume of the ipsilateral breast receiving 100% of the prescription dose was 26% (range, 10-45%), and the mean volume contained within the 50% isodose surface was 47% (range, 23-75%). The lung and heart were spared by treating in the prone position. Acute toxicity was modest, limited mainly to Grade 1-2 erythema. With a median follow-up of 18 months, only Grade 1 late toxicity occurred, and no patient developed local recurrence.

CONCLUSION

These data suggest that this approach is well tolerated, with only mild acute side effects and sparing of the heart and lung.

The validity of surgical clips as a radiographic surrogate for the lumpectomy cavity in image-guided accelerated partial breast irradiation

PURPOSE

We hypothesize that surgical clips placed in the biopsy cavity during lumpectomy can be used as radiographic markers to facilitate image-guided external beam accelerated partial breast irradiation.

METHODS AND MATERIALS

We evaluated 28 patients with surgically placed clips in the lumpectomy cavity and two CT scans on different days. To establish whether the clips remain predictive of the lumpectomy cavity throughout therapy, we analyzed the motion of both cavities with repeat volumetric CT scans. The three-dimensional (3D) locations of each lumpectomy cavity and the associated clips were defined as individual regions of interest (ROIs). A single point of interest (POI) was defined for each ROI. The calculated movements of the lumpectomy cavity POIs between different scans were compared to those of the clip POIs. The second CT data set was then moved in accordance to the calculated clip POI's movement. The volume of the (second) lumpectomy cavity associated with the second scan outside of the (first) cavity of the first scan was measured. In addition, the required amount of a radial margin expansion around the first lumpectomy cavity to ensure coverage of the second lumpectomy cavity both before and after moving the second lumpectomy according to the clip POI movement was calculated.

RESULTS

The two CT scans were obtained on average 27 days apart, and the mean lumpectomy size decreased from 35 to 16 cc. The clip and lumpectomy cavity POIs moved a mean of 3 mm along the three principal Cartesian axes. In moving the second lumpectomy cavity according to the clip POI displacement from its original position, the volume of the second lumpectomy cavity outside of the volume of the first decreased from 2.6 cc to 1.0 cc after correction, and the required radial margin on the first lumpectomy cavity to include the second lumpectomy cavity decreased from 5.5 mm vs. 3.8 mm.

CONCLUSION

The surgically placed clips after lumpectomy are strong radiographic surrogates for the biopsy cavity. If the clips were used to guide accelerated partial breast irradiation, a planning target volume margin of the order of 5 mm could be used, significantly smaller than the 10-mm margin currently employed.