Multicatheter Interstitial Brachytherapy Research Articles

Irradiación parcial acelerada en cáncer de mama: revisión de las diferentes técnicas

Breast conservation therapy is the procedure of choice of early-stage breast cancer. Accelerated partial breast irradiation is an approach that treats only the lumpectomy bed plus a 1-2cm margin, rather than the whole breast. Because of the small volume of irradiation, a higher dose can be delivered, thus reducing the total length of treatment. Growing interest in accelerated partial breast irradiation has prompted the development of phase i-iii clinical studies evaluating distinct techniques within this therapeutic modality; these techniques include multicatheter interstitial brachytherapy, balloon-catheter brachytherapy, conformal external beam radiation therapy, and intraoperative radiation therapy. Balloon-based brachytherapy approaches include MammoSite, Axxent and Contura electronic brachytherapy. Hybrid brachytherapy devices include SAVI and ClearPath. This article reviews the different techniques, identifying the weaknesses and strengths of each approach, and proposes a direction for future research and development. Although further follow-up and mature phase iii data are needed, it seems evident that accelerated partial breast irradiation will play a role in the management of a selected group of patients with early-stage breast cancer.

A Prospective Longitudinal Clinical Trial Evaluating Quality of Life After Breast-Conserving Surgery and High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer

To prospectively examine quality of life (QOL) of patients with early stage breast cancer treated with accelerated partial breast irradiation (APBI) using high-dose-rate (HDR) interstitial brachytherapy. Between March 2004 and December 2008, 151 patients with early stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients included those with Tis-T2 tumors measuring ≤3 cm excised with negative surgical margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. QOL was measured using European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, version 3.0, and QLQ-BR23 questionnaires. The QLQ-C30 and QLQ-BR23 questionnaires were evaluated during pretreatment and then at 6 to 8 weeks, 3 to 4 months, 6 to 8 months, and 1 and 2 years after treatment. The median follow-up was 55 months. Breast symptom scores remained stable in the months after treatment, and they significantly improved 6 to 8 months after treatment. Scores for emotional functioning, social functioning, and future perspective showed significant improvement 2 years after treatment. Symptomatic fat necrosis was associated with several changes in QOL, including increased pain, breast symptoms, systemic treatment side effects, dyspnea, and fatigue, as well as decreased role functioning, emotional functioning, and social functioning. HDR multicatheter interstitial brachytherapy was well tolerated, with no significant detrimental effect on measured QOL scales/items through 2 years of follow-up. Compared to pretreatment scores, there was improvement in breast symptoms, emotional functioning, social functioning, and future perspective 2 years after treatment.

Late toxicity and cosmetic outcomes related to interstitial multicatheter brachytherapy for partial breast irradiation

Late toxicity and cosmetic outcomes related to interstitial multicatheter brachytherapy for partial breast irradiation

Outcome of a phase II prospective study on partial breast irradiation with interstitial multi-catheter high-dose-rate brachytherapy

Background and purposePartial breast irradiation (PBI) is an alternative to whole-breast irradiation after breast-conserving surgery in selected patients. Until the results of randomized phase III studies are available, phase II studies inform about PBI. We report the 5year results of a phase II prospective study with PBI using interstitial multi-catheter high-dose-rate brachytherapy (ClinicalTrials.gov Identifier: NCT00499057). MethodsHundred patients received PBI (4Gy, twice a day for 4days, until 32Gy). Inclusion criteria were: age ⩾40years, infiltrating carcinoma without lobular histology, ductal in situ carcinoma, tumor size ⩽2.5cm, negative surgical margins and axillary lymph nodes. ResultsAt a median follow-up of 60months late toxicity occurred in 25 patients; the 5-year probability of freedom from late toxicity was 72.6% (95% CI: 63.7–81.7). Tamoxifen was the only significant risk factor for late toxicity. Cosmetic results, judged by physicians and patients, were good/excellent in 98 patients. Three local relapses (1 true, 2 elsewhere) and 1 regional relapse occurred. The 5-year probability of local or regional relapse-free survival was 97.7% (95% CI: 91.1–99.4) and 99.0% (95% CI: 92.9–99.8), respectively. ConclusionPBI with interstitial multi-catheter brachytherapy is associated with low relapse and late toxicity rates.

Locoregional Recurrence Following Accelerated Partial Breast Irradiation for Early-Stage Invasive Breast Cancer: Significance of Estrogen Receptor Status and Other Pathological Variables

Understanding risk factors for locoregional recurrence (LRR) after accelerated partial breast irradiation (APBI) can help to guide patient selection for treatment with APBI. Published findings to date have not been consistent. More data are needed as these risk factors continue to be defined. A total of 277 women with early-stage invasive breast cancer underwent lumpectomy and were treated adjuvantly at our institution with APBI using high-dose rate brachytherapy. APBI was delivered using multicatheter interstitial brachytherapy (91%) or single-entry catheter brachytherapy (9%) to a dose of 32-34Gy in 8-10 twice daily fractions. Failure patterns and risk factors for recurrence were analyzed. With a median follow-up of 61months, the 5-year locoregional control rate was 94.4%. Negative estrogen receptor (ER) status was strongly associated with LRR on multivariate analysis (p<0.005). Lobular histology, the presence of an extensive intraductal component, and lymphovascular invasion also were significant but to a lesser degree than ER-negative status. Patients with multiple risk factors were at highest risk for LRR. Age was not significantly associated with increased risk for LRR. The presence of specific pathological features, particularly ER negative status, was associated with increased risk of LRR in this cohort of women treated with APBI. Further investigation is warranted to determine whether patients with adverse pathological risk factors are at higher risk of LRR after APBI than after conventional whole breast irradiation (WBI), as these same features also may place women at risk for LRR after WBI.

Intraoperative radiotherapy of the breast - really a valide option or "only" comfortable.

Intraoperative radiotherapy (IORT) of the breast is an innovative treatment option for early breast cancer and has rapidly entered clinical practice in the last years. There are several indications using a breast IORT. Generally accepted because of excellent long-term results is the intraoperative tumorbed boost followed by an external whole breast irradiation (WBI) (1,2). Considering that most in-breast tumor recurrences are seen in or near to the initial tumor site (3-7) partial breast irradiation (PBI) as the sole radiotherapy treatment modality is of large interest. Different PBI techniques, such as an IORT with electrons or 50 kV X-rays (Intrabeam © ), the interstitial multicatheter or balloncatheter (Mammosite © ) brachytherapy or also the 3D conformal external beam radiotherapy are in clinical use [overview in (8,9)], whereby no superiority could be shown for one of them.

Fourteen-Year Outcomes Using Multicatheter Interstitial Brachytherapy for Accelerated Partial Breast Irradiation

Fourteen-Year Outcomes Using Multicatheter Interstitial Brachytherapy for Accelerated Partial Breast Irradiation

Abstract P4-15-01: Second conservative treatment for ipsilateral breast tumor recurrence: GEC-ESTRO Breast WG study

Abstract For ipsilateral breast cancer tumor (IBTR), radical mastectomy represents the treatment option frequently proposed to the patient. A second conservative treatment (SCT) has been proposed using either lumpectomy alone or associated with a second irradiation of the tumor bed. However, in both clinical situations, the proof level of such therapeutic approaches remains low, based on cased-series or retrospective studies. To analyze the clinical outcome of a SCT using lumpectomy and multicatheter interstitial brachytherapy (MIB) for IBTR, the GEC-ESTRO Breast Working Group retrospectively analyzed the results of 217 patients (pts) with an IBTR treated between 09/00 and 09/10 in 8 European institutions by lumpectomy and MIB (low - LDR, pulse - PDR, or high-dose rate - HDR). Survival rates without 2nd local (2nd LR) and metastatic recurrence, disease free survival (DFS) and specific and overall survivals were analyzed as well as late effects and cosmetic results. Dosimetric data were reported according to the dose rate used. Univariate and multivariate analysis were performed to find local, metastatic and/or DFS progression prognostic factors. With a median follow-up of 14.5 years [3.5–38.2] and 3.9 years [1.1–10.3] from primary tumor and IBTR respectively and a median time interval of 9.4 years [1.1–35.4] between primary and IBTR, 20.7% of the local recurrence were observed at distance from the primary tumor. Median tumor sizes were 15 mm [1–60] and 11 mm [1–40] for the primary and IBTR respectively. Thirty-nine percent of the patient underwent an axillary lymph node dissection at the time of IBTR. Median radiotherapy dose for the primary was 56 Gy [30–69.6]. Positive hormonal receptor status for IBCR was 72.8% while 65% and 19.8% received hormonal and chemotherapy respectively as adjuvant therapy for the IBTR. Five and 10-year actuarial 2nd LR rates were 5.6% [1.5–9.5] and 7.2% [2.1–12.1] respectively. Five and 10-year actuarial metastatic recurrence rates were 9.6% [5.7–15.2] and 19.1% [7.8–28.3] respectively. Five and 10-year actuarial DFS rates were 84.6% [78.9–90.6] and 77.2% [67.5–88.3] respectively. Five and 10-year actuarial overall/specific survival (OS) rates were 88.7% [83.1–94.8] and 76.4% [66.9–87.3] respectively. 141 pts developed 193 complications. Fibrosis was the most frequent complication with 11% of G3-4 complications. Cosmetic result was jugged as excellent/good in 85%. Focusing on multivariate analysis, prognostic factors for 2nd LR, metastatic recurrence and DFS are reported. The results of this study suggest that in case of IBTR, a SCT combining lumpectomy plus MIB is feasible with an overall survival rate at least equivalent to those obtain after salvage mastectomy. The rate of complication remains acceptable with encouraging cosmetic results. The literature analysis suggests that the rate of 2nd LR is 10% [3–32], 25% [7–36] and 10% [2–26], after salvage mastectomy, salvage lumpectomy alone or combined with a second irradiation respectively. However, the 5-y OS rates after salvage mastectomy and SCT seem to be equivalent (75%) mainly influenced by distant metastatic progression. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-15-01.

Accelerated Partial Breast Irradiation for Early-Stage Breast Cancer: Controversies and Current Indications for Use

Radiation therapy options for early-stage breast cancer have evolved during the past 40 years. Several choices are currently available to certain patient subsets that allow radiation oncologists to individualize care. Multiple phase II and several phase III trials have been published that support the safety and efficacy of accelerated partial breast irradiation (APBI) as part of breast conservation in selected patients. In contrast, a recent large retrospective analysis of patients aged 67 or older who received brachytherapy for APBI has raised concerns about its effectiveness. As the radiation community awaits results from NSABP B-39/RTOG 0413, the largest randomized trial of whole breast radiation therapy (WBRT) versus APBI, to provide more conclusive data, many academic and private radiation oncology practices are utilizing APBI off-protocol to treat early-stage breast cancer patients. Because of this, the American Society for Radiation Oncology (ASTRO) published a consensus statement in 2009 to aid in proper patient selection (Table 1). Until more definitive data is garnered, we advocate strict adherence to these selection criteria to ensure optimal outcomes. Specifically, we caution against the use of APBI in lymph node-positive disease outside of a clinical trial. There is a paucity of comparative data to guide oncologists in selection of the best APBI delivery method. The current NSABP B-39/RTOG 0413 trial allows any of the three most common forms of delivery to be utilized (multicatheter interstitial brachytherapy, balloon intracavitary brachytherapy, and external beam 3D conformal therapy) and will be instrumental to compare outcome differences between these methods.

Cosmetic Analysis Following Breast-Conserving Surgery and Adjuvant High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer: A Prospective Clinical Study

To prospectively evaluate cosmetic outcomes in women treated with accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy for early-stage breast cancer. Between 2004 and 2008, 151 patients with early-stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients had stage Tis-T2 tumors of ≤3 cm that were excised with negative margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. Both the patients and the treating radiation oncologist qualitatively rated cosmesis as excellent, good, fair, or poor over time and ascribed a cause for changes in cosmesis. Cosmetic outcome was evaluated quantitatively by percentage of breast retraction assessment (pBRA). Patients also reported their satisfaction with treatment over time. Median follow-up was 55 months. The rates of excellent-to-good cosmesis reported by patients and the treating radiation oncologist were 92% and 97% pretreatment, 91% and 97% at 3 to 4 months' follow-up, 87% and 94% at 2 years, and 92% and 94% at 3 years, respectively. Breast infection and adjuvant chemotherapy were independent predictors of a fair-to-poor cosmetic outcome at 3 years. Compared to pretreatment pBRA (7.35), there was no significant change in pBRA over time. The volume receiving more than 150 Gy (V150) was the only significant predictor of pBRA. The majority of patients (86.6%) were completely satisfied with their treatment. Patients and the treating physician reported a high rate of excellent-to-good cosmetic outcomes at all follow-up time points. Acute breast infection and chemotherapy were associated with worse cosmetic outcomes. Multicatheter interstitial brachytherapy does not significantly change breast size as measured by pBRA.

Analysis of fat necrosis after adjuvant high-dose-rate interstitial brachytherapy for early stage breast cancer

To report the incidence and potential predictors of fat necrosis in women with early stage breast cancer treated with adjuvant high-dose-rate (HDR) multicatheter interstitial brachytherapy. Between 2003 and 2010, 238 treated breasts in 236 women were treated with accelerated partial breast irradiation using HDR interstitial brachytherapy. Selection criteria included patients with Tis-T2 tumors measuring ≤3cm, without nodal involvement, who underwent breast-conserving surgery. Ninety-nine percent of treatments were to a total dose of 34Gy. The presence and severity of fat necrosis were prospectively recorded during followup. Cosmesis was qualitatively scored in all patients. Cosmesis was quantitatively measured via the percentage breast retraction assessment in 151 cases. Median followup was 56 months. The crude rate of fat necrosis was 17.6%. The rate of symptomatic fat necrosis was 10.1%. In univariate analysis, acute breast infection and anthracycline-based chemotherapy, number of catheters, volume encompassed by the prescription isodose, volume encompassed by the 150% isodose (V150), volume encompassed by the 200% isodose, and integrated reference air kerma were significantly associated with fat necrosis. There was significant collinearity between the brachytherapy-related factors; of these, V150 was most predictive. In multivariate analysis, only V150 was significantly associated with fat necrosis. At 3 years, patients with fat necrosis were more likely to have a fair or poor cosmetic outcome and a larger percentage breast retraction assessment. Mammary fat necrosis is a common adverse event after breast-conserving surgery and HDR interstitial brachytherapy. Fat necrosis is associated with worse qualitative and quantitative cosmetic outcomes. Minimizing exposure volumes, such as V150, may decrease the incidence of fat necrosis and improve cosmesis.

Comparison of accelerated partial breast irradiation via multicatheter interstitial brachytherapy versus whole breast radiation

BackgroundBrachytherapy as adjuvant treatment for early-stage breast cancer has become widely available and offers patients an expedited treatment schedule. Given this, many women are electing to undergo brachytherapy in lieu of standard fractionation radiotherapy. We compare outcomes between patients treated with accelerated partial breast irradiation (APBI) via multicatheter interstitial brachytherapy versus patients who were also eligible for and offered APBI but who chose whole breast radiation (WBI).MethodsPatients treated from December 2002 through May 2007 were reviewed. Selection criteria included patients with pTis-T2N0 disease, ≤ 3 cm unifocal tumors, and negative margins who underwent breast conservation surgery. Local control (LC), cause-specific (CSS) and overall survival (OS) were analyzed.Results202 patients were identified in the APBI cohort and 94 patients in the WBI cohort. Median follow-up for both groups exceeded 60 months. LC was 97.0% for the APBI cohort and 96.2% for the WBI cohort at 5 years (ns). Classification by 2010 ASTRO APBI consensus statement categories did not predict worse outcomes.ConclusionAPBI via multicatheter interstitial brachytherapy provides similar local failure rates compared to WBI at 5 years for properly selected patients. Excellent results were seen despite the high fraction of younger patients (< 60 years old) and patients with DCIS.

Brachytherapy catheter spacing and stabilization technique

Purpose/ObjectivesTo facilitate catheter spacing, implant stability, and patient comfort during multicatheter interstitial brachytherapy. Methods and MaterialsUniform and consistent spacing of multiple interstitial implant catheters can be difficult because individual catheters may become displaced during the course of treatment. The authors have developed a brachytherapy catheter fixation method using Jackson-Pratt (JP) drains that can be used within wounds to maintain catheter spacing or on the skin surface for applicator fixation. JP drains are threaded over the implant needles to space and stabilize the implant geometry. The needles are then replaced with the usual brachytherapy catheters. ResultsSurgically directed (“open”) placement of implant catheters is less prone to displacement when a drain connects and spaces the catheters in the wound. Fixation on the skin surface can also be achieved with the JP drains, which make the friction buttons optional. The soft drain material helps avoid discomfort and pressure injury sometimes associated with hard plastic buttons. Small (10 French) round JP drains are suitable for breast, and head and neck sites and larger 7×10-mm flat JP drains for extremity sarcomas, abdominal, or thoracic tumors. ConclusionsThe complex brachytherapy devices fashioned from widely available surgical drains effectively guide and maintain geometry for multicatheter interstitial implants. Stable implant geometry leads to more reliable implementation of brachytherapy dosimetry. Patient comfort is improved and soft tissue injury from hard-edged buttons is avoided.

Accelerated partial breast irradiation: 5-year results of the German-Austrian multicenter phase II trial using interstitial multicatheter brachytherapy alone after breast-conserving surgery

Accelerated partial breast irradiation: 5-year results of the German-Austrian multicenter phase II trial using interstitial multicatheter brachytherapy alone after breast-conserving surgery

Thermal boost combined with interstitial brachytherapy in breast conserving therapy – Assessment of early toxicity

Background Hyperthermia (HT) causes a direct damage to cancerous cells and/or sensitize them to radiotherapy with usually minimal injury to normal tissues. Adjuvant HT is probably one of the most effective radiation sensitizers known and works best when delivered simultaneously with radiation. In breast conserving therapy, irradiation has to minimize the risk of local relapse within the treated breast, especially in an area of a tumor bed. Brachytherapy boost reduces 5-year local recurrence rate to mean 5,5%, so there still some place for further improvement. The investigated therapeutic option is an adjuvant single session of local HT (thermal boost) preceding standard CT-based multicatheter interstitial HDR brachytherapy boost in order to increase the probability of local cure. Aim To report the short-term results in regard to early toxicity of high-dose-rate (HDR) brachytherapy (BT) boost with or without interstitial microwave hyperthermia (MV HT) for early breast cancer patients treated with breast conserving therapy (BCT). Materials and methods Between February 2006 and December 2007, 57 stage IA–IIIA breast cancer patients received a 10 Gy HDR BT boost after conservative surgery and 42.5–50 Gy whole breast irradiation (WBI) ± adjuvant chemotherapy. 32 patients (56.1%) were treated with additional pre-BT single session of interstitial MW HT to a tumor bed (multi-catheter technique). Reference temperature was 43 °C and therapeutic time (TT) was 1 h. Incidence, severity and duration of radiodermatitis, skin oedema and skin erythema in groups with (I) or without HT (II) were assessed, significant p-value ≤ 0.05. Results Median follow-up was 40 months. Local control was 100% and distant metastasis free survival was 91.1%. HT sessions (median): reference temperature 42.2 °C, therapeutic time (TT) 61.4 min, total thermal dose 42 min and a gap between HT and BT 30 min. Radiodermatitis grades I and II occurred in 24 and 6 patients, respectively, differences between groups I and II were not significant. Skin oedema and erythema occurred in 48 (85.7%) and 36 (64.3%) cases, respectively, and were equally distributed between the groups. The incidence and duration of skin oedema differed between the subgroups treated with different fractionation protocols of WBI, p = 0.006. Skin oedema was present up to 12 months. No difference in pattern of oedema regression between groups I and II was observed, p = 0.933. Conclusion Additional thermal boost preceding standard HDR BT boost has a potential of further improvement in breast cancer local control in BCT. Pre-BT hyperthermia did not increase early toxicity in patients treated with BCT and was well tolerated. All side effects of combined treatment were transient and were present for up to 12 months. The increase in incidence of skin oedema was related to hypofractionated protocols of WBI. The study has to be randomized and continued on a larger group of breast cancer patients to verify the potential of local control improvement and to assess the profile of late toxicity.

Dosimetric characteristics of accelerated partial breast irradiation with CT image–based multicatheter interstitial brachytherapy: A single institution’s experience

Purpose To present dosimetric assessment of CT-based high-dose-rate interstitial brachytherapy of breast cancer including dose–volume histogram analysis of dose to critical structures. Methods and Materials Treatment plans of 49 patients with early-stage breast cancer enrolled to the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology trial and treated with interstitial partial breast irradiation were selected for the study. Treatment planning was performed with the use of pre- and postimplant CT imaging. Quantitative dosimetry on target volume including calculation of target volume coverage, dose homogeneity, and conformality indices was performed. Dose nonuniformity ratio was defined as ratio of volumes encompassed by 1.5 times the prescribed dose (PD) and the PD. Dose homogeneity index was defined as ( V100– V150)/ V100. Detailed dose–volume histogram analysis was carried out for the breast, lung and heart. Results Three-, four-, five-, and six-plane implants were used in 17, 21, 10, and 1 patients, respectively. The median number of catheters was 15 (range, 6–28). The mean volume of the planning target volume (PTV) was 66.4 cm 3 (range, 15.5–176 cm 3). On average, 92% (range, 90–96%) of the PTV received the PD. The mean values for dose nonuniformity ratio and dose homogeneity index were 0.32 (range, 0.25–0.41) and 0.65 (range, 0.50–0.76), respectively. The mean conformal index was 0.68 (range, 0.51–0.82) and breast tissue volume around PTV, which received at least the PD ranged between 5.3 and 51 cm 3. The mean maximum doses to skin, lung, and heart were 55%, 44%, and 21%, respectively. Volumes of the lung and heart receiving 5 Gy were 50.6 and 21.0 cm 3, respectively. Conclusions Our implant technique based on two sets of CT scanning resulted in acceptable dose distributions with respect to target coverage, dose homogeneity, and conformality.

Accelerated partial breast irradiation

Whole breast irradiation (WBI) is the standard after breast conservation surgery. However, WBI in selected patients has been questioned. Accelerated partial breast irradiation (APBI) focuses treatment on the lumpectomy bed. Many modalities of delivering APBI have been developed: multicatheter interstitial brachytherapy, MammoSite balloon catheter, single insertion multicatheter devices, three-dimensional conformal external-beam radiation therapy and intraoperative techniques. Numerous studies of APBI have demonstrated excellent local control and cosmetic outcomes in early-stage breast cancer patients.

Association Between Maximal Skin Dose and Breast Brachytherapy Outcome: A Proposal for More Rigorous Dosimetric Constraints

Multiple investigations have used the skin distance as a surrogate for the skin dose and have shown that distances <6 mm have been associated with late toxicity after MammoSite brachytherapy. No publications have yet described the relationship between the actual maximal skin dose and the outcome. The present study analyzed the maximal skin dose delivered and the occurrence of late toxicity in a large cohort of patients with prolonged follow-up. A total of 96 patients treated with breast brachytherapy between 2000 and 2007 for whom complete planning and follow-up data were available were included in the present analysis. The median follow-up was 48 months (range, 24-111). Of the 96 patients, 40 were treated with multicatheter interstitial brachytherapy and 56 with MammoSite. A multivariate statistical analysis was performed to determine the relationship between several dosimetric parameters and patient outcome. The treatment was well tolerated, with 98% of patients experiencing good to excellent cosmesis. Significant late toxicity was uncommon. The maximal dose delivered to the skin was significantly associated with the incidence of any degree of telangiectasia (p= .009) and moderate to severe fibrosis (p= .010). The incidence of late toxicity was significantly increased when the dose to the skin was >4.05 Gy/fraction. The initial skin dose recommendations have been based on safe use and the avoidance of significant toxicity. The results from the present study have suggested that patients might further benefit if more rigorous constraints were applied and if the skin dose were limited to 120% of the prescription dose.

Abstract ES5-1: Emerging Radiation Techniques — The Fast and the Furious

Abstract The equivalence of breast conserving therapy (BCT) to mastectomy in the treatment of women with early-stage breast cancer has been demonstrated in several phase III trials with over 25 years of follow-up. Despite the undisputed efficacy of this treatment approach, recent investigations have explored methods to either reduce the overall time, inconvenience or toxicity of its application. These approaches have included (1) accelerating the dose delivery scheme, (2) reducing the treatment target to less than whole breast, or (3) identifying subgroups of women in which adjuvant radiation therapy (RT) following lumpectomy can be safely omitted Accelerated partial breast irradiation (APBI) has been investigated as a possible option that incorporates both a decrease in the overall treatment time and a reduction in the amount of normal tissue irradiated. Several different treatment techniques have been developed for the delivery of APBI. Within the United States, three ‘classic’ techniques dominate and include multicatheter interstitial brachytherapy, balloon catheter brachytherapy and three-dimensional conformal external beam radiotherapy (3D-CRT). In Europe, in addition to multicatheter brachytherapy, intraoperative radiotherapy has been central to their APBI experience. The majority of results with APBI to date have provided comparable 5 and 10-year outcomes to whole breast irradiation (WBI) in highly selected, low risk patients. In recognition of the success of these single institution experiences, nine phase III studies have now been initiated or completed in the United States and Europe. Despite limited long-term clinical data, the use of APBI outside of clinical trials has increased sharply. Given these concerns, the American Society of Therapeutic Radiology and Oncology (ASTRO) Health Services Research Committee convened a Task Force of breast cancer experts to develop a consensus statement addressing patient selection criteria and best practices for the application of APBI outside of clinical trials. These recently published recommendations were based on the results of a systematic literature review of the limited APBI data and were also supplemented by the expert opinions of the Task Force members using data applying WBI to treat patients. Accelerated whole breast irradiation (AWBI) has also been explored as a potential treatment option to deliver adjuvant irradiation after lumpectomy. Similar to APBI, the goals of this treatment approach are to theoretically increase the frequency that BCT is chosen as a treatment option, provide a logistically faster, convenient and more accessible method for BCT and potentially improve overall quality-of-life for early stage breast cancer patients. The data on AWBI include several phase III trials performed in Europe and North America with some trials reporting results at 10 years. In recognition of the concerns related to appropriate selection criteria for the application of this treatment approach, the ASTRO Health Services Research Committee also convened a Task Force of breast cancer experts to develop a consensus statement addressing patient selection criteria and best practices for the application of AWBI. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr ES5-1.

Altered Fractionation: Rationale and Justification for Whole and Partial Breast Hypofractionated Radiotherapy

Over the last 2 decades, we have seen major advances in the application of radiotherapy after breast-conserving surgery. Two important contributions are the use of whole-breast hypofractionation and accelerated partial-breast irradiation. Three large randomized trials comparing whole-breast hypofractionation versus conventional fractionation for early breast cancer have shown similar rates of local recurrence and morbidity. As a result, whole-breast hypofractionation is now an option for selected patients after breast-conserving surgery. The delivery of accelerated partial-breast irradiation (APBI) has been studied using techniques of multicatheter interstitial brachytherapy, balloon-based brachytherapy, external-beam radiotherapy, and intraoperative radiotherapy. Multiple single and multi-institutional data have been published indicating good long-term results with APBI (in highly selected, low-risk patients) in terms of tumor control and toxicity. However, the long-term results of large, phase III trials comparing APBI with whole-breast irradiation are still pending.