Long-Term Update of NRG Oncology RTOG 0319: A Phase 1 and 2 Trial to Evaluate 3-Dimensional Conformal Radiation Therapy Confined to the Region of the Lumpectomy Cavity for Stage I and II Breast Carcinoma

Prospective study of once-daily accelerated partial breast irradiation using 3-dimensional conformal external beam radiotherapy for Japanese women: 12-year outcomes, toxicity, and cosmesis

BACKGROUND

To analyze in a prospective study the long-term safety and efficacy of 3-dimensional conformal radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI) for Japanese women with early breast cancer.

METHODS

Breast cancer patients with pathological tumor size ≤ 3 cm, age ≥ 20 years, lumpectomy with at least a 5 mm margin, and ≤ 3 positive axillary nodes were eligible. APBI was delivered by 3D-CRT at a dose of 38.5 Gy in 10 fractions over 10 days. The primary endpoints were the frequency and severity of acute and late radiation toxicities, and secondary endpoints were local control, survival, and cosmesis. The sample size was determined based on the incidence of ≥ grade 3 acute and late radiation toxicities, which required 71 enrollments.

RESULTS

Between 2008 and 2010, 73 patients enrolled in this trial. Twelve patients (16%) had 1-3 lymph node metastases. At a median follow-up of 12.6 years (range: 2.7-13.9 years), there were no cases of grade ≥ 3 acute or late toxicity. There were 4 ipsilateral breast tumor recurrence (IBTR) events: 12-year IBTR incidence was 4.4%. The difference in the incidence of IBTR between node-negative and node-positive patients was marginal (1.9% vs. 16.7%, p = 0.055). The majority of patients (94.4% at 2 years, 89.3% at 10 years after enrollment) had excellent/good cosmesis.

CONCLUSIONS

APBI delivered with 3D-CRT is a feasible treatment option for Asian females, but it was indicated that node-positive status might increase IBTR risk.

Comparison of adverse events in partial- or whole breast radiotherapy: investigation of cosmesis, toxicities and quality of life in a meta-analysis of randomized trials

PURPOSE/OBJECTIVE

Adjuvant whole breast radiotherapy and systemic therapy are part of the current evidence-based treatment protocols for early breast cancer, after breast-conserving surgery. Numerous randomized trials have investigated the therapeutic effects of partial breast irradiation (PBI) compared to whole breast irradiation (WBI), limiting the treated breast tissue. These trials were designed to achieve equal control of the disease with possible reduction in adverse events, improvements in cosmesis and quality of life (QoL). In this meta-analysis, we aimed to investigate the differences between PBI and WBI in side effects and QoL.

MATERIAL/METHODS

We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect-sizes for available acute and late adverse events. Additionally, we evaluated cosmetic outcomes as well as general and breast-specific QoL using the EORTC QLQ-C30 and QLQ-BR23 questionnaires.

RESULTS

Sixteen studies were identified (n = 19,085 patients). PBI was associated with a lower prevalence in any grade 1 + acute toxicity and grade 2 + skin toxicity (OR = 0.12; 95% CI 0.09-0.18; p < 0.001); (OR = 0.16; 95% CI 0.07-0.41; p < 0.001). There was neither a significant difference in late adverse events between the two treatments, nor in any unfavorable cosmetic outcomes, rated by either medical professionals or patients. PBI-technique using EBRT with twice-daily fractionation schedules resulted in worse cosmesis rated by patients (n = 3215; OR = 2.08; 95% CI 1.22-3.54; p = 0.007) compared to WBI. Maximum once-daily EBRT schedules (n = 2071; OR = 0.60; 95% CI 0.45-0.79; p < 0.001) and IORT (p = 0.042) resulted in better cosmetic results grade by medical professionals. Functional- and symptom-based QoL in the C30-scale was not different between PBI and WBI. Breast-specific QoL was superior after PBI in the subdomains of "systemic therapy side effects" as well as "breast-" and "arm symptoms".

CONCLUSION

The analysis of multiple randomized trials demonstrate a superiority of PBI in acute toxicity as well breast-specific quality of life, when compared with WBI. Overall, late toxicities and cosmetic results were similar. PBI-technique with a fractionation of twice-daily schedules resulted in worse cosmesis rated by patients.

Accelerated Partial Breast Irradiation: An Opportunity for Therapeutic De-escalation

Partial breast irradiation (PBI) has been demonstrated to have comparable outcomes to whole breast irradiation based on multiple randomized trials with long-term follow-up. However, despite the strength of the data available, PBI remains underutilized despite being an appropriate option for many women diagnosed with early-stage breast cancer. This is significant, as PBI offers the potential to reduce toxicities and shorten treatment duration without impacting outcomes; in addition, for low-risk patients, PBI alone is being investigated as an alternative to endocrine therapy alone. Modern PBI can be delivered with multiple techniques, and advances in treatment planning have allowed for improved therapeutic ratios compared with earlier techniques; one such approach is utilizing stereotactic body radiation therapy approaches allowing for smaller target margins and therefore lower breast doses. Moving forward, studies are ongoing evaluating the use of radiation alone including PBI as compared with endocrine therapy alone, with prospective studies evaluating stereotactic body radiation therapy.

Pre-operative partial breast irradiation: revolutionizing radiation treatment for women with early stage breast cancer

Partial breast irradiation (PBI) has been increasingly accepted as a suitable component of breast conservation in the management of patients with early stage breast cancer, however the majority of existing studies have focused on the use of adjuvant or intra-operative techniques. Several early stage studies have more recently shown that PBI can be safely used in the pre-operative setting. Early data show similar local control without evidence of increased toxicity or worsening cosmesis, as compared to postoperative PBI or standard whole breast irradiation. While long term data are still maturing, pre-operative accelerated PBI (PAPBI) offers a number of possible clinical advantages including reducing the treatment field and increasing the number of patients eligible for PBI, identifying biomarkers of response to radiation, and improving the rates of breast conservation and treatment compliance. This review discusses key concepts and controversies surrounding PBI as it has increasingly been adopted in the US, Canada, and Europe, and introduces the concepts and early studies of PAPBI. In addition, we summarize ongoing clinical trials investigating PAPBI, review clinical benefits and challenges associated with PAPBI versus postoperative PBI, and discuss ongoing limitations as well as next generation technologies important to the implementation of PAPBI in the management of patients with early-stage localized breast cancer.

Partial breast irradiation: An updated consensus statement from the American brachytherapy society

PURPOSE

In recent years, results with mature follow-up have been reported for several Phase III trials randomizing women to receive whole breast irradiation (WBI) versus varying modalities of partial breast irradiation (PBI). It is important to recognize that these methods vary in terms of volume of breast tissue treated, dose per fraction, and duration of therapy. As such, clinical and technical guidelines may vary among the various PBI techniques.

METHODS

Members of the American Brachytherapy Society with expertise in PBI performed an extensive literature review focusing on the highest quality data available for the numerous PBI options offered in the modern era. Data were evaluated for strength of evidence and published outcomes were assessed.

RESULTS

The majority of women enrolled on randomized trials of WBI versus PBI have been age >45 years with tumor size <3 cm, negative margins, and negative lymph nodes. The panel also concluded that PBI can be offered to selected women with estrogen receptor negative and/or Her2 amplified breast cancer, as well as ductal carcinoma in situ, and should generally be avoided in women with extensive lymphovascular space invasion.

CONCLUSIONS

This updated guideline summarizes published clinical trials of PBI methods. The panel also highlights the role of PBI for women facing special circumstances, such as history of cosmetic breast augmentation or prior breast irradiation, and discusses promising novel modalities that are currently under study, such as ultrashort and preoperative PBI. Updated consensus guidelines are also provided to inform patient selection for PBI and to characterize the strength of evidence to support varying PBI modalities.

The Value of 320-Slice Spiral Computed Tomography Perfusion Imaging in Staging and Long-Term Dynamic Evaluation of Breast Cancer

The value of 320-slice spiral computed tomography (CT) perfusion imaging in staging and long-term dynamic evaluation of breast cancer was explored. 120 breast cancer patients who underwent preoperative CT examination and were confirmed by surgery and pathology were selected. All patients underwent preoperative TNM staging of breast cancer, with 120 cases in each stage. According to the results of 320-slice spiral CT, the postoperative pathology and surgical methods were compared and analyzed. CT diagnosis of breast cancer showed that T1 sensitivity was 71% and accuracy was 61%, T2 sensitivity was 74% and accuracy was 64%, T3 sensitivity was 94% and the accuracy was 84%, and the T4 sensitivity was 100% and the accuracy was 91%. The sensitivity of N1 stage was 71%, and the accuracy was 61%; and the sensitivity of N2 ~ N3 stage was 81%, and the accuracy was 76%. There were 7 cases of M1 with distant metastasis, the sensitivity was 71%, and the accuracy was 71%. At T1 stage, blood flow (BF) was 39.2 ± 16.7 mL/min/100 g, blood volume (BV) was 2.66 ± 1.4 mL/100 g, mean transit time (MTT) was 8.16 ± 2.7 s, and permeability surface (PS) was 16.6 ± 9.7 mL/min/100 g. 320-slice spiral CT perfusion imaging technology provided a new diagnostic mode for everyone, which can quantitatively identify breast cancer with multiple parameters, which was of great significance for clinical auxiliary diagnosis.

Delivery of Adjuvant Radiation in 5 Days or Less After Lumpectomy for Breast Cancer: A Systematic Review

BACKGROUND

Recent data have been published supporting the application of ultra-short radiation therapy (RT) regimens for women with early stage breast cancer following breast conserving surgery (BCS). What has remained controversial is whether and how to apply accelerated whole breast irradiation (AWBI) or accelerated partial breast irradiation (APBI) approaches in these patients, as well as the consideration of intraoperative RT (IORT) for this population.

METHODS

We performed a systematic review of the literature searching for randomized and prospective data published evaluating ultra-short RT delivered in 5-days or less with APBI, AWBI, or IORT.

RESULTS

We identified two randomized studies applying AWBI (n=5,011 patients) with 5 to 10 year follow up, which supported the use of ultra-short course AWBI (5 fractions in one week) as compared to hypofractionated WBI. We identified six randomized trials evaluating APBI (as compared to WBI) in 5 days or less (n= 8,415) with numerous (n=55) prospective studies as well, with the data supporting short course APBI as compared to WBI. Finally, we identified two randomized trials evaluating IORT; however, both trials demonstrated elevated rates of recurrence with IORT as compared to WBI.

CONCLUSIONS

The current body of data available for ultra-short adjuvant RT regimens delivered in 5-days or less after BCS overwhelming support their utilization. While data for both exists, APBI regimens have, by far, greater numbers of patients and longer follow-up as compared to AWBI. Also, given increased rates of recurrence seen with IORT with long-term follow-up, this should not be considered a standard approach at this time.

Advances in Breast Cancer Radiotherapy: Implications for Current and Future Practice

Radiation therapy (RT) is an essential component in the management of breast cancer. Following breast-conserving surgery (BCS), adjuvant RT is the standard of care for most patients. Traditionally, RT was delivered with standard whole breast irradiation (WBI) over 5-7 weeks following BCS. However, WBI regimens have evolved; hypofractionated WBI now represents the standard approach, reducing the duration of treatment to 3-4 weeks. Over the past year, five-fraction WBI regimens have also emerged as standard of care for some patients based on data from the FAST and FAST-Forward trials. An alternative to WBI that is also available for patients with early-stage breast cancer following BCS is partial breast irradiation, which can reduce the duration of treatment and the volume of breast tissue irradiated. Outcomes from multiple randomized trials with over a 10-year follow-up have demonstrated the safety and efficacy of partial breast irradiation approaches. Single-fraction intraoperative RT has also been evaluated in two prospective trials although the outcomes available, as well as current guidelines, do not support its utilization outside of prospective studies. For patients requiring RT to the regional lymph nodes, data have demonstrated the safety of hypofractionated approaches for those undergoing BCS or mastectomy without reconstruction. Future directions for early-stage breast cancer radiotherapy include the study of even shorter regimens and studies evaluating the omission of RT versus omission of endocrine therapy for favorable-risk patients. Furthermore, studies are also underway evaluating shorter courses of radiation in patients undergoing breast reconstruction and the use of tumor genomics to identify appropriate patients for omission of radiation with limited nodal involvement.

The effect of imaging modality (magnetic resonance imaging vs. computed tomography) and patient position (supine vs. prone) on target and organ at risk doses in partial breast irradiation

INTRODUCTION

Conventionally computed tomography (CT) has been used to delineate target volumes in radiotherapy; however, magnetic resonance imaging (MRI) is being continually integrated into clinical practice; therefore, the investigation into targets derived from MRI is warranted. The purpose of this study was to evaluate the impact of imaging modality (MRI vs. CT) and patient positioning (supine vs. prone) on planning target volumes (PTVs) and organs at risk (OARs) for partial breast irradiation (PBI).

METHODS

A retrospective data set, of 35 patients, was accessed where each patient had undergone MRI and CT imaging for tangential whole breast radiotherapy in both the supine and prone position. PTVs were defined from seroma cavity (SC) volumes delineated on each respective image, resulting in 4 PTVs per patient. PBI plans were generated with 6MV external beam radiotherapy (EBRT) using the TROG 06.02 protocol guidelines. A prescription of 38.5Gy in 10 fractions was used for all cases. The impact analysis of imaging modality and patient positioning included dose to PTVs, and OARs based on agreed criteria. Statistical analysis was conducted though Mann-Whitey U, Fisher's exact and chi-squared testing (P < 0.005).

RESULTS

Twenty-four patients were eligible for imaging analysis. However, positioning analysis could only be investigated on 19 of these data sets. No statistically significant difference was found in OAR doses based on imaging modality. Supine patient position resulted in lower contralateral breast dose (0.10Gy ± 0.35 vs. 0.33Gy ± 0.78, p = 0.011). Prone positioning resulted in a lower dose to ipsilateral lung volumes (10.85Gy ± 11.37 vs. 3.41Gy ± 3.93, P = <0.001).

CONCLUSIONS

PBI plans with PTVs derived from MRI exhibited no clinically significant differences when compared to plans created from CT in relation to plan compliance and OAR dose. Patient position requires careful consideration regardless of imaging modality chosen. Although there was no proven superiority of MRI derived target volumes, it indicates that MRI could be considered for PBI target delineation.

Do reminder emails and past due notifications improve patient completion and institutional data submission for patient-reported outcome measures?

PURPOSE

NRG Oncology, part of the National Cancer Institute's National Clinical Trials Network, took efforts to increase patient-reported outcome measures (PROMs) completion and institutional data submission rates within clinical trials. Lack of completion diminishes power to draw conclusions and can be a waste of resources. It is hypothesized that trials with automatic email reminders and past due notifications will have PROM forms submitted more timely with higher patient completion.

METHODS

Automatic emails sent to the research associate were added to selected NRG Oncology trials. Comparisons between trials with and without automatic emails were analyzed using Chi-square tests with respect to patient completion and timeliness of form submission rates. Multivariable analyses were conducted using repeated measures generalized estimating equations. If PROMs were not completed, a form providing the reason why was submitted and counted towards form submission.

RESULTS

For both disease sites, form submission was significantly higher within 1 month of the form's due date for the studies with automatic emails vs. those without (prostate: 79.7% vs. 75.7%, p < 0.001; breast: 59.2% vs. 31.3%, p < 0.001). No significant differences in patient completion were observed between the breast trials. The prostate trial with automatic emails had significantly higher patient completion but this result was not confirmed in the multivariable analysis.

CONCLUSIONS

Although patient completion rates were higher on trials with automatic emails, there may be confounding factors requiring future study. The automatic emails appeared to have increased the timeliness of form submission, thus supporting their continued use on NRG Oncology trials.

[Adjuvant and neoadjuvant radiotherapy in breast cancer: A literaure review and update on the state of the evidence in 2020]

Radiation therapy has benefited from many developments over the past 20 years. These developments are mainly linked to the technology, imaging and informatics evolutions which allow better targets definitions, ensure better organs-at-risk sparing and excellent reproducibility of treatments, with a perfect control of patient positioning. In breast cancer radiotherapy, the evolution was marked by the possibility of reducing the duration of treatments from 6-7 to 3-4 weeks by using hypofractionated regimens, or by further reducing the irradiation to one week when treatment is solely focalised to the tumour bed. This concept of accelerated partial breast irradiation has challenged the paradigm of the obligation to irradiate the whole breast after conservative surgery in all patients. In addition, the technical mastery of accelerated partial breast irradiation and the development of stereotactic radiotherapy techniques are currently contributing to the development of research projects in neoadjuvant settings. Thus, numerous ongoing studies are evaluating the impact of high-dose preoperative tumour irradiation, alone or in combination with systemic treatments, on biological tumor changes, on anti-tumour immunity, and on the pathologic complete response, which is considered as predictive of better long-term survival in some molecular breast cancer subtypes. In this review, we discuss all these developments which allow breast radiation therapy to enter the era of personalisation of treatments in oncology.

Treating Positive Axillary Disease in Elderly Breast Cancer Patients: The Impact of Age on Radiation Therapy

Introduction

Breast cancer is the second most common cause of cancer death in females, and 30% of these patients are over the age of 70 years. Studies have shown deviation from the standard treatment paradigms in the elderly, especially in regard to radiation treatment.

Methods

We performed a retrospective chart review on 118 patients over the age of 70 years diagnosed with breast cancer and pathologically proven axillary disease over an 8-year period at an urban academic hospital to examine which patient factors influenced radiotherapy.

Results

Increasing patient age was associated with a decrease in the probability of receiving radiotherapy, while HER2-negative patients were more likely to receive radiation. Neither race, number of coexisting medical conditions, or insurance status showed any influence on radiation treatment.

Conclusion

Patient age has a significant influence if elderly patients with axillary disease receive radiotherapy. Further investigation and validation are needed to understand why chronological age rather than biological age influences treatment modalities.

Update on Partial Breast Irradiation

For early-stage breast cancer, partial breast irradiation (PBI) allows for reduction in the irradiated volume of normal tissues by confining the radiation target to the area surrounding the lumpectomy cavity after breast-conserving surgery. This approach has been supported by phase 2 data. However, widespread adoption of PBI has awaited the results of randomized controlled trials. This review discusses the results of randomized controlled trials comparing whole breast irradiation to PBI, including the recently published National Surgical Adjuvant Breast and Bowel Project (NSABP) B39/Radiotherapy Oncology Group (RTOG) 0413, and the Canadian RAPID trials. PBI techniques, dose/fractionation schedules, and patient selection are also reviewed.

First Experience in Korea of Stereotactic Partial Breast Irradiation for Low-Risk Early-Stage Breast Cancer

Purpose: Accelerated partial breast irradiation (A-PBI) in Korean women has been considered impracticable, owing to small breast volume and lack of high-precision radiotherapy experience. We present the first experience of stereotactic-PBI (S-PBI) with CyberKnife M6 to investigate feasibility of use and early toxicities in Korean women with early breast cancers.

Materials and Methods: A total of 104 breasts receiving S-PBI at our institution between September 2017 and October 2018 were reviewed. Patients were selected based on the American Society for Radiation Oncology (ASTRO), American Brachytherapy Society, American Society of Breast Surgeons, and Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology guidelines. A dose of 30 Gy in 5 fractions (NCT01162200) was used. Gold fiducials were routinely inserted near the tumor bed for tracking. Constraints regarding organs-at-risk followed the NSABP-B39/RTOG 0413 protocol.

Results: Median follow-up was for 13 months. Patients were categorized as “suitable” (71.2%) or “cautionary” (28.8%) according to 2017 the ASTRO guidelines. No tracking failure of inserted gold fiducials occurred. Median planning target volume (PTV) and PTV-to-whole breast volume ratio was 73.6 mL (interquartile range, 58.8–103.9 mL) and 17.0% (13.3–19.1%), respectively. Median PTV V_95%, PTV D_max, and ipsilateral breast V_50% were 97.8% (96.2–98.8%), 105.3% (104.2–106.4%), and 35.5% (28.3–39.8%), respectively. No immediate post-S-PBI toxicity ≥ grade 2 was reported, except grade 2 induration in three breasts. All patients remain disease-free to date.

Conclusion: The first use of S-PBI in Korean women was feasible and safe for selected early breast cancer. Based on these results, we have initiated a prospective study (NCT03568981) to test S-PBI in whole-breast irradiation for low-risk early breast cancer.

Accelerated partial breast irradiation-Redefining the treatment target for women with early stage breast cancer

Following breast conserving surgery, the standard of care has been to deliver adjuvant radiation therapy directed to the whole breast (WBI) over a period of 3-7 weeks. Over the past decade, increasing data have supported the concept that treatment to the whole breast may not be required in selected patients, allowing for the emergence of partial breast irradiation (PBI). Multiple randomized trials with 5-10 years of follow-up have been published documenting the safety and efficacy associated with PBI using multiple techniques. Questions that remain to be answered include (a) what is the optimal PBI technique for each clinical scenario, (b) are there additional patients that can be effectively managed with PBI approaches, and (c) are there different techniques/dose schedules that allow for further reduction in treatment duration and/or toxicities? Partial breast irradiation represents a standard approach for appropriately selected patients. PBI provides comparable clinical outcomes to WBI while allowing for a reduction in the duration treatment and the potential for reduced toxicities. Future studies may also help to better define which patients require no radiation, PBI, hypofractionated WBI or conventional WBI, based upon patient, clinical, pathologic features as well as potentially using tumor genetics.

Ten daily fractions for partial breast irradiation. Long-term results of a prospective phase II trial

Partial breast irradiation (PBI) is an effective adjuvant treatment after breast conservative surgery for selected early-stage breast cancer patients. However, the best fractionation scheme is not well defined. Hereby, we report the 5-year clinical outcome and toxicity of a phase II prospective study of a novel regimen to deliver PBI, which consists in 40 Gy delivered in 10 daily fractions. Patients with early-stage (pT1-pT2, pN0-pN1a, M0) invasive breast cancer were enrolled after conservative surgery. The minimum age at diagnosis was 60 years old. PBI was delivered with 3D-conformal radiotherapy technique with a total dose of 40 Gy, fractionated in 10 daily fractions (4 Gy/fraction). Eighty patients were enrolled. The median follow-up was 67 months. Five-year local control (LC), disease-free survival (DFS), and overall survival (OS) were 95%, 91%, and 96%, respectively. Grade I and II subcutaneous fibrosis were documented in 23% and 5% of cases. No grade III late toxicity was observed. PBI delivered in 40 Gy in 10 daily fractions provided good clinical results and was a valid radiotherapy option for early-stage breast cancer patients.

Three-Fraction Intracavitary Accelerated Partial Breast Brachytherapy: Early Provider and Patient-Reported Outcomes of a Novel Regimen

PURPOSE

To report early adverse events and patient-reported outcomes (PROs) of 3-fraction intracavitary catheter-based partial breast brachytherapy (ICBB).

MATERIALS AND METHODS

Eligible women ≥50 years of age with ≤2.5-cm, lymph node-negative invasive or in situ breast cancer underwent breast-conserving surgery and placement of a brachytherapy applicator. ICBB was initiated on the second weekday after surgery and prescribed to 21 Gy in 3 once-daily fractions. Common Terminology Criteria for Adverse Events, version 4.0; 10-point linear analog scale assessment; the PRO version of the Common Terminology Criteria for Adverse Events; and the Harvard Breast Cosmesis Scale were used for provider and patient-reported assessments.

RESULTS

Seventy-three women were treated for invasive (79%) or in situ (21%) breast cancer. The median time to completion of surgery and radiation therapy was 6 days. After 14-months median follow-up, 2 patients (3%) had developed breast infections that resolved with oral antibiotics. There was no other treatment-associated adverse event grade ≥2. The grade 1 seroma rate at 3 months was 20%, which dropped to 8% at 12 months; no events required intervention. At 12 months, 91% of patients reported an overall quality of life score as ≥8 of 10, and patient-reported cosmesis was good or excellent in 95%. All patients are alive without relapse at the last follow-up.

CONCLUSIONS

Three-fraction ICBB is associated with low rates of early provider and patient- reported adverse events and compares favorably with early outcomes of more protracted ICBB regimens, including twice-daily (3.4 Gy × 10) fractionation studied in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39. Further investigation is warranted.

Accelerated partial breast radiotherapy: a review of the literature and future directions

Breast conservation therapy exemplifies the tailoring of medicine in the care of patients with cancer. Akin to improvements in surgical approaches, accelerated partial breast irradiation (APBI) tailors the treatment volume and duration to the needs of well selected patients. Here, we examine the evidence supporting APBI as well as the lessons in patient selection, dose and delivery techniques. Examination of historical techniques and their associated outcomes will support more correct patient selection and treatment delivery in an era where we await the reports of several large prospective trials.

Alternatives to Standard Fractionation Radiation Therapy After Lumpectomy: Hypofractionated Whole-Breast Irradiation and Accelerated Partial-Breast Irradiation

Adjuvant whole-breast irradiation (WBI) after lumpectomy has been an established standard of care for decades. Standard-fractionation WBI delivered over 5 to 7 weeks can achieve durable tumor control with low toxicity but can be inconvenient for patients and cost ineffective. Hypofractionated WBI can be completed in 3 to 4 weeks and, based on long-term randomized data, is the preferred standard of care in select patients. Accelerated partial-breast irradiation can be delivered using even shorter treatment regimens. Although the available data on accelerated partial-breast irradiation is more limited, early results suggest it is an effective alternative to WBI in select patients.

Treatment Minimization in Older Patients With Early-Stage Breast Cancer

The management of early-stage breast cancer in older patients is complex and requires a careful balance of the risk of cancer death with the competing risks of comorbidities and treatment-related toxicity in women with largely favorable disease. As the US population continues to age, oncologists will increasingly encounter this clinical challenge. Several strategies involving each core component of breast cancer therapy have been investigated to minimize treatment in these patients while still maintaining acceptable outcomes. These include omission of primary tumor resection, surgical axillary evaluation, systemic chemotherapy, and/or radiotherapy, as well as reduction in radiotherapy treatment volume (partial breast irradiation) or total treatment time (hypofractionation). We review these strategies and the literature supporting their use, as well as future directions for treatment minimization.

Patient-reported outcomes of catheter-based accelerated partial breast brachytherapy and whole breast irradiation, a single institution experience

PURPOSE

Accelerated partial breast irradiation (APBI) and whole breast irradiation (WBI) are treatment options for early-stage breast cancer. The purpose of this study was to compare patient-reported-outcomes (PRO) between patients receiving multi-channel intra-cavitary brachytherapy APBI or WBI.

METHODS

Between 2012 and 2015, 131 patients with ductal carcinoma in situ (DCIS) or early stage invasive breast cancer were treated with adjuvant APBI (64) or WBI (67) and participated in a PRO questionnaire. The linear analog scale assessment (LASA), harvard breast cosmesis scale (HBCS), PRO-common terminology criteria for adverse events- PRO (PRO-CTCAE), and breast cancer treatment outcome scale (BCTOS) were used to assess quality of life (QoL), pain, fatigue, aesthetic and functional status, and breast cosmesis. Comparisons of PROs were performed using t-tests, Wilcoxon rank-sum, Chi square, Fisher exact test, and regression methods.

RESULTS

Median follow-up from completion of radiotherapy and questionnaire completion was 13.3 months. There was no significant difference in QoL, pain, or fatigue severity, as assessed by the LASA, between treatment groups (p > 0.05). No factors were found to be predictive of overall QoL on regression analysis. BCTOS health-related QoL scores were similar between treatment groups (p = 0.52).The majority of APBI and WBI patients reported excellent/good breast cosmesis, 88.5% versus 93.7% (p = 0.37). Skin color change (p = 0.011) and breast elevation (p = 0.01) relative to baseline were more common in the group receiving WBI.

CONCLUSIONS

APBI and WBI were both associated with favorable patient-reported outcomes in early follow-up. APBI resulted in a lesser degree of patient-reported skin color change and breast elevation relative to baseline.

A Single Institution Retrospective Comparison Study of Locoregional Recurrence After Accelerated Partial Breast Irradiation Using External Beam Fractionation Compared with Whole Breast Irradiation with 8 Years of Follow-Up

BACKGROUND

Accelerated partial breast irradiation (APBI) was developed to address disadvantages of overall treatment time and potentially unnecessary radiation associated with whole breast irradiation (WBI). We report updated results of our single institution study using an external beam APBI regimen with a median follow-up of 8 years.

METHODS

A total of 290 APBI patients with AJCC Stage 0-II breast cancer were compared with 290 WBI patients with matched tumor characteristics. Toxicities were scored based on the Common Terminology Criteria for Adverse Events (CTCAE v3.0). Cox regression models were used to predict likelihood of freedom from ipsilateral failure.

RESULTS

Median follow-up was 8 years in the APBI group and 7.5 years in the WBI group. In the APBI group, there were 18 (6.2%) ipsilateral breast tumor recurrence (IBTR), 13 (72%) had elsewhere failures (EF), and 5 (28%) had local failures (LF) with a median time to failure of 64.1 months. In the WBI group, there were three (1.0%) IBTR; one (33%) was an EF and two (67%) were LF with a median time to failure of 91 months. APBI was 4.6 times more likely (hazard ratio 4.57, 95% confidence interval 1.3-16.2, p = 0.02) to have an IBTR than WBI after adjusting for age, tumor size, histology, grade, and estrogen receptor status. Fatigue, erythema, and desquamation toxicities were significantly less in the APBI group then the WBI group.

CONCLUSIONS

IBTR rates were higher in external beam APBI group compared with WBI, but APBI had fewer toxicities. Clinicians must weigh the risks and benefits of APBI when making a recommendation for partial breast irradiation after lumpectomy.