Short-Course Hypofractionated Radiation Therapy With Boost in Women With Stages 0 to IIIa Breast Cancer: A Phase 2 Trial

Long-Term Clinical and Cosmetic Outcomes of Once-Daily Accelerated Partial Breast Irradiation in Early Breast Cancer

Purpose

Accelerated partial breast irradiation (APBI) is one of the standard treatment options in early-stage node negative breast cancer in selected patients. However, the optimal dose fractionation schedule still represents a challenge. We present the 12-year follow up results of clinical and cosmetic outcomes of once daily APBI with external beam radiation therapy which provides an APBI radiation dose equivalent to the whole breast radiation with a boost.

Methods and Materials

From July 2008 to August 2010, we enrolled 34 patients with T1, T2 (< 3cm) N0 to receive once daily APBI with three dimensional conformal radiation therapy (3D-CRT) to a total dose of 49.95 Gy over 15 single daily fractions over 3 weeks at 3.33 Gy per fraction. Ipsilateral breast tumor recurrence (IBTR), acute toxicity, late toxicity and cosmesis was analyzed. The median follow-up for all patients is 144 months (12 years).

Results

The median age of the patients was 61 years (range 46-83). Nine patients had ductal carcinoma in situ (DCIS) and 25 patients had invasive cancer. The median size of the tumor with DCIS pathology was 0.5 cm, while median size of the tumor with invasive cancer pathology was 1.0 cm. All of the patients had negative margins and negative nodes. Two IBTR was observed (5.8%). One patient had DCIS at recurrence and other had invasive recurrence. Two patients died due to non-cancer cause. The 12-year actuarial ipsilateral breast recurrence free survival was 93.5% and the 12-year actuarial overall survival was 93.2%. Late Grade 2 toxicity was observed in 6 patients and late grade 3 toxicity was seen in 1 patient. 91% of the patients had excellent to good cosmesis.

Conclusions

This novel APBI dosing schema is based on an equivalent dose compared to whole breast radiation plus a tumor bed boost. This once daily APBI scheme is well-tolerated and demonstrates good to excellent cosmetic outcome and low rates of late complications on long term follow-up.

Hypofractionated whole breast irradiation in association with hypofractionated or normofractionated boost to the tumor bed in early breast cancer: tolerance and efficacy analysis

BACKGROUND

The boost to the tumor bed improves local control in breast cancer and it is an important part of the breast conserving therapy. However, information about the use of a hypofractionated boost is sparse, thus further studies are needed. We conducted a retrospective study with the aim of comparing hypofractionated boost (HB) and normofractionated boost (NB) on skin toxicity and local control.

MATERIALS AND METHODS

A total of 96 women with early breast cancer undergoing breast-conserving surgery and hypofractionated whole breast irradiation (WBI) were retrospectively analyzed divided into hypofractionated boost group and conventional fractionation boost group. Forty-nine patients were treated with NB with 16 Gy in 8 fractions and 47 patients were treated with HB with 13.35 Gy in 5 fractions. We examined acute and chronic toxicity with CTCAE version 5.

RESULTS

The median follow-up was 49.5 months (26-67). Median age was 57 years (36-82). Sixty-six patients (68.7%) were younger than 60 years at the time of boost and 30 (31.2%) were older than 60 years who received the boost due to poor prognostic factors. No differences were found between the two groups in terms of patient, tumor or treatment characteristics. Grade 2 acute skin toxicity was 6.3% in the NB group and 4.2% in the HB group. Chronic skin induration was 4.2% in the NB group and 1% in the HB group. They did not show grade 3 skin toxicity. There were also no differences in acute or late skin toxicity between the two groups. No local recurrences were evidenced.

CONCLUSIONS

Hypofractionated WBI associated with HB treatment is a viable option in the management of conservative breast therapy given the good tolerance and similar local control.

Radiation Oncologists' Views on Breast Radiation Therapy Guidelines: Utilizing an Online Q&A Platform to Assess Current Views on Whole-Breast Irradiation Therapy

INTRODUCTION

Poor adherence to the 2011 American Society for Radiation Oncology (ASTRO) evidence-based guideline on whole-breast irradiation (WBI) has been reported. We utilized theMednet to assess the views of the updated 2018 guideline among radiation oncologists (ROs).

METHODS

We identified 11 questions asked by community ROs on theMednet, a web-based platform, between October 27, 2014 and May 2, 2017 that were updated in the 2018 guideline. New answers provided by senior authors of the 2018 guideline, cited guidelines, and polls to survey ROs were disseminated in 3 theMednet's newsletters between March 16, 2018 and May 1, 2018. Any question with less than 60% consensus was resubmitted on October 9, 2019 and assessed on February 13, 2020.

RESULTS

A total of 792 ROs responded to the initial surveys. In each survey, the answer choice(s) that received the majority of the votes aligned with the 2018 guideline. The strongest consensus was for the use of hypofractionated (HF)-WBI regardless of histology (97%), followed by HF-WBI boost dose (92%), molecular subtype (90%), grade (88%), and concurrent use of trastuzumab (87%). The least consensus was for age at which HF-WBI should be offered with 53% of respondents, specifically 73% of academic ROs versus 47% of community ROs (P = .001), agreeing with the guideline. The re-submitted survey 19 months later showed 77% of 287 new respondents now agreed with the guideline regarding age.

CONCLUSION

The majority of ROs concur with the 2018 WBI guideline in theMednet surveys, with better agreement among academic ROs than community ROs for certain components of the guideline. Further research into the different practice patterns may optimize patient care.

Patient-Reported Outcomes and Cosmesis After Once-Weekly Hypofractionated Breast Irradiation in Medically Underserved Patients

PURPOSE

To evaluate patient-reported outcomes (PROs) and cosmesis from a phase 2 trial of once-weekly hypofractionated breast irradiation (WH-WBI) after breast-conserving surgery (BCS).

METHODS AND MATERIALS

Patients had stage 0-II breast cancer treated with BCS and negative margins. WH-WBI was 28.5 to 30 Gy in 5 weekly fractions of 5.7 to 6 Gy delivered with or without a boost. PROs were collected for 3 years after treatment using the Breast Cancer Treatment Outcome Scale (BCTOS) and European Organization for Research and Treatment of Cancer Breast Cancer-Specific Quality of Life Questionnaire (QLQ-BR23). Physicians rated cosmetic outcome with the Global Cosmesis Score. Longitudinal growth models were used to assess changes in BCTOS across time, and baseline values and changes between time points were correlated with patient and treatment factors.

RESULTS

From 2011 to 2015, 158 women received WH-WBI, and 148 were eligible for analysis after a median follow-up of 39.3 months. Adverse changes (P < .001) in global BCTOS score and breast pain and arm function subscores were observed 6 months after radiation therapy, followed by improvement to near-baseline values at years 1 and 3. Adverse changes in BCTOS cosmetic subscore were also detected at 6 months (P < .001), with no significant improvement at 1 (P = .385) and 3 (P = .644) years. No effect was detected for longitudinal changes in BCTOS scoring for age, body mass index, diabetes, smoking, breast volume, tumor size, seroma volume, dosimetric factors, dose, boost, or systemic therapy. Physician-rated cosmesis at 3 years was excellent/good in 89% and fair/poor in 11%.

CONCLUSIONS

WH-WBI was associated with transient worsening in arm function and breast pain but persistent adverse changes in cosmetic PROs that were typically mild or moderate in severity. Physician-rated cosmetic outcomes were acceptable.

The evolution of adjuvant radiation therapy for early-stage and locally advanced breast cancer

Adjuvant radiation therapy is often delivered after breast cancer surgery, both in the post-lumpectomy and post-mastectomy settings. Standard fractionation whole breast irradiation (SF-WBI), which is typically delivered over 5-7 weeks, was previously considered the standard of care. More recent data has helped to establish hypofractionated whole breast irradiation (HF-WBI), which consists of a 3-4 week regimen, as a new standard of care. This article provides an overview of the major randomized trials that support the routine use of HF-WBI for the majority of patients undergoing breast-conserving surgery for early-stage breast cancer. Newer data on the use of a hypofractionated approach in the post-mastectomy setting, as well as ongoing randomized trials addressing this topic, are also discussed.

Hypofractionated whole breast radiotherapy with or without hypofractionated boost in early stage breast cancer patients: a mono-institutional analysis of skin and subcutaneous toxicity

BACKGROUND

Our study evaluated skin and subcutaneous toxicity analyzing its correlation with patient- and treatment-related factors in a large mono-institutional series of women with early stage breast cancer treated with adjuvant hypofractionated whole breast radiotherapy (WBRT) with or without a sequential hypofractionated boost (HB).

METHODS

Two hundred and nineteen patients, median age 62 years, received adjuvant hypofractionated WBRT in 16 fractions to a total dose of 42.4 Gy. Patients with negative prognostic factors received a HB of 2.65 Gy for 4 or 5 (patients with focal positive surgical margins) fractions. Systemic adjuvant treatments were hormonal therapy (HT) and/or chemotherapy (CHT) and/or Trastuzumab. Toxicities were assessed using the Common Terminology Criteria for Adverse Events (CTCAE 4.03) scale at 5th, 10th, 16th, 20th day from the start of radiotherapy (RT) and 1, 6 and 12 months after the end of RT. Univariate and multivariate analysis estimated toxicity predictive factors.

RESULTS

No case of treatment interruption and no acute or late G3 toxicities occurred. In the univariate analysis HB administration resulted a risk factor for acute toxicity, while CHT administration and number of excised lymph nodes ≥ 10 resulted a risk factor for late toxicity. In the multivariate analysis none of the evaluated factors emerged a risk factor for acute and/or late toxicity.

CONCLUSIONS

Our results confirmed that hypofractionated WBRT even followed by a HB resulted safe and well tolerated. Longer follow-up is warranted to estimate late toxicity and treatment outcomes.

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.

Hypofractionated radiation treatment in the management of breast cancer

INTRODUCTION

The standard treatment for early-stage breast cancer is breast conservation therapy, consisting of breast conserving surgery followed by adjuvant radiation treatment (RT). Conventionally-fractionated whole breast irradiation (CF-WBI) has been the standard RT regimen, but recently shorter courses of hypofractionated whole breast irradiation (HF-WBI) have been advocated for patient convenience and reduction in healthcare costs and resources. Areas covered: This review covers the major randomized European and Canadian trials comparing HF-WBI to CF-WBI with long-term follow-up, as well as additional recently closed randomized trials that further seek to define the applicability of HF-WBI in clinical practice. Randomized data is summarized in terms of clinical utility and for a variety of clinical applications. Recently published consensus guidelines and practical implementation of HF-WBI including its broader effect on the healthcare system are reviewed. Finally, an assessment of the emerging evidence in support of hypofractionation for locally advanced disease is presented. Expert commentary: HF-WBI has replaced CF-WBI as the accepted standard of care in most women with early-stage breast cancer who do not require regional nodal irradiation. Early data supports the continued study of hypofractionation in the locally advanced setting, however broad adoption awaits longer follow-up and additional data from ongoing clinical trials.

Normal tissue damage: its importance, history and challenges for the future

Sir Oliver Scott, a philanthropist and radiation biologist and, therefore, the epitome of a gentleman and a scholar, was an early Director of the BECC Radiobiology Research Unit at Mount Vernon. His tenure preceded that of Jack Fowler, with both contributing to basic, translational and clinical thought and application in radiation across the globe. With respect to this review, Fowler's name in particular has remained synonymous with the use of models, both animal and mathematical, that assess and quantify the biological mechanisms that underlie radiation-associated normal tissue toxicities. An understanding of these effects is critical to the optimal use of radiation therapy in the clinic; however, the role that basic sciences play in clinical practice has been undergoing considerable change in recent years, particularly in the USA, where there has been a growing emphasis on engineering and imaging to improve radiation delivery, with empirical observations of clinical outcome taking the place of models underpinned by evidence from basic science experiments. In honour of Scott and Fowler's work, we have taken this opportunity to review how our respective fields of radiation biology and radiation physics have intertwined over the years, affecting the clinical use of radiation with respect to normal tissue outcomes. We discuss the past and current achievements, with the hope of encouraging a revived interest in physics and biology as they relate to radiation oncology practice, since, like Scott and Fowler, we share the goal of improving the future outlook for cancer 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.

Predictors of radiation-induced acute skin toxicity in breast cancer at a single institution: Role of fractionation and treatment volume

Purpose

The associations among radiation fractionation, body mass index (BMI), and acute skin toxicity with adjuvant radiation for breast cancer is of increasing interest. This study evaluated the rate of grade ≥2 dermatitis and moist desquamation (MD) in patients with a high BMI who were treated to the breast or chest wall to understand the role of radiation target, fractionation regimen, and BMI.

Methods and materials

We retrospectively evaluated 280 patients treated with adjuvant radiation for breast cancer after up-front surgery. We collected information on patient demographics, disease and treatment characteristics, and acute skin toxicities. Multiple logistic regression models were used to evaluate for predictors of grade ≥2 dermatitis and MD.

Results

Patients undergoing post-mastectomy radiation therapy (PMRT) had the highest rate of MD (24%). The rate was lower (8.7%) among lumpectomy patients, but those receiving conventional fractionation had a higher rate of MD (10.9%) compared with hypofractionated therapy (1.8%; P = .05). Among lumpectomy patients, chemotherapy use (odds ratio, 3.74; P = .04) and regional nodal irradiation (odds ratio, 3.29; P = .03) were also significant predictors of MD. Despite an elevated average BMI among lumpectomy patients, hypofractionated therapy resulted in lower rates of skin toxicity.

Conclusions

We identified multiple risk factors for acute skin toxicity, including the use of PMRT and conventionally fractionated regimens. Elevated BMI, regional nodal irradiation, and chemotherapy use were associated with an increased risk of MD. Our findings highlight the need to explore the use of less toxic hypofractionated regimens in patients who are at the highest risk of acute skin toxicity, including those with a higher BMI and those receiving PMRT.

Hypofractionated Postmastectomy Radiation Therapy Is Safe and Effective: First Results From a Prospective Phase II Trial

Purpose Conventionally fractionated postmastectomy radiation therapy (PMRT) takes approximately 5 to 6 weeks. Data supporting hypofractionated PMRT is limited. We prospectively evaluated a short course of hypofractionated PMRT, in which therapy was completed in 15 treatment days. Patients and Methods We delivered PMRT at a dose of 36.63 Gy in 11 fractions of 3.33 Gy over 11 days to the chest wall and the draining regional lymph nodes, followed by an optional mastectomy scar boost of four fractions of 3.33 Gy. Our primary end point was freedom from any grade 3 or higher toxicities. We incorporated early stopping criteria on the basis of predefined toxicity thresholds. Results We enrolled 69 women with stage II to IIIa breast cancer, of whom 67 were eligible for analysis. After a median follow-up of 32 months, there were no grade 3 toxicities. There were 29 reported grade 2 toxicities, with grade 2 skin toxicities being the most frequent (16 of 67; 24%). There were two patients with isolated ipsilateral chest wall tumor recurrences (2 of 67; crude rate, 3%). Three-year estimated local recurrence-free survival was 89.2% (95% CI, 0.748 to 0.956). The 3-year estimated distant recurrence-free survival was 90.3% (95% CI, 0.797 to 0.956). Forty-one patients had chest wall reconstructions; three had expanders removed for infection before radiation therapy. The total rate of implant loss or failure was 24% (9 of 38), and the unplanned surgical correction rate was 8% (3 of 38), for a total complication rate of 32%. Conclusion To our knowledge, our phase II prospective study offers one of the shortest courses of PMRT reported, delivered in 11 fractions to the chest wall and nodes and 15 fractions inclusive of a boost. We demonstrated low toxicity and high local control with this schedule. On the basis of our data, we have designed a cooperative group phase III prospective, randomized trial of conventional versus hypofractionated PMRT that will activate soon.

Relation between Hypofractionated Radiotherapy, Toxicity and Outcome in Early Breast Cancer

To compare adjuvant conventional radiotherapy (C-RT) to hypofractionated schedule (HF-RT) in early breast cancer. Between May 2012 and September 2015, 120 patients were included in the analysis. All patients underwent conservative surgery and adjuvant RT. RT was delivered in C-RT (50 Gy; 2 Gy/fr) or HF-RT (42.5 Gy; 2.66 Gy/fr), followed by a tumor bed boost (10 Gy; 2 Gy/fr). RT-induced toxicity was recorded and compared between groups. Toxicity results were graded according to the Common Terminology Criteria for Adverse Events guidelines. A multivariate analysis was performed of the factors associated with acute toxicity onset. Mild acute skin toxicity was observed in 71.7% of patients. No grade 4 toxicity was observed. From the multivariate analysis, Breast volume and RT fractionation significantly affected acute radiation-related toxicity. No increase in late toxic effects has been reported between C-RT and HF-RT schedules. Overall, the 2-year disease free survival was 94.4%. HF-RT represents a valid adjuvant treatment option in early breast cancer patients, without negative impact on acute and late radiation sequelae, as well as tumor control.