Once-Weekly Hypofractionated Whole-Breast Radiotherapy After Breast-Conserving Surgery in Older Patients: A Potential Alternative Treatment Schedule to Daily 3-Week Hypofractionation

Phase II Evaluation of Ultra-Hypofractionated Postoperative Radiation Therapy for Breast Cancer: Toxicity and Efficacy in a Single-Center Nonrandomized Prospective Study

PURPOSE

To evaluate the toxicity profile and efficacy of postoperative ultra-hypofractionated radiation therapy in elderly patients with breast cancer.

MATERIALS AND METHODS

This is a nonrandomized, single-center, prospective Phase II trial. Patients with breast cancer older than 65 years were treated with ultra-hypofractionated radiation therapy in 5 fractions of 5.7 Gy on alternate days in the breast or chest wall, or regional lymph nodes. The primary end point was acute toxicity.

RESULTS

A total of 60 patients were analyzed, with a median follow-up of 42.5 months (range, 13.8-66.2). Most patients presented pathologic stage I (56.6%, n = 34) or stage II (33.3%, n = 20) disease. Regional lymph node irradiation was performed in 22% (n = 13) of patients. During treatment, 51% (n = 31) of patients experienced grade 1 or 2 acute toxicity, with no cases of grade 3 acute toxicity reported. Late toxicity included 1.7% (n = 1) of patients developing grade 3 fibrosis and 1.7% (n = 1) developing grade 3 pneumonitis. Regional lymph node irradiation was not associated with a statistically significant increase in toxicity risk (P = .194). Cosmesis evaluations revealed no significant changes when comparing pretreatment assessments with evaluations at 10 weeks (P = .223) and 26 weeks (P = .615) post-treatment. Quality of life was not adversely affected, regardless of whether regional lymph nodes were irradiated. Recurrence rates included two patients with both locoregional and distant recurrence and five patients with distant recurrence. The 3-year disease-free survival probability was 81.7%, and the 3-year overall survival probability was 86.7%.

CONCLUSION

This study demonstrates the safety of ultra-hypofractionated radiation therapy in terms of toxicity in patients with breast cancer. The findings for side effects, cosmesis, quality of life, and survival outcomes are consistent with those observed in moderately hypofractionated radiation therapy regimens, suggesting its use as a viable treatment option in this demographic.

Ultra-Hypofractionation for Whole-Breast Irradiation in Early Breast Cancer: Interim Analysis of a Prospective Study

We report on the early clinical outcomes of a prospective series of early breast cancer (EBC) patients treated with ultra-hypofractionated post-operative whole-breast irradiation (WBI) after breast-conserving surgery (BCS) and axillary management. Primary endpoints were patient's compliance and acute toxicity. Secondary endpoints included physician-rated cosmesis and ipsilateral breast tumour recurrence (IBTR). Acute toxicity was evaluated at the end of WBI, 3 weeks and 6 months thereafter, according to the Common Terminology Criteria for Adverse Events (v. 5.0). Patients were treated between September 2021 and May 2022. The treatment schedule for WBI consisted of either 26 Gy in 5 fractions over one week (standard approach) or 28.5 Gy in 5 fractions over 5 weeks (reserved to elders). Inverse planned intensity-modulated radiation therapy (IMRT) was used employing a static technique. A total of 70 patients were treated. Fifty-nine were treated with the 26 Gy/5 fr/1 w and 11 with the 28.5 Gy/5 fr/5 ws schedule. Median age was 67 and 70 in the two groups. Most of the patients had left-sided tumours (53.2%) in the 26 Gy/5 fr/1 w or right-sided lesions (63.6%) in the 28.5 Gy/5 fr/5 ws group. Most of the patients had a clinical T1N0 disease and a pathological pT1pN0(sn) after surgery. Ductal invasive carcinoma was the most frequent histology. Luminal A intrinsic subtyping was most frequent. Most of the patients underwent BCS and sentinel lymph node biopsy and adjuvant endocrine therapy. All patients completed the treatment program as planned. Maximum detected acute skin toxicities were grade 2 erythema (6.7%), grade 2 induration (4.4%), and grade 2 skin colour changes. No early IBTR was observed. Ultra-hypofractionated WBI provides favourable compliance and early clinical outcomes in EBC after BCS in a real-world setting.

Single fraction ablative preoperative radiation treatment for early-stage breast cancer: the CRYSTAL study – a phase I/II clinical trial protocol

Background

Breast-conserving surgery (BCS) and whole breast radiation therapy (WBRT) are the standard of care for early-stage breast cancer (BC). Based on the observation that most local recurrences occurred near the tumor bed, accelerated partial breast irradiation (APBI), consisting of a higher dose per fraction to the tumor bed over a reduced treatment time, has been gaining ground as an attractive alternative in selected patients with low-risk BC. Although more widely delivered in postoperative setting, preoperative APBI has also been investigated in a limited, though increasing, and number of studies. The aim of this study is to test the feasibility, safety and efficacy of preoperative radiotherapy (RT) in a single fraction for selected BC patients.

Methods

This is a phase I/II, single-arm and open-label single-center clinical trial using CyberKnife. The clinical investigation is supported by a preplanning section which addresses technical and dosimetric issues. The primary endpoint for the phase I study, covering the 1st and 2nd year of the research project, is the identification of the maximum tolerated dose (MTD) which meets a specific target toxicity level (no grade 3–4 toxicity). The primary endpoint for the phase II study (3rd to 5th year) is the evaluation of treatment efficacy measured in terms of pathological complete response rate.

Discussion

The study will investigate the response of BC to the preoperative APBI from different perspectives. While preoperative APBI represents a form of anticipated boost, followed by WBRT, different are the implications for the scientific community. The study may help to identify good responders for whom surgery could be omitted. It is especially appealing for patients unfit for surgery due to advanced age or severe co-morbidities, in addition to or instead of systemic therapies, to ensure long-term local control. Moreover, patients with oligometastatic disease synchronous with primary BC may benefit from APBI on the intact tumor in terms of tumor progression free survival. The study of response to RT can provide useful information about BC radiobiology, immunologic reactions, genomic expression, and radiomics features, to be tested on a larger scale.

Trial registration

The study was prospectively registered at clinicaltrials.gov (NCT04679454).

Ultra-hypofractionated whole breast adjuvant radiotherapy in the real-world setting: single experience with 271 elderly/frail patients treated with 3D and IMRT technique

PURPOSE

The purpose of the study was to evaluate the toxicity, local control, overall and disease-free survival of elderly breast cancer (BC) patients treated with adjuvant once-weekly ultra-hypofractionated radiotherapy (RT) either with intensity-modulated RT (IMRT) or 3D conformal RT (3DCRT).

METHODS

From July 2011 to July 2018, BC patients receiving 5.7 Gy once a week for 5 weeks to the whole breast after breast-conserving surgery were considered for the study. Inclusion criteria were: T1-T3 invasive BC, no or limited axillary involvement, age ≥ 65 years or women with commuting difficulties or disabling diseases.

RESULTS

A total of 271 patients were included in the study. Median age was 76 (46-86) years. Most of BC were T1 (77%), while the remaining were T2 (22.2%) and T3 (0.4%). Axillary status was negative in 68.3% of the patients. The only severe acute toxicity (G3) at the end of RT was erythema (0.4%), registered in the 3DCRT group; no G3 edema or epitheliolysis was recorded. With 18 months of median follow-up, severe early-late toxicity (G3) was reported in terms of fibrosis and breast retraction, both with an incidence of 1.4%, mostly in the 3DCRT group. Oncological outcomes at a median follow-up of 2.9 years reported 249/271 (91.9%) patients alive and free from any event and 5 (1.8%) isolated locoregional recurrences. At 3 years, disease-free survival and overall survival were 94.9% and 97.8%, respectively. Breast volume > 500 cm³ was reported as predictive for moderate-severe (≥ G2) acute toxicity.

CONCLUSIONS

Weekly ultra-hypofractionated whole breast RT seems feasible and effective. Toxicity was mild, local control was acceptable, and overall survival was 97.8% at 3 years. Rates of severe toxicity were reduced with the IMRT technique.

Final Analysis of a Phase II Trial of Once Weekly Hypofractionated Whole Breast Irradiation for Early Stage Breast Cancer

INTRODUCTION

We hypothesized that five-fraction once weekly hypofractionated whole breast irradiation (WH-WBI) would be safe and effective following breast conserving surgery for medically underserved patients with breast cancer. We report the protocol-specified primary endpoint of in breast tumor recurrence (IBTR) at five years.

METHODS

After signing informed consent, patients were treated with WH-WBI after breast conserving surgery were followed prospectively on an IRB-approved protocol. Women included in this study had stage 0-II breast cancer treated with negative surgical margins and met pre-specified criteria for being underserved. WH-WBI was 28.5 or 30Gy delivered to the whole breast with no elective coverage of lymph nodes. The primary endpoint was IBTR at 5 years. Secondary endpoints were distant disease-free survival (DDFS), recurrence free survival (RFS), overall survival (OS), adverse events, and cosmesis.

RESULTS

158 patients received WH-WBI on protocol from 2010 to 2015. Median follow-up was 5.5 years (range, 0.2-10.0). Stage distribution was ductal carcinoma in situ (DCIS) 22%; invasive pN0 68%; invasive pN1 10%. 28% of patients had grade 3 tumors, 10% were estrogen receptor negative and 24% required adjuvant chemotherapy. There were six IBTR events. The 5-, 7- and 10-year risks of IBRT for all patients were 2.7% (95% CI 0.89-6.34), 4.7% (95% CI 1.4-11.0) and 7.2% (95% CI 2.4-15.8) respectively. The 5, 7 and 10-year rates of DDFS were 96.4, 96.4 and 86.4%, RFS were 95.8%, 93.6 and 80.7%, and OS were 96.7, 88.6 and 76.7%, respectively. Improvement in IBTR-free time was seen in DCIS, lobular histology, low-grade tumors, T1 stage, Her2 negative tumors and receipt of a radiation boost to the lumpectomy bed.

CONCLUSION

Postoperative WH-WBI had favorable disease-specific outcomes that were comparable to those seen with conventional and moderately hypofractionated radiation techniques. WH-WBI may improve access to care for underserved patients with stage 0-II breast cancer.

Acute toxicity and health-related quality of life after accelerated whole breast irradiation in 5 fractions with simultaneous integrated boost

INTRODUCTION

Acceleration of radiotherapy in 5 fractions for breast cancer can reduce the burden of treatment. We report on acute toxicity after whole-breast irradiation with a simultaneous integrated boost in 5 fractions over 10-12 days.

MATERIAL AND METHODS

Acute toxicity and health-related quality of life (HRQoL) of 200 patients, randomized between a 15- or 5-fractions schedule, were collected, using the CTCAE toxicity scoring system, the Multidimensional Fatigue Inventory, EORTC QLQ-C30 and BR23 and the BREAST-Q questionnaire. The prescribed dose to the breast was either 15∗2.67 Gy (40.05 Gy) or 5∗5.7 Gy (28.5 Gy). 90% of patients received a SIB to a cumulative dose of 46.8 Gy (15∗3.12 Gy) or 31 Gy (5∗6.2 Gy).

RESULTS

Physician-assessed toxicity was lower for the 5-fractions group. A significant difference was observed for breast pain (p = 0.002), fatigue (p < 0.0001), breast edema (p = 0.001) and dermatitis (p = 0.003). Patients treated in 5 fractions reported better mean HRQoL scores for breast symptoms (p = 0.001) and physical well-being (p = 0.001). A clinically important deterioration in HRQoL of 10 points or more was also less frequently observed in the latter group for physical functioning (p = 0.0005), social functioning (p = 0.0007), fatigue (p = 0.003), breast symptoms (p = 0.0002) and physical well-being (p = 0.002).

CONCLUSION

In this single institute study, acute toxicity of accelerated breast radiotherapy in 5 fractions over 10-12 days seems to compare favourably to hypofractionated breast radiotherapy in 15 fractions. Less breast edema, dermatitis, desquamation, breast pain and fatigue are seen. Social and physical functioning are also less disturbed and patients have a better future perspective.

Hypofractionated radiation therapy for breast cancer: Preferences amongst radiation oncologists in Europe - Results from an international survey

BACKGROUND AND PURPOSE

We aimed to assess the prescription preference about hypofractionated radiation therapy (HFRT) for breast cancer (BC) patients amongst radiation oncologists (ROs) practicing in Europe and to identify restraints on HFRT utilisation.

MATERIALS AND METHODS

An online survey was circulated amongst ROs in Europe through personal, RO and BC societies' networks, from October 2019 to March 2020. The statistical analyses included descriptive statistics, chi-squared testing, and logistic regression analysis.

RESULTS

We received 412 responses from 44 countries. HFRT was chosen as the preferred schedule for whole breast irradiation (WBI) by 54.7% and for WBI with regional nodes irradiation (RNI) by 28.7% of the responding ROs. In the case of postmastectomy RT with or without reconstruction, HFRT was preferred by 21.1% and 29.6%, respectively. Overall, 69.2% of the responding ROs selected at least one factor influencing the decision to utilise HFRT, the most frequent of which included age (51.4%), RNI (46.9%), internal mammary lymph nodes irradiation (39.7%), BC stage (33.5%) and implant-based breast reconstruction (31.6%). ROs working in academic centres (odds ratio, (OR), 1.7; 95% confidence interval, (CI); 1.1-2.6, p = 0.019), practicing in Western Europe (OR, 4.2; 95%CI; 2.7-6.6, p < 0.0005) and/or dedicating >50% of clinical time to BC patients (OR, 2.5; 95%CI; 1.5-4.2, p = 0.001) more likely preferred HFRT.

CONCLUSION

Although HFRT is recognised as a new standard, its implementation in routine RT clinical practice across Europe varies for numerous reasons. Better dissemination of evidence-based recommendations is advised to improve the level of awareness about this clinical indication.

Weekly radiotherapy in elderly breast cancer patients: a comparison between two hypofractionation schedules

PURPOSE

Weekly irradiation in breast cancer in elderly patients is a treatment option, whose tolerance may be influenced by the fractionation used. The objective of this study is to compare the tolerance and long-term side effects of two different fractionations.

MATERIALS AND METHODS

47 elderly patients were recruited after conservative or radical treatment that also received irradiation with a dose per fraction of 6.25 Gy or 5 Gy for one session per week, 6 sessions in total. The long-term tolerance results are compared by assessing toxicity using CTCAE version 5.0 scales for dermatitis, telangectasia, fibrosis and pain of the irradiated breast. In addition, objective parameters of skin status (erythema, hyperpigmentation, elasticity and hydration) by a multi-probe MultiSkin Test-Center system were obtained and compared between groups.

RESULTS

After an average follow-up of 5 years, all patients were free of disease and with complete local control. A total of 20 patients with 6.25 Gy fractionation and 27 patients with 5 Gy fractionation have been included. Patients treated with lower fractionation had a lower incidence of dermatitis, telangectasia, fibrosis, or local pain. The decrease in elasticity measured by the multi-probe system was smaller with the fractionation of 5 Gy. No differences were observed in the other objective parameters.

CONCLUSION

Weekly irradiation with 5 Gy fractionation is better tolerated than with higher fractionation.

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.

Omission of postoperative radiation after breast conserving surgery: A progressive paradigm shift towards precision medicine

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Post-operative radiotherapy is standard after breast conservation in early breast cancer.

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To de-escalate the treatment burden, indentifying a subset at very low risk of relapse is crucial.

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Clinical and pathological factors are important, but can be integrated with genomic signatures.

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Ongoing trials will provide evidence on patients at low risk for radiotherapy omission.

Radiation therapy is a standard therapeutic option in the post-operative setting for early breast cancer patients after breast conserving surgery, providing a substantial benefit in reducing the risk of local relapse with a consequent survival gain. Nevertheless, the reduction in the burden related to treatment is becoming crucial in modern oncology for both local and systemic therapies and investigational efforts are being put forward by radiations oncologists to identify a subset of women at very low risk to be potentially omitted from post-operative irradiation after breast conservation. Clinical factors, classical pathological parameters and new predictive scores derived from gene expression and next generation sequencing techniques are being integrated in the quest toward a reliable low-risk profile for breast cancer patients. We herein provide a comprehensive overview on the topic.

Simultaneous Integrated Boost in Once-weekly Hypofractionated Radiotherapy for Breast Cancer in the Elderly: Preliminary Evidence

AIM

To evaluate once-weekly hypofractionated radiotherapy in elderly patients affected by early breast cancer, reporting acute and late toxicity profiles, and treatment feasibility.

PATIENTS AND METHODS

Fifty patients were treated with a hypofractionated regimen: 28.5±2.5 Gy in five fractions at one fraction weekly. Simultaneous integrated boost (SIB) to the tumor bed in high-risk cases.

INCLUSION CRITERIA

patients over 70 years old, pT1-2, N0-1a. Acute and late toxicities were assessed based on Radiation Therapy Oncology Group.

RESULTS

The median follow-up was 20 months and the median patient age was 79 years. SIB was added for 22 patients (44%). Grade 3-4 acute cutaneous toxicities were not observed; grade 2 toxicity occurred only in four patients (8%). Late subcutaneous tissue toxicity consisted of grade 2 fibrosis in two patients (4%), grade 1 in five (10%) and grade 0 in 41(85%).

CONCLUSION

Limiting fraction numbers with a safer profile may improve the management of breast cancer for the elderly.

De-escalation of breast radiotherapy after conserving surgery in low-risk early breast cancer patients

The reduction in the burden related to treatment is becoming more and more important in modern oncology. Radiation therapy is a mainstay option in the postoperative setting for early breast cancer patients after breast-conserving surgery. Nowadays, different options are available to de-escalate radiotherapy in this scenario such as the use of hypofractionated whole-breast radiation, the selective delivery of the boost dose to the lumpectomy cavity, the introduction of accelerated partial breast irradiation and the omission of treatment in appropriately selected patients with low-risk features. We herein provide a review article on this topic.

Once-Weekly Hypofractionated Radiotherapy for Breast Cancer in Elderly Patients: Efficacy and Tolerance in 486 Patients

Purpose

Radiation therapy is a key treatment of breast cancer. Elderly patients with associated diseases that modify their performance status do not tolerate long periods of daily irradiation. The objective of this study is to analyze the results of weekly hypofractionated treatment in these patients.

Material and Methods

Between 1992 and 2016, we included 486 elderly patients presenting concomitant pathology or sociofamilial problems in which it was not feasible to propose conventional treatment. They were treated with conservative surgery or mastectomy and then adjuvant hypofractionated irradiation, administering 5 Gy or 6.25 Gy in 6 fractions, once a week (total dose 30–37.5 Gy) over 6 weeks.

Results

Breast cancer overall survival according to the Kaplan-Meier method at 5 years was 74.2% ± 2.3%; breast cancer disease-free survival was 90% ± 1.6%; local relapse-free survival was 96.5% ± 1% showing that patients die more from other causes and not from their neoplasia. Acute dermatitis was mild (75.6% of the patients grades I–III) and 30.6% had moderate chronic fibrosis.

Conclusions

The once-weekly hypofractionated radiotherapy is a feasible and convenient option for elderly patients with breast cancer. It is a safe treatment modality with similar survival and local control results compared to standard fractionation, while the side effects are acceptable.

Highly Accelerated Irradiation in 5 Fractions (HAI-5): Feasibility in Elderly Women With Early or Locally Advanced Breast Cancer

PURPOSE

To investigate, in a prospective phase 1 to 2 trial, the safety and feasibility of delivering external beam radiation therapy in 5 fractions to the breast or thoracic wall, including boost and/or lymph nodes if needed, to women aged ≥65 years with breast cancer.

METHODS AND MATERIALS

Ninety-five patients aged ≥65 years, referred for adjuvant radiation therapy, were treated in 5 fractions over 12 days with a total dose of 28.5 Gy/5.7 Gy to the breast or thoracic wall and, if indicated, 27 Gy/5.4 Gy to the lymph node regions and 32.5 Gy/6.5 Gy to 34.5 Gy/6.9 Gy to the tumor bed. The primary endpoint was clinically relevant dermatitis (grade ≥2).

RESULTS

Mean follow-up time was 5.6 months, and mean age was 73.6 years. Clinically relevant dermatitis was observed in 11.6% of patients and only occurred in breast irradiation with boost (17.5% grade 2-3 vs 0% in the no-boost group). Although doses were high, treatment delivery with intensity modulated radiation therapy was swift, except for complex treatments, including lymph nodes for which single-arc volumetric modulated arc therapy was needed to reduce beam-on time.

CONCLUSION

Accelerated radiation therapy in 5 fractions was technically feasible and resulted in low acute toxicity. Clinically relevant erythema was only observed in patients receiving a boost, but still at an acceptable rate. Although the follow-up is still short, the results on acute toxicity after accelerated radiation therapy were encouraging. A 5-fraction schedule is well tolerated in the elderly and may lower the threshold for radiation therapy in this population.

[Hypofractionated whole breast irradiation (WBRT): Results and indications]

Breast irradiation after breast-conserving surgery is essential for maximizing local control and overall survival. The increase of breast cancer (BC) incidence, constraints of classical five weeks (w) radiation regimens and scarcity of radiotherapy units have led to test short hypofractionated WBRT schemes. One pilot study and three prospective randomized trials have tested various hypofractionated regimens of WBRT. About 7000 patients were included and follow-up ranged from 5 to 12 years. The conclusion of these trials is similar, showing local control and toxicity equivalent to these of the standard regimens. Three schemes are now clearly validated: 42.5Gy/16fr/3w, 40Gy/15fr/3w, or 42Gy/13fr/5w. However, the majority of included patients had favorable prognostic factors, were treated to the breast only and the boost dose, when indicated, was delivered with a standard fractionation. Therefore, we recommend the regimens preferentially in patients treated to the breast only, and without nodal involvement. These studies did not evaluate the addition of a boost dose with a hypofractionated scheme. If a boost is to be given, a standard fractionation should be used. Particular care should be taken to avoid heterogeneities leading to high fraction doses to organs at risk (lung and heart).

Novel and Highly Compressed Schedules for the Treatment of Breast Cancer

Our thinking about radiotherapy (RT) for early-stage breast cancer has evolved considerably over the last several years. Increasingly patients and physicians together are making the decision to use altered fractionation rather than standard 6-7 weeks of conventional whole breast treatment plus lumpectomy bed boost. Adjuvant hypofractionated whole breast irradiation is now viewed as a preferred strategy for many eligible women, and can be completed in 3-4 weeks. Adjuvant accelerated partial breast irradiation is another alternative that is typically delivered in 8-10 fractions over 4-5 days. With improvements in delivery techniques, there has been renewed interest in shortening treatment times even further, with novel intraoperative approaches and ultrashort courses of external beam RT. This article provides a summary of the status and future directions in intraoperative and ultrashort course RT schedules used in the treatment of breast cancer. Outlined are the benefits as well as the drawbacks of these techniques for abbreviated breast RT.

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

PURPOSE

Conventionally fractionated whole-breast irradiation (WBI) with a boost takes approximately 6 to 7 weeks. We evaluated a short course of hypofractionated (HF), accelerated WBI in which therapy was completed in 3 weeks inclusive of a sequential boost.

METHODS AND MATERIALS

We delivered a whole-breast dose of 36.63 Gy in 11 fractions of 3.33 Gy over 11 days, followed by a lumpectomy bed boost in 4 fractions of 3.33 Gy delivered once daily for a total of 15 treatment days. Acute toxicities were scored using Common Terminology Criteria for Adverse Events version 4. Late toxicities were scored using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale. Cosmesis was scored using the Harvard Cosmesis Scale. Our primary endpoint was freedom from locoregional failure; we incorporated early stopping criteria based on predefined toxicity thresholds. Cosmesis was examined as a secondary endpoint.

RESULTS

We enrolled 83 women with stages 0 to IIIa breast cancer. After a median follow-up of 40 months, 2 cases of isolated ipsilateral breast tumor recurrence occurred (2 of 83; crude rate, 2.4%). Three-year estimated local recurrence-free survival was 95.9% (95% confidence interval [CI]: 87.8%-98.7%). The 3-year estimated distant recurrence-free survival was 97.3% (95% CI: 89.8%-99.3%). Three-year secondary malignancy-free survival was 94.3% (95% CI: 85.3%-97.8%). Twenty-nine patients (34%) had grade 2 acute toxicity, and 1 patient had a late grade 2 toxicity (fibrosis). One patient had acute grade 3 dermatitis, whereas 2 patients experienced grade 3 late skin toxicity. Ninety-four percent of evaluable patients had good or excellent cosmesis.

CONCLUSIONS

Our phase 2 institutional study offers one of the shortest courses of HF therapy, delivered in 15 fractions inclusive of a sequential boost. We demonstrated expected low toxicity and high local control rates with good to excellent cosmetic outcomes. This fractionation scheme is feasible and well tolerated and offers women WBI in a highly convenient schedule.

Hypofractionated Whole-Breast Radiotherapy and Concomitant Boost after Breast Conservation in Elderly Patients

Aims

To report the 5- and 10-year results of accelerated hypofractionated whole-breast radiotherapy (WBRT) with concomitant boost to the tumor bed in 83 consecutive patients with early breast cancer aged >70 years.

Methods

All patients were treated with breast conservation and hypofractionated WBRT. The prescription dose to the whole breast was 45 Gy (2.25 Gy/20 fractions) with an additional daily concomitant boost of 0.25 Gy to the surgical cavity (2.5 Gy/20 fractions up to 50 Gy). The maximum detected toxicity was scored according to the Common Terminology Criteria for Adverse Events, version 3.0. We considered as skin toxicity: erythema, edema, desquamation, ulceration, hemorrhage, necrosis, telangiectasia, fibrosis-induration, hyperpigmentation, retraction and atrophy. Cosmetic results were assessed as set by the Harvard criteria.

Results

With a median follow-up of 60 months (range 36-88), no local recurrence was observed. The maximum detected acute skin toxicity was G0 in 57% of patients, G1 in 40% and G2 in 3%. Late skin and subcutaneous toxicity was generally mild with no ≥G3 events. The cosmetic results were excellent in 69% of patients, good in 22%, fair in 5%, and poor in 4%.

Conclusions

The present results support the use of hypofractionation employing a concomitant boost to the lumpectomy cavity in women aged >70 years. This is a convenient treatment option for both this type of population and health-care providers.

[Current status of hypofractionated external beam radiotherapy for early-stage breast cancer]

The benefits of adjuvant radiotherapy following lumpectomy for early-stage breast cancer are well established. The most widely used method consists of roughly twenty-five fractions of whole-breast irradiation. In recent years, there has been a growing trend towards hypofractionated external beam radiotherapy regimens. Many of these techniques have been shown to be equivalent in terms of tumor control and cosmetic results while minimizing inconvenience and costs both to the patient and health care system. Here, we present the various hypofractionation modalities, patient selection criteria, consensus guideline recommendations and a look at future indications.