The UK Standardisation of Breast Radiotherapy (START) Trial A of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial

Hypofractionated Whole Breast Irradiation and Simultaneous Integrated Boost in Large-breasted Patients: Long-term Toxicity and Cosmesis

INTRODUCTION

The purpose of this study was to evaluate the impact of breast size on long-term toxicity and cosmesis in patients with breast cancer treated with hypofractionated simultaneous integrated boost (SIB) using volumetric modulated arc therapy (VMAT).

PATIENTS AND METHODS

Patients with early stage breast cancer were treated with 3-week hypofractionated SIB-VMAT to the whole breast (40.5 Gy) and tumor bed (48 Gy). Two cohorts were identified: small/medium- (< 1000 cm³) and large- (> 1000 cm³) breasted patients. Acute and late (at 2 and 5 years) skin toxicity and cosmetic data were analyzed. Univariate and multivariate analysis evaluated associations between toxicity and dosimetric/anatomical variables.

RESULTS

From August 2010 to March 2017, a total of 1160 patients were treated; 831 had at least 2 years of follow-up and were analyzed. Treated skin area (TSA) receiving at least 20 Gy > 400 cm² and V_{105% of Boost} > 5 cm³ were significant predictors for acute skin toxicity. Multivariate analysis at 2 years was significant for boost volume > 70 cm³, TSA > 400 cm², and breast size > 1500 cm³. At 5 year analysis (352 patients), none of the analyzed variables was significant. For cosmetic outcome, only the breast size (> 1000 cm³) and the boost size > 70 cm³ at 2 and 5 years, respectively, confirmed significance.

CONCLUSIONS

The TSA > 400 cm² resulted as a significant predictor of both acute and late skin toxicity at 2 years; however, at 5 years, no breast size or dosimetric parameter suggested indications for increased toxicity. A worse cosmetic outcome was recorded at the 2-year follow up for large breasts, but was not confirmed at the 5-year follow-up. These long-term data suggest that hypofractionated SIB-VMAT is a viable modality also in large-breasted patients.

Late-term effects of hypofractionated chest wall and regional nodal radiotherapy with two-dimensional technique in patients with breast cancer

PURPOSE

Hypofractionated radiotherapy (RT) is becoming a new standard in postoperative treatment of patients with early stage breast cancer after breast conservation surgery. However, data on hypofractionation in patients with advanced stage disease who undergo mastectomy followed by local and regional nodal irradiation (RNI) is lacking. In this retrospective study, we report late-term effects of 3 weeks post-mastectomy hypofractionated local and RNI with two-dimensional (2D) technique in patients with stage II and III breast cancer.

METHODS

Between January 1990 and December 2007, 1,770 women with breast cancer who were given radical treatment with mastectomy, systemic therapy and RT at least 10 years ago were included. RT dose was 35 Gy/15 fractions/3 weeks to chest wall by two tangential fields and 40 Gy in same fractions to supraclavicular fossa (SCF) and internal mammary nodes (IMNs). SCF and IMNs dose was prescribed at dmax and 3 cm depth, respectively. Chemotherapy and hormonal therapy was given in 64% and 74% patients, respectively. Late-term toxicities were assessed with the Radiation Therapy Oncology Group (RTOG) scores and LENT-SOMA scales (the Late Effects Normal Tissue Task Force-Subjective, Objective, Management, Analytic scales).

RESULTS

Mean age was 48 years (range, 19 to 75 years). Median follow-up was 12 years (range, 10 to 27 years). Moderate/marked arm/shoulder pain was reported by 254 (14.3%) patients. Moderate/marked shoulder stiffness was reported by 219 (12.3%) patients. Moderate/marked arm edema was seen in 131 (7.4%) patients. Brachial plexopathy was not seen in any patient. Rib fractures were noted in 6 (0.3%) patients. Late cardiac and lung toxicity was seen in 29 (1.6%) and 23 (1.3%) patients, respectively. Second malignancy developed in 105 (5.9%) patients.

CONCLUSION

RNI with 40 Gy/15 fractions/3 weeks hypofractionation with 2D technique seems safe and comparable to historical data of conventional fractionation (ClinicalTrial.gov Registration No. XXXX).

Tumour response 3 months after neoadjuvant single-fraction radiotherapy for low-risk breast cancer

Introduction

Standard treatment for early-stage invasive breast cancer (bca) consists of breast-conserving surgery and several weeks of adjuvant radiotherapy (rt). Neoadjuvant single-fraction rt is a novel approach for early-stage bca. We sought to investigate the effect of delaying surgery after neoadjuvant rt with respect to the rate of pathologic response (pr).

Methods

Women 65 years of age or older with a new diagnosis of stage i luminal A bca were eligible for inclusion. A single 20 Gy dose to the primary breast tumour was given, followed by breast-conserving surgery 3 months later. The primary endpoint was the pr rate assessed by microscopic evaluation using the Miller-Payne system.

Results

To date, 10 patients have been successfully treated. Median age of the patients was 72 years (range: 65-84 years). In 8 patients, neoadjuvant rt resulted in a tumour pr with median residual cellularity of 3%. No immediate rt complications other than mild dermatitis were noted.

Conclusions

This study demonstrates a method for delivering single-fraction rt that can lead to a high level of pr in most patients. Continued accrual to this study and subsequent trials are needed to determine the feasibility, safety, and role of this novel technique in the management of early-stage bca.

Hypofractionated breast radiotherapy for 1 week versus 3 weeks (FAST-Forward): 5-year efficacy and late normal tissue effects results from a multicentre, non-inferiority, randomised, phase 3 trial

BACKGROUND

We aimed to identify a five-fraction schedule of adjuvant radiotherapy (radiation therapy) delivered in 1 week that is non-inferior in terms of local cancer control and is as safe as an international standard 15-fraction regimen after primary surgery for early breast cancer. Here, we present 5-year results of the FAST-Forward trial.

METHODS

FAST-Forward is a multicentre, phase 3, randomised, non-inferiority trial done at 97 hospitals (47 radiotherapy centres and 50 referring hospitals) in the UK. Patients aged at least 18 years with invasive carcinoma of the breast (pT1-3, pN0-1, M0) after breast conservation surgery or mastectomy were eligible. We randomly allocated patients to either 40 Gy in 15 fractions (over 3 weeks), 27 Gy in five fractions (over 1 week), or 26 Gy in five fractions (over 1 week) to the whole breast or chest wall. Allocation was not masked because of the nature of the intervention. The primary endpoint was ipsilateral breast tumour relapse; assuming a 2% 5-year incidence for 40 Gy, non-inferiority was predefined as ≤1·6% excess for five-fraction schedules (critical hazard ratio [HR] of 1·81). Normal tissue effects were assessed by clinicians, patients, and from photographs. This trial is registered at isrctn.com, ISRCTN19906132.

FINDINGS

Between Nov 24, 2011, and June 19, 2014, we recruited and obtained consent from 4096 patients from 97 UK centres, of whom 1361 were assigned to the 40 Gy schedule, 1367 to the 27 Gy schedule, and 1368 to the 26 Gy schedule. At a median follow-up of 71·5 months (IQR 71·3 to 71·7), the primary endpoint event occurred in 79 patients (31 in the 40 Gy group, 27 in the 27 Gy group, and 21 in the 26 Gy group); HRs versus 40 Gy in 15 fractions were 0·86 (95% CI 0·51 to 1·44) for 27 Gy in five fractions and 0·67 (0·38 to 1·16) for 26 Gy in five fractions. 5-year incidence of ipsilateral breast tumour relapse after 40 Gy was 2·1% (1·4 to 3·1); estimated absolute differences versus 40 Gy in 15 fractions were -0·3% (-1·0 to 0·9) for 27 Gy in five fractions (probability of incorrectly accepting an inferior five-fraction schedule: p=0·0022 vs 40 Gy in 15 fractions) and -0·7% (-1·3 to 0·3) for 26 Gy in five fractions (p=0·00019 vs 40 Gy in 15 fractions). At 5 years, any moderate or marked clinician-assessed normal tissue effects in the breast or chest wall was reported for 98 of 986 (9·9%) 40 Gy patients, 155 (15·4%) of 1005 27 Gy patients, and 121 of 1020 (11·9%) 26 Gy patients. Across all clinician assessments from 1-5 years, odds ratios versus 40 Gy in 15 fractions were 1·55 (95% CI 1·32 to 1·83, p<0·0001) for 27 Gy in five fractions and 1·12 (0·94 to 1·34, p=0·20) for 26 Gy in five fractions. Patient and photographic assessments showed higher normal tissue effect risk for 27 Gy versus 40 Gy but not for 26 Gy versus 40 Gy.

INTERPRETATION

26 Gy in five fractions over 1 week is non-inferior to the standard of 40 Gy in 15 fractions over 3 weeks for local tumour control, and is as safe in terms of normal tissue effects up to 5 years for patients prescribed adjuvant local radiotherapy after primary surgery for early-stage breast cancer.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.

Loco-regional outcomes of adjusted breast radiotherapy with conventional fractionation after breast conserving surgery: De-escalation of whole breast irradiation dose

We compared the cumulative incidence of ipsilateral breast tumor recurrence (IBTR) between 2 whole breast irradiation (WBI) dose range with conventional fractionation.We retrospectively reviewed 1122 patients who received WBI at 2 institutions between 2004 and 2012. One institution delivered WBI 41.4 to 45 Gy followed by boost 14 to 18 Gy (adjusted group), while the other delivered WBI 50 to 50.4 Gy followed by boost 10 Gy (standard group).The median follow-up period was 85 months. The 10-year cumulative incidence in all patients was 6.1% (95% confidence interval [CI]: 4.3%-8.4%) for IBTR and 3.0% (95% CI: 1.7%-4.8%) for regional recurrence. The 10-year cumulative incidence of IBTR was not significantly influenced by WBI dose (6.3% in the adjusted group vs 5.2% in the standard group, P = .136). Comparable IBTR rates between the 2 groups were observed regardless of clinical and pathological factors. The WBI dose was not significantly associated with the 10-year cumulative incidence of regional recurrence in these groups (3.5% in the adjusted group vs 0.5% in the standard group, P = .214).De-escalated WBI doses while intensifying tumor bed boost did not compromise local and regional outcomes compared to standard group.

Use of Adjuvant Breast Hypofractionation Radiation Treatment at a Cancer Center in Ontario From 2011 to 2018

BACKGROUND

The adoption of hypofractionated radiotherapy (HFRT) into clinical practice varies widely despite randomized trials and guidelines supporting its equivalence to conventional fractionated radiotherapy (CFRT) for certain patient populations. We assessed the use of HFRT at a single institution from 2011 to 2018, as well as time-savings calculations.

PATIENTS AND METHODS

A retrospective cohort study was conducted for patients with breast cancer receiving adjuvant radiotherapy by HFRT or CFRT. Trends in HFRT use (≤ 16 fractions) were stratified according to 4 subgroups: tangential breast RT, locoregional breast RT, tangential chest wall RT, and locoregional chest wall RT. Treatment time savings were approximated using the institutional median treatment time.

RESULTS

A total of 5190 patients were included. HFRT use in all subgroups increased from 2011 to 2018. Tangential breast HFRT alone increased from 62.2% in 2011 to 96.9% in 2018. Locoregional breast HFRT and tangential chest wall HFRT use increased from less than 10% in 2011 to 76.2% and 76.9% in 2018. In locoregional chest wall RT, HFRT use of 44.9% was observed in 2018. Increased use of locoregional HFRT was mainly due to institutional policy changes. Time-savings calculations showed that 4002 hours of treatment or an additional 1402 HFRT courses could have been administered if all patients received HFRT.

CONCLUSION

The use of HFRT at our center increased in all patient subgroups. More evidence and guidelines for patients receiving chest wall or locoregional HFRT are required because the use of HFRT remains low in these patient cohorts.

Acute Toxicity and Quality of Life of Hypofractionated Radiation Therapy for Breast Cancer

PURPOSE

To assess the acute toxicity and quality of life (QOL) of hypofractionation compared with conventional fractionation for whole breast irradiation (WBI) after breast-conserving surgery.

METHODS AND MATERIALS

Women with node-negative breast cancer who had undergone breast-conserving surgery with clear margins were randomly assigned to conventional WBI of 5000 cGy in 25 fractions over 35 days or hypofractionated WBI of 4256 cGy in 16 fractions over 22 days. Acute skin toxicity and QOL were assessed at baseline and 2, 4, 6, and 8 weeks from the start of treatment for a subgroup of patients. QOL was assessed at baseline and 4 weeks posttreatment for all patients. In the acute toxicity substudy, repeated measures modeling was used to investigate treatment by time interactions over the 8-week period for acute toxicity and QOL mean change score. QOL mean change score from baseline to 4 weeks posttreatment was compared for all patients.

RESULTS

In the acute toxicity substudy, 161 patients participated. In the main trial, 1152 patients participated. Acute skin toxicity was initially similar between groups but was less with hypofractionation compared with conventional fractionation toward the end of the 8-week period (P < .001). QOL at 6 weeks from the start of treatment was improved with hypofractionation for the skin side effects, breast side effects, fatigue, attractiveness, and convenience domains (all P < .05). In the main trial, hypofractionation resulted in improved overall QOL and QOL attributed to skin side effects, breast side effects, and attractiveness (all P < .01).

CONCLUSIONS

Hypofractionated WBI compared with conventional WBI resulted in less acute toxicity and improved QOL. This further supports the benefits of hypofractionation.

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.

Acute radiation-induced skin toxicity in hypofractionated vs. conventional whole-breast irradiation: An objective, randomized multicenter assessment using spectrophotometry

PURPOSE

Radiation dermatitis represents one of the most frequent side effects in breast cancer patients undergoing adjuvant whole-breast irradiation (WBI). Whether hypofractionated WBI induces comparable or less acute radiation-induced skin reactions than conventional WBI is still not fully clarified, as randomized evidence and objective assessments are limited. The aim of this study was to objectively determine frequency and severity of acute radiation-induced skin reactions during hypofractionated vs. conventionally fractionated adjuvant WBI.

METHODS

In this randomized multicenter study, a total of 140 breast cancer patients underwent either hypofractionated or conventional WBI following breast-preserving surgery. Maximum radiation dermatitis severity was assessed at completion and during follow-up by physician-assessed CTCAE v4.03 and the patient-reported RISRAS scale. Additionally, photospectrometric skin readings were performed to objectify skin color differences between both treatment arms.

RESULTS

Radiation dermatitis severity was significantly lower in patients receiving hypofractionation compared with conventional fractionation (mean 1.05 vs. 1.43, p = .024). Grade 0 radiation dermatitis occurred in 21.43% vs. 4.28%, grade ≥2 in 27.14% vs. 42.91% and grade ≥3 in 0% vs. 4.34% of patients following hypofractionated and conventional WBI, respectively. Objective photospectrometric measurements (n = 4200) showed both decreased erythema severity (p = .008) and hyperpigmentation (p = .002) in the hypofractionation arm. Patients allocated to hypofractionated WBI also reported less pain (p = .006), less hyperpigmentation (p = <0.001) and less limitations of day-to-day activities (p = <0.001).

CONCLUSION

Physician and patient-assessed toxicity scorings as well as objective photospectrometric skin measurements revealed that hypofractionated WBI yielded lower rates and severity of acute radiation-induced skin toxicity.

Hypofractionated Radiotherapy Dose Scheme and Application of New Techniques Are Associated to a Lower Incidence of Radiation Pneumonitis in Breast Cancer Patients

Purpose: Radiation pneumonitis (RP) is one of the most severe toxicities experienced by patients with breast cancer after radiotherapy (RT). RT fractionation schemes and techniques for breast cancer have undergone numerous changes over the past decades. This study aimed to investigate the incidence of RP as a function of such changes in patients with breast cancer undergoing RT and to identify dosimetric markers that predict the risk of this adverse event.

Methods and Materials: We identified 1,847 women with breast cancer who received adjuvant RT at our institution between 2015 and 2017. The RT technique was individually tailored based on each patient's clinicopathological features. Deep inspiration breath hold technique or prone positioning were used for patients who underwent left whole-breast irradiation for cardiac sparing, while those requiring regional lymph node irradiation underwent volumetric-modulated arc therapy (VMAT).

Results: Of 1,847 patients who received RT, 21.2% received the conventional dose scheme, while 78.8% received the hypofractionated dose scheme (mostly 40 Gy in 15 fractions). The median follow-up period was 14.5 months, and the overall RP rate was 2.1%. The irradiated organ at risk was corrected concerning biologically equivalent dose. The ipsilateral lung V₃₀ in equivalent dose in 2 Gy (EQD2) was the most significant dosimetric factor associated with RP development. Administering RT using VMAT, and hypofractionated dose scheme significantly reduced ipsilateral lung V₃₀.

Conclusions: Application of new RT techniques and hypofractionated scheme significantly reduce the ipsilateral lung dose. Our data demonstrated that ipsilateral lung V₃₀ in EQD2 is the most relevant dosimetric predictor of RP in patients with breast cancer.

In the Era After the European Organisation for Research and Treatment of Cancer 'Boost' Study, is the Additional Radiotherapy to the Breast Tumour Bed Still Beneficial for Young Women?

AIMS

The European Organisation for Research and Treatment of Cancer (EORTC) 22,881-10,882 trial showed significant benefit of a radiotherapy boost (RTB) in women ≤40 years in a pre-hormone therapy (HT) era. We determined how the use of HT and RTB changed in response to clinical guidelines and whether the benefit of routine RTB was still observed in the HT era.

MATERIALS AND METHODS

Between 1996 and 2004, a provincial database identified all women ≤40 years with breast cancer who met the inclusion criteria of the EORTC trial. In total, 411 patients were classified into three eras defined by the guidelines: era 1 (discretionary HT, discretionary RTB); era 2 (routine HT, discretionary RTB); era 3 (routine HT, routine RTB). HT use, RTB use and cumulative incidence of local recurrence were calculated and compared across eras.

RESULTS

HT use increased after the first policy change from 13% to 75% for oestrogen receptor-positive patients (P < 0.01). RTB use also increased from 33% to 76% following the second policy change (P < 0.01). At 10 years, the cumulative incidence of local recurrence was 12% in era 1, 6% in era 2 and 6% in era 3 (era 2 versus era 3, P = 0.92). For patients in the routine HT era (eras 2 and 3 combined) there was no significant difference in local recurrence between RTB and 'no RTB' patients (6% versus 7%, P = 0.81).

CONCLUSIONS

The routine use of HT and RTB increased significantly after new practice guidelines. Introduction of the HT guideline was associated with a 6% improvement in local recurrence at 10 years. No improvement in local recurrence was associated with the introduction of the RTB guideline in the HT era. The routine use of a boost in unselected young women with negative margins should be re-evaluated in the current HT era.

Feasibility of Breast-Conservation Therapy and Hypofractionated Radiation in the Setting of Prior Breast Augmentation

PURPOSE

Cosmetic outcomes and rate of implant loss are poorly characterized among patients with breast cancer with previous breast augmentation (BA) who undergo breast-conservation therapy (BCT). Here we determine capsular contracture and implant loss frequency after BCT among patients receiving contemporary whole-breast radiation therapy (RT).

METHODS AND MATERIALS

Patients with breast cancer with a history of BA presenting to our institution from January 2006 to January 2017 who elected for BCT were included. Seventy-one breast cancers in 70 patients with a history of BA electing for BCT were retrospectively identified. Clinicopathologic, treatment, and outcome variables were examined. Whole-breast RT included conventional and hypofractionated schedules with and without a boost. Rates of implant loss and cosmetic outcomes among patients who did and did not develop a new/worse contracture based on physician assessment were compared.

RESULTS

In the study, 54.9% of patients received radiation using hypofractionated whole-breast tangents; 81.7% received a boost. In addition, 18 out of 71 cases (25.4%) developed a new/worse contracture after BCT with a mean follow-up of 1.9 years. Furthermore, 9 out of 71 cases (12.7%) were referred to a plastic surgeon for revisional surgery. There were no implant-loss cases. On univariate analysis, implant location, time from implant placement to diagnosis, RT type, RT boost, body mass index, and tumor size were not associated with new/worse contracture. Of 12 patients with existing contracture, only 2 developed worsening contracture. Physician assessment of cosmetic outcome after BCT was noted to be excellent or good for 87.4% of patients.

CONCLUSIONS

BCT for breast cancer patients with prior history of BA has a low risk of implant loss. Hypofractionated RT does not adversely affect implant outcomes. Patients should be counseled regarding risk for capsular contracture, but the majority have good/excellent outcome; BA does not represent a contraindication to BCT.

Hypofractionated whole breast irradiation after conservative surgery for patients aged less than 60 years: a multi-centre comparative study

Background: For decades, conventional fractionated whole breast irradiation (CF-WBI) was used after breast conserving surgery (BCS). Pivotal phase-3 trials on hypofractionated-WBI (HF-WBI) showed its non-inferiority as compared to CF-WBI. However, younger patients are often not treated with HF-WBI. The aim of this multi-centre comparative study is to confirm the safety of HF-WBI in a real-life series of younger patients.Material and methods: Between 2010 and 2016, a total of 786 patients aged less than 60 years old with early-stage breast cancer were treated with postoperative WBI after BCS in three breast cancer centres: 340 underwent HF-WBI while 446 were treated with CF-WBI. Acute toxicity was evaluated at the end of WBI. Late toxicity was evaluated at 6, 12, 24 and 36 months.Results: At univariate logistic analysis, hypofractionation showed a significant protective effect in terms of acute oedema, acute wet desquamation, chronic oedema, chronic erythema/pigmentation and breast fibrosis. At multivariate logistic analysis, hypofractionation was an independent significant factor for acute oedema, acute wet desquamation, and chronic oedema. There were not differences in tumour-related outcomes.Conclusions: HF-WBI showed significantly improved outcomes in terms of acute skin oedema, wet desquamation and chronic skin oedema. HF-WBI after BCS should be strongly encouraged to replace CF-WBI independently of age.

Five-Year Results of the Preoperative Accelerated Partial Breast Irradiation (PAPBI) Trial

PURPOSE

In this multicenter phase 2 feasibility study, we investigated the impact of preoperative accelerated partial breast irradiation (PAPBI) on local control, breast fibrosis, and cosmetic outcome.

METHODS AND MATERIALS

Women aged >60 years with an invasive, unifocal (mammography and magnetic resonance imaging), nonlobular adenocarcinoma of the breast were treated with PAPBI. Six weeks after radiation therapy, a wide local excision was performed. Radiation therapy consisted of 10 × 4 Gy (2010-2013) or 5 × 6 Gy (after 2013) to the tumor (gross target volume) with a 25 mm margin (20 mm from gross target volume to clinical target volume, 5 mm planning target volume).

RESULTS

One hundred thirty-three patients treated between 2010 and 2016 were analyzed with a median follow-up of 5.0 years (0.9-8.8 years). Seventy-eight (59%) patients were treated with 10 × 4 Gy in 2 weeks and 55 (41%) patients with 5 × 6 Gy in 1 week. Eighteen postoperative complications (14%) occurred in 15 patients (11%). The proportion of patients with no to mild fibrosis in the treated part of the breast at 2 years and later time points was around 90%. Cosmesis improved over time in several patients: excellent to good cosmetic score as rated by the physician was 68% at 6 months and 92% at 5 years. Seventy-seven percent (6 months) to 82% (5 years) of patients were "satisfied" or "very satisfied" with their cosmetic outcome. Three recurrences were detected in the biopsy track and 1 recurrence in the ipsilateral breast.

CONCLUSIONS

PAPBI is a feasible method with a low postoperative complication rate, limited fibrosis, and good to excellent cosmetic outcome. The local recurrence rate was 3% at 5 years; however, no local recurrences were observed since removal of the needle biopsy track.

Comparing hypofractionated to conventional fractionated radiotherapy in postmastectomy breast cancer: a meta-analysis and systematic review

Purpose

To compare the efficacy and toxicity of hypofractionated radiotherapy versus conventional fractionated radiotherapy in postmastectomy breast cancer using meta-analysis.

Methods

The PubMed, EMbase, Cochrane Library, Google Scholar, Wan Fang and CNKI databases were searched to identify controlled clinical trials comparing hypofractionated radiotherapy versus conventional fractionated radiotherapy in postmastectomy breast cancer. Overall survival (OS) was the primary endpoint, and disease-free survival (DFS), locoregional recurrence (LRR), distant metastasis (DM), acute skin toxicity, acute lung toxicity, late skin toxicity, lymphedema,, shoulder restriction, and late cardiac related toxicity were the secondary endpoints.

Results

Twenty-five controlled clinical trials involving 3871 postmastectomy breast cancer patients were included in this meta-analysis according to the selection criteria. The meta-analysis revealed that there were no significant differences in OS (OR = 1.08, 95% CI = 0.87~1.33, P = 0.49), DFS (OR = 1.13, 95% CI = 0.91~1.40, P = 0.28), LRR (OR = 1.01, 95% CI = 0.76~1.33, P = 0.96), DM (OR = 1.16, 95% CI = 0.85~1.58, P = 0.34), acute skin toxicity (OR = 0.94, 95% CI = 0.67~1.32, P = 0.72), acute lung toxicity (OR = 0.94, 95% CI = 0.74~1.20, P = 0.62), late skin toxicity (OR = 0.98, 95% CI = 0.75~1.27, P = 0.88), lymphedema (OR = 0.99, 95% CI = 0.77~1.28, P = 0.94), shoulder restriction (OR = 0.75, 95% CI = 0.43~1.31, P = 0.31), or late cardiac related toxicity (OR = 1.17, 95% CI = 0.82~1.65, P = 0.39) between the two groups.

Conclusions

The results of this study show that compared to conventional fractionated radiotherapy, hypofractionated radiotherapy is not significantly different with respect to efficacy or toxicity in postmastectomy breast cancer. Additional large randomized clinical trials are needed to further confirm this conclusion.

Hypofractionated radiation treatment for breast cancer: The time is now

While there is now Level I data with long-term follow-up supporting the routine use of hypofractionated (HF) whole-breast radiation therapy (WBRT) after breast-conserving surgery, its adoption has been slow and variable. This article will review the literature supporting the efficacy and safety of hypofractionated radiation for breast cancer, discuss the radiobiological rationale specific to breast tumors, and make an argument for justifying the routine adoption of shorter, HF-WBRT courses when delivering breast radiation. Data using HF with regional nodal irradiation and in the post-mastectomy setting will also be reviewed. The aim is to provide an in-depth understanding of the use of hypofractionated radiation therapy for breast cancer, its applicability, and topics warranting future research.

Hybrid planning techniques for hypofractionated whole-breast irradiation using flattening filter-free beams

OBJECTIVE

The aim of this study was to assess the feasibility of flattening filter-free (FFF) photon beams in hybrid intensity-modulated radiation therapy (H-IMRT) and hybrid volumetric modulated arc therapy (H-VMAT) for left-sided whole-breast radiation therapy with a boost volume (RT) using a hypofractionated dose regimen.

PATIENTS AND METHODS

RT plans of 25 patients with left-sided early-stage breast cancer were created with H‑IMRT and H‑VMAT techniques under breath-hold conditions using 6‑MV FFF beams. In hybrid techniques, three-dimensional conformal radiotherapy (3DCRT) plans were kept as base-dose plans for the VMAT and IMRT plans. In addition, H‑IMRT in step-and-shoot mode was also calculated to assess its achievability with FFF beams.

RESULTS

All hybrid plans achieved the expected target coverage. H‑VMAT showed better coverage and homogeneity index results for the boost target (p < 0.002), while H‑IMRT presented better results for the whole-breast target (p < 0.001). Mean doses to normal tissues were comparable between both plans, while H‑IMRT reduced the low-dose levels to heart and ipsilateral lung (p < 0.05). H‑VMAT revealed significantly better results with regard to monitor units (MU) and treatment time (p < 0.001).

CONCLUSION

The 6‑MV FFF beam technique is feasible for large-field 3DCRT-based hybrid planning in whole-breast and boost planning target volume irradiation. For breath-hold patients, the H‑VMAT plan is superior to H‑IMRT for hypofractionated dose regimens, with reduced MU and treatment delivery time.

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.

Individualised target volume selection and dose prescription after conservative surgery, mastectomy and reconstruction

Progress in radiotherapy (RT) for early breast cancer, driven by advances in radiobiology and radiation techniques is enabling individualised target volume and dose-fractionation according to recurrence risk. Conventionally fractionated WBI (CF-WBI) has been justified on the basis that it spares dose-limiting late-responding normal tissues more than breast cancer. However, randomised clinical trials (RCTs) testing hypofractionated WBI (HF-WBI) showed equivalent tumour control, improved acute toxicity and similar late toxicity between selected HF-WBI schedules and CF-WBI. RCTs showed that tumour bed boost (TBB) after WBI improved local control but increased breast fibrosis compared to no TBB. RCT comparing sequential TBB and simultaneous integrated TBB using dose intensity modulation showed similar toxicity. Partial breast irradiation (PBI) limits target volume to the tumour bed, which permits safe treatment acceleration. RCTs showed that PBI resulted in low local relapse rates but in some RCTs, higher rates of late toxicity and adverse cosmetic outcome than WBI. Given heterogeneity of PBI techniques, target volumes and dose-fractionation schedules used in RCTs, interpretation of results to distinguish whether outcome variations are caused by target volume or dose-fractionation effect is challenging. RCTs demonstrating efficacy of post-mastectomy RT (PMRT) included the chest wall and regional nodes but did not distinguish relative contributions of nodal target sub-volumes. In patients with smaller axillary tumour burden, IMC irradiation is controversial. RCTs were not powered for comparison between CF-PMRT and HF-PMRT. No increase in arm or shoulder dysfunction with HF-PMRT was observed. No RCT data exist on HF-PMRT in patients with breast reconstruction.

Hydrofilm Polyurethane Films Reduce Radiation Dermatitis Severity in Hypofractionated Whole-Breast Irradiation: An Objective, Intra-Patient Randomized Dual-Center Assessment

Radiation-induced skin injury represents the most frequent side effect in breast cancer patients undergoing whole-breast irradiation (WBI). Numerous clinical studies on systemic and topical treatments for radiation dermatitis have failed to provide sustainable treatment strategies. While protective skin products such as dressings are undoubtedly the standard of care in wound care management, their utilization as preventive treatment in radiotherapy has been somewhat neglected in recent years. In this prospective, intra-patient randomized observational study, Hydrofilm polyurethane films were prophylactically applied to either the medial or lateral breast-half of 74 patients with breast cancer undergoing hypofractionated whole-breast irradiation following breast-preserving surgery. Maximum radiation dermatitis severity was assessed using Common Terminology Criteria for Adverse Events (CTCAE) v4.03 toxicity scores, photospectrometric erythema and pigmentation measurements and patient-assessed modified Radiation-Induced Skin Reaction Assessment Scale (RISRAS) scale. Phantom studies revealed a clinically negligible dose build-up of less than 0.1% with Hydrofilm. Compared to the control compartments physician-assessed radiation dermatitis severity was reduced in the hydrofilm compartments (mean 0.54 vs. 1.34; p = < 0.001). Objective photospectrometric skin measurements showed decreased erythema (p = 0.0001) and hyperpigmentation (p = 0.002) underneath Hydrofilm. Hydrofilm also completely prevented moist desquamation, and significantly reduced patients' treatment-related symptoms of itching, burning, pain, and limitations of day-to-day-activities. Significant beneficial effects were observed in terms of radiation dermatitis severity, erythema, hyperpigmentation as well as subjective treatment-related symptom experiences, while adverse reactions were rare and minor. Therefore, a prophylactic application of Hydrofilm polyurethane films can be suggested in hypofractionated WBI.

Conventional versus hypofractionated postmastectomy radiotherapy: a report on long-term outcomes and late toxicity

Objective

We evaluated the long-term outcomes and late toxicity of conventional fractionated (CF) and hypofractionated (HF) postmastectomy radiotherapy (PMRT) in terms of locoregional recurrence-free survival (LRRFS), disease-free survival (DFS), overall survival (OS), and late toxicity.

Methods

A cohort of 1640 of breast cancer patients receiving PMRT between January 2004 and December 2014 were enrolled. Nine hundred eighty patients were treated with HF-PMRT: 2.65 Gy/fraction to a total of 42.4–53 Gy and 660 patients were treated with CF-PMRT: 2 Gy/fraction to a total of 50–60 Gy.

Results

The median follow-up time was 71.8 months (range 41.5–115.9 months). No significant difference was found in the rates of 5-year LRRFS, DFS, and OS of HF-PMRT vs CF-PMRT; 96% vs. 94% (p = 0.373), 70% vs. 72% (p = 0.849), and 73% vs. 74% (p = 0.463), respectively. We identified a cohort of 937 eligible breast cancer patients who could receive late toxicities assessment. With a median follow-up time of this patient cohort of 106.3 months (range 76–134 months), there was a significant higher incidence of grade 2 or more late skin (4% vs 1%) and subcutaneous (7% vs 2%) toxicity in patients treated with HF-PMRT vs CF-PMRT. Patients who received additional radiation boost were significantly higher in the HF-PMRT group. Grade 2 or more late RTOG/EORTC lung toxicity was significant lesser in HF-PMRT vs CF-PMRT (9% vs 16%). Grade 1 brachial plexopathy was also significant lesser in HF-PMRT vs CF-PMRT (2% vs 8%). Heart toxicity and lymphedema were similar in both groups.

Conclusions

HF-PMRT is feasible to deliver with comparable long-term efficacy to CF-PMRT. HF-PMRT had higher grade 2 or more skin and subcutaneous toxicity but less lung and brachial plexus toxicity.

Hypofractionated radiation therapy for invasive breast cancer: From moderate to extreme protocols

Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.

Toward a New Framework for Clinical Radiation Biology

Radiation biology has entered the era of precision oncology, and this article reviews time-tested factors that determine the effects of fractionated radiation therapy in a wide variety of tumor types and normal tissues: the association of tumor control with radiation dose, the importance of fractionation and overall treatment time, and the role of tumor hypoxia. Therapeutic gain can only be achieved if the increased tumor toxicity produced by biological treatment modifications is balanced against injury to early-responding and late-responding normal tissues. Developments in precision oncology and immuno-oncology will allow an emphasis on treatment individualization and predictive biomarker development.

Hypofractionation for clinically localized prostate cancer

BACKGROUND

Using hypofractionation (fewer, larger doses of daily radiation) to treat localized prostate cancer may improve convenience and resource use. For hypofractionation to be feasible, it must be at least as effective for cancer-related outcomes and have comparable toxicity and quality of life outcomes as conventionally fractionated radiation therapy.

OBJECTIVES

To assess the effects of hypofractionated external beam radiation therapy compared to conventionally fractionated external beam radiation therapy for men with clinically localized prostate cancer.

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), Embase (Ovid) and trials registries from 1946 to 15 March 2019 with reference checking, citation searching and contact with study authors. Searches were not limited by language or publication status. We reran all searches within three months (15th March 2019) prior to publication.

SELECTION CRITERIA

Randomized controlled comparisons which included men with clinically localized prostate adenocarcinoma where hypofractionated radiation therapy (external beam radiation therapy) to the prostate using hypofractionation (greater than 2 Gy per fraction) compared with conventionally fractionated radiation therapy to the prostate delivered using standard fractionation (1.8 Gy to 2 Gy per fraction).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Two authors independently assessed trial quality and extracted data. We used Review Manager 5 for data analysis and meta-analysis. We used the inverse variance method and random-effects model for data synthesis of time-to-event data with hazard ratios (HR) and 95% confidence intervals (CI) reported. For dichotomous data, we used the Mantel-Haenzel method and random-effects model to present risk ratios (RR) and 95% CI. We used GRADE to assess evidence quality for each outcome.

MAIN RESULTS

We included 10 studies with 8278 men in our analysis comparing hypofractionation with conventional fractionation to treat prostate cancer.Primary outcomesHypofractionation may result in little or no difference in prostate cancer-specific survival [PC-SS] (HR 1.00, 95% CI 0.72 to 1.39; studies = 8, participants = 7946; median follow-up 72 months; low-certainty evidence). For men in the intermediate-risk group undergoing conventional fractionation this corresponds to 976 per 1000 men alive after 6 years and 0 more (44 fewer to 18 more) alive per 1000 men undergoing hypofractionation.We are uncertain about the effect of hypofractionation on late radiation therapy gastrointestinal (GI) toxicity (RR 1.10, 95% CI 0.68 to 1.78; studies = 4, participants = 3843; very low-certainty evidence).Hypofractionation probably results in little or no difference to late radiation therapy genitourinary (GU) toxicity (RR 1.05, 95% CI 0.93 to 1.18; studies = 4, participants = 3843; moderate-certainty evidence). This corresponds to 262 per 1000 late GU radiation therapy toxicity events with conventional fractionation and 13 more (18 fewer to 47 more) per 1000 men when undergoing hypofractionation.Secondary outcomesHypofractionation results in little or no difference in overall survival (HR 0.94, 95% CI 0.83 to 1.07; 10 studies, 8243 participants; high-certainty evidence). For men in the intermediate-risk group undergoing conventional fractionation this corresponds to 869 per 1000 men alive after 6 years and 17 fewer (54 fewer to 17 more) participants alive per 1000 men when undergoing hypofractionation.Hypofractionation may result in little to no difference in metastasis-free survival (HR 1.07, 95% CI 0.65 to 1.76; 5 studies, 4985 participants; low-certainty evidence). This corresponds to 981 men per 1000 men metastasis-free at 6 years when undergoing conventional fractionation and 5 more (58 fewer to 19 more) metastasis-free per 1000 when undergoing hypofractionation.Hypofractionation likely results in a small, possibly unimportant reduction in biochemical recurrence-free survival based on Phoenix criteria (HR 0.88, 95% CI 0.68 to 1.13; studies = 5, participants = 2889; median follow-up 90 months to 108 months; moderate-certainty evidence). In men of the intermediate-risk group, this corresponds to 804 biochemical-recurrence free men per 1000 participants at six years with conventional fractionation and 42 fewer (134 fewer to 37 more) recurrence-free men per 1000 participants with hypofractionationHypofractionation likely results in little to no difference to acute GU radiation therapy toxicity (RR 1.03, 95% CI 0.95 to 1.11; 4 studies, 4174 participants at 12 to 18 weeks' follow-up; moderate-certainty evidence). This corresponds to 360 episodes of toxicity per 1000 participants with conventional fractionation and 11 more (18 fewer to 40 more) per 1000 when undergoing hypofractionation.

AUTHORS' CONCLUSIONS

These findings suggest that moderate hypofractionation (up to a fraction size of 3.4 Gy) results in similar oncologic outcomes in terms of disease-specific, metastasis-free and overall survival. There appears to be little to no increase in both acute and late toxicity.

Treatment results in patients with ductal carcinoma in situ treated with adjuvant radiotherapy

Background/aim

The aim of this study was to evaluate the treatment results of patients undergoing adjuvant radiotherapy (ART) after breast surgery with the diagnosis of ductal carcinoma in situ (DCIS).

Materials and methods

A total of 61 women who had undergone radiotherapy following extensive surgical excision were enrolled. All patients underwent 50 Gy ART. Survival analysis was performed using Kaplan–Meier analysis and SPSS 20.0.

Results

The median age was 52 years (range: 28–86). The median follow-up period after RT was 92 months (range: 23–237). The median overall survival and distant and regional recurrence-free and disease-specific survival was 96 months (range: 26–240), while disease-free and local recurrence-free survival was 96 months (range: 22–240). While the 15-year and 20-year overall survival rates were 87% and 87%, respectively, the recurrence-free survival rates were 98% and 98%, respectively; the rates of disease-specific survival were 100% and 100%, respectively.

Conclusion

The results of this study with a long follow-up period have shown that ART in DCIS is an effective treatment method to provide local disease control. However, further large studies are needed to identify the prognostic factors.

Hypofractionated radiation in older women with breast cancer

BACKGROUND

American Society of Radiation Oncology Choosing Wisely campaign recommends hypofractionated radiation and against routine use of intensity-modulated radiation therapy (IMRT) in early-stage estrogen receptor-positive breast cancer. We analyzed guideline recommendation adherence and financial implications in a modern Medicare cohort of women treated across the southeastern United States.

METHODS

Our study population comprised Medicare patients over 65 years of age with breast cancer diagnosis from 12 cancer centers in the Southeast United States with stage 0-II breast treated with lumpectomy from 2012 to 2015. Hypofractionation was defined as 4 or fewer weeks of radiation treatments. Factors associated with utilization of hypofractionation and IMRT were identified using Poisson regression. Median costs during radiation treatments were compared for hypofractionation and IMRT.

RESULTS

In older women (median age 71), 75% were treated with conventional fractionation, and 20% received IMRT. Hypofractionated women were more likely to have a positive estrogen(ER) or progestorone(PR) receptor status, lower comorbidity scores, and be treated at a high volume center (all P < 0.05). IMRT was utilized in 20% of patients and was more common in women treated with conventional fractionation (P < 0.001). Positive ER/PR status (P < 0.001) and utilization of hormonal blockade (P = 0.02) were associated with increased utilization of IMRT.

CONCLUSION

In an older cohort of patients with early-stage breast cancer, a majority were treated with conventional fractionated radiation, while approximately 20% were treated with IMRT. Both of which were associated with increased cost relative to hypofractionation.

Accelerated partial-breast irradiation with high-dose-rate brachytherapy: Mature results of a Phase II trial

PURPOSE

The purpose of this study was to report mature clinical and cosmetic results of accelerated partial-breast irradiation with interstitial multicatheter high-dose-rate brachytherapy (HDR-BRT) in patients with early breast cancer.

METHODS AND MATERIALS

133 patients were recruited in a Phase II trial of exclusive HDR-BRT. Inclusion criteria were age ≥40 years, PS 0-2, unifocal invasive ductal cancer, intraductal cancer component <25%, negative axillary nodes, and tumor size ≤2.5 cm. Treatment schedule was 4 Gy twice a day up to a total dose of 32 Gy in eight fractions.

RESULTS

Median age was 67 years (range, 42-85). There were 7 (5%) pT1a, 48 (36%) pT1b, 72 (54%) pT1c, and 6 (5%) pT2. Estrogen and progesterone receptors were positive in 119 (89%) and 93 (70%) patients, respectively. The median followup was 110 months (range, 12-163). After HDR-BRT, there were 3 (2%) in-field breast recurrences and 1 (1%) out-field breast recurrence. 5 (4%) patients developed contralateral breast cancer, another one (1%) isolated regional relapse in axillary node and 3 (2%) distant progression of disease. 19 (14%) patients reported a second primary cancer. 5-, 10-, and 13-year overall survival and cancer-specific survival were 95% and 100%, 84.5% and 100%, and 81.4% and 100%, respectively. Cosmetic outcome was excellent in 80% of cases. Late toxicity was significantly related to the skin administered doses (≤55% vs. > 55% of the prescribed dose, p < 0.05).

CONCLUSIONS

Accelerated partial-breast irradiation delivered with HDR-BRT in selected patients with breast cancer was associated to high local control and survival with excellent cosmetic outcomes overall when skin dose was ≤55%.

Outcomes of Breast Cancer Management from an Urban Specialist Breast Center in South India

Context and Aims: The disease pattern and presentation of breast cancer in India are thought to differ from the West. The purpose of this study is to describe and to discuss the presentation, clinicopathological data, and survival from an urban specialist breast center in Southern India. Materials and Methods: Prospectively collected data were analyzed for clinicopathological details, treatment variables, and survival outcomes were analyzed. Cumulative survival curves were estimated using the Kaplan–Meier method for patients treated from 2007 to 2011. Results: A total of 1671 patients were operated at our center from January 2007 to December 2016. Average age at diagnosis was 54.2 years. Over 70% had Stage I and Stage II disease, infiltrating duct carcinoma was predominant in 88.2%. Average clinical tumor size was three centimeters. Breast conservation was performed in 22.4%. Sentinel lymph node biopsy was performed in 44.6%. Estrogen-receptor positivity was seen in 64.6%, 22.2% were Her2Neu positive. Triple negative disease was seen in 19.1%. Survival analysis was done using the Kaplan–Meier curves for 540 patients treated from 2007 to 2011. The median follow-up of surviving patients was 70 months with 10% lost to follow-up. In our study population, the 5 years overall survival rate is 88.3% and disease-free survival is 85.7%. Conclusion: Our study reflects a higher percentage of early breast cancer with outcomes comparable to the West. More research is required to understand the genetic predisposition in our population.

Temporal impact of the publication of guidelines and randomised evidence on the adoption of hypofractionated whole breast radiotherapy for early-stage breast cancer

INTRODUCTION

Clinical data supporting the use of hypofractionated whole breast radiotherapy (HF-WBRT) in early-stage breast cancer patients have accumulated over the last decade. Despite the availability of the published evidence, the adoption rate of HF-WBRT has been slower-than-expected. We sought to assess the temporal impact of the publication of the guidelines and randomised evidence on the practice pattern of HF-WBRT and identify clinical predictors of its utilisation.

METHODS

Women with early-stage breast cancer who received adjuvant WBRT at Canberra Health Services between 2008 and 2016 were identified from clinical databases. The patterns of HF-WBRT use were analysed in relation to pre-specified time periods (before and after the guideline publications) in the entire cohort as well as in a patient subset fulfilling the criteria for HF-WBRT according to the guidelines (referred to as 'guideline-endorsed subset'). The impact of clinical variables, treating clinicians and the time periods on the adoption of HF-WBRT was assessed by hierarchical multivariate logistic regressions.

RESULTS

Of the entire cohort (n = 1171), the guideline-endorsed subset constituted 51.6% (n = 604) of the patients. HF-WBRT was utilised in 32.8% of the entire cohort and 46.2% of the guideline-endorsed subset. Between 2008 and 2016, HF-WBRT use rate increased from 12.1% to 56.6% in a non-linear pattern. Release of international and local consensus guidelines significantly correlated with the increase in HF-WBRT utilisation rate. The use of chemotherapy and/or tumour bed boost radiotherapy (TBBR), chest wall sepJMIROtion distance (CWSD) and patient age were significant predictors of HF-WBRT use on multivariate analyses. After factoring in the effects of individual clinicians and the time periods on hierarchical multivariate analyses, the use of chemotherapy, TBBR, and CWSD remained as significant variables. Clinicians contributed to the variability in the HF-WBRT adoption pattern.

CONCLUSION

The temporal uptake pattern and the predictors of adjuvant HF-WBRT use in early breast cancer patients largely reflected the accumulating clinical evidence and the publication of the consensus guidelines. This study identified potentially modifiable factors associated with slower-than-expected uptake rate of HF-WBRT. Understanding why there is variability in clinicians' readiness to adopt the abbreviated treatment despite the availability of advanced radiotherapy techniques and the updated evidence is an important step towards formulating effective strategies to optimise the radiotherapeutic management of this common malignancy.

Cardiac Structure Doses in Women Irradiated for Breast Cancer in the Past and Their Use in Epidemiological Studies

PURPOSE

Incidental cardiac exposure during radiation therapy may cause heart disease. Dose-response relationships for cardiac structures (segments) may show which ones are most sensitive to radiation. Radiation-related cardiac injury can take years to develop; thus, studies need to involve women treated using 2-dimensional planning, with segment doses estimated using a typical computed tomography (CT) scan. We assessed whether such segment doses are accurate enough to use in dose-response relationships using the radiation therapy charts of women with known segment injury. We estimated interregimen and interpatient segment dose variability and segment dose correlations.

METHODS AND MATERIALS

The radiation therapy charts of 470 women with cardiac segment injury after breast cancer radiation therapy were examined, and 41 regimens were identified. Regimens were reconstructed on a typical CT scan. Doses were estimated for 5 left ventricle (LV) and 10 coronary artery segments. Correlations between cardiac segments were estimated. Interpatient dose variation was assessed in 10 randomly selected CT scans for left regimens and in 5 for right regimens.

RESULTS

For the typical CT scan, interregimen segment dose variation was substantial (range, LV segments <1-39 Gy; coronary artery segments <1-48 Gy). In 10 CT scans, interpatient segment dose variation was higher for segments near field borders (range, 3-47 Gy) than other segments (range, <2 Gy). Doses to different left-anterior descending coronary artery (LADCA) segments were highly correlated with each other, as were doses to different LV segments. Also, LADCA segment doses were highly correlated with doses to LV segments usually supplied by the LADCA. For individual regimens there was consistency in hotspot location and segment ranking of higher-versus-lower dose.

CONCLUSIONS

The scope for developing quantitative cardiac segment dose-response relationships in patients who had 2-dimensional planning is limited because different segment doses are often highly correlated, and segment-specific dose uncertainties are not independent of each other. However, segment-specific doses may be reliably used to rank segments according to higher-versus-lower doses.

Can patient-reported outcomes be used instead of clinician-reported outcomes and photographs as primary endpoints of late normal tissue effects in breast radiotherapy trials? Results from the IMPORT LOW trial

BACKGROUND

In an era of low local relapse rates after adjuvant breast radiotherapy, risks of late normal-tissue effects (NTE) need to be balanced against risk of relapse. NTE are assessed using patient-reported outcome measures (PROMs), clinician-reported outcomes (CRO) and photographs. This analysis investigates whether PROMs can be used as primary NTE endpoints in breast radiotherapy trials.

METHODS

Analyses were conducted within IMPORT LOW (ISRCTN12852634) at 2 and 5 years. NTE were recorded by CRO, photographs and PROMs. Measures of agreement tested concordance, risk ratios for radiotherapy groups were compared, and influence of baseline characteristics on concordance investigated.

RESULTS

In 1095 patients who consented to PROMS and photographs, PROMs were available at 2 and/or 5 years for 976 patients, of whom 909 had CRO and 844 had photographs. Few patients had moderate/marked NTE, irrespective of method used (eg. 19% patients and 9% clinicians reported breast shrinkage at year-5). Patients reported more NTE than assessed from CRO or photographs (p < 0.001 for most NTE). Concordance between assessments was poor on an individual patient level; eg. for year-5 breast shrinkage, % agreement = 48% and weighted kappa = 0.17. Risk ratios comparing radiotherapy schedules were consistent between PROMs and CRO or photographs.

CONCLUSIONS

Few patients had moderate/marked NTE irrespective of method used. Patients reported more NTE than CRO and photographs, therefore NTE may be underestimated if PROMs are not used. Despite poor concordance between methods, effect sizes from PROMs were consistent with CRO and photographs, suggesting PROMs can be used as primary NTE endpoints in breast radiotherapy trials.

Hypofractionated volumetric modulated arc therapy with SIB adjuvant to breast preservation surgery: retrospective experience from a Regional Cancer Centre in Eastern India

Background:

The incidence of breast cancer has surpassed cervical cancer in India and it has now become the most common cancer in women. Multiple randomised studies have reported low α/β value in the range of 3–4 for breast cancer, which predict a potential radiobiological advantage for hypofractionated radiotherapy resulting in such schedules becoming standard in many centers with reduction in overall treatment time. Volumetric modulated arc therapy (VMAT) is a novel technique of delivering radiotherapy that reduces treatment delivery time, requires less monitor units (MU) and offers good conformity. The mean dose to normal tissue may be minimised using this technique although there will be inferior sparing if we consider the low-dose volume such as V5, the effect of which is not quantifiable yet.

Aim:

Reporting acute toxicity, cosmetic effects, and quality of life in patients of early breast cancer treated with adjuvant hypofractionated VMAT with SIB.

Material and Methods:

The records of 44 patients registered at the hospital between August 2014 and December 2015 were included in this analysis. Acute toxicities were analysed using CTCAE v4.03. Cosmetic outcomes were assessed using Harvard scale, while quality of life outcomes were assessed using EORTC scales and Health Related quality of life (HRQOL) questionnaires (QLQ-C30 and QLQ-BR23).

Results:

No grade ≥2 skin toxicities were recorded. Breast pain was recorded as Grade 1 in 13·8% patients and Grade 1 fatigue in 18·2%. The maximum haematological abnormality grade recorded was Grade 1. Cosmesis was assessed at the baseline, 6 months, 1 year and 2 years. A total of 88·6% of the patients had an Excellent or good cosmesis at the baseline, which was similar even at 6 months, at 88·7%, improved further at 1 year to 90·9%. At 6 months post radiotherapy, high functional scale QOL scores were noted.

Conclusion:

The technique is associated with minimum acute toxicity, good to excellent cosmesis and acceptable quality of life.

Influence of Radiation Dose to Reconstructed Breast Following Mastectomy on Complication in Breast Cancer Patients Undergoing Two-Stage Prosthetic Breast Reconstruction

Purpose: This study investigated the association between radiation dose and complication rate in patients who underwent breast reconstruction to understand the role of radiation hypofractionated regimen, boost radiation therapy (RT), and RT techniques.

Methods: We retrospectively evaluated 75 patients treated with post-mastectomy adjuvant RT for breast cancer in the setting of two-stage prosthetic breast reconstruction. Near maximum radiation dose (D_max) in the 2 or 0.03 cc of reconstructed breast or overlying breast skin was obtained from dose-volume histograms.

Results: Post-RT complications occurred in 22.7% of patients. Receiver operating characteristic analysis showed that all near D_max parameters were able to predict complication risk, which retained statistical significance after adjusting other variables (odds ratio 1.12 per Gy, 95% confidence interval 1.02–1.23) with positive dose-response relationship. In multiple linear regression model (R² = 0.92), conventional fractionation (β = 11.7) and 16 fractions in 2.66 Gy regimen (β = 3.9) were the major determinants of near D_max compared with 15 fractions in 2.66 Gy regimen, followed by utilization of boost RT (β = 3.2). The effect of bolus and dose inhomogeneity seemed minor (P > 0.05). The location of hot spot was not close to the high density metal area of the expander, but close to the surrounding areas of partially deflated expander bag.

Conclusions: This study is the first to demonstrate a dose-response relationship between risk of complications and near D_max, where hypofractionated regimen or boost RT can play an important role. Rigorous RT-quality assurance program and modification of dose constraints could be considered as a critically important component for ongoing trials of hypofractionation. Based on our findings, we initiated a multi-center retrospective study (KROG 18-04) and a prospective study (NCT03523078) to validate our findings.

Validation of a normal tissue complication probability model for late unfavourable aesthetic outcome after breast-conserving therapy

PURPOSE

To validate a normal tissue complication probability (NTCP) model for late unfavourable aesthetic outcome (AO) after breast-conserving therapy.

MATERIALS/METHODS

The BCCT.core software evaluated the AO using standardized photographs of patients treated at the University Hospitals Leuven between April 2015 and April 2016. Dose maps in 2 Gy equivalents were calculated assuming α/β = 3.6 Gy. The discriminating ability of the model was described by the AUC of the receiver operating characteristic curve. A 95% confidence interval (CI) of AUC was calculated using 10,000 bootstrap replications. Calibration was evaluated with the calibration plot and Nagelkerke R². Patients with unfavourable AO at baseline were excluded. Patient, tumour and treatment characteristics were compared between the development and the validation cohort. The prognostic value of the characteristics in the validation cohort was further evaluated in univariable and multivariable analysis.

RESULTS

Out of 175 included patients, 166 were evaluated two years after RT and 44 (26.51%) had unfavourable AO. AUC was 0.66 (95% CI 0.56; 0.76). Calibration was moderate with small overestimations at higher risk. When applying all of the univariable significant clinicopathological and dosimetrical variables from the validation cohort in a multivariable model, the presence of a seroma and V45 were selected as significant risk factors for unfavourable AO (Odds Ratio 4.40 (95% CI 1.96; 9.86) and 1.14 (95% CI 1.03; 1.27), p-value <.001 and .01, respectively).

CONCLUSIONS

The NTCP model for unfavourable AO shows a moderate discrimination and calibration in the present prospective validation cohort with a small overestimation in the high risk patients.

Automated Field-In-Field (FIF) Plan Framework Combining Scripting Application Programming Interface and User-Executed Program for Breast Forward IMRT

Purpose:

To develop an one-click option on treatment planning system that enables for the automated breast FIF planning by combining the Eclipse Scripting application programming interfaces and user-executed programming in Windows.

Methods:

Scripting application programming interfaces were designed to promote automation in clinical workflow associated with radiation oncology. However, scripting cannot provide all functions that users want to perform. Thus, a new framework proposes to integrate the benefits of the scripting application and user-executed programming for the automated field-in-field technique. We adopted the Eclipse Scripting applications, which provide an interface between treatment planning system server and client and enable for running the executed program to create dose clouds and adjust the planning parameters such as multi-leaf collimator placements and monitor unit values. Importantly, all tasks are designed to perform with one-click option on treatment planning system, including the automated pushback of the proposed plan to the treatment planning system.

Results:

The plans produced from the proposed framework were validated against the manual field-in-field plans with 40 retrospective breast patient cases in planning efficiency and plan quality. The elapsed time for running the framework was less than 1 minute, which significantly reduced the manual multi-leaf collimator/monitor unit adjustment time. It decreased the total planning time by more than 50%, relative to the manual field-in-field planning. In dosimetric aspects, the mean and maximum dose of the heart, lung, and whole breast did not exceed 1% deviation from the manual plans in most patient cases, while maintaining the target dose coverage and homogeneity index inside the target volume. From numerical analysis, the automated plans were demonstrated to be sufficiently close to the manual plans.

Conclusion:

The combination of scripting applications and user-executed programming for automated breast field-in-field planning accomplished a significant enhancement in planning efficiency without degrading the plan quality, relative to the manual field-in-field procedure.

Hypofractionated radiotherapy with concomitant boost for breast cancer: a dose escalation study

METHODS:

Patients with breast cancer with pathological stage pT 1-2 and at least one risk factor for local recurrence such as N1 disease, lymphovascular invasion, extensive intraductal component, close margins, non-hormone sensitive disease, grading G3 were enrolled. Patients were treated with hypofractionated RT to whole breast with a dose of 40.05 Gy in 15 fractions. The dose was escalated to the tumour bed through a daily concomitant boost technique at three dose levels: 48 Gy (3.2 Gy/die), 50.25 Gy(3.35 Gy/die) and 52.5 Gy (3.5 Gy/die). Dose escalation to a higher step was carried out if all patients of the lower dose had completed the treatment without dose limiting toxicity (DLT). Skin toxicity, cosmetic evaluation and quality of life was evaluated at baseline, at treatment end and at 3 and 12 months after RT end.

RESULTS:

Three patients for each dose level were enrolled. No DLT occurred. The maximum toxicity collected during RT was G2 skin toxicity in 3 (33.3%) patients, one for each dose level. No G2 toxicity at 3 and 12 months was collected. At median follow up of 21.8 months (range: 13.5 - 40.9 months), no G2 late toxicity was recorded.

CONCLUSION:

The 3 week course of post-operative RT with dose escalation to the tumour bed to 52.5 Gy has been achieved without dose limiting toxicities and can be tested in Phase II trials.

ADVANCES IN KNOWLEDGE:

In our study, we tested the highest dose level to the tumour bed ever reported in studies using accelerated hypofractionation with concomitant boost in high risk patients.

Trends in utilization of hypofractionated whole breast irradiation (HF-WBI) in triple negative breast cancer (TNBC): a national cancer database (NCDB) analysis

PURPOSE

We sought to identify trends over time with respect to the use of hypofractionated whole breast irradiation (HF-WBI) in women with triple negative breast cancer (TNBC) in the national cancer database (NCDB).

METHODS

Trends in utilization of HF-WBI in women diagnosed with T1-2N0 TNBC in the NCDB between 2008 and 2013 were analyzed. Case-matched luminal A women were used for comparison. Variables included age, race, year of diagnosis, insurance status, income quartile, receipt of neoadjuvant chemotherapy, and institution (academic vs. community). Chi square, logistic regression, and multivariate analysis was performed.

RESULTS

Utilization of HF-WBI among the 53,269 TNBC women identified steadily increased from 4.7% in 2008 to 14.0% in 2013 for women with TNBC compared to luminal A cancer whose utilization increased from 7.3 to 23.3% over the same time frame (p < 0.001). On univariate analysis, HF-WBI was associated with increasing age (p < 0.001), Medicare insurance (p < 0.001), race (p = 0.041), diagnosis after 2011 (p < 0.001), higher income quartile (p < 0.001), and treatment at academic institutions (p < 0.001). On multivariate analysis, age (p < 0.001, OR 1.038 per year), income quartile (p = 0.002, OR 1.061 per increase in quartile), treatment at an academic institution (p < 0.001, OR 1.78) significantly increased use of HF-WBI.

CONCLUSIONS

Treatment at an academic center and year of diagnosis were most correlated with increased HF-WBI in T1-2N0 TNBC women in the NCDB from 2008 to 2013, followed by increasing age and income. Only 14% of T1-2N0 TNBC women received HF-WBI in 2013. Focus on increased utilization is needed for non-academic centers, lower income, and younger women.

Extreme Oncoplastic Surgery for Multifocal/Multicentric and Locally Advanced Breast Cancer

Introduction

Breast conserving surgery (BCS) followed by radiation therapy (RT) has become the preferred alternative to mastectomy for patients with early stage breast cancer (BC). Randomized trials have confirmed equivalent locoregional control and overall survival for BCS and mastectomy. Extreme Oncoplasty (EO) extends the indications of BCS for patients who would otherwise require mastectomy, ensuring better aesthetic outcomes and oncological safety.

Methods

BC patients with multifocal/multicentric (MF/MC) tumors, extensive DCIS, or large tumor >50mm underwent EO at our breast unit. Therapeutic reduction mammaplasty (TRM) with wise pattern preoperative markings and dual pedicle technique involving parenchymal rearrangement was used for oncoplastic reconstructions in majority of the cases followed by RT. Patient reported outcome measures (PROMs) were assessed using the validated Breast-Q questionnaire.

Results

Of the 39 patients in the study, 36 had unilateral and 3 had bilateral BC. Mean age was 47.2 years. Median tumor size was 75mm. 17 (43.6%) patients received NACT; none achieved a complete clinical response. 28 (71.8%) patients were administered to adjuvant chemotherapy. 33(84.6%) patients received RT to the breast with a median dose of 50Gy in 28 fractions and a boost dose of 10Gy in 5 fractions to the tumor bed. No major complications or local recurrences were observed. Excellent Breast-Q scores were observed in patients undergoing EO after 12 months of follow-up.

Conclusion

EO followed by RT results in acceptable local-regional control, low rate of complications, and high patient satisfaction. In selected patients, EO could provide a safe alternative for breast conservation surgery instead of mastectomy.

Recommendations for hypofractionated whole-breast irradiation

This recommendation consensus for hypofractionated whole-breast radiotherapy (RT) was organized by the Brazilian Society of Radiotherapy (SBRT) considering the optimal scenario for indication and safety in the technology applied. All controversies and contraindication matters (hypofractionated RT in patients who underwent chemotherapy [CT], hypofractionated RT in lymphatic drainage, hypofractionated RT after mastectomy with or without immediate reconstruction, boost during surgery, hypofractionated RT in patients under 50 years old, hypofractionated RT in large breasts, hypofractionated RT in histology of carcinoma in situ [DCIS]) was discussed during a meeting in person, and a consensus was reached when there was an agreement of at least 75% among panel members. The grade for recommendation was also suggested according to the level of scientific evidence available, qualified as weak, medium, or strong. Thus, this consensus will aid Brazilian radiotherapy experts regarding indications and particularities of this technique as a viable and safe alternative for the national reality.

Radiation therapy after sentinel lymph node biopsy for early stage breast cancer using a magnetic tracer: Results of a single institutional prospective study of tolerance

PURPOSE

. The aim of the study was, through a single institutional analysis of a large population of breast cancer patients, to assess the feasibility of and the tolerance to radiotherapy after the use of magnetic detection method for sentinel lymph node biopsy.

MATERIAL AND METHODS

The super paramagnetic iron oxide particles database was collected prospectively and identified 520 cases from October 2013 to December 2016 at our institution. All of them received super paramagnetic iron oxide particles injection 20minutes before the surgical procedure and some of them received also isotope technique. Injection site for super paramagnetic iron oxide particles and isotope was periareolar. Among them, 288 patients received adjuvant radiotherapy. In our study, we evaluated the tolerance of postoperative radiotherapy.

RESULTS

The median age of the patients was 64 years. The median follow-up period was 16 months (range: 1-42 months). Double detection of sentinel lymph node was done in the first 30 patients (10.4%). The sentinel lymph node identification rate was 99.7% (287 out of 288). There were 34 axillary lymph node dissections, of which 58.8% were realized straightaway. The total radiation dose was 50Gy EQD2 (range: 28.5-66Gy). Regarding the occurrence of radiodermatitis, 95.8% of patients had grade 0-2 radiodermatitis and 1% had grade 3. During follow-up, 19.4% of patients developed grade 1-2 post-therapeutic fibrosis (of which 92.9% grade 1).

CONCLUSION

The results of this large-scale study show that the radiotherapy after sentinel lymph node biopsy using super paramagnetic iron oxide particles is feasible, and that no increase of the toxicity was observed.