Comparing Hypofractionated With Conventional Fractionated Radiotherapy After Breast-Conserving Surgery for Early Breast Cancer: A Meta-Analysis of Randomized Controlled Trials

Impact of deep inspiration breath hold, surface-guided radiotherapy, and daily CBCT on the organs at risk in breast cancer radiotherapy

The goal of the study was to assess the impact of deep inspiration breath hold technique (DIBH), surface-guided radiotherapy (SGRT), and daily kilovoltage cone-beam computed tomography (kV-CBCT) on the dose to organs at risk (OAR) in left-sided breast cancer radiotherapy. Twenty-six consecutive left-sided breast cancer patients treated using Volumetric Intensity Modulated Arc Therapy (VMAT), DIBH, SGRT, and a hypofractionated regimen were retrospectively evaluated in this study. Dose parameters were extracted from dose-volume histograms (DVH). The Wilcoxon Matched Pairs test was used to test dose parameters obtained in free breathing (FB) and DIBH for statistical significance. Multivariable analysis of variance (ANOVA) and receiver operating characteristics (ROC) analysis were used to identify parameters and cut-off points associated with the reduction of the mean heart dose (MHD) by DIBH. Based on published models, the risk of cardiac and lung toxicity (pneumonitis) using SGRT or daily kV-CBCT was estimated and compared. DIBH substantially reduced the MHD (median, 43.6%; range, 4.2% to 75.1%; P < 0.00001). The risk of cardiac toxicity using SGRT increased by 1%, compared to 3.6% to 20.5% using daily kV-CBCT. No significant difference in the risk of radiation-induced pneumonitis using SGRT versus daily kV-CBCT was detected. The ANOVA revealed the relative increase of the left lung volume by DIBH as the only significant impact factor for the MHD. The ROC analysis of this parameter showed an area under the curve (AUC) of 0.89 (95%CI, 0.71 to 0.98; P < 0.0001). DIBH can substantially reduce the MHD in left-sided breast cancer patients treated with modern radiotherapy techniques and hypofractionation. Patient setup using SGRT compared to daily kV-CBCT may be the preferred option for many patients. In our patient cohort, the relative reduction of the left lung volume by DIBH can be used as a predictor to select patients who benefit from DIBH.

Barrier films or dressings for the prevention of acute radiation dermatitis in breast cancer: a systematic review and network meta-analysis

BACKGROUND

Barrier films or dressings were reported to be effective in preventing radiation dermatitis (RD) in breast cancer patients, but their comparative efficacy is unknown.

METHODS

A systematic literature search was performed on Embase, MEDLINE and Cochrane CENTRAL Registry of Clinical Trials from inception to October 20, 2023. Randomised controlled trials (RCTs) comparing barrier films or dressings to the standard of care (SOC) or other interventions were included. We estimated summary odds ratios and mean differences using network meta-analysis with random effects. This study was registered with PROSPERO (ID: CRD42023475021).

RESULTS

Fourteen RCTs met inclusion criteria. Six interventions were analysed: 3M™ Moisturizing Double Barrier Cream (MDBC), 3M™ No Sting Barrier Film (BF), Hydrofilm® (HF), Mepitel® Film (MF), Silver Leaf Nylon Dressing and StrataXRT®. HF, MF and StrataXRT® reduced the incidence of moist desquamation compared to SOC (HF: OR = 0.08; p = 0.02; MF: OR = 0.31 p < 0.01; StrataXRT®: OR = 0.22, p = 0.04). The ranking of agents from most to least effective in preventing moist desquamation according to P-scores was HF (92.5%), MF (78.5%), StrataXRT® (70.1%), BF (46.4%), Silver Leaf Nylon Dressing (24.9%), MDBC (22.9%) and SOC (14.7%). Only four RCTs on HF and MF included patient-reported outcome (PRO) assessments that allowed pooling for analysis. HF and MF were more effective in reducing pain, itchiness and burning sensation compared to SOC (p < 0.01 for all symptoms).

CONCLUSION

HF and MF were effective in preventing RD in breast cancer. Future RCTs should compare these interventions to effective cream preparations, such as topical corticosteroids.

Randomised controlled trials on radiation dose fractionation in breast cancer: systematic review and meta-analysis with emphasis on side effects and cosmesis

OBJECTIVE

To provide a comprehensive assessment of various fractionation schemes in radiation therapy for breast cancer, with a focus on side effects, cosmesis, quality of life, risks of recurrence, and survival outcomes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (from inception to 23 October 2023).

STUDY SELECTION

Included studies were randomised controlled trials focusing on conventional fractionation (CF; daily fractions of 1.8-2 Gy, reaching a total dose of 50-50.4 Gy over 5-6 weeks), moderate hypofractionation (MHF; fraction sizes of 2.65-3.3 Gy for 13-16 fractions over 3-5 weeks), and/or ultra-hypofractionation (UHF; schedule of only 5 fractions).

DATA EXTRACTION

Two independent investigators screened studies and extracted data. Risk of bias and quality of evidence were assessed using the Cochrane Collaboration's tool and the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach, respectively.

DATA SYNTHESIS

Pooled risk ratios (RRs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using a random effects model. Heterogeneity was analysed using Cochran's Q test and I2 statistic. Network meta-analysis was used to integrate all available evidence.

MAIN OUTCOME MEASURES

The pre-specified primary outcome was grade ≥2 acute radiation dermatitis and late radiation therapy related side effects; secondary outcomes included cosmesis, quality of life, recurrence, and survival metrics.

RESULTS

From 1754 studies, 59 articles representing 35 trials (20 237 patients) were assessed; 21.6% of outcomes showed low risk of bias, whereas 78.4% had some concerns or high risk, particularly in outcome measurement (47.4%). The RR for grade ≥2 acute radiation dermatitis for MHF compared with CF was 0.54 (95% CI 0.49 to 0.61; P<0.001) and 0.68 (0.49 to 0.93; P=0.02) following breast conserving therapy and mastectomy, respectively. Hyperpigmentation and grade ≥2 breast shrinkage were less frequent after MHF than after CF, with RRs of 0.77 (0.62 to 0.95; P=0.02) and 0.92 (0.85 to 0.99; P=0.03), respectively, in the combined breast conserving therapy and mastectomy population. However, in the breast conserving therapy only trials, these differences in hyperpigmentation (RR 0.79, 0.60 to 1.03; P=0.08) and breast shrinkage (0.94, 0.83 to 1.07; P=0.35) were not statistically significant. The RR for grade ≥2 acute radiation dermatitis for UHF compared with MHF was 0.85 (0.47 to 1.55; P=0.60) for breast conserving therapy and mastectomy patients combined. MHF was associated with improved cosmesis and quality of life compared with CF, whereas data on UHF were less conclusive. Survival and recurrence outcomes were similar between UHF, MHF, and CF.

CONCLUSIONS

MHF shows improved safety profile, cosmesis, and quality of life compared with CF while maintaining equivalent oncological outcomes. Fewer randomised controlled trials have compared UHF with other fractionation schedules, but its safety and oncological effectiveness seem to be similar with short term follow-up. Given the advantages of reduced treatment time, enhanced convenience for patients, and potential cost effectiveness, MHF and UHF should be considered as preferred options over CF in appropriate clinical settings, with further research needed to solidify these findings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023460249.

A bibliometric worldview of breast-conserving surgery for breast cancer from 2013 to 2023

Over the last decade, significant advancements have been made in breast-conserving surgery (BCS) for breast cancer. However, there is a lack of analytical and descriptive investigations on the trajectory, essential research directions, current research scenario, pivotal investigative focuses, and forthcoming perspectives. The objective of this research is to provide a thorough update on the progress made in BCS for breast cancer over the preceding decade. Retrieved from the Web of Science database, the data span from January 1, 2013, to November 30, 2023. Utilizing a set of advanced analytical instruments, we conducted comprehensive bibliometric and visual analyses. The findings underscore the predominant influence of the USA, representing 35.77% of the overall publications and playing a pivotal role in shaping research within this field. Notable productivity was evident at various institutions, including the Memorial Sloan Kettering Cancer Center, the University of Texas MD Anderson Cancer Center, and the University of Toronto. Annals of Surgical Oncology contributed the most publications in this field. An examination of keywords indicated a change in the concentration of research attention, transitioning from molecular subtype, ultrasonography, and intraoperative aspects to SEER, male breast cancer, and adjuvant measures. By offering a comprehensive bibliometric assessment, this study enhances our understanding of BCS for breast cancer. Consequently, this benefits both experienced researchers and newcomers alike, providing prompt access to essential information and fostering the extraction of innovative concepts within this specific field.

A meta-analysis of randomized controlled trials comparing breast-conserving surgery and mastectomy in terms of patient survival rate and quality of life in breast cancer

The study aimed to assess the effects of breast-conserving surgery (BCS) versus mastectomy on survival and quality of life in Stages I, II, and III breast cancer, providing solid evidence for clinical decisions. We conducted a meta-analysis of randomized controlled trials on breast cancer treatments, searching databases such as PubMed and the Cochrane Library to compare BCS, and mastectomy's effects on survival and quality of life. A combined total of 16 734 patients in the control group and 17 435 patients in the experimental group were included in this analysis. This meta-analysis used RevMan 5.3 (Cochrane Collaboration, Copenhagen, Denmark) software for analysis. Our meta-analysis of 34 169 patients from 11 studies showed that BCS significantly reduced the overall recurrence rate at a median follow-up of 29 months, with a mean difference of 1.27 and a 95% confidence interval of 1.19-1.36, strongly supporting its effectiveness (P < .00001). Furthermore, our analysis found no significant increase in 5-year local recurrence rates for BCS versus mastectomy, indicating its long-term effectiveness with a mean difference of 1.13 (95% confidence interval: [1.03, 1.24], P = .01). Additionally, there was a notable decrease in tissue ischaemic necrosis among patients who had received BCS, with a mean difference of 0.37 (95% confidence interval: [0.33, 0.42], P < .00001), underscoring its benefits and long-term viability. BCS resulted in fewer cases of tissue ischaemic necrosis and higher body image scores compared with mastectomy, suggesting that it is a preferable option for better cosmetic outcomes and potentially favourable effects on prognosis and quality of life.

Hypofractionated whole breast IMRT with HDR brachytherapy boost in early-stage breast cancer: Long-term results from a single-center

INTRODUCTION/OBJECTIVES

The addition of a boost to the lumpectomy bed after whole-breast (WB) radiotherapy plays a key role in the treatment of patients with breast cancer (BC). The clinical benefits of a boost with high-dose-rate brachytherapy (HDR-BT) after conventional fractionation is supported by a large body of evidence. However, few studies have described its outcomes after a hypofractionated scheme.

MATERIALS AND METHODS

We included all patients treated with adjuvant WB-IMRT in 15 sessions followed by a single-session HDR-BT boost with local anesthesia on an outpatient basis.

RESULTS

Between 2009 and 2017, 638 patients with early-stage BC were treated according to the aforementioned protocol after breast-conserving surgery. Median follow-up was 6 years (4-11). Despite the low incidence of side effects and their slightness, we did identify an impact of breast volume on the risk of acute radiodermatitis, fibrosis, pain and edema. However, we did not identify any relationship between the volume in cubic centimeters of the BT-implant with acute or long-term side effects. 2.2% patients had an actual local relapse, 2.4% a 2nd primary in the same breast and 2.39% were diagnosed with contralateral BC. Event-free survival at 11 years was 85.5% with an overall survival of 95.7%.

CONCLUSION

Adjuvant hypofractionated whole-breast IMRT followed by a single dose HDR-BT boost has a low incidence of acute and chronic toxicity and excellent oncological outcomes. However, it may be worthwhile to intensify self-care protocols and surveillance in women with large breasts who may be at increased risk of side effects.

Efficacy and safety analysis of hypofractionated and conventional fractionated radiotherapy in postoperative breast cancer patients

OBJECTIVES

In this meta-analysis, we conducted a comparative analysis of the safety and efficacy of hypofractionated and conventional fractionated radiotherapy in individuals who had undergone surgery for breast cancer.

METHODS

This study involved a systematic and independent review of relevant research articles published in reputable databases such as PubMed, Embase, Cochrane Library, and Web of Science. Two investigators conducted the review, which included studies published up to January 3, 2023. The quality of the eligible studies was evaluated and data were extracted using Review Manager software 5.4 (RevMan 5.4) to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The analysis comprised 35 studies and encompassed a collective sample of 18,246 individuals diagnosed with breast cancer. We did not find a statistically significant disparity in efficacy between conventional fractionated (CF) radiotherapy and hypofractionated (HF) radiotherapy regarding local recurrence (LR; OR = 0.91, 95% CI: 0.76-1.09, P = 0.30), disease-free survival (DFS; OR = 1.20, 95% CI: 1.01-1.42, P = 0.03), and overall survival (OS; OR = 1.08, 95% CI: 0.93-1.26, P = 0.28). Concerning safety, there was no significant difference between the HF and CF regimens in terms of breast pain, breast atrophy, lymphedema, pneumonia, pulmonary fibrosis, telangiectasia, and cardiotoxicity. However, the HF regimen resulted in lower skin toxicity (OR = 0.43, 95% CI: 0.33-0.55, P < 0.01) and improved patient fatigue outcomes (OR = 0.73, 95% CI: 0.60 - 0.88, P < 0.01).

CONCLUSIONS

Although there is no substantial difference in LR, DFS, OS, or many other side effects between the HF and CF regimens, the HF regimen reduces skin toxicity and relieves patient fatigue. If these two issues need to be addressed in clinical situations, the HF regimen may be a superior alternative to conventional radiotherapy in postoperative breast cancer patients.

Optimizing Clinical Implementation of Hypofractionation: Comprehensive Evidence Synthesis and Practical Guidelines for Low- and Middle-Income Settings

The global cancer burden, especially in low- and middle-income countries (LMICs), worsens existing disparities, amplified by the rising costs of advanced treatments. The shortage of radiation therapy (RT) services is a significant issue in LMICs. Extended conventional treatment regimens pose significant challenges, especially in resource-limited settings. Hypofractionated radiotherapy (HRT) and ultra-hypofractionated/stereotactic body radiation therapy (SBRT) offer promising alternatives by shortening treatment durations. This approach optimizes the utilization of radiotherapy machines, making them more effective in meeting the growing demand for cancer care. Adopting HRT/SBRT holds significant potential, especially in LMICs. This review provides the latest clinical evidence and guideline recommendations for the application of HRT/SBRT in the treatment of breast, prostate, and lung cancers. It emphasizes the critical importance of rigorous training, technology, stringent quality assurance, and safety protocols to ensure precise and secure treatments. Additionally, it addresses practical considerations for implementing these treatments in LMICs, highlighting the need for comprehensive support and collaboration to enhance patient access to advanced cancer care.

Lymphovascular invasion is a significant risk factor for non-sentinel nodal metastasis in breast cancer patients with sentinel lymph node (SLN)-positive breast cancer: a cross-sectional study

BACKGROUND

A connection between lymphovascular invasion and axillary lymph node metastases in breast cancer has been observed, but the findings are inconsistent and primarily based on research in Western populations. We investigated the association between lymphovascular invasion and non-sentinel lymph node (non-SLN) metastasis in breast cancer patients with sentinel lymph node (SLN) metastasis in western China.

METHODS

This study comprised 280 breast cancer patients who tested positive for SLN through biopsy and subsequently underwent axillary lymph node dissection (ALND) at The People's Hospital of Guangxi Zhuang Autonomous Region between March 2013 and July 2022. We used multivariate logistic regression analyses to assess the association between clinicopathological characteristics and non-SLN metastasis. Additionally, we conducted further stratified analysis.

RESULTS

Among the 280 patients with positive SLN, only 126 (45%) exhibited non-SLN metastasis. Multivariate logistic regression demonstrated that lymphovascular invasion was an independent risk factor for non-SLN in breast cancer patients with SLN metastasis (OR = 6.11; 95% CI, 3.62-10.32, p < 0.05). The stratified analysis yielded similar results.

CONCLUSIONS

In individuals with invasive breast cancer and 1-2 positive sentinel lymph nodes, lymphovascular invasion is the sole risk factor for non-SLN metastases. This finding aids surgeons and oncologists in devising a plan for local axillary treatment, preventing both over- and undertreatment.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Contralateral breast radiation doses in breast cancer patients treated with helical tomotherapy

We aimed to evaluate contralateral breast doses calculated with a Treatment Planning System (TPS) and verified with metal oxide semiconductor field effect transistor (MOSFET) detectors in patients with early-stage breast cancer (BC) who received helical tomotherapy (HT) after breast-conserving surgery. The dosimetric data of 30 patients (15 left-sided and 15 right-sided) with BC treated with 50.4 Gy to the whole breast and 64.4 Gy to the tumor bed in 28 fractions were analyzed. TPS doses were calculated and MOSFET doses were measured in the contralateral breast (CB) at cranial, caudal, and midpoint and 2 cm lateral to the central point. TPS and MOSFET doses were compared in the entire cohort as well as by tumor location (inner vs outer quadrant) and planning target volume of the breast (<1200 cc vs ≥1200 cc). The average doses at superior, inferior, central, and lateral points calculated with the TPS were 0.26 ± 0.15 cGy, 0.21 ± 0.09 cGy, 0.65 ± 0.14 cGy, and 0.50 ± 0.11 cGy, respectively, and were 0.37 ± 0.16 cGy, 0.34 ± 0.12 cGy, 0.60 ± 0.18 cGy, and 0.34 ± 0.15 cGy, respectively in MOSFET readings. Except for the central point, TPS-calculated doses and MOSFET readings were differed. The doses to the CB in patients with inner and outer quadrant tumors were not significantly different. In patients with large breasts, MOSFET doses were higher at superior and lateral points than TPS doses, but TPS doses were greater at inferior points. MOSFET readings were higher than TPS calculated doses in patients with inner or outer quadrant tumors in small or large breast volumes. The dose calculated by the TPS and that measured by MOSFET differed by a very small amount. The maximum dose to the CB administered at the midpoint was 1.8 Gy, as calculated using the TPS and confirmed using MOSFET detectors, in patients with early-stage BC undergoing breast-only radiotherapy with HT.

Quantitative evaluation of radiation-induced metabolic changes in the ipsilateral breast by FDG-PET/CT

Background and aim

There are no reports of quantitative evaluation of metabolic changes in the mammary gland after radiation therapy. The purpose of this study was to investigate metabolic changes in the ipsilateral mammary gland after radiation therapy and to evaluate the late radiation effects.

Patients and methods

Metabolic changes of the ipsilateral and contralateral mammary glands were retrospectively evaluated by F-18 fluorodeoxyglucose (FDG) PET/CT after whole breast irradiation following lumpectomy in five breast cancer patients. The maximum standardized uptake values (SUVmax) of the ipsilateral mammary gland (S1) and the contralateral mammary gland (S0) were measured. The relative SUVmax (= S1/S0) was measured immediately before, one year after, three years after, and five years after radiation therapy.

Results

The SUVmax of the ipsilateral mammary gland decreased gradually, but there was no decrease in the SUVmax of the contralateral mammary gland. Relative SUVmax values before, 1, 3, and 5 years after radiation therapy were 1.33 ± 0.20, 1.13 ± 0.35, 0.99 ± 0.26 and 0.62 ± 0.10, respectively. Relative SUVmax value at 5 years was significantly lower than before radiation therapy (P < 0.01).

Conclusions

18F-FDG PET/CT may be useful in assessing mammary gland function and predict lactation disorders in advance.

Effectiveness of hypofractionated and normofractionated radiotherapy in a triple‐negative breast cancer model

Breast cancer (BC) is one of the most diagnosed malignant carcinomas in women with a triple-negative breast cancer (TNBC) phenotype being correlated with poorer prognosis. Fractionated radiotherapy (RT) is a central component of breast cancer management, especially after breast conserving surgery and is increasingly important for TNBC subtype prognosis. In recent years, moderately hypofractionated radiation schedules are established as a standard of care, but many professionals remain skeptical and are concerned about their efficiency and side effects. In the present study, two different triple-negative breast cancer cell lines, a non-malignant breast epithelial cell line and fibroblasts, were irradiated daily under normofractionated and hypofractionated schedules to evaluate the impact of different irradiation regimens on radiation-induced cell-biological effects. During the series of radiotherapy, proliferation, growth rate, double-strand DNA break-repair (DDR), cellular senescence, and cell survival were measured. Investigated normal and cancer cells differed in their responses and receptivity to different irradiation regimens, indicating cell line/cell type specificity of the effect. At the end of both therapy concepts, normal and malignant cells reach almost the same endpoint of cell count and proliferation inhibition, confirming the clinical observations in the follow-up at the cellular level. These result in cell lines closely replicating the irradiation schedules in clinical practice and, to some extent, contributing to the understanding of growth rate or remission of tumors and the development of fibrosis.