Comparison of hypofractionated and conventionally fractionated whole-breast irradiation for early breast cancer patients: a single-institute study of 1,098 patients

Dosimetric Correlation of Acute Radiation Dermatitis in Patients With Breast Cancer Undergoing Hypofractionated Proton Beam Therapy Using Pencil Beam Scanning

PURPOSE

Pencil-beam scanning (PBS) is a modern delivery technique used in proton beam therapy (PBT) to reduce normal tissue reactions. No dosimetric correlation between dermatitis and PBS has been reported for breast cancer. The current study aimed to investigate the factors associated with grade 2 or higher dermatitis in patients with breast cancer undergoing PBT using PBS.

METHODS

The medical data of 42 patients with breast cancer who underwent adjuvant radiotherapy between December 2019 and September 2023 were reviewed. All patients received hypofractionated radiotherapy (HFRT), either 26 Gy (relative biological effectiveness [RBE])/five fractions or 40.05 or 43.5 Gy (RBE)/15 fractions, for the whole breast/chest wall with or without nodal irradiation. The duration of acute radiation dermatitis was defined as within 90 days from the start of radiotherapy. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate analyses of the actuarial rates of grade 2-3 dermatitis.

RESULTS

Twenty-two (52.4%) and 20 (47.6%) patients were diagnosed with grade 1 and 2 dermatitis, respectively. Multivariate analysis revealed a clinical target volume (CTV) ≥ of 320 cc (p = 0.035) and a skin dose of D10cc ≥ 38.3 Gy (RBE) (p = 0.009) as independent factors of grade 2 dermatitis. The 10-week cumulative grade 2 dermatitis rates were 88.2%, 39.4%, and 8.3% (p < 0.001) for patients with both high, either high, and neither high CTV and D10cc, respectively.

CONCLUSION

To the best of our knowledge, this is the first study on dosimetric correlations for dermatitis in patients with breast cancer who underwent hypofractionated PBT using PBS. In the era of HFRT, skin dose modulation using PBS may reduce the incidence of dermatitis.

Dosimetry and Toxicity Outcomes in Patients Treated with Hypofractionated Regional Nodal Irradiation for Breast Cancer: What is the Best Dose-Volume Limit to Minimize Risks of Radiation Pneumonitis?

PURPOSE

Although published data have supported the use of hypofractionated regional nodal irradiation (HF-RNI) for breast cancer, limited dosimetric data exist to evaluate predictors of lung toxicity. The ongoing RT CHARM trial limits the percentage of ipsilateral lung volume that receives ≥18 Gy to 35 to 40%. We assessed dosimetry, toxicity, and disease outcomes in patients with breast cancer treated with HF-RNI with a particular focus on pneumonitis.

METHODS AND MATERIALS

We retrospectively reviewed all patients with breast cancer treated with HF-RNI (40-43 Gy in 15-16 fractions) after either lumpectomy or mastectomy at The University of Pittsburgh Medical Center from September 2018 to December 2021 to collect dosimetric and outcomes data. All post-radiation therapy chest computed tomography (CT) scans were manually reviewed for evidence of acute (≤6 months postradiation) or chronic (>6 months postradiation) pneumonitis.

RESULTS

One-hundred-ninety-one patients qualified with a median follow-up of 20.3 months (range, 5.1-42.2). Acute grade 1 (G1) pneumonitis was observed in 6.8% of the overall cohort (13 of 191 patients) and 39.4% of the patients (13 of 33) who received a chest CT ≤6 months postradiation therapy. Only 1 patient developed acute G2 pneumonitis. Chronic G1 pneumonitis was observed in 29.8% of the overall cohort (57 of 191 patients) and 77% of patients (57 of 74 patients) who received a chest CT >6 months postradiation therapy. No patients developed acute G3+ or chronic G2+ pneumonitis.

CONCLUSIONS

Rates of symptomatic pneumonitis were low in this cohort of patients treated with HF-RNI, even with integration of HER2/neu-directed therapy, chemotherapy, hormone therapy, and internal mammary nodal irradiation. Lung V20Gy <26% appeared safe in this cohort to limit symptomatic pneumonitis, though this is not meant to represent the safe upper limit. Given the low event rate of symptomatic pneumonitis, data from larger cohorts will be needed to assess dosimetric predictors and the safe upper limit of lung dose.

Cost-effectiveness of Post-Mastectomy Radiotherapy (PMRT) for breast cancer in India: An economic modelling study

Background

The role of post-mastectomy radiotherapy (PMRT) for breast cancer is controversial when 3-or-less lymph nodes are metastatic. Apart from local control, survival and toxicity, cost also plays an important role in decision-making.

Methods

A Markov model was designed to assess cost, health outcomes and cost-effectiveness of different radiotherapy techniques for management of PMRT patients. Thirty-nine scenarios were modelled based on type of radiotherapy, laterality, pathologic nodal burden, and dose fractionation. We considered a societal perspective, lifetime horizon and a 3% discount rate. The data on quality of life (QoL) was derived using the cancer database on cost and QoL. Published data on cost of services delivered in India were used.

Findings

Post-mastectomy radiotherapy results in incremental quality adjusted life years (QALYs) that ranged from -0.1 to 0.38 across different scenarios. The change in cost ranged from estimated median savings of USD 62 (95% confidence intervals: -168 to -47) to incurring an incremental cost of USD 728 (650-811) across different levels of nodal burden, breast laterality and dose fractionation. For women with node-negative disease, disease-specific systemic therapy remains to be the preferred strategy. For women with node-positive disease, two-dimensional radiotherapy (2DRT) with hypofractionation is the most cost-effective strategy. However, a CT based planning is preferred when maximum heart distance (MHD) >1cm, irregular chest wall contour and inter-field separation >18cm.

Interpretation

PMRT is cost-effective for all node-positive patients. With similar toxicity and effectiveness profile compared with conventional fractionation, moderate hypofractionation significantly reduces the cost of treatment and should be the standard of care. Conventional techniques for PMRT are cost-effective over newer modalities which provide minimal additional benefit, at high cost.

Funding

The funding to collect primary data for study was provided by Department of Health Research, Ministry of Health and Family Welfare, New Delhi, wide letter number F. No. T.11011/02/2017-HR/3100291.

Comparative effectiveness and toxicity of radiotherapy regimens in limited stage small cell lung cancer: A network meta-analysis

PURPOSE

The aim of this Network Meta-analysis was to compare the current radiotherapy regimens of limited-stage small cell lung cancer (LS-SCLC), in terms of overall survival (OS), progression-free survival (PFS), and the incidence of acute radioactive esophagitis and radioactive pneumonia.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were comprehensively searched until January 2022. The studies were included, comparing radiotherapy regimens in LS-SCLC patients. We compared hypofractionated radiotherapy (HypoTRT), hyperfractionated radiotherapy (HyperTRT), and conventionally fractionated radiotherapy (ConvTRT1(<60 Gy), ConvTRT2(≥60 Gy)).

RESULTS

There was similar efficacy among the contemporary radiotherapy regimens for PFS of LS-SCLC. HypoTRT and HyperTRT significantly improved the OS of LS-SCLC compared with ConvTRT1 (<60 Gy), while not improving the OS of LS-SCLC compared with ConvTRT2 (≥60 Gy). There was no significant difference between HypoTRT and HyperTRT, between ConvTRT1(<60 Gy) and ConvTRT2(≥60 Gy), respectively. HyperTRT developed the highest odds of acute radioactive esophagitis compared to ConvTRT1(<60 Gy) and ConvTRT2(≥60 Gy). There was no significant difference in the incidence of acute radioactive esophagitis between HypoTRT and HyperTRT, ConvTRT1(<60 Gy), ConvTRT2(≥60 Gy), respectively and between ConvTRT1 and ConvTRT2. There was no statistically significant difference among radiotherapy regimens for the incidence of acute radioactive pneumonia.

CONCLUSION

The current radiotherapy regimens are similar in efficacy and toxicity for LS-SCLC, except for ConvTRT1(<60 Gy). Given the lower costs and convenient logistics management of HypoTRT comparatively, it is an acceptable alternative for LS-SCLC.

Risk Factors Related to Acute Radiation Dermatitis in Breast Cancer Patients After Radiotherapy: A Systematic Review and Meta-Analysis

Background

Acute radiation dermatitis (ARD) is the most common acute response after adjuvant radiotherapy in breast cancer patients and negatively affects patients’ quality of life. Some studies have reported several risk factors that can predict breast cancer patients who are at a high risk of ARD. This study aimed to identify patient- and treatment-related risk factors associated with ARD.

Methods

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and WanFang literature databases were searched for studies exploring the risk factors in breast cancer patients. The pooled effect sizes, relative risks (RRs), and 95% CIs were calculated using the random-effects model. Potential heterogeneity and sensitivity analyses by study design, ARD evaluation scale, and regions were also performed.

Results

A total of 38 studies composed of 15,623 breast cancer patients were included in the analysis. Of the seven available patient-related risk factors, four factors were significantly associated with ARD: body mass index (BMI) ≥25 kg/m² (RR = 1.11, 95% CI = 1.06–1.16, I² = 57.1%), large breast volume (RR = 1.02, 95% CI = 1.01–1.03, I² = 93.2%), smoking habits (RR = 1.70, 95% CI = 1.24–2.34, I² = 50.7%), and diabetes (RR = 2.24, 95% CI = 1.53–3.27, I² = 0%). Of the seven treatment-related risk factors, we found that hypofractionated radiotherapy reduced the risk of ARD in patients with breast cancer compared with that in conventional fractionated radiotherapy (RR = 0.28, 95% CI = 0.19–0.43, I² = 84.5%). Sequential boost and bolus use was significantly associated with ARD (boost, RR = 1.91, 95% CI = 1.34–2.72, I² = 92.5%; bolus, RR = 1.94, 95% CI = 1.82–4.76, I² = 23.8%). However, chemotherapy regimen (RR = 1.17, 95% CI = 0.95–1.45, I² = 57.2%), hormone therapy (RR = 1.35, 95% CI = 0.94–1.93, I² = 77.1%), trastuzumab therapy (RR = 1.56, 95% CI = 0.18–1.76, I² = 91.9%), and nodal irradiation (RR = 1.57, 95% CI = 0.98–2.53, I² = 72.5%) were not correlated with ARD. Sensitivity analysis results showed that BMI was consistently associated with ARD, while smoking, breast volume, and boost administration were associated with ARD depending on study design, country of study, and toxicity evaluation scale used. Hypofractionation was consistently shown as protective. The differences between study design, toxicity evaluation scale, and regions might explain a little of the sources of heterogeneity.

Conclusion

The results of this systematic review and meta-analysis indicated that BMI ≥ 25 kg/m² was a significant predictor of ARD and that hypofractionation was consistently protective. Depending on country of study, study design, and toxicity scale used, breast volume, smoking habit, diabetes, and sequential boost and bolus use were also predictive of ARD.

Ipsilateral breast tumor control following hypofractionated and conventional fractionated whole-breast irradiation for early breast cancer: a long-term follow-up

PURPOSE

Long-term follow-up of Japanese women with breast cancer who underwent hypofractionated whole-breast irradiation (HF-WBI) has not been well documented. Therefore, we compared the treatment results of HF-WBI and conventional fractionated (CF)-WBI.

METHODS

Patients with stage 0-II breast cancer receiving partial mastectomy were eligible for this prospective observational study. The HF-WBI consisted of 43.2 Gy in 16 fractions to the whole breast, with an additional tumor-bed boost of 8.1 Gy in three fractions for patients with positive or less than 5 mm surgical margins. A total of 615 patients (400: HF-WBI and 215: CF-WBI) who were treated between 2006 and 2008 were investigated. Propensity score matching was conducted based on age, tumor grade, and margin status, and 372 matched cases were investigated for examining factors relating to intrabreast tumor recurrence (IBTR).

RESULTS

With a median follow-up period of 9.4 years, age and margin status were independent factors associated with IBTR occurrence (P = 0.006 and 0.016, respectively). The 10-year ipsilateral breast tumor control (IBTC) rates after HF-WBI and CF-WBI were 96.5% and 95.3%, respectively (P = 0.606). The 10-year IBTC rates according to margin status were 88.0% with positive margins, 94.9% with 5 mm margins, and 98.0% with negative margins (P = 0.014).

CONCLUSIONS

There was no difference in IBTC between CF-WBI and HF-WBI in our patients. Positive surgical margin was a risk factor independently associated with IBTC rates after CF-WBI and HF-WBI. Further investigation is required to establish adequate treatment strategies for patients with positive surgical margins.

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.

Tumor Resection Margin Definitions in Breast-Conserving Surgery: Systematic Review and Meta-analysis of the Current Literature

Worldwide, various guidelines recommend what constitutes an adequate margin of excision for invasive breast cancer or for ductal carcinoma-in-situ (DCIS). We evaluated the use of different tumor resection margin guidelines and investigated their impact on positive margin rates (PMR) and reoperation rates (RR). Thirteen guidelines reporting on the extent of a positive margin were reviewed along with 31 studies, published between 2011 and 2016, reporting on a well-defined PMR. Studies were categorized according to the margin definition. Pooled PMR and RR were determined with random-effect models. For invasive breast cancer, most guidelines recommend a positive margin of tumor on ink. However, definitions of reported positive margins in the clinic vary from more than focally positive to the presence of tumor cells within 3 to 5 mm from the resection surface. Within the studies analyzed (59,979 patients), pooled PMRs for invasive breast cancer ranged from 9% to 36% and pooled RRs from 77% to 99%. For DCIS, guidelines vary between no DCIS on the resection surface to DCIS cells found within a distance of 2 mm from the resection edge. Pooled PMRs for DCIS varied from 4% to 23% (840 patients). Given the differences in tumor margin definition between countries worldwide, quality control data expressed as PMR or RR should be interpreted with caution. Furthermore, the overall definition for positive resection margins for both invasive disease and DCIS seems to have become more liberal.

ACCELERATED REGIMENS OF ADJUVANT RADIOTHERAPY IN THE TREATMENT OF BREAST CANCER

Treatment of breast cancer (BC) is a complex multidisciplinary problem. Often, radiation therapy is an obligatory component of treatment of breast cancer patients. Numerous large randomized trials have proved the efficacy of adjuvant radiotherapy in both the standard fractionation regimen in a single focal dose of 2 Gy to a total focal dose of 50 Gy for 25 fractions and in modes of hypofractionation using radiation exposure at a larger daily dose with a reduction in the total treatment time. The presented review summarizes the data of the largest studies on the modes of hypofractionation of postoperative radiotherapy for breast cancer. Most of the studies comparing the standard mode of fractionation of postoperative radiotherapy with the modes of hypofractionation showed comparable results for the main oncological parameters with similar tolerability, frequency of complications and good cosmetic results. It also shows the economic feasibility of applying accelerated regimes in everyday practice. Despite the fact that radiotherapy in the mode of hypofractionation has already become the standard of treatment and is recommended for use by the largest European and American cancer associations, indications for its conduct, the criteria for selection in the studies and the range of recommended single focal doses differ. The obtained results do not give an opportunity to confidently judge the advantage of one or another regime. It is necessary to determine the factors of a favorable and unfavorable prognosis, to clarify the indications for the use of various radiotherapy techniques. Therefore, questions about the optimal mode of hypo-fractionation of adjuvant radiotherapy, the timing of its initiation and the criteria for selecting patients for this type of therapy as part of the comprehensive treatment of breast cancer have not yet been fully resolved. Also open is the choice of optimal single and total doses of radiation, its combination with drug therapy.

Hypofractionated boost after whole breast irradiation in breast carcinoma: chronic toxicity results and cosmesis

PURPOSE

To evaluate the impact of hypofractionated boost after hypofractionated whole breast irradiation in breast carcinoma.

METHODS AND MATERIALS

Patients after breast conservative surgery were treated all time with hypofractionation of 2.67 Gy/day. Whole breast dose was 40.05 Gy followed in case of risk of local relapse by a boost of 16.02 Gy or 8.01 Gy. Acute and chronic toxicity results were evaluated including cosmetic software-assisted assessment and objective evaluation of fibrosis parameters (elasticity and hydration) by means of a skin tester.

RESULTS

A total of 362 patients were evaluated. Acute toxicities comprised grade 1 dermatitis in 48.1 %, grade 2 in 44.5 % and grade 3 in 17 patients 4.7 %, respectively. After a median follow-up of 4.5 years, in 308 cases (86.6 %) there was no chronic skin or subcutaneous changes. In the first consecutive 50 patients, measures with skin tester showed no statistical differences in parameters for skin and subcutaneous fibrosis. Cosmetic results were considered excellent and good in 26 and 62 %, respectively.

CONCLUSIONS

Boost to tumour bed with hypofractionated doses is well tolerated and acute and chronic toxicities are mild with good cosmetic results. Objective systems are encouraging methods to assess skin quality and cosmesis.

Impact of hypofractionation and tangential beam IMRT on the acute skin reaction in adjuvant breast cancer radiotherapy

Background

The purpose of the study was to evaluate the impact of multiple prognostic factors on the acute skin reaction in adjuvant breast cancer radiotherapy, in particular the impact of hypofractionation (HF) compared to conventional fractionation (CF) and tangential beam (TB) IMRT compared to three-dimensional conformal radiotherapy (3DCRT).

Methods

Two-hundred and sixty-six breast cancer patients with postoperative radiotherapy after breast conserving surgery or mastectomy were retrospectively evaluated. Patients were treated with HF (15 fractions of 2.67 Gy; n = 121) or CF (28 fractions of 1.8 Gy or 25 fractions of 2.0 Gy; n = 145) and TB-IMRT (n = 151) or 3DCRT (n = 115). The acute skin reactions were prospectively assessed using the CTCAE v4 grading scale. Ordinal regression analysis was used to assess the impact of possible prognostic factors on the maximal acute skin reaction.

Results

Grade 2 skin reactions were observed in 19 % of the patients treated with CF compared to 2 % treated with HF. On univariate analysis, the fractionation regimen, the PTV (breast versus chest wall), the volume of the PTV and the body mass index were significant prognostic factors for the maximum acute skin reaction. On multivariate analysis, the fractionation regimen (p < 0.00001) and the volume of the PTV (p = 0.0002) remained as independent significant factors.

Conclusions

Our data suggest that HF is associated with a significantly reduced maximal acute skin reaction compared to CF.

Use of hypofractionated post-mastectomy radiotherapy reduces health costs by over $2000 per patient: An Australian perspective

INTRODUCTION

The most recent clinical practice guidelines released by Cancer Australia draw attention to unanswered questions concerning the health economic considerations associated with hypofractionated radiotherapy. This study aimed to quantify and compare the healthcare costs at a regional Australian radiotherapy institute with respect to conventionally fractionated post-mastectomy radiotherapy (Cf-PMRT) versus hypofractionated post-mastectomy radiotherapy (Hf-PMRT) administration.

METHODS

Medical records of 196 patients treated with post-mastectomy radiotherapy at the NSW North Coast Cancer Institute from February 2008 to June 2014 were retrospectively reviewed. Australian Medicare item numbers billed for patients receiving either Cf-PMRT of 50 Gy in 25 daily fractions or Hf-PMRT of 40.05 Gy in 15 daily fractions were calculated. Decision tree analysis was used to model costs. Independent-samples t-tests and Mann-Whitney U-tests were used to compare crude average costs for Cf-PMRT and Hf-PMRT and determine which treatment components accounted for any differences.

RESULTS

Hf-PMRT, with or without irradiation to the regional lymph nodes, was associated with significantly reduced Medicare costs ($5613 AUD per patient for Hf-PMRT vs $8272 AUD per patient for Cf-PMRT; P < 0.001). Savings associated with Hf-PMRT ranged from $1353 (22.1%) for patients receiving no regional irradiation to $2898 (32.0%) for patients receiving both axillary and supraclavicular therapy.

CONCLUSIONS

Hf-PMRT results in a significant reduction in the financial costs associated with treating breast cancer patients in a regional Australian setting when compared with Cf-PMRT.

Systematic review and meta-analysis comparing hypofractionated with conventional fraction radiotherapy in treatment of early breast cancer

BACKGROUND

The purpose of this meta-analysis is to evaluate the efficacy and safety of altered radiation fraction size on outcomes for early breast cancer patients.

METHODS

A search of MEDLINE, EMBASE, WEB OF SCIENCE, Cochrane Library and ClinicalTrials.gov was conducted. Quality of the randomized controlled trials (RCTs) or non-RCTs were evaluated according to Cochrane's risk of bias tool or Methodological Index for non-Randomized Studies (MINORS). Pooled risk ratio (RR) and 95% confidence interval (CI) were calculated. Subgroup analysis was applied according to different fraction dose and sensitivity analysis was performed according to RCTs or non-RCTs.

RESULTS

23 studies were included in this systematic review. Meta-analysis demonstrated hypofractionation radiotherapy (HFRT) was associated with decreased grade 2/3 acute skin reactions compared with conventional fraction RT (CFRT), either 2.5-3.0 Gy per fraction or 5.0-6.5 Gy per fraction. HFRT with 2.5-3.0 Gy per fraction significantly decreased moderate/marked photographic changes in breast appearance compared with CFRT [RR = 0.80, 95% CI (0.70, 0.91), P = 0.001], while HFRT with more than 3.0 Gy per fraction significantly increased moderate/marked photographic changes [RR = 1.21, 95% CI (1.06, 1.38), P = 0.004]. In addition HFRT cost one-third lower than CFRT. Regarding to local regional recurrence, distant metastasis, overall survival, disease free survival, excellent/good cosmetic comes, symptomatic radiation pneumonitis, ischemic heart disease and symptomatic rib fracture, there was no significant difference between two arms.

CONCLUSIONS

Based on available evidence, HFRT with 2.5-3.0 Gy per fraction should be the better choice for treatment of early breast cancer patients.