Effect of radiotherapy after mastectomy and axillary surgery on 10-year recurrence and 20-year breast cancer mortality: meta-analysis of individual patient data for 8135 women in 22 randomised trials

Personalized Deep Learning Model for Clinical Target Volume on Daily Cone Beam Computed Tomography in Breast Cancer Patients

Purpose

Herein, we developed a deep learning algorithm to improve the segmentation of the clinical target volume (CTV) on daily cone beam computed tomography (CBCT) scans in breast cancer radiation therapy. By leveraging the Intentional Deep Overfit Learning (IDOL) framework, we aimed to enhance personalized image-guided radiation therapy based on patient-specific learning.

Methods and Materials

We used 240 CBCT scans from 100 breast cancer patients and employed a 2-stage training approach. The first stage involved training a novel general deep learning model (Swin UNETR, UNET, and SegResNET) on 90 patients. The second stage used intentional overfitting on the remaining 10 patients for patient-specific CBCT outputs. Quantitative evaluation was conducted using the Dice Similarity Coefficient (DSC), Hausdorff Distance (HD), mean surface distance (MSD), and independent samples t test with expert contours on CBCT scans from the first to 15th fractions.

Results

IDOL integration significantly improved CTV segmentation, particularly with the Swin UNETR model (P values < .05). Using patient-specific data, IDOL enhanced the DSC, HD, and MSD metrics. The average DSC for the 15th fraction improved from 0.9611 to 0.9819, the average HD decreased from 4.0118 mm to 1.3935 mm, and the average MSD decreased from 0.8723 to 0.4603. Incorporating CBCT scans from the initial treatments and first to third fractions further improved results, with an average DSC of 0.9850, an average HD of 1.2707 mm, and an average MSD of 0.4076 for the 15th fraction, closely aligning with physician-drawn contours.

Conclusion

Compared with a general model, our patient-specific deep learning-based training algorithm significantly improved CTV segmentation accuracy of CBCT scans in patients with breast cancer. This approach, coupled with continuous deep learning training using daily CBCT scans, demonstrated enhanced CTV delineation accuracy and efficiency. Future studies should explore the adaptability of the IDOL framework to diverse deep learning models, data sets, and cancer sites.

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.

Comparative Analysis of Dosimetry: IMRT versus 3DCRT in Left-Sided Breast Cancer Patients with Considering Some Organs in Out - of - Field Borders

Purpose

The local management approach for node-positive breast cancer has undergone substantial evolution. Consequently, there exists a pressing need to enhance our treatment strategies by placing greater emphasis on planning and dosimetric factors, given the availability of more conformal techniques and delineation criteria, achieving optimal goals of radiotherapy treatment. The primary aim of this article is to discuss how the extent of regional nodal coverage influences the choice between IMRT and 3D radiation therapy for patients.

Patients and Methods

A total of 15 patients diagnosed with left breast cancer with disease involved lymph nodes were included in this study. Delivering the recommended dose required the use of a linear accelerator (LINAC) with photon beams energy of 6 mega voltage (6MV). Each patient had full breast radiation using two planning procedures: intensity-modulated radiotherapy (IMRT) and three-dimensional radiotherapy (3D conformal). Following the guidelines set forth by the Radiation Therapy Oncology Group (RTOG), the planned treatment coverage was carefully designed to fall between 95% and 107% of the recommended dose. Additionally, Dose Volume Histograms (DVHs) were generated the dose distribution within these anatomical contours.

Results and Conclusion

The DVH parameters were subjected to a comparative analysis, focusing on the doses absorbed by both Organs at Risk (OARs) and the Planning Target Volume (PTV). The findings suggest that low doses in IMRT plan might raise the risk of adverse oncological outcomes or potentially result in an increased incidence of subsequent malignancies. Consequently, the adoption of inverse IMRT remains limited, and the decision to opt for this therapy should be reserved for situations where it is genuinely necessary to uphold a satisfactory quality of life. Additionally, this approach helps in reducing the likelihood of developing thyroid problems and mitigates the risk of injuries to the supraclavicular area and the proximal head of the humerus bone.

Optimal management of breast cancer with physical exam negative/radiological abnormal axilla

For breast cancer patients with physical exam node negative but radiological finding node abnormal (cN0/rNa), the NCCN and ASCO guidelines recommend sentinel lymph node biopsy (SLNB) as the first-line axillary staging. However, patients who undergo surgery firstly may be upstaged to pathological II-III status, and these patients happen to be the adaptive population of neoadjuvant therapy (NAT). There is no consensus on the optimal management of cN0/rNa patients. The aim is to explore the optimal management strategy of these patients. We performed a retrospective real-world study of 1414 cN0/rNa patients from June 2014 to October 2022. There were 1003 patients underwent surgery first and 411 patients underwent surgery after NAT. We analyzed the real-world conditions of these patients, compared axilla tumor burden between these two groups. In addition, we compared benefit ratio of axillary surgery and regional nodal irradiation (RNI) de-escalation under the two strategies. Among 1003 patients underwent surgery first, the positive and negative rates of fine needle aspiration (FNA) were 18.5% and 81.5%, respectively. There were 66.1% had ≤ 2 lymph nodes+. There were 40.8% of FNA+ patients could be exempted from ALND underwent surgery first. In 411 patients underwent surgery after NAT, the FNA positive and negative rates were 60.8% and 49.2%, respectively. There were 54.4% of FNA+ patients achieved axilla pathologic complete response (apCR) and could omit ALND after NAT. The apCR was 67.3% in HER2+/TNBC subtypes. According to the NSABP-B51 trial, there were 0 and 54.4% of FNA+ patients could omit RNI among surgery first and after NAT, respectively. Among 1-2 sentinel lymph node (SLN)-positive patients underwent surgery first, with a median follow-up 49 months, there was no difference of survival benefit between SLNB-only and SLNB-ALND. Compared with 1-2 SLN+ patients without RNI, RNI could bring better invasive disease-free survival (97.38% vs. 89.36%, P = 0.046) and breast cancer special survival (100% vs. 94.68%, P = 0.020). It is safe to perform SLNB omitting ALND when detected 1-2 positive SLNs in cN0/rNa patients. Patients with HER2+/TNBC subtypes underwent surgery after NAT had more chance to benefit from dual de-escalation, including axillary surgery and RNI de-escalation.

Pre-operative chemoradiotherapy followed by mastectomy and breast reconstruction-A systematic review of clinical, oncological, reconstructive and aesthetic outcomes

BACKGROUND

Pre-operative radiotherapy (PRT) and pre-operative chemoradiotherapy (PCRT) prior to mastectomy and immediate breast reconstruction for locally advanced breast cancer have the potential to reduce radiation late-effects and expedite oncologic treatment. Recent feasibility work indicates that PCRT is safe and technically possible. Here, we present a systematic review of currently available data on clinical, oncological, reconstructive and aesthetic outcomes.

METHODS

A prospectively registered search of Medline (Ovid), EMBASE (Ovid), EMCARE (Ovid) and CINAHL (EBSCO) databases was performed in August 2023. Clinical, oncological, reconstructive and aesthetic outcomes were appraised with risk of bias (ROBINS-I) and methodological quality determined (STROBE checklist) for each study.

RESULTS

Twenty-two published articles (19 journal articles and 3 abstracts) were identified reporting the outcomes of 1258 patients with median follow-up between 19.0-212.4 months. Patients received neoadjuvant chemotherapy in 20 studies. Rates of locoregional recurrence and overall survival ranged between 0-21.7% and 82.0%-98.3% respectively. Rates of flap loss or necrosis ranged from 0-7.6%. Rates of revisional procedures ranged between 1.9-35.3%. Patient-reported outcomes were reported in 7 studies and were mostly 'good' or 'excellent'.

CONCLUSION

PRT and PCRT preceding mastectomy and breast reconstruction produce acceptable oncological outcomes with rates of surgical complication and reconstructive outcomes within normal limits, however, the majority of available studies are of low methodological quality and at high risk of bias. A pragmatic randomised trial comparing PRT versus PMRT in the setting of breast reconstruction is now urgently required to guide surgical practice.

Estimated Doses to the Heart, Lungs and Oesophagus and Risks From Typical UK Radiotherapy for Early Breast Cancer During 2015-2023

PURPOSE

Breast cancer radiotherapy can increase the risks of heart disease, lung cancer and oesophageal cancer. At present, the best dosimetric predictors of these risks are mean doses to the whole heart, lungs and oesophagus, respectively. We aimed to estimate typical doses to these organs and resulting risks from UK breast cancer radiotherapy.

METHODS

A systematic review and meta-analysis was conducted of planned or delivered mean doses to the whole heart, lungs or oesophagus from UK breast cancer radiotherapy in studies published during 2015-2023. Average mean doses were summarised for combinations of laterality and clinical targets. Heart disease and lung cancer mortality risks were then estimated using established models.

RESULTS

For whole heart, thirteen studies reported 2893 doses. Average mean doses were higher in left than in right-sided radiotherapy and increased with extent of clinical targets. For left-sided radiotherapy, average mean heart doses were: 2.0 Gy (range 1.2-8.0 Gy) breast/chest wall, 2.7 Gy (range 0.6-5.6 Gy) breast/chest wall with either axilla or supraclavicular nodes and 2.9 Gy (range 1.3-4.7 Gy) breast/chest wall with nodes including internal mammary. For right-sided radiotherapy, average mean heart doses were: 1.0 Gy (range 0.3-1.0 Gy) breast/chest wall and 1.2 Gy (range 1.0-1.4 Gy) breast/chest wall with either axilla or supraclavicular nodes. There were no whole heart dose estimates from right internal mammary radiotherapy. For whole lung, six studies reported 2230 doses. Average mean lung doses increased with extent of targets irradiated: 2.6 Gy (range 1.4-3.0 Gy) breast/chest wall, 3.0 Gy (range 0.9-5.1 Gy) breast/chest wall with either axilla or supraclavicular nodes and 7.1 Gy (range 6.7-10.0 Gy) breast/chest wall with nodes including internal mammary. For whole oesophagus, two studies reported 76 doses. Average mean oesophagus doses increased with extent of targets irradiated: 1.4 Gy (range 1.0-2.0 Gy) breast/chest wall with either axilla or supraclavicular nodes and 5.8 Gy (range 1.9-10.0 Gy) breast/chest wall with nodes including internal mammary.

CONCLUSIONS

The typical doses to these organs may be combined with dose-response relationships to estimate radiation risks. Estimated 30-year absolute lung cancer mortality risks from modern UK breast cancer radiotherapy for patients irradiated when aged 50 years were 2-6% for long-term continuing smokers, and <1% for non-smokers. Estimated 30-year mortality risks for heart disease were <1%.

Underuse of Postoperative Radiation After Nipple-Sparing Mastectomy for Standard Radiation Indications

Purpose

Nipple areola complex-sparing surgeries, such as nipple-sparing mastectomy (NSM), are increasingly used for women with early-stage breast cancer. In the postoperative setting, 2 major indications for postoperative radiation (PORT) with/without regional nodal irradiation (RNI) are: positive margins (margin+) and pathologically involved lymph nodes (pN+). The frequency of these adverse pathologic features and the rate of PORT utilization following NSM for these 2 indications are unknown. We determined the frequency of margin+ and pN+ following NSM compared with nipple-sparing lumpectomy/breast-conserving surgery [BCS] and identified trends in appropriate PORT administration for these standard indications in the NSM setting.

Methods and Materials

Using the National Cancer Database (NCDB), women diagnosed with cT1 to cT3,N0M0 invasive carcinoma between 2004 and 2017 who underwent NSM were compared with those who underwent BCS (with nipple preservation). The frequencies of margin+ and pN+ by surgical subtype and use of PORT with/without RNI were assessed by cohort to determine if the type of surgery was associated with radiation delivery. Overall survival between the 2 cohorts was also compared. We performed univariable/multivariable logistic and Cox regression with ORs to control for confounders.

Results

Of 624,075 women included, 611,907 underwent BCS, and 12,168 underwent NSM. The surgical margin+ rate was significantly higher for NSM at 4.5% (n = 544) than for BCS at 3.7% (n = 22,449) (P < .001) and remained significant on multivariable analysis (MVA; OR, 1.13; CI, 1.03-1.25; P = .012). Use of PORT for margins+ was significantly lower by MVA after NSM (OR, 0.07; CI, 0.06-0.09; P < .001). Similarly, pN+ rate was significantly higher for NSM at 22.5% (n = 2740) versus BCS at 13.5% (n = 82,288) (P < .001), retaining significance on MVA (OR, 1.12; CI, 1.06-1.19; P < .001). For pN+ undergoing NSM, PORT with RNI was delivered significantly less often on MVA (OR, 0.73; CI, 0.67-0.81; P < .001). Neither high-risk subgroup had differences in overall survival on MVA.

Conclusions

NSM is associated with a higher rate of margin+ and pN+ compared with BCS. Radiation is underused after NSM for these standard indications. Our results highlight the need to further refine patient selection for NSM and the importance of communicating the higher potential for adverse pathologic features (and thus, the potential need for radiation) to patients undergoing NSM.

Impact of immediate breast reconstruction on perioperative therapy: insights from a Japanese Nationwide Registry

BACKGROUND

Immediate breast reconstruction (IBR) is a common oncoplastic procedure used in breast cancer surgery. This study aims to investigate compliance with prosthetic breast reconstruction guidelines and its impact on perioperative treatment.

METHODS

We reviewed data from the National Clinical Database-Breast Cancer Registry between January 2019 and December 2020. We compared perioperative treatment implementation between the IBR and non-IBR groups by subtype matching for age, menopausal status, T stage, N stage, and histology.

RESULTS

A total of 8,860 patients with breast cancer who underwent IBR (6,075 breast prostheses, 2,492 autologous tissues, and 293 others) were identified. The compliance rate with the guidelines for prosthetic breast reconstruction was 97.7%. After matching, chemotherapy for luminal A-like diseases was significantly less frequent in the IBR group than in the non-IBR group (16.3% vs 20.5%, p < 0.001), and radiotherapy was less frequent in luminal A-like and HER2-positive patients (7.2% vs 9.0%, p = 0.010 and 7.1% vs 11.4%, p = 0.005, respectively). Among the 1-3 node-positive cases, fewer patients with prosthetic IBR received radiotherapy than those without IBR (15.7% vs 26.4%, p < 0.001).

CONCLUSION

Prosthetic breast reconstruction was performed with strict adherence to the Japanese guidelines. The implementation rates of chemotherapy and radiotherapy were lower in the specific IBR group than those in the non-IBR group. Therefore, large-scale, long-term follow-up data are required.

Cancer therapy-related cardiac dysfunction after radiation therapy for breast cancer: results from the BACCARAT cohort study

BACKGROUND

Radiation therapy (RT) for breast cancer (BC) can result in subtle cardiac dysfunction that can occur early after treatment. In 2022, the European Society of Cardiology (ESC) published the first guidelines in cardio-oncology with a harmonized definition of cancer therapy-related cardiac dysfunction (CTRCD). The aim of this study was to evaluate CTRCD occurrence over 24 months of follow-up after RT in BC patients and to analyze the association with cardiac radiation exposure.

METHODS

The prospective monocentric BACCARAT study included BC patients treated with RT without chemotherapy, aged 40-75 years, with conventional and 2D Speckle tracking echocardiography performed before RT, 6 and 24 months after RT. Based on ESC cardio-oncology guidelines, CTRCD and corresponding severity were defined with left ventricle ejection fraction and global longitudinal strain decrease, occurring at 6 or 24 months after RT. Dosimetry for whole heart, left ventricle (LV) and left coronary artery (left anterior descending and circumflex arteries (CX)) was considered to evaluate the association with CTRCD, based on logistic regressions (Odds Ratio - OR and 95% confidence interval - 95%CI). Youden index based on receiver operating characteristic curve analysis was used to identify the optimal threshold of dose-volume parameters for predicting CTRCD.

RESULTS

The study included 72 BC patients with a mean age of 58 ± 8.2 years. A total of 32 (44%) patients developed CTRCD during follow-up: 20 (28%) mild CTRCD, 7 (9%) moderate CTRCD, and 5 (7%) severe CTRCD. Cardiac radiation doses were generally higher among patients with CTRCD rather than non-CTRCD. Dose-response relationships were significant for mean CX dose (OR = 2.48, 95%CI (1.12-5.51), p = 0.02) and marginally significant for V2 of LV (OR = 1.03 95%CI (1.00-1.06), p = 0.05). V2 of LV ≥ 36% and mean CX dose ≥ 1.40 Gy thresholds were determined to be optimal for predicting CTRCD.

CONCLUSION

For BC patients treated with RT without chemotherapy, CTRCD can be observed in an important proportion of the population over 24 months after treatment. Left ventricle and circumflex coronary artery exposure were found to be associated with CTRCD and could be used for the prediction of such cardiotoxicity. Further research remains needed to confirm these results.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier- NCT02605512.

Residual breast tissue after mastectomy and reconstruction: A substudy of the Spatial location of breast cancer local rECurRence aftEr masTectomy (SECRET) project

The current project is part of the Spatial location of breast cancer local rECurRence aftEr masTectomy (SECRET) study (NCT06130111). Herein we compared the chest wall thickness after non-skin sparing mastectomy (non-SSM) with the chest wall thickness after SSM, as a surrogate for residual breast tissue after mastectomy.

METHODS

The study was approved by the ethics committee of relevant institutions. Data of patients with a local recurrence (LR) after non-SSM was collected from the Netherlands Cancer Registry (NCR); data of patients undergoing SSM were collected from Sheba Medical Center. Student's t-test was used to evaluate the difference between the cohorts. Chest wall thickness was measured on postoperative images.

RESULTS

Out of 4949 patients who underwent mastectomy from the NCR cohort, a total of 173 (3.5 %) had a LR at 5 years, of these a total of 153 patients included in the non-SSM cohort. The median age was 59 years (age 33-92), LR occurred at a median of 23.6 months (2.5-60 months). The SSM cohort included 84 patients, with a median age of 38.4 years (28-63.5), overall, 5 LRs occurred at a median of 15 months (5-46 months). The SSM cohort had significantly thicker chest walls compared to non-SSM (p < 0.001). Most LRs in both groups occurred in the subcutis.

CONCLUSION

The chest wall thickness differed according to mastectomy procedures. Most of the LR occurred at the subcutis. The role of residual breast tissue and residual cancer in relation to type of mastectomy should be further investigated.

Effects of Exercise on Cancer-Related Fatigue in Breast Cancer Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The primary objective of this study was to assess the influence of exercise interventions on cancer-related fatigue (CRF), specifically in breast cancer patients, with the ultimate goal of establishing an optimal exercise prescription for breast cancer patients. A comprehensive search was undertaken across multiple databases, including Embase, PubMed, Cochrane Library, Web of Science, and Scopus, covering data published up to 1 September 2023. A meta-analysis was conducted to calculate the standardized mean difference (SMD) along with its corresponding 95% confidence interval (CI), thereby quantifying the effectiveness of exercise in alleviating CRF in the breast cancer patient population. Twenty-six studies met the inclusion criteria. Aerobic exercise (SMD, -0.17, p = 0.02), resistance exercise (SMD, -0.37, p = 0.0009), and combined exercise (SMD, -0.53, p < 0.0001) significantly improved CRF in breast cancer patients. In addition, exercise intervention conducted ≥3 times per week (SMD, -0.47, p = 0.0001) for >60 min per session (SMD, -0.63, p < 0.0001) and ≥180 min per week (SMD, -0.79, p < 0.0001) had greater effects on improving CRF in breast cancer patients, especially middle-aged patients (SMD, -0.42, p < 0.0001). Exercise is an effective approach to improving CRF in breast cancer patients. When devising an exercise program, the primary consideration should be the incorporation of combined exercise as the principal intervention. This entails ensuring that participants engage in the program at least three times weekly, with each session lasting for more than 60 min. The ultimate aim is to achieve a total weekly exercise duration of 180 min by progressively increasing the frequency of exercise sessions.

A nomogram and risk stratification system for predicting survival in T1-2N0-1 breast cancer patients with liver metastasis in females: a population-based study

PURPOSE

Liver was one of the most common distant metastatic sites in breast cancer. Patients with distant metastasis were identified as American Joint Committee on Cancer (AJCC) stage IV indicating poor prognosis. However, few studies have predicted the survival in females with T1-2N0-1 breast cancer who developed liver metastasis. This study aimed to explore the clinical features of these patients and establish a nomogram to predict their overall survival.

RESULTS

1923 patients were randomly divided into training (n = 1154) and validation (n = 769) cohorts. Univariate and multivariate analysis showed that age, marital status, race, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), chemotherapy, surgery and bone metastasis, brain metastasis were considered the independent prognostic indicators. We developed a nomogram according to these ten parameters. The consistency index (c-index) was 0.72 (95% confidence interval CI 0.70-0.74) in the training cohort, 0.72 (95% CI 0.69-0.74) in the validation cohort. Calibration plots indicated that the nomogram-predicted survival was consistent with the recorded 1-, 3- and 5-year prognoses. Decision curve analysis curves in both the training and validation cohorts demonstrated that the nomogram showed better prediction than the AJCC TNM (8th) staging system. Kaplan Meier curve based on the risk stratification system showed that the low-risk group had a better prognosis than the high-risk group (P < 0.001).

CONCLUSIONS

A predictive nomogram and risk stratification system were constructed to assess prognosis in T1-2N0-1 breast cancer patients with liver metastasis in females. The risk model established in this study had good predictive performance and could provide personalized clinical decision-making for future clinical work.

Dosimetric and radiobiological advantages from deep inspiration breath-hold and free breath technique for left-sided breast radiation using 3DCRT, IMRT and Rapid Arc methods-a complete assessment

The verification and use of the best treatment approach using 3D conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and Rapid Arc methods for left breast radiation with dosimetric and radiobiological characteristics. The use of custom-built Python software for the estimation and comparison of volume, mean dose, maximum dose, monitor units and normal tissue integral dose along with radiobiological parameters such as NTCP, tumor control probability, equivalent uniform dose and LKB's effective volume from 3DCRT, IMRT and Rapid Arc planning with deep inspiration with breath holding (DIBH) and free breadth (FB) techniques. Volume growth of three-fourth in DIBH compared with FB causes a decrease in cardiac doses and complications because the left lung expands, pulling the heart away from the chest wall and the treatment area. A tiny area of the left lung was exposed during treatment, which reduced the mean dose. There was little difference in the treatment approaches because the spinal cord was immobile in both techniques. Rapid Arc is the unmatched modality for left-sided breast irradiation with significant patient breath-hold, as shown by the comparison of dosimetric and radiobiological parameters from treatment techniques with a deep inspiration breath-hold approach.

Hypofractionated vs Conventionally Fractionated Postmastectomy Radiation After Implant-Based Reconstruction: A Randomized Clinical Trial

Importance

Postmastectomy radiation therapy (PMRT) improves local-regional disease control and patient survival. Hypofractionation (HF) regimens have comparable efficacy and complication rates with improved quality of life compared with conventional fractionation (CF) schedules. However, the use of HF after mastectomy in patients undergoing breast reconstruction has not been prospectively examined.

Objective

To compare HF and CF PMRT outcomes after implant-based reconstruction.

Design, Setting, and Participants

This randomized clinical trial assessed patients 18 years or older undergoing mastectomy and immediate expander or implant reconstruction for breast cancer (Tis, TX, or T1-3) and unilateral PMRT from March 8, 2018, to November 3, 2021 (median [range] follow-up, 40.4 [15.4-63.0] months), at 16 US cancer centers or hospitals. Analyses were conducted between September and December 2023.

Interventions

Patients were randomized 1:1 to HF or CF PMRT. Chest wall doses were 4256 cGy for 16 fractions for HF and 5000 cGy for 25 fractions for CF. Chest wall toxic effects were defined as a grade 3 or higher adverse event.

Main Outcomes and Measures

The primary outcome was the change in physical well-being (PWB) domain of the Functional Assessment of Cancer Therapy-Breast (FACT-B) quality-of-life assessment tool at 6 months after starting PMRT, controlling for age. Secondary outcomes included toxic effects and cancer recurrence.

Results

Of 400 women (201 in the CF arm and 199 in the HF arm; median [range] age, 47 [23-79] years), 330 patients had PWB scores at baseline and at 6 months. There was no difference in the change in PWB between the study arms (estimate, 0.13; 95% CI, -0.86 to 1.11; P = .80), but there was a significant interaction between age group and study arm (P = .03 for interaction). Patients younger than 45 years had higher 6-month absolute PWB scores if treated with HF rather than CF regimens (23.6 [95% CI, 22.7-24.6] vs 22.0 [95% CI, 20.7-23.3]; P = .047) and reported being less bothered by adverse effects (mean [SD], 3.0 [0.9] in the HF arm and 2.6 [1.2] in the CF arm; P = .02) or nausea (mean [SD], 3.8 [0.4] in the HF arm and 3.6 [0.8] in the CF arm; P = .04). In the as-treated cohort, there were 23 distant (11 in the HF arm and 12 in the CF arm) and 2 local-regional (1 in the HF arm and 1 in the CF arm) recurrences. Chest wall toxic effects occurred in 39 patients (20 in the HF arm and 19 in the CF arm) at a median (IQR) of 7.2 (1.8-12.9) months. Fractionation was not associated with chest wall toxic effects on multivariate analysis (HF arm: hazard ratio, 1.02; 95% CI, 0.52-2.00; P = .95). Fewer patients undergoing HF vs CF regimens had a treatment break (5 [2.7%] vs 15 [7.7%]; P = .03) or required unpaid time off from work (17 [8.5%] vs 34 [16.9%]; P = .02).

Conclusions and Relevance

In this randomized clinical trial, the HF regimen did not significantly improve change in PWB compared with the CF regimen. These data add to the increasing experience with HF PMRT in patients with implant-based reconstruction.

Trial Registration

ClinicalTrials.gov Identifier: NCT03422003.

Revisiting surgical margins for invasive breast cancer patients treated with breast conservation therapy - Evidence for adopting a 1 mm negative width

Clinical trials have demonstrated conclusively the non-inferiority of breast-conserving surgery followed by breast radiation therapy (BCT) compared with mastectomy for the treatment of early-stage invasive breast cancer (BC). The definition of the required surgical margin to ensure adequate removal of the cancer by BCT to obtain an acceptable low local recurrence (LR) rate remains controversial. Meta-analyses published by Houssami et al. in 2010 and 2014 demonstrated significantly lower LR rates for patients with a negative margin compared with those with positive (ink on tumour) or close (defined as ≤1 mm or ≤2 mm) margins. Neither meta-analysis addressed whether 'no ink on tumour' was adequate to define a negative margin because of a lack of data. Nevertheless, in 2014, the Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO) with advice from pathologists reviewed these data together and published guidelines recommending that a margin of 'no ink on tumour' was sufficient to define a clear margin in BCT. Subsequently, clinical practice has varied with some national and international bodies endorsing 'no ink on tumour', whilst others have recommended a ≥1 mm margin as acceptable margins for BCT. A more recent meta-analysis conducted by Bundred and colleagues in 2022 did have sufficient data to compare 'no ink on tumour' and 1 mm and concluded that 1 mm rather than 'no ink on tumour', should be used as a minimum negative margin, and recommended that international guidelines be revised. The current review presents a balanced assessment of the evidence relating margin width and local recurrence after BCT. This review concludes that guidelines should consider re-defining a negative margin as ≥1 mm rather than 'no ink on tumour' in the context of BCT, recognising there will be variation to tailor therapy for any individual patient situation to ensure optimal patient care.

Palliative Radiotherapy for Symptomatic Primary Tumors in Patients With Locally Advanced Breast Cancer

Breast cancer remains a significant health concern for women, with a significant number of women facing unresectable, symptomatic, and advanced disease that severely affects their quality of life. Palliative radiotherapy (RT) is a well-established modality for managing such cases and alleviating symptoms. Recent advancements in systemic therapies and the resulting increase in long-term survival rates have not only heightened the need for retreatment in certain patients, but have also emphasized the importance of achieving durable local control. Additionally, inconsistencies in RT referral timing and variations in disease severity and extent contribute to diverse RT objectives and expected outcomes. The optimal dose fractionation for RT remains underexplored. Furthermore, a deeper understanding of breast radiobiology, along with the introduction of ultra- and moderately hypofractionated regimens and the widespread adoption of conformal techniques such as intensity-modulated RT, has diversified the approaches in RT dose and target volume. This review aimed to provides a comprehensive summary of the current evidence on the efficacy, outcomes, and toxicity profiles of palliative RT for symptomatic breast cancer. It highlights the need for more optimized regimens and further research to address the evolving treatment landscape and differing expectations of patients and physicians regarding RT.

General analysis of breast cancer patients tested for BRCA mutations and evaluation of acute radiotherapy toxicity

OBJECTIVE

The objective of our study is to evaluate breast cancer patients with BRCA1 or BRCA2 gene mutations and compare them with patients without these mutations. Specifically, we aim to assess the acute side effects of radiotherapy in both groups.

METHODS

Data were collected from four participating centers, comprising information from 73 patients who underwent known mutation analysis and had complete data. Patients were monitored on a weekly basis throughout their treatment for acute toxicity, which was evaluated using the Radiation Therapy Oncology Group (RTOG) acute toxicity criteria.

RESULTS

The median age of the 73 patients included in our study was 43. Among them, 17 had BRCA1-positive mutations and 19 had BRCA2-positive mutations. Invasive ductal carcinoma was present in 67 patients, all of whom underwent surgery. Of the patients, 57 received conventional radiotherapy doses, while 16 received hypofractionated radiotherapy doses. During follow-up, metastasis occurred in three patients. In BRCA-positive patients, those under 40 years of age (p<0.001), with high nodal positivity (p=0.008), grade 2-3 (p=0.022), and lymphovascular invasion (p=0.002) were significantly more frequent compared to BRCA-negative patients (p<0.001). The median survival was 35.8 months. Grade 1 dysphagia developed in seven BRCA-negative patients and four BRCA-positive patients, with no significant difference observed between the two groups (p=0.351). There was also no statistical difference observed in the occurrence of grade 2-3 skin reactions, with 11 BRCA-negative patients and eight BRCA-positive patients experiencing these side effects.

CONCLUSION

Our study supports existing literature by identifying an association between the presence of BRCA mutations and young age, nodal status, grade, and lymphovascular invasion. Additionally, we found no significant difference in the occurrence of radiotherapy toxicity between BRCA-positive and BRCA-negative patients. These findings suggest that radiotherapy can be safely administered to BRCA-positive patients after breast-conserving surgery or mastectomy. Keywords for our study include breast cancer, BRCA mutation, radiotherapy, and side effects.

Interpretable deep learning insights: Unveiling the role of 1 Gy volume on lymphopenia after radiotherapy in breast cancer

BACKGROUND

Lymphopenia is known for its significance on poor survivals in breast cancer patients. Considering full dosimetric data, this study aimed to develop and validate predictive models for lymphopenia after radiotherapy (RT) in breast cancer.

MATERIAL AND METHODS

Patients with breast cancer treated with adjuvant RT were eligible in this multicenter study. The study endpoint was lympopenia, defined as the reduction in absolute lymphocytes and graded lymphopenia after RT. The dose-volume histogram (DVH) data of related critical structures and clinical factors were taken into account for the development of dense neural network (DNN) predictive models. The developed DNN models were validated using external patient cohorts.

RESULTS

A total of 918 consecutive patients with invasive breast cancer enrolled. The training, testing, and external validating datasets consisted of 589, 203, and 126 patients, respectively. Treatment volumes at nearly all dose levels of the DVH were significant predictors for lymphopenia following RT, including volumes at very low-dose 1 Gy (V1) of organs at risk (OARs) including lung, heart and body, especially ipsilateral-lung V1. A final DNN model, combining full DVH dosimetric parameters of OARs and three key clinical factors, achieved a predictive accuracy of 75 % or higher.

CONCLUSION

This study demonstrated and externally validated the significance of full dosimetric data, particularly the volume of low dose at as low as 1 Gy of critical structures on lymphopenia after radiation in patients with breast cancer. The significance of V1 deserves special attention, as modern VMAT RT technology often has a relatively high value of this parameter. Further study is warranted for RT plan optimization.

Post-mastectomy radiation therapy after breast reconstruction: from historic dogmas to practical expert agreements based on a large literature review of surgical and radiation therapy considerations

Breast reconstruction (BR) after mastectomy is important to consider for a woman's body image enhancement and psychological well-being. Although post-mastectomy radiation (PMRT) significantly improves the outcome of patients with high-risk breast cancer (BC), PMRT after BR may affect cosmetic outcomes and may compromise the original goal of improving quality of life (QoL). With the lack of practical guidelines, it seems essential to work on a consensus and provide some "expert agreements" to offer patients the best option for PMRT after BR. We report a global "expert agreement" that results from a critical review of the literature on BR and PMRT during the 6th international multidisciplinary breast conference in March 2023.

Re-Evaluating the Omission of Radiation Therapy in Low-Risk Patients With Early-Stage Breast Cancer

Traditionally, management of early-stage breast cancer has required adjuvant radiation therapy following breast conserving surgery, due to decreased local recurrence and breast cancer mortality. However, over the past decade, there has been an increasing emphasis on potential overtreatment of patients with early-stage breast cancer. This has given rise to questions of how to optimize deintensification of treatment in this cohort of patients while maintaining clinical outcomes. A multitude of studies have focused on identification of a subset of patients with invasive breast cancer who were at low risk of local recurrence based on clinicopathologic features and therefore suitable for RT omission. These studies have failed to identify a subset that does not from RT with respect to local control. Several ongoing trials are evaluating alternative approaches to deintensification while focusing on tumor biology. With regards to ductal carcinoma in situ (DCIS), the role of RT has been questioned since breast conservation was utilized. Paralleling invasive disease studies, studies have sought to use clinicopathologic features to identify low risk patients suitable for RT omission but have failed to identify a subset that does not from RT with respect to local control. Use of new assays in patients with DCIS may represent the ideal approach for risk stratification and appropriate deintensification. At this time, when considering deintensification, individualizing treatment decisions with a focus on shared decision making is paramount.

RecurIndex-Guided postoperative radiotherapy with or without Avoidance of Irradiation of regional Nodes in 1-3 node-positive breast cancer (RIGAIN): a study protocol for a multicentre, open-label, randomised controlled prospective, phase III trial

INTRODUCTION

Postoperative radiotherapy in patients with breast cancer with one to three lymph node metastases, particularly within the pT1-2N1M0 cohort with a low clinical risk of local-regional recurrence (LRR), has incited a discourse surrounding personalised treatment strategies. Multigene testing for Recurrence Index (RecurIndex) model capably differentiates patients based on their level of LRR risk. This research aims to validate whether a more aggressive treatment approach can enhance clinical outcomes in N1 patients who possess a clinically low risk of LRR, yet a high RecurIndex-determined risk of LRR. Specifically, this entails postoperative whole breast irradiation combined with regional lymph node irradiation (RNI) following breast-conserving surgery or chest wall irradiation with RNI after mastectomy.

METHODS AND ANALYSIS

The RIGAIN (RecurIndex-Guided postoperative radiotherapy with or without Avoidance of Irradiation of regional Nodes in 1-3 node-positive breast cancer) Study is a multicentre, prospective, randomised, open-label, phase III clinical trial that is being conducted in China. In this study, patients with low clinical LRR risk but high RecurIndex-LRR risk are randomly assigned in a 1:1 ratio to the experimental group or the control group. In the experimental group, RNI is performed and the control group omits RNI. Efficacy and safety analyses will be conducted, enrolling a total of 540 patients (270 per group). The primary endpoint is invasive disease-free survival, and secondary endpoints include any first recurrence, LRR-free survival, distant metastasis-free survival, recurrence-free survival, overall survival, disease-free survival, breast cancer-specific mortality and assessment of patient quality of life. The study began in April 2023 and with a follow-up period of 60 months after the last participant completes radiation therapy.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University (SYSKY-2022-097-02, V.3.1). It adheres to the Helsinki Declaration and Good Clinical Practice. Research findings will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04069884.

Proton therapy reduces the effective dose to immune cells in breast cancer patients

BACKGROUND

The effective dose to circulating immune cells (EDIC) is associated with survival in lung and esophageal cancer patients. This study aimed to evaluate the benefit of intensity-modulated proton therapy (IMPT) for EDIC reduction as compared to volumetric modulated arc therapy (VMAT) in patients with locally advanced breast cancer (BC).

MATERIALS AND METHODS

Ten BC patients treated with locoregional VMAT after breast-conserving surgery were included. Mean dose to the heart (MHD), lungs (MLD), and liver (MlD), as well as the integral dose to the body (ITD), were retrieved, and we calculated EDIC as 0.12 × MLD + 0.08 × MHD + 0.15 × 0.85 × √(n/45) × MlD + (0.45 + 0.35 × 0.85 × √(n/45)) × ITD/(62 × 103), where n is the number of fractions. EDIC was compared between VMAT and IMPT plans.

RESULTS

Median EDIC was reduced from 3.37 Gy (range: 2.53-5.99) with VMAT to 2.13 Gy (1.31-3.77) with IMPT (p < 0.01). For left-sided BC patients, EDIC was reduced from 3.15 Gy (2.53-3.78) with VMAT to 1.65 Gy (1.31-3.77) with IMPT (p < 0.01). For right-sided BC patients, EDIC was reduced from 5.60 Gy (5.06-5.99) with VMAT to 3.38 Gy (3.10-3.77) with IMPT (p < 0.01). Right-sided BC patients had a higher EDIC irrespective of the technique. Integral dose reduction was the main driver of EDIC reduction with IMPT and was associated with lung sparing for left-sided BC patients or liver sparing for right-sided BC patients.

CONCLUSION

IMPT significantly reduced EDIC in BC patients undergoing locoregional adjuvant radiotherapy. Integral total dose reduction, associated with improved lung sparing in left-sided BC patients or liver sparing in right-sided BC patients, mainly drove EDIC reduction with IMPT. The emergence of dynamic models taking into account the circulatory kinetics of immune cells may improve the accuracy of the estimate of the dose received by the immune system compared to calculation of the EDIC, which is based solely on static dosimetric data.

Postoperative complications of hypofractionated and conventional fractionated radiation therapy in patients with implant-based breast reconstruction: A systematic review and meta-analysis

INTRODUCTION

Post-mastectomy radiation therapy is an important component of adjuvant therapy for high-risk patients. However, radiation to reconstructed breasts can cause various complications. Recently, hypofractionated (HF) protocols have been adopted in several countries. Here, we aimed to assess the impact of HF protocols on implant-reconstructed breasts through a meta-analysis and systematic review of the currently available literature.

METHODS

Records published until August 2023 were systematically searched in PubMed, Cochrane Library, and EMBASE databases. Keywords included hypofractionation radiotherapy, mastectomy, and breast reconstruction. Studies that utilized HF and conventional fractionation (CF) after prosthetic reconstruction were selected. Due to the rarity of events in outcomes, Mantel-Haenszel's odds ratios were calculated using a fixed-effect model to compare the complication rates between HF and CF groups. For analysis with high heterogeneity, a random effect model was used.

RESULTS

Seven articles with 924 implant reconstructions, in which 506 (54.8 %) underwent HF were included. HF patients received 43.8 Gy on average, while CF patients received 51.2 Gy. Mean follow-up ranged from 10.6 to 35 months. Seven studies were included in the meta-analysis. HF groups had a significantly lower risk of capsular contracture (OR 0.25, 95 % CI 0.11-0.55), major revision surgery (OR 0.19, 95 % CI 0.05-0.80), and wound dehiscence (OR 0.24, 95 % CI 0.07-0.78) compared to CF groups. The risks of other complications were not statistically significant.

CONCLUSION

This study indicates that HF protocols are associated with fewer complications than CF protocols in implant-reconstructed patients. These findings suggest that the application of HF PMRT in implant-reconstructed patients with breast cancer is plausible.

Neoadjuvant Reirradiation for Radiation Therapy-Associated Angiosarcoma of the Breast

PURPOSE

Radiation-associated angiosarcoma of the breast (RAASB) is a rare side effect after breast radiation and has been associated with poor outcomes. At this time, there is no consensus regarding management of RAASB, and the role of reirradiation remains controversial. We present our modern institutional outcomes in managing RAASB with incorporation of neoadjuvant hyperfractionated reirradiation.

METHODS AND MATERIALS

Patients identified were treated between 2016 and 2020 with inclusion of any histologically proven RAASB without metastatic disease at diagnosis, while excluding those with a history of radiation therapy outside of the breast/chest wall or other sarcoma histologies. Major wound complications were defined as requiring wound care and/or wound vacuum or return to the operating room for wound repair at any time after surgery.

RESULTS

Eight patients were identified, and the median follow-up was 34 months. Median time to RAASB development was 8 years from initial radiation therapy. With respect to RAASB management, all underwent surgery and neoadjuvant reirradiation therapy, and all but 1 patient received taxol-based chemotherapy. At last follow-up, 7 patients remained free of disease, and 1 patient died with distant disease. With respect to acute toxicity after reirradiation, all patients developed at least acute grade 2 toxicities. Five of the 8 patients developed a major wound complication.

CONCLUSIONS

Our institutional analysis suggests excellent local control and survival outcomes for RAASB treated with neoadjuvant hyperfractionated reirradiation, surgery, and taxol-based chemotherapy. However, major wound complications represent a major challenge with this approach. Future studies should consider how best to improve the therapeutic ratio while maintaining high rates of local control and survival.

A BRILLIANT-BRCA study: residual breast tissue after mastectomy and reconstruction

INTRODUCTION

Different types of mastectomies leave different amounts of residual breast tissue. The significance of the residual breast volume (RBV) is not clear. Therefore, we developed an MRI tool that allows to easily assess the RBV. In this study we evaluated factors associated with RBV after skin or nipple sparing mastectomy (SSM/NSM) in breast cancer BRCA pathogenic variant (PV) carriers who underwent both therapeutic and risk reducing SSM/NSM and its relation to breast cancer outcomes using an innovative MRI-based tool.

METHODS

Data of breast cancer BRCA PV who were treated between 2006 and 2020 were retrieved from of the oncogenetics unit databases. Only patients who underwent SSM/NSM and had a postoperative breast MRI available for analysis were included. Data collected included demographics, clinicopathological features, and outcomes. The MRI tool was developed by a breast cancer imaging laboratory. A logistic regression test and 95% confidence interval (CI) were used to assess the associated risk of increased RBV. A forward stepwise linear regression was used to correlate tumour-patient specific factors and RBV, and a Kaplan-Meier curve to show the probability of locoregional relapse.

RESULTS

A total of 84 patients undergoing 89 mastectomies were included. At a median follow-up of 98 months, 5 local, 2 regional, and 4 distant recurrences were observed. RBV was not significantly related with breast cancer outcomes (p value = NS). A higher body mass index (BMI) was associated with a higher RBV (p < 0.0001). A larger number of involved axillary nodes was associated with a smaller RBV (p = 0.025). The RBV on the risk-reducing mastectomy side was significantly higher compared to the breast cancer side (p value = 0.007). Local recurrences occurred in the vicinity of the primary tumour.

Post-Operative Radiation in Early Breast Cancer with N1 Disease: 10-Year Follow-Up

Post-operative radiotherapy for post-menopausal women with early breast cancer and N1 disease is controversial. Although locoregional control is improved, overall survival (OS) benefit is unclear. The clinical benefit of post-operative irradiation in this group of patients over 10 years was reviewed. We aimed to evaluate the OS, disease-free survival (DFS), and factors affecting OS and DFS. A retrospective review of 191 post-menopausal women with early breast cancer and N1 disease from 2004 to 2011 was performed. Demographics, post-operative histology, adjuvant treatment, OS, and DFS were evaluated. Post-operative radiation was given to 95 of 191 women (49.7%). Younger age at diagnosis (p < 0.001), a greater number of involved nodes (p = 0.004), lymphovascular invasion (LVI), and a higher tumor grade (p = 0.001) were more likely in women who received post-operative radiation. Nodal radiation did not improve 10-year DFS (p = 0.084) or OS (p = 0.203). Post-operative nodal radiation was associated with significant improvement in 10-year OS in women who received only hormonal therapy (p = 0.047) and no other systemic therapy. Women with unfavorable risk factors were more likely to receive post-operative radiation, likely due to a perceived higher risk of recurrence. Nodal radiation did not significantly improve 10-year DFS or OS in early breast cancer patients with N1 disease, and the benefit was not clearly demonstrated. However, in those who were on hormonal therapy, radiotherapy was beneficial in improving overall survival.

Hypofractionation for Regional Nodal Irradiation in Breast Cancer: Best of Both the Worlds

Locoregional radiotherapy play an important role in controlling the disease after surgery in patients with breast cancer. Radiotherapy schedules vary from conventional fraction to hypofractionation. The purpose of this review is to get an insight into the data on regional nodal irradiation (RNI) with hypofractionation in patients with breast cancer. This systematic review was constructed in accordance with Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) framework. Electronic databases such as PubMed, Cochrane and EMBASE were searched from January 1, 2023 to March 31, 2023 to identify studies published in English language on hypofractionated RNI in post mastectomy patients. The search was carried out with the National Library of Medicine's Medical Subject Heading (MeSH) terms like "regional nodal irradiation," "hypofractionated" and "hypofractionation in breast cancer" with different Boolean operators (and/or). A manual search of reference lists of included articles was also performed to make sure there were no additional cases unidentified from the primary search. Studies deemed potentially eligible were identified and assessed by same independent reviewers to confirm eligibility. RNI data are mainly from a randomized study from Beijing and pooled data from START trials. There are also data from retrospective and single institutional studies and a few phase II studies with limited number of patients using different dose fractionations and techniques of radiotherapy. Doses used in these trials ranged from 26-47.7 Gy in 5-19 fractions over 1-4 weeks. Grade ≥ 2 pulmonary fibrosis and lymphedema rate ranged from 2%-7.9% and 3%-19.8% respectively. Grade ≥ 2 shoulder dysfunction and brachial plexopathy ranged from 0.2%-28% and 0%-< 1%, respectively. Late effects with a dose range of 26-40 Gy delivered in 5 to 15 fractions over 1-3 weeks were less/similar to conventional fraction. Current data showed lower/similar rates of toxicity with hypofractionated RNI compared with conventional fractionation RNI. Doses of 26 Gy to 40 Gy delivered in 5 to 15 fractions over 1-3 weeks are safe for RNI. With limited data, ultra-hypofractionation 26 Gy/5 fractions/1 week also seems to be safe. However, long-term outcome is awaited and many trials are going on to address its efficacy and safety.

Assessment of Postmastectomy Radiation Therapy Receipt by Age and Association With Outcomes in Women With Breast Cancer

PURPOSE

Postmastectomy radiation therapy (PMRT) reduces locoregional recurrence (LRR) and improves overall survival (OS) in patients with breast cancer. Young age has been recognized as a risk factor for LRR. The primary objective of this study was to determine if recommendations for PMRT differed among patients younger than 50 years as compared to women aged 50 years or older.

METHODS

We reviewed medical records of patients with breast cancer who underwent mastectomy with or without PMRT from 2010 through 2018. Univariable and multivariable models were used to estimate the association of age with PMRT.

RESULTS

Of 2471 patients, 839 (34%) were <50 years; 1632 (66%) were ≥50 years. Patients <50 years had a higher percentage of grade 3 tumors, hormone receptor (HR) negative and/or Her-2/neu positive tumors, clinical stage T2/T3 tumors, and nodal involvement. Compared with patients ≥50 years, patients <50 years were more likely to undergo PMRT (OR 1.57; P = .001) and regional node irradiation (RNI) to the internal mammary nodes. Advanced clinical and pathologic stage, invasive tumor histology, the presence of lymphovascular invasion, and treatment with systemic chemotherapy were predictors of PMRT receipt for patients <50 years (P < .05). PMRT was associated with improved OS and recurrence free survival (RFS) among all patients (P < .01).

CONCLUSION

Patients <50 years were more likely to undergo PMRT and to receive RNI to the internal mammary nodes but were also more likely to have other risk factors for recurrence that would warrant a PMRT recommendation. PMRT improved OS and RFS for all patients.

Patient-Reported Outcomes and Complication Profiles of Implant-Based Breast Reconstruction in Patients With Postmastectomy Radiation Therapy

OBJECTIVE

This study aims to investigate the patient-reported outcomes (PROs) and complications of distinct implant-based breast reconstruction modality for patients with postmastectomy radiation therapy (PMRT).

METHODS

A retrospective review was conducted on breast cancer patients with stage II-III disease who performed implant-based breast reconstruction following with PMRT between September 2016 and April 2022. The patients were categorized into two matched groups: (1) patients receiving prepectoral breast reconstruction (PBR) or (2) subpectoral breast reconstruction (SBR) followed by PMRT. Following reconstruction, the patients were further compared for PMRT with the tissue expander (PMRT-TE) versus PMRT with permanent implant (PMRT-PI). PROs were measured with BREAST-Q questionnaire. Early and late complications were recorded and analyzed.

RESULTS

A total of 55 eligible patients were recruited. Patients who underwent PBR reported significantly higher satisfaction with breasts scores (P = 0.003) compared with the SBR group. The PMRT-TE group had higher satisfaction with breasts (P = 0.001) but lower physical well-being (P = 0.029) scores compared with PMRT-PI group. Moreover, patients in SBR cohort had a higher risk of capsular contracture (Baker grade III or IV) (20.5% vs 6.3%) and implant dislocation (48.7% vs 12.5%) than patients in PBR cohort. Patients in PMRT-PI group had a slightly higher rate of capsular contracture (Baker grade III or IV) than PMRT-TE group (20.8% vs 12.9%).

CONCLUSIONS

PBR was associated with lower rates of late complications, especially for implant dislocation, and higher satisfaction with breasts scores compared to SBR. In addition, compared to PMRT-TE with PMRT-PI, patients in PMRT-TE cohort reported superior PROs of satisfaction with breasts.

Implementation of ultra-hypofractionated radiotherapy schedules for breast cancer during the COVID-19 pandemic in the Netherlands

Background and purpose

The COVID-19 pandemic resulted in an accelerated recommendation to use five-fraction radiotherapy schedules, according to the FAST- and FAST-Forward trial. In this study, trends in the use of different radiotherapy schedules in the Netherlands were studied, as well as the likelihood of receiving five fractions.

Materials and methods

Data from the NABON Breast Cancer Audit-Radiotherapy and Netherlands Cancer Registry was used. Women receiving radiotherapy for their primary invasive breast cancer or DCIS between 01-01-2020 and 31-12-2021 were included. Logistic regression was used to investigate the association between patient-, tumour-, treatment-, and radiotherapy institution-related characteristics and the likelihood of receiving five fractions in tumours meeting the FAST and FAST-Forward criteria.

Results

Detailed information about radiotherapy treatment was available for 9,392 tumours. Shortly after the start of the COVID-19 pandemic, i.e. April 2020, 19% of the tumours being treated with radiotherapy received five fractions of 5.2 or 5.7 Gray (Gy). While only 3% of the tumours received five fractions in March 2020. The usage of five fractions increased to 26% in December 2021. Partial breast irradiation, compared to whole breast irradiation, was significantly associated with the administration of five fractions, as well as radiotherapy delivered in an academic radiotherapy institution compared to an independent institution.

Conclusion

The start of the COVID-19 pandemic was associated with the early use of ultra-hypofractionated radiotherapy schedules. After publication of the trials, and mainly after the recommendation by the national radiotherapy society, the implementation further increased. These schedules were not yet used in all patients meeting the eligibility criteria for the FAST- or FAST-Forward trial.

Breast Cancer Presenting With Intravascular Tumor Emboli in Axillary Soft Tissue: Recurrence Risk and Radiation Therapy Outcomes

Purpose

Intravascular tumor emboli in axillary soft tissue (ITE) is a rare pathologic finding in breast cancer and is associated with higher axillary nodal disease burden. The independent prognostic and predictive value of this entity is unknown, as is the role of radiation therapy for ITE.

Methods and Materials

We analyzed a prospectively maintained database of breast cancer patients treated from 1992 to 2020. Patients with ITE were matched to those without (1:2) based on propensity scores to control for potential confounding factors. Locoregional (LRR) and distant recurrence (DR) were evaluated using competing risks methods accounting for death as a competing event. Overall survival (OS) and disease-free survival (DFS) were evaluated by Cox regression models. Among patients with ITE, we also evaluated whether RT improved outcomes.

Results

Among 2377 total patients, 129 had ITE, of whom 126 were propensity score matched to 252 without ITE. Median follow-up from time of surgery was 5.5 years (IQR 2.3, 9.7). There were no statistically significant differences in the 5-year incidence of LRR between groups (5.4% [95% CI, 1.6%-13%] with ITE vs 10% [95% CI, 6.7%-15%] without, P = .53) or DR (24% [95% CI, 15% 35%] with ITE vs 21% [95% CI, 16%-27%] without, P = .51). Five-year OS and DFS did not differ between groups (P > .9 for both comparisons, patients with ITE vs without ITE). In analyzing the effect of RT among patients with ITE, receipt of RT was associated with significantly improved DFS (HR, 0.34, 95% CI, 0.12-0.93, P = .04).

Conclusions

Patients with ITE do not exhibit significantly worse LRR, DR, DFS, or OS compared with a propensity-score-matched cohort without ITE. However, among patients with ITE, those who received RT demonstrated significantly improved DFS. Larger studies with longer follow-up are needed to evaluate the prognostic and predictive implications of ITE.

Retrospective evaluation of the contribution of radiotherapy to survival in breast cancer treatment with propensity score based on stage and subgroup

BACKGROUND

Breast cancer has been a disease in which treatment strategy has changed over time under the influence of different hypotheses and evidence for more than a century. We analyzed the contribution of radiotherapy to disease-free survival and overall survival by classifying according to stage, 1-3 lymph node involvement, and molecular subgroups.

METHODS

Following the approval of the Institutional Review Board, records of patients with breast cancer who were admitted to University School of Medicine Departments of Radiation Oncology and Medical Oncology between July 1999 and December 2020 were reviewed. Using data propensity score matching was performed between the groups that did and did not receive radiotherapy using an optimal matching algorithm (optimum, 1:1). Disease-free survival and overall survival after propensity score matching were calculated using the Kaplan-Meier method. Univariate and multivariate Cox regression analysis was used to estimate hazard ratios.

RESULTS

In the radiotherapy and non-radiotherapy groups, disease-free survival was 257.42 ± 5.46 (246.72- 268.13), 208,96 ± 8,15 (192,97-224,94) months respectively, (p = < 0.001), overall survival was 272,46 ± 8,68 (255,43-289,49), 219,05 ± 7,32 (204,70-233,41) months respectively (p = .002). We compared the 19 N1 patient groups who received radiotherapy with the 19 patients who did not receive radiotherapy and calculated the disease-free survival times was 202,21 ± 10,50 (181,62-222,79) and 148,82 ± 24,91 (99,99-197,65) months respectively (p = .011) and overall survival times was 200,85 ± 12,79 (175,77-225,92) and 166,90 ± 20,39 (126,93-206,82) months respectively (p = .055). We examined disease-free survival and overall survival times in both groups according to Luminal A, Luminal B, TNBC, and HER2-enriched subgroups. In the Luminal B subgroup, the disease-free survival duration in the groups receiving radiotherapy and not receiving radiotherapy was 264.83 ± 4.95 (255.13-274.54) and 187.09 ± 11.06 (165.41-208.78) months (p < .001), and overall survival times were 252.29 ± 10.54 (231.62-272.97) and 197.74 ± 9.72 (178.69-216.80) months (p = .001) respectively.

CONCLUSIONS

Thanks to studies proving that RT increases long-term survival rates in breast cancer as a result of reducing locoregional recurrence and systemic metastasis rates, it has been understood that the spectrum hypothesis is the hypothesis that most accurately describes breast cancer to date. We found that patients with Luminal B invasive breast cancer benefited significantly more from RT compared to other subgroups.

Incidence of local breast cancer recurrence with delayed radiation therapy

BACKGROUND

The purpose of this research was to examine the probability of ipsilateral breast cancer recurrence in individuals whose RT was delayed after the first chemotherapy and surgery.

PURPOSE

To analyze the effect of delaying RT for breast cancer patients (by more than 6 weeks after treatment).

METHODOLOGY

A retrospective analysis comprised 136 female breast cancer patients treated at the Baghdad Centre for Radiation Oncology and Nuclear Medicine from 2021 to May 2022. External beam radiation was started more than 6 weeks after chemotherapy was finished for all patients who also had surgery. Clinical examination and ultrasound were part of the follow-up process.

RESULTS

Patients' ages varied from 28 to 71, and the majority (83%) had a mastectomy. The majority of cases (95.5%) were diagnosed as invasive ductal carcinoma on histopathology, with 49.6% being at stage 2 and 42.6% being at stage 3. Seventy-six percent of patients tested positive for hormones. Although 10 patients (7.35%) acquired distant metastases within 5 years, only 2 (1.47%) had local recurrence because of the delay in RT. Specifically, 91.1% had complete local control with no evidence of disease spread.

CONCLUSION

Delaying RT by more than 6 weeks in patients with breast cancer did not substantially affect local control, according to the results of a new research, the first of its type in Iraq.

Surface-guided radiotherapy systems in locoregional deep inspiration breath hold radiotherapy for breast cancer - a multicenter study on the setup accuracy

Background

Daily image-guided radiotherapy (IGRT) and deep inspiration breath hold (DIBH) technique are recommended for locoregional RT of breast cancer. The optimal workflow for a combination of surface-guided RT (SGRT) with DIBH technique is of current clinical interest.

Materials and methods

The setup accuracy at three hospitals was evaluated using different SGRT workflows. A total of 150 patients (2269 image pairs) were analyzed in three groups: patient setup with the AlignRT® SGRT system in Tampere (Site 1, n = 50), the Catalyst™ SGRT system in Turku (Site 2, n = 50) and the Catalyst™ SGRT system in Jönköping (Site 3, n = 50). Each site used their routine workflow with SGRT-based setup and IGRT positioning. Residual errors of the bony chest wall, thoracic vertebra (Th 1) and humeral head were evaluated using IGRT images.

Results

Systematic residual errors in the cranio-caudal (CC) direction and in pitch were generally larger at Site 2 than those at Sites 1 and 3 (p = 0.01-0.7). With daily IGRT, only a small difference (p = 0.01-0.9) was observed in residual random errors of bony structures in other directions between sites.

Conclusion

The introduction of SGRT and the use of daily IGRT lead to small residual errors when combining the best workflow practices from different hospitals. Our multicenter evaluation led to improved workflow by tightening the SGRT tolerances on Site 2 and fixation modification. Because of mainly small random errors, systematic posture errors in the images need to be corrected after posture correction with new setup surfaces. We recommend tight SGRT tolerances, good fixation and correction of systematic errors.

Clinical practicality and patient performance for surface-guided automated VMAT gating for DIBH breast cancer radiotherapy

BACKGROUND AND PURPOSE

To evaluate the performance of automated surface-guided gating for left-sided breast cancer with DIBH and VMAT.

MATERIALS AND METHODS

Patients treated in the first year after introduction of DIBH with VMAT were retrospectively considered for analysis. With automated surface-guided gating the beam automatically switches on/off, if the surface region of interest moved in/out the gating tolerance (±3 mm, ±3°). Patients were coached to hold their breath as long as comfortably possible. Depending on the patient's preference, patients received audio instructions during treatment delivery. Real-time positional variations of the breast/chest wall surface with respect to the reference surface were collected, for all three orthogonal directions. The durations and number of DIBHs needed to complete dose delivery, and DIBH position variations were determined. To evaluate an optimal gating window threshold, smaller tolerances of ±2.5 mm, ±2.0 mm, and ±1.5 mm were simulated.

RESULTS

525 fractions from 33 patients showed that median DIBH duration was 51 s (range: 30-121 s), and median 4 DIBHs per fraction were needed to complete VMAT dose delivery. Median intra-DIBH stability and intrafractional DIBH reproducibility approximated 1.0 mm in each direction. No large differences were found between patients who preferred to perform the DIBH procedure with (n = 21) and without audio-coaching (n = 12). Simulations demonstrated that gating window tolerances could be reduced from ±3.0 mm to ±2.0 mm, without affecting beam-on status.

CONCLUSION

Independent of the use of audio-coaching, this study demonstrates that automated surface-guided gating with DIBH and VMAT proved highly efficient. Patients' DIBH performance far exceeded our expectations compared to earlier experiences and literature. Furthermore, gating window tolerances could be reduced.

Anatomical assessment of local recurrence site in breast cancer patients after breast reconstruction and post-mastectomy radiotherapy: implications for radiation volumes and techniques

INTRODUCTION

Post-mastectomy radiotherapy (PMRT) improves local control rates and survival in patients with adverse prognostic features. The dose coverage to target volumes is critical to yield maximum benefit to treated patients, increasing local control and reducing risk of toxicity. This study aims to assess patterns of breast cancer relapse in patients treated with mastectomy, breast reconstruction and PMRT.

METHODS

Breast cancer patients treated with PMRT between 1992 and 2017 were retrospectively reviewed. Clinical and pathological characteristics of patients were collected. Recurrences were defined as "in field," "marginal" or "out of field." Survival analyses were performed in relation to progression-free survival (PFS) and overall survival (OS). Correlation between baseline features was explored.

RESULTS

Data of 140 patients are collected. After a median follow-up time of 72 months, median PFS and OS of 63 and 74 months were detected, respectively. Neoadjuvant chemotherapy, lympho-vascular space invasion (LVI) and size of primary tumor were all significantly associated with worst PFS and OS. Ten patients developed local recurrence: 30% "in field," 30% marginal recurrences, 20% "out of field" and 20% both "in field" and "out of field." No recurrence was detected under the expander, 80% above the device and 20% patients relapsed on IMN chain. The mean distant relapse-free survival was 39 months. Overall, 39 of 140 patients developed distant metastases.

CONCLUSIONS

The onset of local-regional relapses occurred mainly above the expander/prosthesis, underlying the importance of inclusion of the subcutaneous tissues within the target volume. In order to refine new contouring recommendations for PMRT and breast reconstruction, future prospective studies are needed.

Acute skin toxicity and self-management ability among Chinese breast cancer radiotherapy patients: a qualitative study

OBJECTIVES

Radiation dermatitis is the most common reaction to radiotherapy, almost all breast cancer patients receive radiotherapy on an outpatient basis. Currently, there are no studies on the experience of radiation dermatitis and the ability to self-manage it. Therefore, we aimed to use qualitative approaches to gain a deeper understanding of the actual experiences and self-management ability in order to provide a reference for further improving the effectiveness of self-management and to optimize symptom management strategies.

METHODS

A descriptive qualitative study was conducted using purposive sampling to select 17 breast cancer patients undergoing radiotherapy. Semi-structured interviews were conducted from September to November 2023. The Colaizzi seven-step analysis method was used to classify the data into summarized themes.

RESULTS

Four themes were identified from the interview responses: (1) multiple self-reported skin symptoms in breast cancer patients with radiation dermatitis; (2) the multidimensional impact on patient's quality of life, especially pruritus, ulceration; (3) the ability to self-manage radiation dermatitis: strong mental toughness, positive response, and self-doubt; (4) challenges faced: concerns about radiotherapy side effects and recurrence, targeted symptom management and continuity of care after the radiotherapy.

CONCLUSIONS

Healthcare professionals should consider patients' self-reported symptoms when assessing radiation dermatitis. For pruritus and pain, we can enhance precision symptom management to improve patients' quality of life. By utilizing information technology tools, we can increase breast cancer patients' ability and confidence in managing radiation dermatitis effectively while enhancing accurate symptom management during radiotherapy.

The impact of bolus on clinical outcomes for post-mastectomy breast cancer patients treated with IMRT: data from China

PURPOSE

This study aims to investigate the effects of chest wall bolus in intensity-modulated radiotherapy (IMRT) technology on clinical outcomes for post-mastectomy breast cancer patients.

MATERIALS AND METHODS

This retrospective study included patients with invasive carcinoma ((y)pT0-4, (y)pN0-3) who received photon IMRT after mastectomy at the Affiliated Hospital of Qingdao University from 2014 to 2019. The patients were divided into two groups based on whether they received daily bolus application or not, and the baseline characteristics were matched using propensity score matching (PSM). Cumulative incidence (CI) of local recurrence (LR), locoregional recurrence (LRR), overall survival (OS) and disease-free survival (DFS) were evaluated with a log-rank test. Acute skin toxicity and late radiation pneumonia was analyzed using chi-square test.

RESULTS

A total of 529 patients were included in this study, among whom 254 (48%) patients received bolus application. The median follow-up time was 60 months. After matching, 175 well-paired patients were selected. The adjusted 5-year outcomes (95% confidence interval) in patients treated with and without bolus were, respectively: CI of LR 2.42% (0.04-4.74) versus 2.38% (0.05-4.65), CI of LRR 2.42% (0.04-4.74) versus 3.59% (0.73-6.37), DFS 88.12% (83.35-93.18) versus 84.69% (79.42-90.30), OS 94.21% (90.79-97.76) versus 95.86% (92.91-98.91). No correlation between bolus application and skin toxicity (P = 0.555) and late pneumonia (P = 0.333) was observed.

CONCLUSIONS

The study revealed a low recurrence rate using IMRT technology. The daily used 5 mm chest wall bolus was not associated with improved clinical outcomes.

Determinants of radiation dose to immune cells during breast radiotherapy

BACKGROUND

The immune system has been identified as an organ at risk in esophageal and lung cancers. However, the dosimetric impact of radiotherapy on immune system exposure in patients treated for breast cancer has never been studied.

METHODS

A monocentric retrospective dosimetric study included 163 patients treated at the Institut Curie (Paris, France) between 2010 and 2016 with locoregional helical tomotherapy after conservative surgery or total mastectomy. The effective dose to the immune system (EDIC) was calculated based on diverse dosimetric parameters. The clinical and volumetric determinants of EDIC in adjuvant radiotherapy of breast cancer were analyzed.

RESULTS

The median EDIC for the population was 4.23 Gy, ranging from 1.82 to 6.19 Gy. Right-sided radiotherapy and regional lymph node irradiation were associated with significantly higher EDIC in univariate (4.38 Gy vs. 3.94 Gy, p < 0.01, and 4.27 Gy vs. 3.44 Gy, p < 0.01, respectively) and multivariate analyses (p < 0.01 and p < 0.01). Liver overexposure was the main contributor to EDIC increase in right-sided breast cancer patients (+0.38 Gy [95%CI: +0.30; +0.46]), while the integral total dose increase was the main contributor to EDIC increase in cases of regional node irradiation (+0.63 Gy [95%CI: +0.42; +0.85]).

CONCLUSION

The EDIC score during adjuvant radiotherapy after breast cancer was statistically significantly higher in the case of right-sided radiotherapy and regional lymph node irradiation. Liver irradiation is the main contributor to immune system exposure in adjuvant irradiation of right-sided breast cancer. Populations in which an association between EDIC and survival would exist have yet to be identified but could potentially include patients treated for triple-negative breast cancer with a poor response to neoadjuvant chemoimmunotherapy.

Modeling of a tissue expander with a radiofrequency identification port in postmastectomy radiation therapy planning

The purpose of this study was to evaluate the dose attenuation of Motiva Flora® (Flora, Establishment Labs, Alajuela, Costa Rica) tissue expander with a radiofrequency identification port locator and to develop a model for accurate postmastectomy radiation therapy planning. Dose attenuation was measured using an EBT3 film (Ashland, Bridgewater, NJ), and the optimal material and density assignment for the radiofrequency identification coil for dose calculation were investigated using the AcurosXB algorithm on the Eclipse (Varian Medical Systems, Palo Alto, CA) treatment planning system. Additionally, we performed in vivo dosimetry analysis using irradiation tangential to the Flora tissue expander to validate the modeling accuracy. Dose attenuations downstream of the Flora radiofrequency identification coil was 1.29% for a 6 MV X-ray and 0.99% for a 10 MV X-ray when the coil was placed perpendicular to the beam. The most suitable assignments for the material and density of the radiofrequency identification coil were aluminum and 2.27 g/cm3, respectively, even though the coil was actually made of copper. Gamma analysis of in vivo dosimetry with criteria of 3% and 2 mm did not fail in the coil region. Therefore, we conclude that the model is reasonable for clinical use.

Risk of thoracic soft tissue sarcoma after breast cancer radiotherapy: a population-based cohort study in Osaka, Japan

Postoperative radiotherapy for breast cancer reportedly increases the risk of thoracic soft tissue sarcomas, particularly angiosarcomas; however, the risk in the Japanese population remains unknown. Therefore, this study aimed to investigate the incidence of thoracic soft tissue sarcoma among patients with breast cancer in Japan and determine its association with radiotherapy. This retrospective cohort study used data from the population-based cancer registry of the Osaka Prefecture. The inclusion criteria were female sex, age 20-84 years, diagnosis of breast cancer between 1990 and 2010, no supraclavicular lymph node or distant metastasis, underwent surgery and survived for at least 1 year. The primary outcome was the occurrence of thoracic soft tissue sarcomas 1 year or later after breast cancer diagnosis. Among the 13 762 patients who received radiotherapy, 15 developed thoracic soft tissue sarcomas (nine angiosarcomas and six other sarcomas), with a median time of 7.7 years (interquartile range, 4.0-8.6 years) after breast cancer diagnosis. Among the 27 658 patients who did not receive radiotherapy, four developed thoracic soft tissue sarcomas (three angiosarcomas and one other sarcoma), with a median time of 11.6 years after diagnosis. The 10-year cumulative incidence was higher in the radiotherapy cohort than in the non-radiotherapy cohort (0.087 vs. 0.0036%, P < 0.001). Poisson regression analysis revealed that radiotherapy increased the risk of thoracic soft tissue sarcoma (relative risk, 6.8; 95% confidence interval, 2.4-24.4). Thus, although rare, breast cancer radiotherapy is associated with an increased risk of thoracic soft tissue sarcoma in the Japanese population.

The impact of the new ESTRO-ACROP target volume delineation guidelines for postmastectomy radiotherapy after implant-based breast reconstruction on breast complications

The European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) updated a new target volume delineation guideline for postmastectomy radiotherapy (PMRT) after implant-based reconstruction. This study aimed to evaluate the impact on breast complications with the new guideline compared to the conventional guidelines. In total, 308 patients who underwent PMRT after tissue expander or permanent implant insertion from 2016 to 2021 were included; 184 received PMRT by the new ESTRO-ACROP target delineation (ESTRO-T), and 124 by conventional target delineation (CONV-T). The endpoints were major breast complications (infection, necrosis, dehiscence, capsular contracture, animation deformity, and rupture) requiring re-operation or re-hospitalization and any grade ≥2 breast complications. With a median follow-up of 36.4 months, the cumulative incidence rates of major breast complications at 1, 2, and 3 years were 6.6%, 10.3%, and 12.6% in the ESTRO-T group, and 9.7%, 15.4%, and 16.3% in the CONV-T group; it did not show a significant difference between the groups (p = 0.56). In multivariable analyses, target delineation is not associated with the major complications (sHR = 0.87; p = 0.77). There was no significant difference in any breast complications (3-year incidence, 18.9% vs. 23.3%, respectively; p = 0.56). Symptomatic RT-induced pneumonitis was developed in six (3.2%) and three (2.4%) patients, respectively. One local recurrence occurred in the ESTRO-T group, which was within the ESTRO-target volume. The new ESTRO-ACROP target volume guideline did not demonstrate significant differences in major or any breast complications, although it showed a tendency of reduced complication risks. As the dosimetric benefits of normal organs and comparable oncologic outcomes have been reported, further analyses with long-term follow-up are necessary to evaluate whether it could be connected to better clinical outcomes.

Nomograms for metastasis of non-sentinel lymph nodes or more than three lymph nodes in patients with one or two positive sentinel lymph nodes

Purpose

The purpose of this study was to provide advice for the indication of regional nodal irradiation (RNI) in patients with one to two positive sentinel lymph nodes (SLNs) without axillary lymph node dissection (ALND).

Methods

We conducted a retrospective study in Shandong Cancer Hospital, Fudan University Shanghai Cancer Center, and West China Hospital. Logistic analysis was performed in order to explore the influencing factors of positive non-SLNs (NSLNs) and >3 positive nodes among patients with one to two SLNs+. Then, nomograms were constructed.

Results

Between May 2010 and 2020, among the 2,845 patients with one to two SLNs+ undergoing ALND (1,992 patients in the training set and 853 patients in the validation set), there were 34.3% harbored NSLNs+ and 15.6% harbored >3 positive nodes. Multivariate analysis showed that cN stage, the number of positive/negative SLN, pathological tumor stage, lympho-vascular invasion (LVI), multicenter, and molecular subtypes were significantly associated with NSLN metastasis. Similarly, multivariate analysis also showed that cN stage, the number of positive/negative SLNs, pathological tumor stage, and LVI could be independent predictors of >3 positive nodes. Then, nomograms for NSLN metastasis and >3 positive nodes were constructed using these parameters, respectively.

Conclusions

The nomograms will be useful in estimating positive NSLNs and >3 positive nodes, and they might provide advice for the optimization of RNI.

Autologous fat transplantation prior to permanent expander implant breast reconstruction enhances the outcome after two years: a randomized controlled trial

Radiotherapy is important in breast cancer treatment. A side effect of the treatment is fibrosis that decreases the possibility for a successful breast reconstruction with expanders and with high patient satisfaction with the result. The most common option for mastectomized, irradiated women wishing for a breast reconstruction is autologous tissue transplantation. However, some patients are not suitable for flap surgery. Fifty mastectomized and irradiated women were included in a randomized controlled trial. They underwent breast reconstruction with expanders and were allocated 1:1 to either receive pre-treatment with autologous fat transplantation (AFT) or not. Primary outcomes were frequency of reoperations and complications. Secondary outcomes were number of days in hospital, number of outpatient visits to surgeon or nurse and patient reported outcome as reported with Breast Q. Follow-up time was 2 years. Fifty-two per cent of the intervention group and 68% of the controls underwent reoperations (p = 0.611). Thirty-two per cent of the intervention group and 52% of the controls had complications (p = 0.347). The median number of consultations with the nurse was four in the intervention group and six in the control group (p = 0.002). The AFT patients were significantly more satisfied with their breasts and psychosocial well-being after 2 years. They also had higher increase in satisfaction with breasts, psychosocial well-being, and sexual well-being when comparing baseline with 2 years postoperatively. This randomized controlled trial indicates benefits of AFT prior to breast reconstruction with expanders, especially on patient reported outcome even if the study sample is small.

Surface dose measurement and comparison between TLD and OSLD during modified re constructive mastectomy irradiation

Radiotherapy (RT) is one of the major treatment modalities among surgery and chemotherapy for carcinoma breast. The surface dose study of modified reconstructive constructive Mastectomy (MRM) breast is important due to the heterogeneity in the body contour and the conventional treatment angle to save the lungs and heart from the radiation. These angular entries of radiation beam cause an unpredictable dose deposition on the body surface, which has to be monitored. Thermoluminescent dosimeter (TLD) or optically stimulated luminescent dosimeter (nano OSLD) are commonly preferable dosimeters for this purpose. The surface dose response of TLD and nano OSLD during MRM irradiation has been compared with the predicted dose from the treatment planning system (TPS). The study monitored 100 MRM patients by employing a total 500 dosimeters consisting of TLD (n = 250) and nano OSLD (n = 250), during irradiation from an Elekta Versa HD 6 MV Linear accelerator. The study observed a variance of 3.9% in the dose measurements for TLD and 3.2% for nano OSLD from the planned surface dose, with a median percentage dose of 44.02 for nano OSLD and 40.30 for TLD (p value 0.01). There was no discernible evidence of variation in dose measurements attributable to differences in field size or from patient to patient. Additionally, no variation was observed in dose measurements when comparing the placement of the dosimeter from central to off-centre positions. In comparison, a minor difference in dose measurements were noted between TLD and nano OSLD, The study's outcomes support the applicability of both TLD and nano OSLD as effective dosimeters during MRM breast irradiation for surface dose evaluation.

A Comparative Analysis of Implant-sparing Plan Versus Conventional Plans Utilizing Helical Tomotherapy in Breast Cancer Patients Undergoing Breast Reconstruction

BACKGROUND/AIM

To compare implant sparing irradiation with conventional radiotherapy (RT) using helical (H) and TomoDirect (TD) techniques in breast cancer patients undergoing immediate breast reconstruction (IBR).

PATIENTS AND METHODS

The dosimetric parameters of 40 patients with retropectoral implants receiving 50.4 Gy delivered in 28 fractions were analyzed. Three plans were created: H plan using conventional planning target volume (PTV) that included the chest wall, skin, and implant; TD plan using conventional PTV; and Hs plan using implant-sparing PTV. The H, TD, and Hs plans were compared for PTV doses, organ-at-risk (OAR) doses, and treatment times.

RESULTS

Dose distribution in the Hs plan was less homogeneous and uniform than that in the H and TD plans. The TD plan had lower lung, heart, contralateral breast, spinal cord, liver, and esophagus doses than the Hs plan. Compared to the Hs plan, the H plan had lower lung volume receiving 5Gy (V5) (39.1±3.9 vs. 41.2±3.9 Gy; p<0.001), higher V20 (12.3±1.3 vs. 11.5±2.6 Gy; p=0.02), and higher V30 (7.5±1.6 vs. 4.4±1.7 Gy; p<0.001). H plan outperformed Hs plan in heart dosimetric parameters except V20. The Hs plan had significantly lower mean implant doses (43.4±2.1 Gy) than the H plan (51.4±0.5 Gy; p<0.001) and the TD plan (51.9±0.6 Gy; p<0.001). Implementing an implant sparing technique for silicone dose reduction decreases lung doses.

CONCLUSION

Conventional H and TD plans outperform the implant sparing helical plan dosimetrically. Because capsular contracture during RT is unpredictable, long-term clinical outcomes are required to determine whether silicon should be spared.

Organ-sparing techniques and dose-volume constrains used in breast cancer radiation therapy - Results from European and Latin American surveys

Background

Advances in local and systemic therapies have improved the outcomes of patients with breast cancer (BC), leading to a possible increased risk for postoperative radiation therapy (RT) late adverse events. The most adequate technologies and dose constraints for organs at risk (OAR) in BC RT have yet to be defined.

Methods

An online survey was distributed to radiation oncologists (ROs) practicing in Europe and Latin America including the Caribbean (LAC) through personal contacts, RO and BC professional groups' networks. Demographic data and clinical practice information were collected.

Results

 The study included 585 responses from ROs practicing in 57 different countries. The most frequently contoured OAR by European and LAC participants were the whole heart (96.6 % and 97.7 %), the ipsilateral (84.3 % and 90.8 %), and contralateral lung (71.3 % and 77.4 %), whole lung (69.8 % and 72.9 %), and the contralateral breast (66.4 % and. 83.2 %). ESTRO guidelines were preferred in Europe (33.3 %) and the RTOG contouring guideline was the most popular in LAC (62.2 %), while some participants used both recommendations (13.2 % and 19.2 %). IMRT (68.6 % and 59.1 %) and VMAT (65.6 % and 60.2 %) were the preferred modalities used in heart sparing strategies, followed by deep inspiration breath-hold (DIBH) (54.8 % and 37.4 %) and partial breast irradiation (PBI) (41.6 % and 24.6 %). Only a small percentage of all ROs reported the dose-volume constraints for OAR used in routine clinical practice. A mean heart dose (Heart-Dmean) between 4 and 5 Gy was the most frequently reported parameter (17.2 % and 39.3 %).

Conclusion

 The delineation approaches and sparing techniques for OAR in BC RT vary between ROs worldwide. The low response rate to the dose constraints subset of queries reflects the uncertainty surrounding this topic and supports the need for detailed consensus recommendations in the clinical practice.

Comparison of Volumetric Modulated Arc Therapy (VMAT) and Conventional Intensity-Modulated Radiotherapy (IMRT) for Locally Advanced Head and Neck Squamous Cell Carcinoma: A Retrospective Cohort Study

Purpose This study examines the outcomes of locally advanced head and neck squamous cell carcinoma (HNSCC) following the adoption of conventional intensity-modulated radiotherapy (cIMRT) and volumetric-modulated arc therapy (VMAT) over a decade. The region under study has higher comorbidities associated with increased HNSCC incidence and poorer prognosis. Materials and methods A 10-year retrospective review of electronic medical records included 296 patients with stage III, IVA, and IVB HNSCC (American Joint Committee on Cancer, Seventh edition). Survival outcomes were compared between VMAT and cIMRT using Kaplan-Meier survival curves and adjusted for relevant demographic factors using Cox's proportional hazards model. Analysis was performed using R software (R Foundation, Vienna, Austria). Results The median age of the cohort was 63 years, comprising of 80% males. The oropharynx was the most common primary tumor site. 264 (89%) received 50Gy or higher dose radiation by either cIMRT (22%) or VMAT (67%). At five years, locoregional control (LC) and overall survival (OS) rates were 79.5% and 56.7%, respectively. VMAT showed a significant improvement in five-year OS (63.4% versus 43.8% for cIMRT, p=0.0023) but no significant difference in five-year LC (81% VMAT versus 74.5% cIMRT, p=0.17). Grade 3-4 acute toxicity was observed in 22% of patients. Conclusions VMAT and cIMRT demonstrated excellent LC in locally advanced HNSCC despite high comorbidity rates. Notably, VMAT was associated with significantly better OS compared to cIMRT. These outcomes surpass historical data, suggesting that VMAT technology may lead to improved patient outcomes. However, larger randomized controlled trials and dosimetric studies are needed to confirm these findings.

Meta-Analysis of Immediate Implant-Based Breast Reconstruction Versus Autologous Breast Reconstruction in the Setting of PMRT

BACKGROUND

It is still a controversial debate that which type of immediate breast reconstruction should be operated on breast cancer patients in the setting of postmastectomy radiotherapy. This meta-analysis compared incidence of complications requiring reoperation (CRR), reconstruction failure (RF) and patient-reported outcome between immediate autologous breast reconstruction (ABR) and immediate implant-based breast reconstruction (IBBR), tissue expander/implant reconstruction mostly, in the setting of postmastectomy radiotherapy.

METHODS

Systematic and thorough research was conducted to search for studies published before August 1, 2022, by using three online databases. Studies that covered complications or reconstruction failure between two cohorts were included. To evaluate the possible bias in the included studies, the Newcastle-Ottawa Scale was applied.

RESULTS

Eight studies presenting 1261 patients were enrolled. The relative risk associated with reconstructive failure favored IBBR (RR = 8.61; 95% CI, 2.84-26.08; P = 0.0001). While the risk for complications requiring reoperation was not significantly different between two groups, either include reconstruction failure (RR = 1.45 95% CI, 0.82-2.55; P = 0.20) or not (RR = 0.63 95% CI, 0.28-1.43; P = 0.27). However, because statistical definitions and methodologies vary, the synthesized result should be taken critically.

CONCLUSION

Patients with IBBR have more possibility experiencing RF compared that with ABR, while the chance for CRR is not that different between two groups. For the purpose of clinical practice refinement, more high-quality studies are needed.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Impact of Timing of Delayed Autologous Breast Reconstruction following Postmastectomy Radiation Therapy on Postoperative Morbidity

BACKGROUND

 The ideal time to perform reconstruction after the completion of postmastectomy radiation therapy (PMRT) in patients with locally advanced breast cancer is currently unknown. We evaluate the association between the timing of delayed autologous breast reconstruction following PMRT and postoperative complications.

METHODS

 Patients who underwent mastectomy, PMRT, and then delayed autologous breast reconstruction from 2009 to 2016 were identified from the Truven Health MarketScan Research Databases. Timing of reconstruction following PMRT was grouped 0-3, 3-6, 6-12, 12-24, and after 24 months. Multivariable models were used to assess associations between timing of reconstruction following PMRT and key measures of morbidity.

RESULTS

 A total of 1,039 patients met inclusion criteria. The rate of any complications for the analytic cohort was 39.4%, including 13.3% of patients who experienced wound complications and 11.3% of patients requiring additional flaps. Unadjusted rates of complications increased from 23.4% between 0 and 3 months to 49.4% between 3 and 6 months and decreased thereafter. Need for additional flaps was highest within 3 to 6 months (14.0%). Multivariate analysis revealed higher rates of any complications when reconstruction was performed between 3 and 6 months (odds ratio [OR]: 3.04, p < 0.001), 6 and 12 months (OR: 2.66, p < 0.001), or 12 and 24 months (OR: 2.13, p = 0.001) after PMRT. No difference in complications were noted in reconstructions performed after 24 months compared with those performed before 3 months (p > 0.05). However, rates of wound complications were least likely in reconstructions after 24 months (OR: 0.34, p = 0.035).

CONCLUSION

 These findings suggest plastic surgeons may consider performing autologous breast reconstruction early for select patients, before 3 months following PMRT without increasing postoperative morbidity.