Regional Nodal Irradiation Research Articles

Evaluation of early cardiotoxicity in HER2-positive breast cancer patients receiving radiotherapy and concurrent trastuzumab.

Overexpression of human epidermal growth factor receptor 2 (HER-2) is associated with aggressive disease in breast cancer. Trastuzumab and radiotherapy are standard treatments for patients with HER-2 + breast cancer, but they may increase the risk of cardiotoxicity. This study aimed to assess early cardiotoxicity in patients receiving radiotherapy (RT) and concurrent trastuzumab. The study included 116 patients with HER-2 + breast cancer who received concurrent treatment with trastuzumab and RT (52 right-side; 64 left-side). Five left ventricular ejection fraction (LVEF) measurements were performed: one before treatment and four subsequent measurements taken at three-month intervals. LVEF was also assessed before (preRT-EF) and after (postRT-EF) radiotherapy. The baseline LVEF was 62.27 ± 5.5%, while the 12-month LVEF was 59.8 ± 5.8% (p < 0.05). In subgroups, post-RT LVEF values ​​were significantly lower than pre-RT LVEF values (p < 0.05). No significant difference was found between the reduction in LVEF for patients receiving 50Gy and 60Gy doses. Moreover, the contribution of regional lymph node irradiation to the decrease in LVEF could not be demonstrated. A positive correlation was found between the total trastuzumab dose and the decrease in LVEF from preRT to postRT. Additionally, a positive correlation was observed between the total taxane dose and the reduction in LVEF from baseline to 9months, both in the overall group and in the left breast cancer group. In our study,it was found that not only trastuzumab but also taxane-based agents could be cardiotoxic. However, no connection was found between RT doses and the decrease in LVEF.

Validation of different automated segmentation models for target volume contouring in postoperative radiotherapy for breast cancer and regional nodal irradiation

IntroductionTarget volume delineation is routinely performed in postoperative radiotherapy (RT) for breast cancer patients, but it is a time-consuming process. The aim of the present study was to validate the quality, clinical usability and institutional-specific implementation of different auto-segmentation tools into clinical routine. MethodsThree different commercially available, artificial intelligence-, ESTRO-guideline-based segmentation models (M1-3) were applied to fifty consecutive reference patients who received postoperative local RT including regional nodal irradiation for breast cancer for the delineation of clinical target volumes: the residual breast, implant or chestwall, axilla levels 1 and 2, the infra- and supraclavicular regions, the interpectoral and internal mammary nodes. Objective evaluation metrics of the created structures were conducted with the Dice similarity index (DICE) and the Hausdorff distance, and a manual evaluation of usability. ResultsThe resulting geometries of the segmentation models were compared to the reference volumes for each patient and required no or only minor corrections in 72 % (M1), 64 % (M2) and 78 % (M3) of the cases. The median DICE and Hausdorff values for the resulting planning target volumes were 0.87–0.88 and 2.96–3.55, respectively. Clinical usability was significantly correlated with the DICE index, with calculated cut-off values used to define no or minor adjustments of 0.82–0.86. Right or left sided target and breathing method (deep inspiration breath hold vs. free breathing) did not impact the quality of the resulting structures. ConclusionArtificial intelligence-based auto-segmentation programs showed high-quality accuracy and provided standardization and efficient support for guideline-based target volume contouring as a precondition for fully automated workflows in radiotherapy treatment planning.

Combined analysis of the MF18-02/MF18-03 NEOSENTITURK studies: ypN-positive disease does not necessitate axillary lymph node dissection in patients with breast cancer with a good response to neoadjuvant chemotherapy as long as radiotherapy is provided.

The omission of axillary lymph node dissection (ALND) remains controversial for patients with residual axillary disease after neoadjuvant chemotherapy (NAC), regardless of the residual burden. This study evaluated the oncologic safety and factors associated with outcomes in patients with residual axillary disease. These patients were treated solely with sentinel lymph node biopsy (SLNB) or targeted axillary dissection (TAD), without ALND, after NAC. A joint analysis of two different multicenter cohorts-the retrospective cohort registry MF18-02 and the prospective observational cohort registry MF18-03 (NCT04250129)-was conducted between January 2004 and August 2022. All patients received regional nodal irradiation. Five hundred and one patients with cT1-4, N1-3M0 disease who achieved a complete clinical response to NAC underwent either SLNB alone (n=353) or TAD alone (n=148). At a median follow-up of 42 months, axillary and locoregional recurrence rates were 0.4% (n=2) and 0.8% (n=4). No significant difference was found in disease-free survival (DFS) and disease-specific survival (DSS) rates between patients undergoing TAD alone versus SLNB alone, those with breast positive versus negative pathologic complete response, SLN methodology, total metastatic LNof one versus ≥2, or metastasis types as isolated tumor cells with micrometastases versus macrometastases. In the multivariate analysis, patients with nonluminal pathology were more likely to have a worse DFS and DSS, respectively, without an increased axillary recurrence. The omission of ALND can be safely considered for patients who achieve a complete clinical response after NAC, even if residual disease is detected by pathologic examination. Provided that adjuvant radiotherapy is administered, neither the SLNB method nor the number of excised LNs significantly affects oncologic outcomes.

Excluding Upper Axillary Level 1 in Regional Nodal Irradiation Does Not Increase Axillary Recurrence Risk in Patients With Breast Cancer

PurposeThe optimal extent of regional nodal irradiation (RNI) in postoperative radiotherapy for breast cancer, particularly regarding axillary level 1 (AXL1), remains uncertain. This study aims to compare clinical outcomes between extensive RNI including the entire axilla and limited RNI excluding the upper AXL1 in patients with breast cancer. MethodsA retrospective analysis included 1,780 women with non-metastatic unilateral breast cancer who underwent RNI during postoperative radiotherapy between 2007 and 2018. Patients were classified into extensive and limited RNI groups based on the upper AXL1 inclusion in the radiation field. Propensity score matching yielded a cohort of 1,020 patients. Non-inferiority of limited RNI compared to extensive RNI was assessed with a defined margin of ≤2% in the 5-year axillary recurrence rate. ResultsAfter a median follow-up of 67.9 months, the 5-year axillary recurrence rates were similar between extensive and limited RNI groups (1.2% vs. 1.6%; Plog-rank=0.790). Limited RNI demonstrated non-inferiority with a 0.4% difference (95% confidence interval, -1.1%–1.9%; Pnon-inferiority=0.019). Disease-free survival (87.9% vs. 91.5%; Plog-rank=0.122) and overall survival (94.1% vs. 96.9%; Plog-rank=0.260) at 5 years were not significantly different between extensive and limited RNI groups. Multivariable analysis revealed that lymphovascular invasion (hazard ratio [HR], 5.17; P=0.02) and negative hormone receptor status (HR, 11.73; P=0.002) were associated with a higher risk of axillary recurrence, while limited RNI showed no significant association (HR, 1.35; P=0.652). Subgroup analysis demonstrated that extensive RNI did not improve axillary control in patients with lymphovascular invasion, hormone receptor negativity, positive lymph node metastasis, or a small number of nodes removed. ConclusionLimited RNI, excluding the upper AXL1 from the radiation field, demonstrated axillary recurrence rates comparable to those of extensive RNI in patients with breast cancer. The study suggests that extensive RNI may not provide additional therapeutic benefits, while limited RNI appears to be a valid option for regional control.

Intensity-modulated proton radiotherapy spares musculoskeletal structures in regional nodal irradiation for breast cancer: a dosimetric comparison.

Regional nodal irradiation (RNI) for breast cancer delivers radiation in proximity to the shoulder and torso, and radiation exposure may contribute to long-term upper extremity and postural morbidity. To date, no studies have assessed the differential dosimetric impact of proton versus photon radiation on shoulder and torso anatomy. This study examined clinically relevant musculoskeletal (MSK) structures and assessed the dose delivered with each modality. Ten MSK structures were contoured on IMPT (intensity-modulated proton therapy) and VMAT (volumetric modulated arc therapy) plans for 30 patients receiving RNI. Relevant dose metrics were compared for each of the structures. Intensity-modulated proton therapy dose was calculated using the relative biological effective value of 1.1. Hypo-fractionated plans were scaled to the equivalent dose in 2 Gy fractions (EQD2) using an alpha/beta ratio of four. Wilcoxon signed rank sum tests compared doses. Select three-dimensional and optimised VMAT plans were also informally compared. Each of the 10 structures received a statistically significantly lower dose with the use of IMPT compared with VMAT. Differences were greatest for posterior structures, including the trapezius, latissimus dorsi and glenohumeral joint. Mean absolute differences were as great as 23 Gy (supraspinatus D5cc) and up to 30-fold dose reductions were observed (deltoid D50cc). An average 3.7-fold relative dose reduction existed across all structures. Measures of low/intermediate dose (V15Gy and D50cc) showed the largest differences. Intensity-modulated proton therapy results in statistically lower radiation exposure to relevant shoulder and torso anatomy compared to photon radiation for patients requiring RNI. Prospective study is needed to correlate functional outcomes with radiation dose.

The EORTC 22922/10925 trial investigating regional nodal irradiation in stage I-III breast cancer: Outcomes according to locoregional and systemic therapies

The EORTC 22922/10925 trial aimed to investigate the impact on overall survival (OS) of elective internal mammary and medial supraclavicular (IM-MS) radiation therapy (RT) in breast cancer stage I–III. Surgery for the primary tumour and axillary lymph nodes, chest wall RT, boost RT after whole breast RT in breast conserving therapy (BCT), RT to operated axilla, and systemic therapy were per physician’s preference. The aim of the current analysis is to assess breast cancer outcomes according to different locoregional and systemic therapy used in the trial. Material/MethodsData with a median follow-up of 15.7 years were extracted from the trial’s case report forms. Kaplan-Meier curves of disease-free and OS and cumulative incidence curves of breast cancer events were produced. An exploratory analysis of the effect of the type of locoregional and systemic therapy on breast cancer outcomes was conducted using the Cox model or the Fine & Gray model accounting for competing risks, both models being adjusted for baseline patient and disease characteristics and treatment. The significance level was set at 5 %, 2-sided. ResultsOf the 4,004 patients included, 625 (16%) did not receive any postoperative systemic therapy, 1,185 (30%) received endocrine therapy only, 994 (25%) chemotherapy only, and 1,200 (30%) both chemotherapy and endocrine therapy, without differences between the randomisation arms.Administration and type of therapy was associated with age, menopausal status, clinical T- and N-stage and ER status (p < 0.0001). Local control was better with mastectomy (with/without postmastectomy RT) as compared to BCT, but mastectomy was associated with more distant metastasis (DM) as first event. Similarly, DM as first event occurred more in the BCT group that received a boost as compared to no boost and in those who received RT to the lower axillary level. IM-MS RT reduced significantly regional recurrences and improved disease-free survival in a sensitivity stratified analysis. OS was worse with mastectomy as compared to BCT and with irradiation of the axilla but better with sentinel node dissection and adjuvant combined chemo and hormonal therapy. ConclusionDifferent components of therapy influenced the site of first event. IM-MS RT improved outcomes in different breast cancer outcomes were most probably related that the group were balanced due to the trial arms and stratification methods.

Financial toxicity in breast cancer patients receiving regional nodal irradiation: Variation by cancer subtype

BackgroundWe evaluated sociodemographic and clinical predictors of financial toxicity (FT) among patients with breast cancer with higher risk clinical factors warranting regional nodal irradiation (RNI). MethodsAmong 183 participants in a clinical trial of conventional vs. hypofractionated treatment with RNI, 125 (68 %) completed a pilot survey of FT measured using the validated Economic Strain and Resilience in Cancer (ENRICh) instrument, scored from 0 (minimal) to 10 (severe) FT. Associations with predictors were evaluated using Pearson correlation coefficients and Kruskal Wallis, Mann-Whitney U, and Jonckheere-Terpstra tests. Predictors of severe FT (ENRICh≥5) were tested using multivariable logistic regression with odds ratios converted to relative risks (RR). ResultsOf the sample, all received RNI, 92 % chemotherapy, 67 % axillary dissection, 26 % mastectomy without reconstruction, and 32 % mastectomy with reconstruction. At a median follow up of 1.48 years, median FT score was 2.13 (IQR 0.93–4.6), with 20.8 % of patients experiencing severe FT. Unadjusted worse FT score was associated with younger age (P = 0.003), Hispanic ethnicity (P = 0.006), lower income (P = 0.02), shorter interval from diagnosis to FT assessment (P = 0.02), and chemotherapy receipt (P = 0.05), but not with breast surgery type (P = 0.42), axillary surgery type (P = 0.33), or pathologic T (P = 0.68) or N stage (P = 0.47). In multivariable analysis, triple negative subtype was the sole clinical factor predicting severe FT (RR = 3.38; 95 % CI 1.48–4.99; P = 0.01). ConclusionAmong patients with breast cancer receiving RNI, triple negative subtype was associated with severe FT, suggesting that tumor receptor subtype may help identify a key breast cancer subpopulation for early FT intervention.

Oncological outcomes in patients with residual triple-negative breast cancer after preoperative chemotherapy.

This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC). We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45-65 Gy in 15-30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan-Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model. During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00-3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57-14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI. In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

13-year survival oligometastatic Merkel cell carcinoma: a case report

BackgroundMerkel cell carcinomas are rare, aggressive skin tumors with high metastatic potential and poor prognosis. Their treatment is classically based on surgery with adjuvant external radiotherapy for localized tumors or on immunotherapy or chemotherapy, sometimes associated with radiotherapy, for metastatic stages. Those tumors are highly radiosensitive due to their neuroendocrine and undifferentiated nature, but they usually fail to rapidly respond to treatment.Case presentationWe report the case of a 65-year-old retired female patient of Caucasian (German) origin with locally advanced Merkel cell carcinoma of the buttock, with pancreatic metastases synchronous at diagnosis, treated with local radiotherapy of the right buttock without regional lymph node irradiation followed by a sequential chemotherapy; 1 year later, the patient developed an isolated pancreatic recurrence treated with exclusive radiotherapy. The patient was still alive at 13 years with complete remission.ConclusionExternal radiotherapy can be an effective alternative to surgery for locally advanced or even oligometastatic Merkel cell carcinomas.

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.

Patient-Reported Outcomes Between Whole-Breast Plus Regional Irradiation and Whole-Breast Irradiation Only in pN1 Breast Cancer After Breast-Conserving Surgery and Taxane-Based Chemotherapy: A Randomized Phase 3 Clinical Trial (KROG 17-01)

BackgroundThe role of regional node irradiation (RNI) with whole-breast irradiation (WBI) in patients with pN1 breast cancer receiving taxane-based adjuvant chemotherapy is not well defined. The KROG 1701 trial, a phase III, multicenter, non-inferiority study, aimed to compare the disease-free survival between WBI+RNI and WBI alone in this patient cohort. Comprehensive patient-reported outcomes (PROs) collected at multiple time points are reported. MethodsThe trial (NCT03269981) enrolled patients with pN1 breast cancer after breast-conserving surgery and taxane-based adjuvant chemotherapy, allocating them to receive either WBI +RNI or WBI only. PROs were assessed using EORTC QLQ-C30 and QLQ-BR23 modules at baseline, during RT, and at subsequent follow-up intervals of 3-6 months, and annually up to 4years. ResultsFrom April 2017 to December 2021, 840 patients were enrolled; 777 received intervention as assigned, and 750 completed baseline PRO questionnaires (387 in WBI+RNI, 363 in WBI only). All PRO domains showed improvements over time (p<0.001). During RT, the WBI+RNI group reported greater fatigue and nausea. Higher arm symptom scores were observed in the WBI+RNI group 3 months post-treatment (p=0.030). No other significant PRO domain differences, including arm/breast symptoms, were observed between the two groups. ConclusionIn patients with pN1 breast cancer treated with taxane-based chemotherapy, adding RNI to WBI resulted in minor, temporary declines in specific PRO domains, but these differences were not clinically significant. This indicates that overall patient experience between WBI+RNI and WBI is comparable, supporting the safety and patient tolerability of both treatments.

How Effective is Deep Inspiration Breath Hold in Minimizing Cardiac Doses During Hybrid Radiotherapy Treatment for Left-Sided Breast Cancer with Comprehensive Regional Nodes?

In the context of left breast cancer radiotherapy, long term cardiopulmonary toxicity has been well-documented, significant efforts have been undertaken to mitigate such toxicity by using 4D gating, deep inspiration breath-hold(DIBH) and active breath control(ABC) techniques. To evaluate and compare the cardio-pulmonary radiation doses incurred during postmastectomy radiotherapy (PMRT) in two distinct breathing conditions such as DIBH and Free Breathing (FB), with a specific focus on the left chest wall with comprehensive regional nodal irradiation. A prospective dosimetric study was conducted on 15 patients who received adjuvant loco-regional radiotherapy of chest-wall (CW), supraclavicular fossa(SCF), and internal mammary region(IMC), with or without axilla. Two sets of planning CT scans were taken in DIBH and FB conditions. The dosimetric difference between DIBH CT and FB CT plans analyzed using Wilcoxon signed-rank test, employing SPSS software version 21.0. Comparison of DIBH and FB parameters for target coverage revealed a statistically significant advantage with DIBH in SCF(D95, V90, p<0.017) and IMC(D98, V90 & V95, p<0.03). Dosimetric characteristics of heart and LAD exhibited statistically significant lower doses with DIBH (V20, V25, and Dmean, p<0.001) compared to FB plans. Lung doses were similar with no discernible advantage of one technique over the other. Other OARs such as contralateral breast (p=0.027) and esophagus (p=0.001) received lower doses with the DIBH technique while the spinal cord (p=0.691) and thyroid(p=0.496) showed no significant difference. Maximum heart distance (p= 0.001), central lung distance (p= 0.011) and Haller index (p= 0.001) exhibited statistical significance between the two techniques, whereas chest wall separation showed no significant statistical difference (p=0.629). DIBH demonstrates a substantial reduction in cardiac and LAD doses compared to the FB technique. This study underscores the efficacy of DIBH as a viable strategy for mitigating cardiac and LAD radiation doses in left-sided breast cancer patients undergoing PMRT of chest wall with comprehensive regional nodes.

Postoperative Radiotherapy Using VMAT for RNI Including IMN in Breast Cancer: Report of Short-term Follow-up.

The application of volumetric-modulated arc therapy (VMAT) in postoperative radiotherapy for breast cancer has recently garnered considerable interest, especially when regional lymph node irradiation (RNI), is extended to include the internal mammary node (IMN) region, along with whole-breast or chest wall irradiation. This study aimed to assess both acute and late toxicities, as well as breast cancer outcomes, during the observation period. This retrospective study aimed to assess the safety and feasibility of VMAT in postoperative radiotherapy, including the IMN region, for patients with breast cancer at our hospital. We included 33 eligible patients who received postoperative VMAT radiotherapy, including the IMN region, between November 2018 and July 2021. The primary indications for implementing VMAT were the presence of IMN metastases before primary systemic therapy or more than four axillary lymph node metastases. The median prescribed dose for the chest wall or conserved breast and regional lymph nodes was 50 Gy in 25 fractions. In 16 cases, a simultaneous boost (median, 10 Gy) was administered to residual lymph node metastases. VMAT facilitated a reduction in the mid- or high-dose range to organs at risk, exemplified by V20Gy and V40Gy of the ipsilateral lung, which were 24.10% and 6.84%, respectively, while ensuring adequate target dose irradiation, V45Gy=95.23%. No serious adverse events, including symptomatic radiation pneumonitis, occurred during the 15-month median observation period. Our findings demonstrate the safety and effectiveness of postoperative radiotherapy for breast cancer, including the IMN region, when using VMAT.

PTCOG international survey of practice patterns and trends in utilization of proton therapy for breast cancer

Purpose/objectivesThe indications, techniques, and extent to which proton beam therapy (PBT) is employed for breast cancer are unknown. We seek to determine PBT utilization for breast cancer. Materials/methodsThe Particle Therapy Co-Operative Group (PTCOG) Breast Subcommittee developed an IRB-approved 29-question survey and sent it to breast cancer radiation oncologists at all active PBT centers worldwide in June 2023. Descriptive statistics were used to summarize responses, and comparisons by continent were performed using Fisher’s exact tests. ResultsOf 79 surveys distributed, 28 recipients submitted responses (35 % response rate) representing fifteen U.S., 8 European, and 5 Asian centers (continent response rate 50 %, 38 %, and 18 %, respectively). Overall, 93 % reported treating breast cancer patients with PBT; 13 (50 %) have treated ≥100 breast cancer patients at their center since opening. Most (89 %) have pencil beam scanning technology. Nearly half (46 %) use moderate hypofractionation (15–20 fractions) for regional nodal irradiation and 42 % conventional fractionation (25–30 fractions). More European centers prefer hypofractionation (88 %) vs. Asian (50 %) and U.S. (21 %) centers (p = 0.003). Common patient selection methods were practitioner determination/patient preference (n = 16) and comparative plan evaluation (n = 15). U.S. centers reported the most experience with breast PBT, with 71 % having treated ≥100 breast cancer patients vs. 38 % in Europe and none in Asia (p = 0.001). Of respondent centers, 39 % enrolled ≥75 % of breast PBT patients on a research study. ConclusionUtilization, patient selection methods, and dose-fractionation approaches for breast cancer PBT vary worldwide. These survey data serve as a benchmark from which successor surveys can provide insight on practice pattern evolution.

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

IntroductionPostoperative 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...

Echocardiographic Functional Outcomes Following Regional Nodal Irradiation for Breast Cancer Using Volumetric Modulated Arc Therapy

Regional nodal irradiation (RNI) for breast cancer yields improvements in disease outcomes, yet comprehensive target coverage often increases cardiac radiation therapy (RT) dose. Volumetric modulated arc therapy (VMAT) may mitigate high-dose cardiac exposure, although it often increases the volume of low-dose exposure. The cardiac implications of this dosimetric configuration (in contrast to historic 3D conformal techniques) remain uncertain. Eligible patients receiving adjuvant RNI using VMAT for locoregional breast cancer were prospectively enrolled in an IRB-approved study. Echocardiograms were performed prior to RT, at the conclusion of RT, and 6 months following RT. Echocardiographic parameters were measured by a single reader and measures were compared pre- and post-RT via the signed-rank test. Changes in echocardiographic parameters over time were compared to mean and max heart doses via the Spearman correlation test. Among 19 evaluable patients (median age 38 years), 89% (n = 17) received doxorubicin and 37% (n = 7) received trastuzumab/pertuzumab combination therapy. All patients received VMAT-based whole-breast/chest wall and RNI. The average mean heart dose was 456 cGy (range, 187-697 cGy) and the average max heart dose was 3001 cGy (1560-4793 cGy). Among salient echocardiographic parameters, no significant decrement in cardiac function was observed when comparing pre-RT to 6 months post-RT: mean left ventricular ejection fraction (LVEF) was 61.8% (SD 4.4%) pre-RT and 62.7% (SD 3.8%) 6 months post-RT (P = .493); mean global longitudinal strain (GLS) was -19.3% (SD 2.2%) pre-RT and -19.6% (SD 1.8%) 6 months post-RT (P = .627). No individual patient exhibited reduced LVEF or sustained decrement in GLS. No correlations were observed for changes in LVEF or GLS when compared to mean or maximum heart doses (P > .1 for all). VMAT for left-sided RNI yielded no significant early decrement in echocardiographic parameters of cardiac function, including LVEF and GLS, within this limited cohort. No patient exhibited significant LVEF changes, and none exhibited sustained decrements in GLS. VMAT may be a reasonable approach to cardiac avoidance in patients requiring RNI, including those receiving anthracyclines and HER2-directed therapy. Larger cohorts with longer follow-ups will be needed to validate these findings.

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

BackgroundNipple areola complex-sparing surgeries, such as nipple-sparing mastectomy (NSM), are increasingly utilized for women with early-stage breast cancer. In the post-operative setting, two major indications for post-operative radiation (PORT) with/without regional nodal irradiation (RNI) are positive margins (margin+) and pathologically involved lymph nodes (pN+), though the frequency of these adverse pathologic features and the rate of indicated PORT use following NSM is unknown. We determined the frequency of margin+ and pN+ following NSM compared to nipple-sparing lumpectomy (BCS) and identified trends in appropriate PORT administration for these standard indications in the NSM setting. MethodsUsing the National Cancer Database, women diagnosed with cT1-3N0M0 invasive carcinoma between 2004-2017 who received NSM were compared to those who received BCS with nipple preservation. The frequencies of margin+ and pN+ by surgical subtype and utilization 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 two cohorts was also compared. We performed univariable/multivariable logistic & Cox regression (MVA) with odds ratios to control for confounders. ResultsOf 624,075 women included, 611,907 had BCS and 12,168 had NSM. The surgical margin+ rate was significantly higher for NSM at 4.5% (n=544) than 3.7% for BCS (n=22,449) (p<0.001), and remained significant on MVA (OR 1.13 CI 1.03-1.25, p= 0.012). Utilization of PORT for margins+ was significantly lower by MVA after NSM (OR 0.07 CI 0.06-0.09, p<0.001). Similarly, pN+ rate was significantly higher for NSM at 22.5% (n=2,740) versus BCS 13.5% (n=82,288)(p<0.001), retaining significance on MVA (OR 1.12 CI 1.06-1.19, p<0.001). PORT with RNI for pN+ occurred less often for NSM on multivariable analysis (OR 0.73, CI 0.67-0.81, p<0.001). Neither high-risk subgroup had differences in overall survival on MVA. DiscussionNSM is associated with a higher rate of margin+ and pN+ versus BCS. Radiation is underutilized 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.

Dosimetric risk factors for radiation esophagitis in patients with breast cancer following regional nodal radiation

BACKGROUND Radiation esophagitis (RE) is one of the most common clinical symptoms of regi-onal lymph node radiotherapy for breast cancer. However, there are fewer studies focusing on RE caused by hypofractionated radiotherapy (HFRT). AIM To analyze the clinical and dosimetric factors that contribute to the development of RE in patients with breast cancer treated with HFRT of regional lymph nodes. METHODS Between January and December 2022, we retrospectively analysed 64 patients with breast cancer who met our inclusion criteria underwent regional nodal intensity-modulated radiotherapy at a radiotherapy dose of 43.5 Gy/15F. RESULTS Of the 64 patients in this study, 24 (37.5%) did not develop RE, 29 (45.3%) developed grade 1 RE (G1RE), 11 (17.2%) developed grade 2 RE (G2RE), and none developed grade 3 RE or higher. Our univariable logistic regression analysis found G2RE to be significantly correlated with the maximum dose, mean dose, relative volume 20-40, and absolute volume (AV) 20-40. Our stepwise linear regression analyses found AV30 and AV35 to be significantly associated with G2RE (P &lt; 0.001). The optimal threshold for AV30 was 2.39 mL [area under the curve (AUC): 0.996; sensitivity: 90.9%; specificity: 91.1%]. The optimal threshold for AV35 was 0.71 mL (AUC: 0.932; sensitivity: 90.9%; specificity: 83.9%). CONCLUSION AV30 and AV35 were significantly associated with G2RE. The thresholds for AV30 and AV35 should be limited to 2.39 mL and 0.71 mL, respectively.

Lymphedema after regional nodal irradiation for breast cancer: a retrospective cohort study.

We aimed to analyze the occurrence of lymphedema as a side effect in patients who underwent regional nodal irradiation (RNI) following surgery for breast cancer. This retrospective study was conducted on patients with breast cancer who underwent surgery from July 2014 to October 2020 at Inje University Busan Paik Hospital. The analysis included 113 cT1-3N1-3M0 breast cancer patients who underwent RNI as part of radiotherapy (RT). Mostly, surgeries were performed using breast-conserving surgery (n = 99, 87.6%), except for 14 patients with modified radical mastectomy. The total RT dose for RNI was 45-60 Gy, and the fraction size was 1.8-2.0 Gy. Most patients underwent chemotherapy (n = 98, 86.7%), including taxanes (n = 92, 81.4%). The median follow-up was 61.1 months (range, 5.0-110.5 months). Lymphedema occurred in 54 patients (47.8%) after surgery. Twenty of them (17.7%) developed a new onset of lymphedema after RT, while 34 (30.1%) detected lymphedema before the completion of RT. Over the follow-up, 16 patients (14.2%) experienced recurrence. High radiation dose (>50.4 Gy) for RNI (P = 0.003) and taxane use (P = 0.038) were related to lymphedema occurrence after RT. Moreover, lymphedema occurrence after RT was also related to recurrence after surgical resection (P = 0.026). Breast-conserving surgery was related to early-onset lymphedema before the completion of RT (P = 0.047). Furthermore, the degree of lymph node dissection (≤4) was related to the overall occurrence of lymphedema (P = 0.045). Considering a reduction in RNI dose may be beneficial in mitigating the incidence of lymphedema after RT in patients with breast cancer.

Patient-reported outcomes in N1 breast cancer: A phase III trial comparing whole-breast to whole-breast plus regional irradiation after taxane-based chemotherapy (KROG 1701).

577 Background: Recent randomized trials have highlighted the benefits of regional node irradiation (RNI) in high-risk node-positive or pN1 breast cancer, yet its impact in the context of modern taxane-based adjuvant chemotherapy remains unclear. In this multi-center phase III trial, we study to prove the hypothesis that there is no difference in terms of disease-free survival between standard whole-breast irradiation (WBI) with RNI and WBI alone in pN1 breast cancer patients receiving taxane-based adjuvant chemotherapy. Comprehensive patient-reported outcomes (PROs) collected at multiple time points are now reported. Methods: The KROG 17-01 trial (NCT03269981), a prospective, multicenter, non-inferiority study, randomized patients with pN1 breast cancer after breast-conserving surgery and adjuvant taxane-containing chemotherapy to WBI or WBI+RNI. Both conventional and hypofractionated radiotherapy (RT) were allowed. PROs were assessed using the EORTC QLQ-C30 and QLQ-BR23 modules. All data were collected at baseline, during RT, and at follow-up intervals of 3-6 months, 1, 2, 3, 4, and 5 years post-treatment. Linear mixed models were used to compare PROs between treatment arms. Results: From April 2017 to December 2021, 840 patients were enrolled; 777 received intervention as assigned, and 750 completed baseline PRO questionnaires (387 in WBI+RNI, 363 in WBI). Overall, PRO domains improved over time (p&lt;0.001). During RT, the WBI+RNI group experienced more fatigue, nausea, and vomiting (p&lt;0.05), and reported lower global health (p=0.090) and physical functioning (p=0.049) with borderline significance compared to the WBI group. At 3-6 months post-RT, WBI+RNI group also showed higher arm symptom scores (p=0.030). Apart from these specific timepoints, no significant differences were observed in other PRO domain scores, including arm and breast symptoms, between treatment arms. In addition, there was no significant differences in PRO domains according to RT techniques and fractionation, except for breast symptoms during RT, favoring hypofractionation and intensity-modulated RT. Conclusions: In patients with pN1 breast cancer treated with taxane-based adjuvant chemotherapy, adding RNI was associated with minor, transient declines in specific PRO domains. However, these differences were not clinically significant, indicating comparable overall patient experiences between the two treatment arms. Clinical trial information: NCT03269981 .