Quantifying radiation in the axillary bed at the site of lymphedema surgical prevention.

PURPOSE: Immediate lymphatic reconstruction (ILR) is a procedure known to reduce the risk of lymphedema in patients undergoing axillary lymph node dissection (ALND). However, patients who receive adjuvant radiotherapy are at increased risk of lymphedema. The aim of this study was to quantify the extent of radiation at the site of surgical prevention. METHODS: We recently began deploying clips at the site of ILR to identify the site during radiation planning. A retrospective review was performed to identify breast cancer patients who underwent ILR with clip deployment and adjuvant radiation therapy from October 2020 to April 2022. Patients were excluded if they had not completed radiotherapy. The exposure and dose of radiation received by the site was determined and recorded. RESULTS: In a cohort of 11 patients, the site fell within the radiation field in 7 patients (64%) and received a median dose of 4280 cGy. Among these 7 patients, 3 had sites located within tissue considered at risk of oncologic recurrence and the remaining 4 sites received radiation from a tangential field treating the breast or chest wall. The median dose to the ILR site for the 4 patients whose sites were outside the radiation fields was 233 cGy. CONCLUSION: Our findings suggest that even when the site of surgical prevention was not within the targeted radiation field during treatment planning, it remains susceptible to radiation. Strategies for limiting radiation at this site are needed.

Cost-effectiveness analysis of endocrine therapy alone versus partial-breast irradiation alone versus combined treatment for low-risk hormone-positive early-stage breast cancer in women aged 70 years or older.

PURPOSE: We performed a cost-effectiveness analysis of three strategies for the adjuvant treatment of early breast cancer in women age 70 years or older: an aromatase inhibitor (AI-alone) for 5 years, a 5-fraction course of accelerated partial-breast irradiation using intensity-modulated radiation therapy (APBI-alone), or their combination. METHODS: We constructed a patient-level Markov microsimulation from the societal perspective. Effectiveness data (local recurrence, distant metastases, survival), and toxicity data were obtained from randomized trials when possible. Costs of side effects were included. Costs were adjusted to 2019 US dollars and extracted from Medicare reimbursement data. Quality-adjusted life-years (QALY) were calculated using utilities extracted from the literature. RESULTS: The strategy of AI-alone ($12,637) was cheaper than both APBI-alone ($13,799) and combination therapy ($18,012) in the base case. All approaches resulted in similar QALY outcomes (AI-alone 7.775; APBI-alone 7.768; combination 7.807). In the base case, AI-alone was the cost-effective strategy and dominated APBI-alone, while combined therapy was not cost-effective when compared to AI-alone ($171,451/QALY) or APBI-alone ($107,932/QALY). In probabilistic sensitivity analyses, AI-alone was cost-effective at $100,000/QALY in 50% of trials, APBI-alone in 28% and the combination in 22%. Scenario analysis demonstrated that APBI-alone was more effective than AI-alone when AI compliance was lower than 26% at 5 years. CONCLUSIONS: Based on a Markov microsimulation analysis, both AI-alone and APBI-alone are appropriate options for patients 70 years or older with early breast cancer with small cost differences noted. A prospective trial comparing the approaches is warranted.

The Diminishing Impact of Margin Definitions and Width on Local Recurrence Rates following Breast-Conserving Therapy for Early-Stage Invasive Cancer: A Meta-Analysis.

BACKGROUND: The optimal tumor-free margin definition and width following breast-conserving therapy (BCT) for early-stage invasive cancers has been evaluated in previous meta-analyses and guidelines. We performed an updated meta-analysis to assess how improvements in treatment over time have affected the impact of margins on local recurrence (LR) rates over time. METHODS: A systematic literature review identified 38 eligible studies comprising 54,502 patients treated between 1968 and 2010. Inclusion criteria included patients treated with BCT and minimum follow-up of 50 months, pathologic definitions of margin status explicitly stated, and LR data in relation to margin status. Data were pooled using a Bayesian logistic regression model to evaluate the risk of LR in relation to both margin status and study enrollment periods. RESULTS: Median follow-up was 7.25 years. Absolute LR rates decreased over time for each margin width cohort, with maximum differences between negative margin groups of less than 1% for the most recent enrollment period. However, relative rates of LR between different margin groups remained stable over time. CONCLUSIONS: With an additional 22,000 patients compared with the previous meta-analysis, this updated meta-analysis supports the consensus guideline of "no tumor on ink" for the majority of patients. Additionally, while concerns exist regarding a benefit with wider margins from previous studies, the analysis demonstrates the impact of margin width on LR rates has declined substantially over time, with very small differences between the narrowest and widest margin groups in the most recent cohort. Hence, older studies appear to have limited value to inform current management guidelines.

Local recurrence after breast-conserving therapy for phyllodes tumors: A 15-year retrospective review.

There are few data on the long-term outcomes of patients with phyllodes tumors following breast-conserving surgery with or without radiation therapy (RT). We reviewed 69 patients diagnosed from 2000 to 2015 with surgical specimens available for central pathology assessment for outcome in relation to histopathologic subtype, margin width, and utilization of RT. Median follow-up was 63 months (interquartile range, 35-131 months). Forty-eight patients had benign, 13 borderline, and eight malignant phyllodes tumors, with local recurrence rates of 4%, 0%, and 38%, respectively (P ≤ .04 comparing malignant lesions to both benign and borderline lesions). None of the eight patients who received RT suffered a local recurrence. Two of the 26 (8%) patients with benign phyllodes tumors who did not receive RT with margins that were positive or <1 mm had local recurrence, compared to none of 18 patients with margins 1 mm or wider who did not receive RT. The one patient with a malignant phyllodes tumor who did not receive RT with margins that were positive or <1 mm did not locally recur, while both patients with margins 10 mm or wider who did not receive RT had local recurrence. One patient with a malignant phyllodes tumor developed distant recurrence following local recurrence. Phyllodes histologic type and margin width were both associated with the risk of local recurrence following breast-conserving surgery without RT, though the number of events and patients was too small to show these trends were statistically significant.

Lymphedema Incidence After Axillary Lymph Node Dissection: Quantifying the Impact of Radiation and the Lymphatic Microsurgical Preventive Healing Approach.

BACKGROUND: Axillary surgery and radiotherapy are important aspects of breast cancer treatment associated with development of lymphedema. Studies demonstrate that Lymphatic Microsurgical Preventive Healing Approach (LYMPHA) may greatly reduce the incidence of lymphedema in high-risk groups. The objective of this study is to summarize the evidence relating lymphedema incidence to axillary lymph node dissection (ALND), regional lymph node radiation (RLNR) therapy, and LYMPHA. METHODS: We performed a literature search to identify studies involving breast cancer patients undergoing ALND with or without RLNR. Our primary outcome was the development of lymphedema. We analyzed the effect of LYMPHA on lymphedema incidence. We chose the DerSimonian and Laird random-effects meta-analytic model owing to the clinical, methodological, and statistical heterogeneity of studies. RESULTS: Our search strategy yielded 1476 articles. After screening, 19 studies were included. Data were extracted from 3035 patients, 711 of whom had lymphedema. The lymphedema rate was significantly higher when RLNR was administered with ALND compared with ALND alone (P < 0.001). The pooled cumulative incidence of lymphedema was 14.1% in patients undergoing ALND versus 2.1% in those undergoing LYMPHA and ALND (P = 0.029). The pooled cumulative incidence of lymphedema was 33.4% in those undergoing ALND and RLNR versus 10.3% in those undergoing ALND, RLNR, and LYMPHA (P = 0.004). CONCLUSION: Axillary lymph node dissection and RLNR are important interventions to obtain regional control for many patients but were found to constitute an increased risk of development of lymphedema. Our findings support that LYMPHA, a preventive surgical technique, may reduce the risk of breast cancer-related lymphedema in high-risk patients.

Treatment Strategies in Octogenarians with Early-Stage, High-Risk Breast Cancer.

BACKGROUND: Octogenarians with early-stage breast cancer often have low-risk tumor biology. However, optimal treatment strategies for those with high-risk biology remain unclear. METHODS: We reviewed the records of women ages 80-89 years with biopsy-proven, Stage I-II invasive breast cancer who were referred for surgical evaluation from January 2001 through December 2010. High-risk was defined as human epidermal growth factor receptor-positive (HER2+), triple-negative (TN), or histologic grade 3 disease. RESULTS: Among 178 patients, 40 (22%) were high-risk: 12 were grade 1-2 (10 HER2 + , 2 TN); 28 were grade 3 (7 HER2+, 6 TN, 15 estrogen receptor-positive (ER+)/HER2-). The high-risk group had larger tumors and more often had ductal histology and lymphovascular invasion than the low-risk group and was more likely to undergo mastectomy (18 vs. 5%, p = 0.02), radiotherapy (55 vs. 36%, p = 0.03), and chemotherapy (10 vs. 0%, p = 0.002). Endocrine therapy use was similar among ER+ patients in both groups. The four patients in the high-risk group given chemotherapy were HER2+ and received trastuzumab-based regimens, without any reported toxicities. At median follow-up of 67 months, 10% of the high-risk group had a recurrence (3 distant-only, 1 simultaneous locoregional and distant in a patient treated with mastectomy without radiotherapy). CONCLUSIONS: Tailored locoregional and systemic therapy resulted in low incidence of failure in these octogenarians with high-risk cancers with low morbidity. Modern adjuvant therapies should be considered for elderly women with high-risk cancers in the absence of significant comorbidities.

Breast-Conserving Surgery Alone for Ductal Carcinoma In Situ: Factors Associated with Increased Risk of Local Recurrence.

PURPOSE: This retrospective study was aimed at identifying clinicopathologic characteristics associated with an increased risk for ipsilateral local recurrence (LR) in patients with ductal carcinoma in situ (DCIS) treated with wide local excision (WLE) alone without radiotherapy (RT). METHODS: All patients with DCIS treated with WLE alone at the Beth Israel Deaconess Medical Center, Boston, MA, USA, between the years 2000 and 2010 were identified. We collected data on demographics, parity, personal or family history of breast cancer, exogenous hormone use, tobacco use, comorbidities, genetic mutation carrier status, imaging interval, and tumor-specific characteristics. RESULTS: Overall, 222 patients were included in the study. Median follow-up time was 8 years. LR occurred in 9% of patients, with a recurrence rate of 11.3 per 1000 person-years. The risk of recurrence was lower for patients with nuclear grade (NG) I tumors than for patients with NG II or NG III tumors (3, 8.5, and 19%, respectively; p = 0.01). The median margin width was 1 mm in patients experiencing LR versus 1.8 mm in patients without LR (p = 0.3). Patients who had used exogenous hormones, or patients with a history of tobacco use, had higher rates of LR than those who did not, although the difference did not reach statistical significance. CONCLUSIONS: Our data indicate that higher NG, narrower margin width, use of exogenous hormones, and smoking history may be associated with an increased risk of LR. The evaluation of these factors may be helpful when considering whether or not to use adjuvant RT for patients with DCIS.

Postmastectomy Radiotherapy: An American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology Focused Guideline Update.

PURPOSE: A joint American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology panel convened to develop a focused update of the American Society of Clinical Oncology guideline concerning use of postmastectomy radiotherapy (PMRT). METHODS: A recent systematic literature review by Cancer Care Ontario provided the primary evidentiary basis. The joint panel also reviewed targeted literature searches to identify new, potentially practice-changing data. RECOMMENDATIONS: The panel unanimously agreed that available evidence shows that PMRT reduces the risks of locoregional failure (LRF), any recurrence, and breast cancer mortality for patients with T1-2 breast cancer with one to three positive axillary nodes. However, some subsets of these patients are likely to have such a low risk of LRF that the absolute benefit of PMRT is outweighed by its potential toxicities. In addition, the acceptable ratio of benefit to toxicity varies among patients and physicians. Thus, the decision to recommend PMRT requires a great deal of clinical judgment. The panel agreed clinicians making such recommendations for individual patients should consider factors that may decrease the risk of LRF, attenuate the benefit of reduced breast cancer-specific mortality, and/or increase risk of complications resulting from PMRT. When clinicians and patients elect to omit axillary dissection after a positive sentinel node biopsy, the panel recommends that these patients receive PMRT only if there is already sufficient information to justify its use without needing to know additional axillary nodes are involved. Patients with axillary nodal involvement after neoadjuvant systemic therapy should receive PMRT. The panel recommends treatment generally be administered to both the internal mammary nodes and the supraclavicular-axillary apical nodes in addition to the chest wall or reconstructed breast.

Clinical Utility of the 12-Gene DCIS Score Assay: Impact on Radiotherapy Recommendations for Patients with Ductal Carcinoma In Situ.

OBJECTIVE: The aim of this study was to determine the impact of the results of the 12-gene DCIS Score assay on (i) radiotherapy recommendations for patients with pure ductal carcinoma in situ (DCIS) following breast-conserving surgery (BCS), and (ii) patient decisional conflict and state anxiety. METHODS: Thirteen sites across the US enrolled patients (March 2014-August 2015) with pure DCIS undergoing BCS. Prospectively collected data included clinicopathologic factors, physician estimates of local recurrence risk, DCIS Score results, and pre-/post-assay radiotherapy recommendations for each patient made by a surgeon and a radiation oncologist. Patients completed pre-/post-assay decisional conflict scale and state-trait anxiety inventory instruments. RESULTS: The analysis cohort included 127 patients: median age 60 years, 80 % postmenopausal, median size 8 mm (39 % ≤5 mm), 70 % grade 1/2, 88 % estrogen receptor-positive, 75 % progesterone receptor-positive, 54 % with comedo necrosis, and 18 % multifocal. Sixty-six percent of patients had low DCIS Score results, 20 % had intermediate DCIS Score results, and 14 % had high DCIS Score results; the median result was 21 (range 0-84). Pre-assay, surgeons and radiation oncologists recommended radiotherapy for 70.9 and 72.4 % of patients, respectively. Post-assay, 26.4 % of overall recommendations changed, including 30.7 and 22.0 % of recommendations by surgeons and radiation oncologists, respectively. Among patients with confirmed completed questionnaires (n = 32), decision conflict (p = 0.004) and state anxiety (p = 0.042) decreased significantly from pre- to post-assay. CONCLUSIONS: Individualized risk estimates from the DCIS Score assay provide valuable information to physicians and patients. Post-assay, in response to DCIS Score results, surgeons changed treatment recommendations more often than radiation oncologists. Further investigation is needed to better understand how such treatment changes may affect clinical outcomes.

Persistence of dysphagia and odynophagia after mediastinal radiation and chemotherapy in patients with lung cancer or lymphoma.

Esophageal symptoms are common during radiation and chemotherapy. It is unclear how often these symptoms persist after therapy. We retrospectively reviewed medical records of 320 adults treated for nonmetastatic breast cancer (84), lung cancer (109), or Hodgkin and non-Hodgkin lymphoma (127) who were disease-free at 10-14 months after therapy. Treatment included chemotherapy with or without nonmediastinal radiation therapy (150 patients), chemotherapy plus sequential mediastinal radiation therapy (MRT) (48 patients), chemotherapy plus concurrent MRT (61 patients), or non-MRT only (61 patients). Proton pump inhibitor use was documented. All treatment groups had similar prevalence of the esophageal symptom of heartburn before therapy. Rates were higher during treatment in those who received MRT with or without chemotherapy, but declined by 10-14 months after treatment. However, low baseline rates of dysphagia (4%) and odynophagia (2%) increased significantly after combined chemotherapy and MRT to 72% for dysphagia and 62% for odynophagia (P < 0.01) during treatment and stayed significantly elevated over baseline with 27% of the patients having dysphagia and 11% having odynophagia at 10-14 months after treatment. The use of proton pump inhibitors by patients who had MRT with chemotherapy was significantly increased during and after treatment (P = 0.002). Dysphagia, odynophagia and the use of proton pump inhibitors were significantly more common both during and after treatment than before treatment in patients who received both chemotherapy and mediastinal radiation. Our data highlight the important challenge for clinicians of managing patients with lung cancer and lymphoma who have persistent esophageal problems, particularly dysphagia and odynophagia, at approximately 1 year after treatment.

Early-Stage Breast Cancer in the Octogenarian: Tumor Characteristics, Treatment Choices, and Clinical Outcomes.

BACKGROUND: Nodal staging with sentinel node biopsy (SLNB), post-lumpectomy radiotherapy (RT), and endocrine therapy (ET) for estrogen receptor-positive (ER+) tumors is valuable in the treatment of early-stage (stages 1 or 2) breast cancer but used less often for elderly women. METHODS: This retrospective study investigated women referred for surgical evaluation of biopsy-proven primary early-stage invasive breast cancer from January 2001 to December 2010. Clinicopathologic features, treatment course, and outcomes for women ages 80-89 years and 50-59 years were compared. RESULTS: The study identified 178 eligible women ages 80-89 years and 169 women ages 50-59 years. The elderly women more often had grade 1 or 2 disease (p = 0.003) and ER+ tumors (p = 0.007) and less frequently had undergone adjuvant therapies (all p ≤ 0.001). Lumpectomy was performed more commonly for the elderly (92 vs. 83 %, p = 0.02), and axillary surgery was less commonly performed (46 vs. 96 %; p < 0.001). Fewer elderly women had undergone post-lumpectomy RT (42 vs. 89 %; p < 0.001) and ET for ER+ tumors (72 vs. 95 %; p < 0.001). During the median follow-up period of 56 months for the 80- to 89-year old group and 98 months for the 50- to 59-year-old group, death from breast cancer was similar (4 vs. 5 %; p = 0.5). The two groups respectively experienced 7 versus 6 locoregional recurrences and 11 versus 13 distant recurrences. CONCLUSIONS: The octogenarians had disease survivorship similar to that of the younger women despite less frequent use of adjuvant therapies, likely reflecting lower-risk disease features. Whether increased use of axillary surgery, post-lumpectomy RT, and/or ET for ER+ tumors would further improve outcomes is an important area for further study, but treatment should not be deferred solely on the basis of age.

Internal Mammary Node Irradiation Debate: Case Closed? Not Yet, and Maybe Never.

The IMN debate is still open and may never be closed for reasons outlined in this Comments and Controversies piece.

Lumpectomy without radiation for ductal carcinoma in situ of the breast: 20-year results from the ECOG-ACRIN E5194 study.

We report the 20-year rate of ipsilateral breast event (IBE) for patients with ductal carcinoma in situ (DCIS) treated with lumpectomy without radiation on a non-randomized prospective clinical trial. Patients were enrolled in cohort 1: low- or intermediate-grade DCIS, size ≤ 2.5 cm (n = 561); or cohort 2: high-grade DCIS, size ≤ 1 cm (n = 104). The Kaplan-Meier method was used to estimate time-to-event distributions. Cox proportional hazard methods were used to estimate hazard ratios (HRs) and tests for significance for event times. 561 patients were enrolled in cohort 1 and 104 in cohort 2. After central pathology review, 26% in cohort 1 were recategorized as high-grade and 26% in cohort 2 as low- or intermediate-grade. Mean DCIS size was similar at 7.5 mm in cohort 1 and 7.8 mm in cohort 2. Surgical margin was ≥3 mm in 96% of patients, and about 30% received tamoxifen. Median follow-up was 19.2 years. There were 104 IBEs, of which 54 (52%) were invasive. The IBE and invasive IBE rates increased in both cohorts up to 15 years, then plateaued. The 20-year IBE rates were 17.8% for cohort 1 and 28.7% for cohort 2 (p = 0.005), respectively. Invasive IBE occurred in 9.8% and 15.1% (p = 0.09), respectively. On multivariable analysis, IBE risk increased with size and was higher in cohort 2, but grade and margin width were not significantly associated with IBE. For patients with DCIS treated with excision without radiation, the rate of IBE increased with size and assigned cohort mostly in the first 15 years.

Omission of Radiotherapy After Breast-Conserving Surgery for Women With Breast Cancer With Low Clinical and Genomic Risk: 5-Year Outcomes of IDEA.

PURPOSE: Multiple studies have shown a low risk of ipsilateral breast events (IBEs) or other recurrences for selected patients age 65-70 years or older with stage I breast cancers treated with breast-conserving surgery (BCS) and endocrine therapy (ET) without adjuvant radiotherapy. We sought to evaluate whether younger postmenopausal patients could also be successfully treated without radiation therapy, adding a genomic assay to classic selection factors. METHODS: Postmenopausal patients age 50-69 years with pT1N0 unifocal invasive breast cancer with margins ≥2 mm after BCS whose tumors were estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor 2-negative with Oncotype DX 21-gene recurrence score ≤18 were prospectively enrolled in a single-arm trial of radiotherapy omission if they consented to take at least 5 years of ET. The primary end point was the rate of locoregional recurrence 5 years after BCS. RESULTS: Between June 2015 and October 2018, 200 eligible patients were enrolled. Among the 186 patients with clinical follow-up of at least 56 months, overall and breast cancer-specific survival rates at 5 years were both 100%. The 5-year freedom from any recurrence was 99% (95% CI, 96 to 100). Crude rates of IBEs for the entire follow-up period for patients age 50-59 years and age 60-69 years were 3.3% (2/60) and 3.6% (5/140), respectively; crude rates of overall recurrence were 5.0% (3/60) and 3.6% (5/140), respectively. CONCLUSION: This trial achieved a very low risk of recurrence using a genomic assay in combination with classic clinical and biologic features for treatment selection, including postmenopausal patients younger than 60 years. Long-term follow-up of this trial and others will help determine whether the option of avoiding initial radiotherapy can be offered to a broader group of women than current guidelines recommend.

Matched-pair and propensity score comparisons of outcomes of patients with clinical stage I non-small cell lung cancer treated with resection or stereotactic radiosurgery.

BACKGROUND: Stereotactic body radiotherapy (SBRT) is an alternative to surgery for clinical stage I non-small cell lung cancer (NSCLC), but comparing its effectiveness is difficult because of differences in patient selection and staging. METHODS: Two databases were combined which contained patients treated from 1999 to 2008 by lobectomy (LR, n = 132), sublobar resection (SLR, n = 48), and SBRT (n = 137) after negative staging. Univariate and multivariate analysis were performed for survival (OS), total recurrence control (TRC comprises local-regional and distant control), and locoregional control (LRC) in our entire population. A matched-pair analysis was also performed that compared surgery and SBRT results. Median follow-up for the entire study population was 25.8 months. RESULTS: On univariate analysis, OS was significantly worse with SBRT and also correlated with histology, the Charlson comorbidity index, tumor size, and aspirin use; TRC correlated only with histology; and no variable significantly correlated with LRC. OS was significantly poorer for SBRT in the matched-pair analysis than for patients treated with surgery, but TRC and LRC were not significantly different between these groups. Multivariate analyses including propensity score as a covariate (controlling for all factors affecting treatment selection) found that OS correlated only with Charlson comorbidity index, and TRC correlated only with tumor grade. LRC correlated only with tumor size with or without propensity score correction. CONCLUSIONS: This retrospective study has demonstrated similar OS, LRC, and TRC with SBRT or surgery after controlling for prognostic and patient selection factors. Randomized clinical trials are needed to better compare the effectiveness of these treatments.

Trade-offs associated with axillary lymph node dissection with breast irradiation versus breast irradiation alone in patients with a positive sentinel node in relation to the risk of non-sentinel node involvement: implications of ACOSOG Z0011.

Recent data suggest that axillary lymph node dissection (ALND) may be unnecessary for patients with positive sentinel lymph node biopsy (SLNB) receiving whole-breast irradiation (ACOSOG Z0011). The purpose of this study was to use decision analysis with simulated patients to determine subgroups with positive SLNB who may still benefit from ALND. We performed a decision analysis simulating axillary recurrence (ALR) risk, lymphedema, and quality of life following breast-conserving surgery (BCS) with positive SLNB and either completion ALND and whole-breast radiation (ALND + BRT) or breast radiation (BRT) alone. Simulated patients were divided into two risk groups based on the likelihood of disease in non-sentinel axillary nodes after positive SLNB: those with risk 30-60 % ("high-risk") and those with risk under 30 % ("low-risk," similar to average Z0011 patients). In simulated patients aged 55, BRT alone resulted in 1 month of additional QALE in the low-risk group versus ALND + BRT, while ALND + BRT resulted in 9.7 months of additional QALE in the high-risk group versus BRT alone. Overall survival was similar at 5 years in this simulation with either treatment in both groups, but ALND + BRT was superior to BRT alone at 20 years in the high-risk group (42 vs. 38 %). In the low-risk group, BRT alone is preferable unless ALR risk with BRT is greater than 1.6 % or lymphedema risk with ALND is under 10 %. Patients eligible for Z0011 but at a higher risk of residual nodal disease following BCS and positive SLNB may benefit from ALND + BRT, rather than BRT alone.

A Prospective Study of Radiation Therapy After Immediate Lymphatic Reconstruction: Analysis of the Dosimetric Implications.

PURPOSE: Axillary lymph node dissection (ALND) and regional nodal irradiation (RNI) are the primary causes of breast cancer-related lymphedema (BCRL). Immediate lymphatic reconstruction (ILR) is a novel surgical procedure that reduces the incidence of BCRL after ALND. The ILR anastomosis is placed in a location thought to be outside the standard radiation therapy fields to prevent radiation-induced fibrosis of the reconstructed vessels; however, there is excess risk of BCRL from RNI even after ILR. The purpose of this study was to understand the radiation dose distribution in relation to the ILR anastomosis. METHODS AND MATERIALS: This prospective study included 13 patients treated with ALND/ILR from October 2020 to June 2022. A twirl clip deployed during surgery was used to identify the ILR anastomosis site during radiation treatment planning. All cases were planned using a 3D-conformal technique with opposed tangents and an obliqued supraclavicular (SCV) field. RESULTS: RNI deliberately targeted axillary Levels 1 to 3 and the SCV nodal region in 4 patients and was limited to Level 3 and SCV nodes in 9 patients. The ILR clip was located in Level 1 in 12 patients and Level 2 in 1 patient. In patients with radiation directed at only Level 3 and SCV, the ILR clip was still within the radiation field in 5 of these patients and received a median dose of 3939 cGy (range, 2025-4961 cGy). The median dose to the ILR clip was 3939 cGy (range, 139-4961 cGy) for the entire cohort. The median dose was 4275 cGy (range, 2025-4961 cGy) when the ILR clip was within any radiation field and 233 cGy (range, 139-280 cGy) when the clip was outside all fields. CONCLUSION: The ILR anastomosis was often directly irradiated with 3D-conformal techniques and received substantial radiation dose, even when the site was not deliberately targeted. Long-term analysis will help determine whether minimizing radiation dose to the anastomosis will decrease BCRL rates.

Cost-Effectiveness Analysis of Ultra-Hypofractionated Whole Breast Radiation Therapy Alone Versus Hormone Therapy Alone or Combined Treatment for Low-Risk ER-Positive Early Stage Breast Cancer in Women Aged 65 Years and Older.

PURPOSE: The optimal management of early-stage, low-risk, hormone-positive breast cancer in older women remains controversial. Recent trials have shown that 5-fraction ultrahypofractionated whole-breast irradiation (U-WBI) has similar outcomes to longer courses, reducing the cost and inconvenience of treatment. We performed a cost-utility analysis to compare U-WBI to hormone therapy alone or their combination. METHODS AND MATERIALS: We simulated 3 different treatment approaches for women age 65 years or older with pT1-2N0 ER-positive invasive ductal carcinoma treated with lumpectomy with negative margins using a Markov microsimulation model. The strategies were U-WBI performed with a 3-dimensional conformal technique over 5 fractions without a boost ("radiation therapy [RT] alone"), adjuvant hormone therapy (anastrozole for 5 years) without RT ("aromatase-inhibitor [AI] alone"), or the combination of the 2. The combination strategy was calibrated to match trial results, and the relative effectiveness of the RT alone and AI alone strategies were inferred from previous randomized trials. The primary endpoint was the cost-effectiveness of the 3 strategies over a lifetime horizon as measured by the incremental cost-effectiveness ratio (ICER), with a value of $100,000/quality-adjusted life-year deemed "cost-effective." RESULTS: The model results compared with the prespecified target outcomes. On average, RT alone was the least expensive strategy ($14,775), with AI alone slightly more ($14,998), and combination therapy the costliest ($19,802). RT alone dominated AI alone (the incremental cost-effectiveness ratio [ICER] -$5089). Combination therapy, compared with RT alone, was slightly more expensive than our definition of cost-effective (ICER $113,468) but was cost-effective compared with AI alone (ICER $54,451). Probabilistic sensitivity analysis demonstrated RT alone to be cost-effective in 50% of trials, with combination therapy in 36% and AI alone in 14%. CONCLUSIONS: U-WBI alone appears the more cost-effective de-escalation strategy for these low-risk patients, compared with AI alone. Combining U-WBI and AI appears more costly but may be preferred by some patients.