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Radiotherapy (RT) is an effective and standard treatment for bone metastases. While data supporting the superiority of treatment with > 5 fractions for any and > 1 fraction for uncomplicated bone metastases are limited, longer treatment courses are routinely used. We report our ongoing efforts to promote use of shorter treatment courses within a statewide quality consortium. Consecutive patients receiving RT for bone metastases from primary breast, lung, melanoma, prostate, or renal cancer(s) between 3/1/18 and 6/30/23 were prospectively enrolled in the Michigan Radiation Oncology Quality Consortium database. Quality metrics promoting use of single fraction RT for uncomplicated bone metastases and ≤5 fraction RT for all bone metastases were introduced in 1/1/20 and 1/1/22, respectively. Uncomplicated metastases were defined as painful, not previously irradiated, and not associated with spinal cord or nerve root compression, fracture, surgery, or a soft tissue component. SBRT plans were excluded from the ≤5 fraction analysis given that all were ≤5 fractions. Patient, treatment, physician, and facility characteristics were captured. Mixed models with a random intercept for centers were generated with significance defined as p<0.05. In total, 2,700 patients were enrolled across 29 treatment facilities. Among all patients, 1890 of 3760 (50.3%) unique treatment plans were delivered in ≤5 fractions. From 2018 to 2023, observed annual rates of ≤5 fraction regimens increased from 32% to 67%. Among 825 patients treated for uncomplicated metastases, 327 of 1089 (30%) unique treatment plans utilized a single fraction. From 2018 to 2023, observed annual rates of single fraction use increased from 15% to 40%. Significant predictors of ≤5 fraction use and single fraction use are summarized in Table 1. Our efforts to shorten treatment courses for bone metastases in our statewide quality consortium have been successful. The number and variety of factors that predict the use of shorter courses highlight the complexity of the decision making when treating these patients. [ABSTRACT FROM AUTHOR]

Managing locally advanced non-small cell lung cancer (LA-NSCLC) includes chemoradiation and immunotherapy, presenting risks for delayed cardiac and pulmonary complications. This study hypothesizes that certain patient and treatment-related characteristics are predictors for these adverse events. We aim to quantify the incidence of post-treatment cardiac and pulmonary hospitalizations in LA-NSCLC patients and identify predictors to personalize treatment. A prospectively gathered database of LA-NSCLC patients undergoing radiation in a statewide multicenter quality consortium was analyzed. From 2018 to 2023, hospitalization data due to lung and heart complications were compiled annually. Death and hospice entry were treated as competing risks when estimating cumulative incidence. Utilizing univariate and multivariate models, we explored potential associations with several patient demographic and treatment factors, including planning target volume (PTV), oxygen dependency, Eastern Cooperative Oncology Group (ECOG) performance status, Chronic Obstructive Pulmonary Disease (COPD), and radiation treatment dosimetry. Follow-up time ranged from 1 to 5 years post RT, with 1 year of follow-up in 66% (405/613) and 2 or more years of follow-up in 34% (208). In total, 128 patients were hospitalized for lung-related complications including COPD exacerbation (n = 44), pneumonia (n = 64), and pneumonitis (n = 17). Cardiac events led to hospitalization in 40 patients including arrhythmias (n = 20), congestive heart failure (CHF) (n = 8), pericardial effusion (n = 3), and myocardial infarctions (n = 8) The cumulative incidence of any lung-related hospitalization was 0.16 at one year and 0.28 at 3 years. The 1- and 3-year cumulative incidence of any cardiac-related hospitalization was 0.04 and 0.09 respectively. Notable predictors (p<0.05) of any lung and any cardiac related hospitalizations included ECOG status and baseline oxygen dependency. Mean lung dose and ECOG were identified as jointly significant predictors of pneumonitis-related admissions. Those treated with immunotherapy showed a reduced rate of cardiac admissions, likely due to healthier patients being selected for such therapies. Additionally, mean heart dose, was a significant predictor of any lung hospitalization, signifying a nuanced interaction of cardiopulmonary complications. This "real world" analysis of a large prospectively gathered data from a statewide consortium has revealed significant associations between mean heart dose and ECOG performance status with the incidence of cardiac and pulmonary hospitalizations following LA-NSCLC treatment. Understanding these relationships further is necessary for the implementation of risk-tailored, patient-specific treatment modalities, aiming to improve long term quality of life of LA-NSCLC patients. [ABSTRACT FROM AUTHOR]

For patients receiving radiation therapy for non-small cell lung cancer (NSCLC), unplanned interruptions prolong the treatment course and may be associated with adverse outcomes. However, little is known regarding patient and treatment planning characteristics that contribute to interruptions. The purpose of this study was to characterize the frequency, type duration and predictors of interruptions in radiation therapy in patients with NSCLC treated with conventional fractionation throughout a statewide quality collaborative. Clinical and dosimetric data as well as frequency and duration of treatment interruptions (> or ≤ 5 days) were prospectively collected by 29 institutions within the Michigan Radiation Oncology Quality Consortium between 2012 and 2024 for patients with NSCLC treated with conventional fractionation using a physician-assessed survey. In version 1 of the survey (2012 to August 2017) data regarding toxicity breaks only were recorded. In version 2 of the survey (September 2017 to 2024) data regarding both any treatment interruption and toxicity breaks were recorded. We modeled the influence of patient, disease and treatment characteristics including mean and other radiation dose metrics for lung, heart and esophagus on the odds of any treatment interruption using multivariate logistic regression. Toxicity breaks were reported in 9% (131/1476) of patients and toxicity breaks greater than 5 days were reported in 3.5% (51/1476) of patients. Any treatment interruption was reported in 18% (154/867) of patients and toxicity breaks were reported in 6% (56/867) of patients enrolled during version 2 of the survey. Stepwise modeling identified a MV model for any toxicity break including heart V10Gy (OR per 10% increase = 1.16, p = 0.001), concurrent chemotherapy (Yes vs No = 2.67, p = 0.024) and ECOG (OR per 1 point increase = 1.91, p<0.001). In this model, all of the other tested heart dose metrics (mean and V10-V60) were significant predictors for any toxicity break and mean esophagus dose was not a significant predictor for any toxicity break. Stepwise modeling identified a MV model for toxicity break > 5 days including heart V10Gy (OR per 10% increase = 1.12, p<0.001) and ECOG (OR per 1 point increase = 1.87, p <0.001). Additionally, stepwise modeling selected smoking status (p = 0.05), ECOG (p<0.01) and lung V10Gy (p<0.01) as jointly significant predictors of any toxicity related break. PTV volume was not associated with treatment interruptions in all 3 models. Both clinical and dosimetric factors are associated with treatment interruptions in patients with NSCLC undergoing conventional fractionation. Efforts should be made to identify patients at increased risk of interruptions to optimize treatment planning and minimize toxicity. [ABSTRACT FROM AUTHOR]

Acute radiation dermatitis (ARD) is a common toxicity in breast radiotherapy (RT). There is a plethora of topical treatments that physicians prescribe, or patients use, with little consensus or data to guide recommendations. Here we attempt to review the use of preventive therapy (PT) versus reactive therapy for ARD in breast cancer patients and to determine if there is an association between the use of PT and improvement in patient reported outcomes (PROs). Patients receiving RT (conventional or hypofractionation, with or without boost) to the breast from 1/1/2012-12/31/2020 were prospectively enrolled in a statewide quality consortium. Included patients had completed the baseline PROs form for week 1 of therapy through final week. A PT was defined as topical "aloe vera/plant gel, Eucerin, Aquaphor, lotion/cream, Calendula/my girls, or Vaseline," used at baseline – defined as first week of radiotherapy. All other topical therapies administered after first week were defined as reactive. Patient groups were compared using chi-squared test via the data management and decision management software. 8386 patients met inclusion criteria. 34 unique topicals were reported as used by patients. 3403 patients (40%) reported use of a PT during 1st week of RT (baseline). The percentage of patients using reactive treatment increased steadily throughout the course of RT; 16% at week 2 and 39% by final week but was more frequently used by patients who had not initiated PT at baseline (35.9% vs. 30.7% P <0.0001). Patients who used a PT at baseline were less likely to report subsequent skin peeling (23% vs 15.5%, P <0.001) or redness in the treated breast (55.8% vs 40.5%). However, these patients were more likely to report hurting (20.4% vs 17.8%, P = 0.0084), stinging (22% vs 20%, P = 0.0481), itching (24.1% vs 21%, P = 0.0023), and pain (27.8% vs 23.5%, P <0.0001), than patients not initiated on a topical PT at start of treatment. The association of redness varied across race with white patients (59.6% vs 42.2%, P <0.001) and, "other" patients (58.5% vs 41.3% P = 0.0153) reporting significantly less redness with the use of PT. No significant association was found for black patients (33.9% vs 32.6%). The use of topical PT and RT for ARD in breast RT is common and variable. PT reduced breast redness for white and "other" patients but not black patients, highlighting the limitations of assessing the full extent of skin toxicities in women of color. Further, white patients may be more aggressively treated with reactive therapies because erythema is more apparent. Patients of any race who use a PT are less likely to report skin peeling. Discordantly, use of a PT was associated with statistically more, though small absolute difference, in pain. This may be due to separate processes mediating desquamation versus breast pain, with topical treatment only impacting the former. [ABSTRACT FROM AUTHOR]

Patients with cancer who use cannabis frequently note pain as a reason for their cannabis use. Available data do support cannabis use for management of pain in some settings, though the effectiveness of cannabis for cancer-associated pain is less clear. Based on limited data, some have suggested that cannabis might be used as an alternative to opiates for management of cancer-related pain. We sought to determine the relationship between cannabis use and opioid use in a multicenter cohort of patients undergoing radiotherapy for bone metastases. On January 1, 2021, questions about cannabis use were added to Michigan Radiation Oncology Quality Consortium (MROQC) questionnaires for bone metastasis patients. Pain scores, opioid use, social, demographic, and disease characteristics were also prospectively collected. A multivariable model using logistic regression identified associations between recent cannabis use and opioid use, accounting for relevant patient and disease characteristics. Since questions on cannabis were introduced, 2,096 patients have been enrolled. A total of 1143 of 2096 (54.5%) completed questionnaires about recent cannabis use; 1912 of 2096 (91%) completed questionnaires about current opioid use; and 1064 of 2096 (51%) completed both. Among those who completed both, 132 of 1064 (12%) reported recent opioid and cannabis use, 320 of 1064 (30%) reported recent opioid but not cannabis use, 57 of 1064 (5%) reported no recent opioid but recent cannabis use, 281 of 1064 (26%) reported no recent opioid or cannabis use, and the remaining individuals (274/1064 [26%]) declined to answer cannabis use questions by selecting "decline to answer". In a multivariable model, cannabis use [OR = 2.11 (95% CI = 1.37, 3.26) P = 0.001], along with pain score [Score 1-3 vs 0, OR = 2.32 (95% CI = 1.36, 3.94); Score 4-7 vs 0, OR = 6.55 (95% CI = 4.06, 10.6); Score 8-10 vs 0, OR = 11.20 (95% CI = 6.32, 19.8), P < 0.001], NSAID use [OR = 1.66 (95% CI = 1.17, 2.37) P = 0.005], prior systemic therapy [OR = 0.54 (95% CI = 0.37, 0.78) P = 0.005], and number of metastatic lesions [3-5 vs 1-2, OR = 1.57 (95% CI = 0.95, 2.26); 5-10 vs 1-2, OR = 1.54 (95% CI = 0.91, 2.59); 11+ vs 1-2, OR = 3.26 (95% CI = 2.06, 5.15) P < 0.001] predicted opiate use while age, gender, and race did not. Patients with bone metastases frequently use cannabis, opioids, or both. Though it has been suggested that cannabis availability might reduce opioid use among patients with cancer, our finding that cannabis use predicts opioid use does not support this hypothesis. These data suggest a more complex relationship between cannabis use and opioid use in this population. Further study is needed to assess risks of concurrent cannabis and opioid use and to explore patient rationale for concurrent usage. [ABSTRACT FROM AUTHOR]

National guidelines on LS-SCLC treatment give preference to a hyperfractionated regimen of 45 Gy in 30 fractions (Fx) delivered twice-daily (BID) but allow for daily fractionation (QD) to 60-70 Gy in certain circumstances. Use of the BID regimen has been reportedly low, however this is based upon small retrospective series, national databases that lack radiation treatment specifics, or survey data. We sought to characterize the fractionation regimens used to treat LS-SCLC in actual practice across academic and community settings and analyze factors associated with fractionation and toxicity. As part of a quality improvement initiative, the Michigan Radiation Oncology Quality Consortium prospectively collects clinical, dosimetric, and physician- and patient-reported outcomes data from patients treated for lung cancer at 29 institutions, which represent about 60% of the radiation oncology volume in the state. Between 2012 and 2021, 3,962 lung cancer cases were enrolled. Of those, 680 (17%) had SCLC histology and the 502 patients with LS-SCLC and known fractionation regimen represent the population studied here. Among the 502 LS-SCLC patients, 98% were current or former smokers (50 pack-year mean) and 98% received chemotherapy. In total, 73 (15%) were treated BID to a median dose of 45 Gy / 30 Fx (IQR same) and 429 (85%) were treated QD to a median dose of 60 Gy / 30 Fx (IQR 60-64.8 Gy / 30-36 Fx). The proportion of patients treated BID did not vary by practice setting or demographics except those treated BID were significantly more likely to be married or living with someone (64% vs 51%, p=0.035). There was no difference between the groups in baseline clinical factors such as performance status, weight loss, comorbidities, or pulmonary function. QD treated patients were more likely to experience a treatment break due to toxicity (24% vs 6%, p<0.01) despite no differences in physician-reported toxicity or patient-reported swallowing difficulty at the end of treatment. However, BID treated patients did report twice the rate of difficulty swallowing solids at 1 month (42% vs 19%, p<0.01). Despite evidence in its favor, the twice-daily fractionation regimen for LS-SCLC remains infrequently prescribed (15%) in a large multicenter prospectively collected cohort. BID treated patients were more likely to be married or living with someone, perhaps relating to the logistic burden of BID treatment. Despite similar end of treatment toxicity, QD treated patients had more treatment breaks. However, BID treated patients had twice the rate of swallowing difficulty at 1 month suggesting BID toxicity may peak later than QD toxicity, which is consistent with prior reports. Analysis of late toxicity, chemotherapy specifics, and additional physician- and patient-reported outcomes is ongoing. [ABSTRACT FROM AUTHOR]

Randomized trials support a supplemental radiation dose (Boost) to the lumpectomy (L) cavity region after whole breast irradiation (WBI), providing a 20-30% relative reduction of in-breast recurrence (IBR); with the disadvantage that it extends treatment duration ⁓ 1 week. Hypofractionated WBI (H-WBI) in ≤ 3 weeks is used after L to deliver adjuvant WBI with acceptable toxicity and comparable IBR as conventional WBI (C-WBI) 50 Gy in 2 Gy fractions (F). NRG RTOG 1005 sought to determine whether a boost delivered concomitantly with H-WBI over 15 F is non-inferior for IBR compared to boost delivered sequentially after C-WBI in patients (pts) considered at High Risk of IBR. Protocol-specified High Risk pts post L with stages 0, I & II breast cancer were randomized to C-WBI 50 Gy in 25 F or 42.7 Gy in 16 F plus sequential boost of 12 Gy in 6 F or 14 Gy in 7 F (Arm I) or H-WBI 40 Gy in 15 F plus concomitant boost of 8 Gy in 15 F of 0.53 Gy per day (Arm II). Radiation was target based 3-dimensional conformal radiation therapy (3DCRT) or intensity modulated radiation therapy (IMRT) and quality review (QA) was required. Stratification was by age (<50 vs ≥ 50), adjuvant chemotherapy (Y vs N), ER status (+ vs -) and histologic grade (1, 2 v 3). The primary endpoint is IBR. Assuming Arm I 5‐year IBR of 1.59%, 90% CI upper bound hazard ratio (HR) of 2.12 and 1‐sided significance level = 0.05, 2150 pts with at least 46 IBR events provide >80% power to conclude non‐inferiority. IBR was analyzed comparing the cause-specific hazards. Adverse Events (AE) were graded with NCI CTCAE v4. Physician-reported NRG-RTOG Global Cosmetic Score (GCS) was grouped as excellent/good vs fair/poor, and arms compared with chi-square. 2262 of 2354 randomized pts were eligible (Arm I n=1124; Arm II n=1138). Median age 55 years, 34% Stage II, 52% grade 3, 30% ER-, 17% close/+ margins consistent with a "High Risk" population. Radiation was 3DCRT 81%, IMRT 19%, and the QA was per protocol 81% and 88% on Arm I vs II, respectively. With a median follow-up of 7.3 years and 56 IBR events, the 5 and 7-year IBR were 2.0% and 2.2% on Arm I and 1.9% and 2.6% on Arm II. The non-inferiority comparison (Arm I reference level) resulted in a HR (90% CI): 1.32 (0.84, 2.05) and p = 0.039, thus meeting non-inferiority. No differences in AEs noted between arms, with low rates of ≥ grade 3 treatment-related AEs, 3.3% vs 3.5% for Arm I vs II, respectively (p=0.79). No difference in 3-year excellent/good cosmesis by arm: 86% for Arm I vs 84% Arm II (p=0.61). Concomitant boost with H-WBI results in non-inferior IBR compared to sequential boost after C-WBI in high-risk cases and reduces overall treatment time. Using target based 3DCRT or IMRT, there are no differences in toxicity or cosmetic outcome for concomitant v sequential boost or the WBI fractionation regimen. [ABSTRACT FROM AUTHOR]

Purpose/objective(s): Early concerns were raised about higher rates of radionecrosis (RN) with concurrent use of immune checkpoint inhibition (ICI) and stereotactic radiotherapy (SRT) for brain metastases (BM). We sought to clarify if this same concern translated to linear accelerator-based SRT for BM.Materials/methods: We retrospectively reviewed cases of SRT delivered at a single institution for BM (2004-2019). In total, 251 patients and 723 courses of treatment were analyzed on a per-treatment basis for any grade RN. RN was graded by CTCAE v5 and defined as an enlarging lesion after SRT that resolved spontaneously, resolved with steroids, or was surgically resected and found to have no viable tumor. Differences were assessed with Chi-squared, Kaplan-Meier, and univariable/multivariable Cox regression analyses with candidate variables including timing of ICI with SRT (neoadjuvant, concurrent defined as within 3 months, or adjuvant), primary histology, and symptomatic vs not at time of BM diagnosis, among others.Results: In total, 251 patients received SRT for BM: 53 without ICI, 58 neoadjuvant ICI, 102 concurrent ICI, and 38 adjuvant ICI. Median follow up for the surviving patients who received any ICI was 24.0 months (IQR 7.6-41.4) and not different from those without ICI at 26.8 months (IQR 8.8-45.6) (P = 0.22) with 38% of patients alive at last follow up. Analyzed by timing of ICI at the patient level, those not receiving ICI were more likely to have a diagnosis of breast or other cancers as compared to melanoma, lung, and kidney primaries that were more common with ICI (P < 0.01). This is likely due to the longer historical use of ICI in these malignancies. The overall rates of Grade 1-3 RN were 4.0%, 4.6%, and 2.2% (no Grade 4+ events). Median time to RN was 11.4 months (IQR 6.0-22.5). Analyzed by timing of ICI on a per-treatment basis, there was no difference among rates of any grade RN for no (13.5%), neoadjuvant (9.8%), concurrent (8.5%), and adjuvant ICI (14.1%) (P = 0.052). On univariable analysis, primary histology, performance status, SRT fractionation, and metastasis diameter were significantly associated with time to RN (all P < 0.05). Time to RN did not vary among treatment courses with neoadjuvant, concurrent, adjuvant, or no ICI (P = 0.72). On multivariable analysis, once histology and SRT fractionation were included, only a performance status of ECOG 0 (HR 0.43 CI 0.23-0.81) and increasing diameter (HR 1.58 CI 1.24-2.03) remained significant (both P < 0.01).Conclusion: In this large single-institution study of linear accelerator-based SRT, consistent with previous reports, we found that lesion diameter positively correlated with risk of RN. However, there was not an increased risk of RN in patients who received ICI. On subset analysis, there was no association of RN with ICI timing - including with concurrent administration. These data suggest that linear accelerator-based SRT is safe to combine with ICI.Author Disclosure: S.G. Allen: Employee; University of Michigan Mott Children's Hospital. J.J. Waninger: None. S.R. Birer: None. S. Journey: None. J. Skvarce: None. D.R. Wahl: Research Grant; Agios Inc, Innocrin Inc, American Cancer Society, NIH. Stock Options; Lycera Inc. Advisory Board Member; Agios Inc. T.S. Lawrence: None. J.A. Hayman: Research Grant; Blue Cross Blue Shield of Michigan. M.M. Kim: Research Grant; Blue Earth Diagnostics.; Red Journal. Site PI of ongoing CCTG CE.7, N0577, A071801, and NCI 9979 trials; NCTN (Alliance, NRG, CCTG) and ETCTN.M. Green: None. [ABSTRACT FROM AUTHOR]

Purpose/objective(s): Cannabis use rates are increasing throughout the United States along with shifts in state-level policy. Patients with cancer use cannabis for a broad range of indications, but there is limited quality data to support many of these uses. To date, few studies have sought to understand cannabis use in populations of patients served by radiation oncology departments.Materials/methods: Standardized electronic medical record prompts were used by clinicians for cannabis history documentation for 1050 adult patients seen for initial consultation or follow-up between 10/2020 and 2/2021 at an academic radiation oncology department. Cannabis use data, including recency/frequency of use, indication, and mode of administration, were later gathered using the Michigan Radiation Oncology Analytics Resource (M-ROAR) under an IRB-approved protocol. Cannabis use characteristics were summarized, and logistic regression was used to explore associations between age and gender and recent cannabis use.Results: In total, 54 (5.1%) of 1050 unique patients declined to answer questions about cannabis use. Of the remaining 996 patients, 106 (10.6%) endorsed recent cannabis use (≤1 month ago), 71 (7.1%) noted remote use (> 1 month ago), and 819 (82.2%) denied history of cannabis use. The median age of those with recent cannabis use was 59.5 (IQR: 49.7-66.4) vs. 65.4 (IQR: 57.1-73.5) in all others. A multivariable logistic regression analysis revealed an association between age (OR 0.96; 95% CI: 0.95-0.97; P < 0.001) but not gender (male OR 1.24; 95% CI: 0.82-1.88; P = 0.310) and recent cannabis use. Patients noted pain (46.2%), anxiety (23.6%), insomnia (17.9%), "for the high" (17.0%), nausea (15.1%), poor appetite (14.2%), "to fight cancer" (4.7%), and depression (1.9%) as indications for use. The most common mode of administration was inhalation via smoking (47.2%), followed by oral (edibles, 36.8%), topical (15.1%), oral (drinks, 4.7%), vaping (3.8%), sublingual (1.0%), and rectal (1.0%). Most patients used cannabis daily (58.5%). Only 4 individuals (3.8%) noted use multiple times daily, while the remainder endorsed weekly (20.8%) or less than weekly (17.0%) use.Conclusion: Approximately 10% of patients seen in a radiation oncology department reported recent cannabis use for a variety of reasons. These findings suggest a need for: 1) collection of cannabis use history in radiation oncology departments, 2) efforts to destigmatize cannabis use to facilitate frank discussions between patients and providers, 3) patient education about the fact that cannabis is not an evidence-based cancer treatment, 4) recommendation against inhaled forms of cannabis, which may carry risk of pulmonary toxicity, and 5) careful application of proven therapies to address symptoms when appropriate to provide alternatives to cannabis. Further research is needed to assess changes in cannabis use patterns over the course of cancer treatment and to evaluate risks and benefits of cannabis use in patients with cancer. [ABSTRACT FROM AUTHOR]

Purpose/objective(s): The benefit of radiotherapy (RT) in poor-prognosis patients with leptomeningeal disease (LMD) is not well characterized. This study assessed the overall survival (OS) and clinical improvement of a largely symptomatic cohort of breast cancer patients with LMD, to identify patient subsets most likely to benefit from palliative RT.Materials/methods: Patients with breast cancer and classic radiographic LMD (36% cytology-confirmed) treated with palliative whole brain and/or partial spine RT between 2000-2020 at a single academic institution were included in this retrospective analysis. OS was calculated from date of LMD diagnosis using the Kaplan-Meier method, and differences in subgroups were determined using the log-rank test. Multivariate Cox proportional hazards models adjusting for estrogen receptor (ER), progesterone receptor (PR), HER2, ECOG performance status (ECOG), and systemic disease status assessed factors associated with OS. Domain-specific and any symptom improvement were ascertained by chart review of patient- and physician-report, and a multivariate logistic regression model developed incorporating ER/PR status, HER2 status, ECOG and steroid use to identify factors associated with symptom benefit.Results: Among 64 patients of median age 50 years (IQR 31-69), the radiographic distribution of LMD was in the brain (58%), spine (22%), or both (20%). A total of 63% had concurrent brain metastases, and 57% of patients had ER+ and/or PR+ tumors, 22% HER2+, and 38% triple-negative disease. Among 92% of symptomatic patients whose primary symptom domains were cranial nerve deficit (34%), sensory/motor deficits due to intracranial disease (25%) sensory/motor deficits due to spine disease (27%), and headaches/nausea (14%), 42% had > 1 reported symptom domain. Two-thirds of patients were on steroids prior to RT, and only 13% of patients received intrathecal therapy. Following a median dose of 30 Gy in 10 fractions, symptom improvement in any domain was noted in 59% of patients with symptoms pre-RT, with similar improvement rate across domains (12%, 15%, 19%, 14%, respectively); 21% of patients had improvement in > 1 symptom domain. Overall survival was only 2.1 months (95% CI 1.8-3.3) in the triple-negative subgroup, and higher among patients with HER2+ disease (5.2 months, 95% CI 3.8-NR, P = 0.003). On multivariate analysis, ER+ (HR 0.4, 95% CI 0.2-0.8, P = 0.009) and HER2+ (HR 0.4, 95% CI 0.2-0.9, P = 0.018) disease were associated with improved OS. Hormone receptor positivity was independently associated with symptom improvement following RT (OR 3.5, 95% CI 1.2-11, P = 0.029).Conclusion: Even in this poor-prognosis cohort of breast cancer patients with LMD, palliative RT yields symptomatic improvement, and may especially be of benefit among better-prognosis patients with hormone receptor-positive or HER2-positive disease.Author Disclosure: J. Takayesu: None. E. Sapir: Research Grant; LipoMedix, BioProtect. Consultant; AstraZeneca, MSD, Belong.Life. J. Xie: None. Y. Sun: None. A. Morikawa: Institutional research; Novartis, Lilly, Takeda, Eisai/H3b, Pfizer/National Comprehensive Cancer Network. L. Junck: Advisory Board; Orbus Therapeutics. D. Leung: None. Y. Umemura: None. J. Heth: None. W. Al-Holou: None. D.R. Wahl: Research Grant; Agios Inc, Innocrin Inc, American Cancer Society, NIH. Stock Options; Lycera Inc. Advisory Board Member; Agios Inc. T.S. Lawrence: None. C. Mayo: None. J.A. Hayman: Research Grant; Blue Cross Blue Shield of Michigan. M.M. Kim: Research Grant; Blue Earth Diagnostics. [ABSTRACT FROM AUTHOR]

Purpose/objective(s): Cardiac radiation exposure is associated with an increased rate of adverse cardiac events in patients receiving radiation therapy for locally advanced non-small cell lung carcinoma (NSCLC). Previous analysis of practice patterns within the statewide Michigan Radiation Oncology Quality Consortium (MROQC) revealed 1 in 4 patients received a mean heart dose > 20 Gy and significant heterogeneity existed among treatment centers in using cardiac dose constraints. The purpose of this study is to analyze the effect of education and initiation of standardized cardiac dose constraints on heart dose across a statewide consortium.Materials/methods: From 2012 to 2020, 1604 patients from 27 academic and community centers who received radiation therapy for locally advanced NSCLC were included in this analysis. Dosimetric endpoints including mean heart dose (MHD), mean lung dose, and mean esophagus dose were calculated using data from dose-volume histograms. These dose metrics were grouped by year of treatment initiation for all patients. Education regarding data for cardiac dose constraints was discussed in small lung cancer working group meetings and consortium-wide starting in 2016. This was followed in 2018 by implementation of a quality metric requiring mean heart dose < 20 Gy while maintaining dose coverage (D95) to the tumor. Dose metrics were compared before (2012-2016) and after (2017-2019) initiation of interventions targeting cardiac constraints. Statistical analysis was performed using the Wilcoxon Rank Sum test.Results: Following education and implementation of the heart dose performance metric, mean MHD declined from an average of 12.2 Gy pre-intervention to 10.4 Gy post-intervention, and the percentage of patients receiving MHD > 20 Gy reduced by half. (Table). Mean lung dose and mean esophagus dose did not increase, and tumor coverage remained unchanged.Conclusion: Education and implementation of a standardized cardiac dose quality measure across a statewide consortium was associated with a reduction of mean heart dose in patients receiving radiation therapy for locally advanced NSCLC. These dose reductions were achieved without sacrificing tumor coverage, increasing mean lung dose or mean esophagus dose. Analysis of the clinical ramifications of the reduction in cardiac doses is ongoing. [ABSTRACT FROM AUTHOR]

Purpose/objective(s): Regional collaborative quality initiatives that incent participation through direct payment and streamlined reimbursement for high-performing sites have been shown to drive improvements in surgical outcomes. Numerous quality measures have been proposed in radiation oncology, and research has identified readily measurable indicators like dose to critical structures that predict for subsequent toxicity in patients. A decade ago, we initiated a voluntary statewide collaboration for quality improvement in radiation oncology and now describe its impact on care delivery.Materials/methods: Following SQUIRE guidelines, we describe the approach and measures that the program has implemented. To evaluate impact, we describe compliance at baseline and now with active measures among participating practices.Results: Since beginning data collection in 2012, radiation oncologists, physicists, data abstractors, and practice administrators from sites in one state (currently numbering 27) have convened thrice yearly. At these meetings, experts have spoken regarding trends within the field and inspired discussions regarding potential targets for quality improvement within the consortium. Blinded data on practices at various sites have also been regularly presented, and the group has iteratively developed new initiatives and consensus-based benchmarks to improve radiation oncology care delivery, patient experiences, and outcomes. An observational dataset with detailed information from over 20,000 patients has been assembled to evaluate quality. Compliance with select measures is described in the table, including use of guideline-concordant hypofractionated radiotherapy, motion management, doses to targets/normal tissues, and consistency in delineating and naming contoured structures (a precondition for quality evaluation).Conclusion: Although observational analysis cannot fully exclude secular trends, contextual data revealing slow uptake of best practices elsewhere in the US suggests that this initiative has improved the consistency, efficiency, and quality of radiation oncology care in its member practices and may be a model for other regions. [ABSTRACT FROM AUTHOR]