Intracranial Control Research Articles

BIOM-34. INTRACRANIAL MANAGEMENT OF HER-2 OVEREXPRESSION BREAST CANCER WITH EXTENSIVE VOLUME OR SYMPTOMATIC BRAIN METASTASES

Abstract BACKGROUND HER-2 overexpression in breast cancer often leads to brain metastases, necessitating effective intracranial control strategies. This study aimed to evaluate the correlation between intracranial disease volume, symptomatic presentation, and treatment outcomes in HER-2 overexpressing breast cancer patients with brain metastases. METHODS A retrospective analysis was conducted on cases of HER-2 overexpressing breast cancer patients with brain metastases. Clinical records were reviewed to extract patient demographics, treatment modalities, and intracranial disease characteristics. Intracranial tumor burden was quantified at diagnosis and post-initial treatment. High intracranial tumor burden was defined as either total metastatic volume >15 cc, or the largest lesion >3 cm. Responses were assessed using established criteria. The correlation between intracranial disease parameters and intracranial progression-free survival (PFS) and overall survival (OS) was determined. RESULTS The study comprised 65 patients with HER-2 overexpression breast cancer and brain metastases. Symptomatic presentation was observed in 69.2% of patients at the diagnosis of brain metastases. Treatment with HER-2 target therapy alone or in combination with other modalities resulted in substantial intracranial responses, with 81.5% achieving at least a partial response at 3 months from therapy initiation. Median intracranial PFS and OS for patients with high intracranial burden were 9 and 22 months, respectively. Patients with high intracranial burden and symptomatic presentation at diagnosis demonstrated worse PFS and OS to those with lower burden and absence of symptoms (p < 0.05 for each). CONCLUSION Intracranial control in HER-2 overexpressing breast cancer patients with large volume or symptomatic brain metastases appears promising with combination with HER-2 targeted therapy and radiotherapy. Despite the varying intracranial disease burdens and symptomatic presentations, the use of HER-2 targeted therapy combined with radiotherapy demonstrates favorable intracranial responses, highlighting their potential in managing such cases.

RADT-11. FACTORS ASSOCIATED WITH LOCAL FAILURE AFTER STEREOTACTIC RADIATION TO THE SURGICAL BED OF BREAST CANCER PATIENTS WITH A SINGLE BRAIN METASTASIS

Abstract BACKGROUND Metastatic breast cancer is the second most common cancer associated with brain metastases (BCBM). In our study we evaluated variables that influence local control in this breast cancer patients with a single BCBM who underwent surgical resection and stereotactic radiation to resection cavity. METHODS After ethics approval, we conducted a retrospective review of the medical records of BCBM patients treated with stereotactic radiation for BCBM between 2011 to 2022. Only breast cancer patients with a single BCBM who underwent surgical resection and stereotactic radiation to the surgical cavity were included. Clinical and dosimetric variables were analyzed to evaluate their impact on local control. Statistical analysis included descriptive analyses. X2 test was used for categorical variables. Total dose, dose per fraction, biologically effective dose (BED), and planning target volumes were analyzed as both continuous and categorical variables at different thresholds. A binary regression model was applied to study variables shown to impact local control. RESULTS A total of 62 patients included local control was 70.9% at 12 months. HER-2 disease, luminal-B, size of BCBM, time from craniotomy, total dose, inclusion of corridor, and non-cystic lesion were significant for local control. CONCLUSION Our data supports previous publications about the importance of tumor bed delineation, dose and fractionation, and time from craniotomy as factors associated with better local control. Our study shows that the role of BCBM subtype and new systemic therapies in contributing to local and intracranial control should be further explored.

RADT-28. THE ROLE OF CRANIAL RE-IRRADIATION IN EGFR MUTANT LUNG CANCER PATIENTS WITH BRAIN METASTASES

Abstract INTRODUCTION Re-irradiation with stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT) may be used for treating recurrent brain metastases. Here, we are reporting on the rate of cranial re-irradiation based on our institutional experience in patients with mutated Epidermal Growth Factor Receptor Non-Small Cell Lung Cancer (mEGFR-NSCLC). METHODS This is a retrospective review of patients from three NYP-WCM hospitals with brain metastases treated with radiotherapy and Tyrosine Kinase Inhibitors (TKIs) from December 2012 to May 2023. RESULTS Ninety-eight patients (60.5%) out of 162 with brain metastases from mEGFR-NSCLC were treated with radiation. Twenty-seven patients (27.5%) were treated with WBRT. Among 71 patients treated with SRS, 10 (14.1%) patients underwent surgical resection of the dominant brain lesion followed by fractioned SRS (FSRS) to the surgical bed. Sixty-one (85.9%) patients received SRS for intact brain lesions ranging from single fraction 16-20Gy to FSRT with 24Gy –30Gy in 3-5 fractions based on the size and eloquence of the brain site of the brain metastasis. In the SRS group, fifteen (21.1%) patients required at least one more course of cranial irradiation. The mean duration of local intracranial control between the first and the second course of radiation was 19.6 months [range from 2.0- 56.7 months], while from the start of TKI to the first intracranial failure was 11.3 months [0.8m-45.3 months]. In the WBRT group, two patients (7.4%) were treated with another course of WBRT 20Gy in 5 fractions. These two patients started TKI simultaneously with their first course of WBRT; the mean duration of intracranial local control was 12.8 months [range from 11.6-14.1 months]. Both patients suffered significant cognitive declines. CONCLUSION In the Tyrosine Kinase Inhibitor era, patients with brain metastases from mEGFR-NSCLC have protracted progression-free survival. Multiple courses of cranial re-irradiation may be needed. Stereotactic radiotherapy should be preferred for the best results in preserving cognitive functions.

CTIM-32. PHASE I/II STUDY OF STEREOTACTIC RADIOSURGERY WITH CONCURRENT OLAPARIB FOLLOWED BY ADJUVANT DURVALUMAB AND PHYSICIAN’S CHOICE SYSTEMIC THERAPY IN SUBJECTS WITH BREAST CANCER BRAIN METASTASES (SOLARA)

Abstract BACKGROUND Despite progress in the treatment of brain metastasis for HER2+ breast cancer, outcomes for patients with HER2-negative breast cancer brain metastases remain poor. Preclinical studies show inhibitors of poly(ADP-ribose) polymerase (PARP) are effective in combination with radiation therapy as a DNA damage response inhibitor. Triple-negative breast cancer (TNBC) has higher rates of homologous recombination deficiency compared to other subtypes, and together with HER2-negative, BRCA-mutated breast cancer would be particularly sensitive to PARP inhibition. PARP inhibition has also demonstrated promising efficacy combined with immunotherapy in patients with germline BRCA-mutant and metastatic TNBC in clinical trials. In addition, immunotherapy with stereotactic radiosurgery (SRS) is associated with favorable intracranial control and survival in patients with brain metastases. We hypothesize that this biologically-driven combination will enhance local control of SRS-treated brain metastases through synergy with PARP inhibition, while controlling micrometastatic disease via potentiation of the immune response. METHODS We are conducting a multi-institution, Phase I/II trial of SRS plus olaparib, followed by durvalumab (with physician’s choice systemic therapy), for patients with TNBC (any BRCA status) or HER2-negative with BRCA-mutated (germline or somatic) breast cancer brain metastases [NCT04711824]. A total of 41 patients are planned for enrollment at 8 sites. The primary objectives are to evaluate safety and tolerability (Phase I) and determine intracranial disease control at 6 months (Phase II). Secondary objectives include assessing intracranial and global progression-free survival, overall survival, and intracranial and extracranial response rate. Exploratory objectives will assess potential biomarkers of treatment response, including changes in circulating tumor cells and DNA in blood and cerebrospinal fluid, germline and tumor mutations in DNA repair pathway genes, and PD-L1 expression, as well as quality of life and patient-reported outcomes. As of May 2024, phase I has been completed without dose-limiting toxicity, and phase II is currently enrolling. Funding/drug provision from AstraZeneca.

Delayed and Concurrent Stereotactic Radiosurgery in Immunotherapy-Naïve Melanoma Brain Metastases

Melanoma remains a formidable challenge in oncology, causing the majority of skin cancer deaths in the United States, with brain metastases contributing substantially to this mortality. This paper reviews the current therapeutic strategies for melanoma brain metastases, with a focus on delayed and concurrent stereotactic radiosurgery (SRS). While surgery and traditional chemotherapy offer limited efficacy, recent advances in immunotherapy, particularly immune checkpoint inhibitors (ICIs), have played a major role in the advancement and improved efficacy of the treatment of cancers, including brain metastases. Recent studies indicate that monotherapy with ICIs may lead to a higher median overall survival compared to historical benchmarks, potentially allowing patients to delay radiosurgery. Other studies have found that combining SRS with ICIs demonstrates promise, with results indicating improved intracranial control. Ongoing clinical trials explore novel combinations of immunotherapies and radiotherapies, aiming to optimize treatment outcomes while minimizing adverse effects. As treatment options expand, future studies will be necessary to understand the interplay between therapies and their optimal sequencing to improve patient outcomes.

Efficacy of Prophylactic Cranial Irradiation in Early to Mid-stage Small Cell Lung Cancer Patients in the Era of Magnetic Resonance Imaging

BackgroundRecent advancements in magnetic resonance imaging (MRI) for staging have highlighted the critical question of the need for prophylactic cranial irradiation (PCI) in managing early to mid-stage small cell lung cancer (SCLC). This study assesses the impact of PCI on overall survival (OS) and intracranial control among patients with stage I-IIB SCLC. MethodsData from 148 stage I-IIB SCLC patients treated with thoracic radiation therapy (TRT) at two centers were examined. Patients were categorized based on PCI administration: 63 received PCI, while 85 did not. All underwent pretreatment MRI, achieving at least a partial response to therapy. A 1:1 propensity score matching analysis corrected for potential biases. ResultsPropensity scores were generated to 116 patients, considering patient demographics, disease progression, and treatment methods. Death was included as a competing risk. The 3-year brain metastases (BM) occurrence rate was significantly higher in patients who did not receive PCI (30.0%) compared to those who did (14.8%), however, the difference was not statistically significant (No PCI vs. PCI, hazard ratio [HR]: 2.08, 95% CI [0.93-4.55], P = .07). No significant effect of PCI on OS was observed [PCI vs. No PCI, HR: 0.80, 95% CI (0.45-1.43), P = .45]. A subgroup analysis of stage IIB patients showed a significant increase in BM risk and mortality for those not receiving PCI (No PCI vs. PCI, BM risk HR: 5.85, 95% CI: 1.83-18.87, P = .003; mortality HR: 2.78, 95% CI: 1.14-6.67, P = .02), with less pronounced effects in stages I-IIA. ConclusionWith modern MRI-based screening, PCI may markedly benefit stage IIB SCLC patients by reducing BM and improving OS after initial sensitive treatment. This benefit does not appear to extend to stage I-IIA patients.

Hypofractionated stereotactic radiotherapy for brain metastases in lung cancer patients: dose‒response effect and toxicity

BackgroundLung cancer is a common cause of brain metastases, approximately 40% of patients with lung cancer will develop brain metastases at some point during their disease. Hypofractionated stereotactic radiotherapy (HSRT) has been demonstrated to be effective in controlling limited brain metastases. However, there is still no conclusive on the optimal segmentation of HSRT. The aim of our study was to explore the correlation between the HSRT dosage and its treatment effect and toxicity.MethodsA retrospective analysis was conducted on patients with non-small cell lung cancer (NSCLC) brain metastasis at Hangzhou Cancer Hospital from 1 January 2019 to 1 January 2021. The number of brain metastases did not exceed 10 in all patients and the number of fractions of HSRT was 5. The prescription dose ranges from 25 to 40 Gy. The Kaplan–Meier method was used for estimation of the localised intracranial control rate (iLC). Adverse radiation effects (AREs) were evaluated according to CTCAE 5.0. This study was approved by the Institutional Ethics Review Board of the Hangzhou Cancer Hospital (#73/HZCH-2022).ResultsForty eligible patients with a total of 70 brain metastases were included in this study. The 1-year iLC was 76% and 89% in the prescribed dose ≤ 30 Gy and > 30 Gy group, respectively (P < 0.05). For patients treated with HSRT combined with targeted therapy, immunotherapy and chemotherapy, the 1-year iLC was 89%, 100%, and 45%, respectively. No significant associations were observed between the number, maximum diameter, location, and type of pathology of brain metastases. The rate of all-grade AREs was 33%. Two patients who received a total dose of 40 Gy developed grade 3 headache, the rest of the AREs were grade 1–2.ConclusionsIncreasing the prescription dose of HSRT improves treatment effect but may also exacerbate the side effects. Systemic therapy might impact the iLC rate, and individualized treatment regimens need to be developed.

The Effect of Intracranial Control After Intracranial Local Therapy on the Prognosis of Patients with Brain Metastasis of Lung Adenocarcinoma.

The aim of the present study was to assess the clinical outcomes and prognostic factors of lung adenocarcinoma patients with brain metastases (BMs) after intracranial local therapy. A total of 83 lung adenocarcinoma patients with BMs who underwent craniotomy combined with radiotherapy or intracranial radiotherapy alone were retrospectively analyzed. The intracranial tumor response was determined according to the Response Assessment in Neuro-Oncology of Brain Metastases (RANO-BM) criteria. The median overall survival (OS), intracranial progression-free survival (iPFS), and related prognostic factors were analyzed with the Kaplan‒Meier estimator method and Cox proportional hazards regression model. Among 83 patients, 20 patients received craniotomy combined with radiotherapy, and 63 patients received intracranial radiotherapy alone. Following intracranial local therapy, 11 patients (13.3%) achieved complete response (CR); among them, 8 patients underwent neurosurgical resection. In addition, 32 patients (38.55%) achieved partial response (PR), 32 patients (38.55%) experienced stable disease (SD), and 8 (9.6%) experienced progressive disease (PD). The median follow-up period was 25.4 months (range 0.8-49.6 months). The median follow-up time for the iPFS was 16.2 months (range 0.6-41.2 months). The median OS, iPFS were 28.2 months and 24.7 months. Epidermal growth factor receptor (EGFR) / anaplastic lymphoma kinase (ALK) mutations (HR 3.216, 95% confidence interval (CI) 1.269-8.150, p = 0.014) and iPFS (HR 0.881, 95% CI 0.836-0.929, p < 0.001) were found to be beneficial factors for OS. An intracranial-tumor CR was associated with a longer iPFS (PR: HR 0.052, 95% CI 0.009-0.297, p = 0.001; SD: HR 0.081, 95% CI 0.025-0.259, p < 0.001; PD: HR 0.216, 95% CI 0.077-0.606, p = 0.004). Prolonged iPFS was associated with better OS in lung adenocarcinoma patients with BMs following intracranial local therapy, and mutations of EGFR / ALK or an intracranial-tumor CR are independent prognostic factors for prolonged survival.

Prognostic factors for patients with breast cancer brain metastasis after stereotactic radiotherapy.

e13109 Background: Breast cancer (BC) is the most common cancer in females and BC brain metastasis (BCBM) is considered as the second most frequent brain metastasis. Numerous prognostic factors are associated with survival for patients with BCBMs. Here we investigated the clinical factors associated with overall survival (OS) and distant intracranial control (DIC) after stereotactic radiotherapy (SRT) for BCBM. Methods: The records of BCBM patients treated with SRT were collected from electronic database in Cancer Center, Union Hospital, Tongji medical college, Huazhong University of Science and Technology Hospital. Based on the univariate and multivariate Cox regression analysis, the prognostic significance of available variables was assessed. The nomogram was created from Cox models and internally validated by use of bootstrap and cross-validation. Model discrimination was measured by calibration plots and the concordance index, and the clinical benefits were evaluated through clinical decision curve analysis (DCA). Results: 101 BCBM patients receiving SRT were analyzed in this study, and 5 patients were excluded with other primary malignancies or missing data. Median observation time was 15.0 months, and median OS was 22.0 months. OS rate was 71.5% in 1 year, 45.8% in 2 years, and 32.8% in 3 years. DIC was 49.8% in 1 year, 26.6% in 2 years, and 18.3% in 3 years. Multivariable analysis identified prognostic factors for OS including number of the brain metastasis, molecular subtypes type, brain metastasis as the first metastasis site, Karnofsky performance status (KPS), and receiving systemic therapy after SRT. KPS&lt;80, triple-negative subtype, the existence of extracranial metastases, the existence of lung metastases were associated with decreased DIC. Selected by the Akaike information criterion (AIC), the nomogram model contains age, KPS, histological subtype, number of brain metastases, brain metastasis as first metastasis site, PTV size, liver metastases, albumin and neutrophils. The calibration curve for probability of survival showed high consistencies between prediction by nomogram and actual observation. The C-index of the nomogram for predicting survival was 0.823, and the bias-corrected C-index generated by bootstrap validation with 1,000 resamples was 0.772, which was statistically higher than the C-index values of the other systems: Recursive partitioning analysis (RPA) (0.627), Graded prognostic assessment (GPA) (0.637), Breast-specific Graded Prognostic Assessment (breast-GPA) (0.699). BCBM patients receiving SRT were divided into four risk groups: I group (risk score &lt; 150), II group (150≤risk score&lt; 220), III group (220≤risk score&lt;290) and IV group (risk score≥290). The Kaplan‐Meier OS curves showed great discrimination among the four risk groups. Conclusions: The proposed nomogram resulted in a more-accurate prognostic prediction for BCBM patients receiving SRT.

Efficacy and safety evaluation of combined therapies incorporating whole-brain radiotherapy in patients with brain metastases: a systematic review and meta-analysis.

Whole-brain radiotherapy (WBRT) is a standard and effective approach for brain metastases, but it is linked to neurocognitive complications, specifically issues related to the hippocampus. Innovative strategies are being explored to enhance outcomes. However, a consensus is yet to be reached in this field. Our aim is to investigate the efficacy and safety of WBRT combined with simultaneous integrated boost (SIB), memantine, and hippocampal avoidance (HA) techniques in treatment of brain metastases. In this systematic review and meta-analysis, we comprehensively searched PubMed, MEDLINE, Embase, and Cochrane for studies reporting the efficacy and toxicity of WBRT-based combination therapies from inception to September 19, 2023. Data were pooled using random-effects models. Results were reported as risk ratios (RRs) and risk differences (RDs) for dichotomous outcomes, along with their 95% confidence intervals (CIs). Heterogeneity was evaluated using the I2 statistic. Among 2175 articles, 29 studies involving 3460 patients were included. The meta-analysis revealed that compared to WBRT alone, combination therapies significantly mitigated neurocognitive function decline (RD = -0.09, 95% CI [-0.18-0.01]; P = 0.03) and intracranial control failure (RR = 0.86, 95% CI [0.52-1.44]; P = 0.02), without increasing the risk of hippocampal recurrence or high-grade toxicities. Notably, HA-WBRT + SIB/memantine demonstrated improved neurocognitive outcomes and survival benefits. WBRT-based combination therapies demonstrate improved efficacy and comparable safety to WBRT alone, with specific emphasis on the effectiveness of HA-WBRT + Memantine and HA-WBRT + SIB in optimizing therapeutic outcomes for brain metastases.

Gross Tumor and Intracranial Control Benefits with Fractionated Radiotherapy Compared with Stereotactic Radiosurgery for Patients with WHO Grade 2 Meningioma

ObjectiveSurgical resection is the mainstay of treatment for WHO grade 2 meningioma. Fractionated radiation therapy (RT) is frequently employed following surgery, though many centers utilize stereotactic radiosurgery (SRS) for recurrence or progression. Herein, we report disease control outcomes from an institutional cohort with adjuvant fractionated RT versus salvage SRS. MethodsWe identified 32 patients from an institutional database with WHO grade 2 meningioma and residual/recurrent tumor treated with either SRS or fractionated RT. Patients were treated between 2007 and 2021 and had at least 1 year of follow-up. Kaplan-Meier estimators were used to determine gross tumor control (GTC) and intracranial control (IC). Univariate Cox proportional hazards models using biologically effective dose (BED) as a continuous parameter were used to assess for dose responses. ResultsWith a median follow-up of 5.5 years, 13 patients (41%) received SRS to a recurrent or progressive nodule, 2 (6%) fractionated radiation to a recurrent or progressive nodule, and 17 (53%) adjuvant fractionated radiation following subtotal resection. 5-year GTC was higher with fractionated RT versus SRS (82% vs. 38%, p=0.03). 5-year IC was also better with fractionated RT versus SRS (82% vs. 11%, p<0.001). On univariate analysis, increasing BED10 was significantly associated with better GTC (p=0.039); increasing BED3 was not (p=0.82). ConclusionsIn this patient cohort, GTC and IC were significantly higher in patients treated with adjuvant fractionated RT compared to salvage SRS. Increasing BED10 was associated with better GTC. Fractionated RT may provide a better therapeutic ratio than SRS for grade 2 meningiomas.

Abstract PO5-20-03: Phase I/II study of stereotactic radiosurgery with concurrent olaparib followed by adjuvant durvalumab and physician’s choice systemic therapy in subjects with breast cancer brain metastases

Abstract BACKGROUND: Despite progress in the treatment of brain metastasis for HER2+ breast cancer, outcomes for patients with HER2-negative breast cancer brain metastases remain poor. Current standard of care consists of local therapies, including surgery and radiotherapy, followed by systemic therapy. Preclinical studies show inhibitors of poly(ADP-ribose) polymerase (PARP) are effective in combination with radiation therapy as a DNA damage response inhibitor. Triple-negative breast cancer (TNBC) has higher rates of homologous recombination deficiency compared to other breast cancer subtypes, and together with HER2-negative, BRCA-mutated breast cancer would be particularly sensitive to PARP inhibition. PARP inhibition has also demonstrated promising efficacy combined with immunotherapy in patients with germline BRCA-mutant and metastatic TNBC in clinical trials (MEDIOLA, TOPACIO). In addition, immunotherapy with stereotactic radiosurgery (SRS) is associated with favorable intracranial control and survival in patients with brain metastases. We hypothesize that this biologically-driven combination will enhance local control of SRS-treated brain metastases through synergy with PARP inhibition, while controlling micrometastatic disease in the brain and extracranial sites via potentiation of the immune response. METHODS: We are conducting a multi-institution, Phase I/II trial of SRS plus olaparib, followed by durvalumab (with physician’s choice systemic therapy), for patients with TNBC (any BRCA status) or HER2-negative with BRCA-mutated (germline or somatic) breast cancer brain metastases [NCT04711824]. A total of 41 patients are planned for enrollment at 8 sites. The primary objectives are to evaluate safety and tolerability (Phase I) and determine intracranial disease control at 6 months (Phase II) of this treatment combination. Secondary objectives include determining clinical activity via intracranial and global progression-free survival, overall survival, and intracranial and extracranial response rate. Exploratory objectives will assess potential biomarkers of treatment response, including changes in circulating tumor cells and DNA in blood and cerebrospinal fluid, germline and tumor mutations in DNA repair pathway genes, and PD-L1 expression, as well as quality of life and patient-reported outcomes. A surgical sub-study (n=5) will evaluate olaparib concentration/distribution in resected brain metastases. As of June 2023, cohort 2 of phase I has been completed without dose-limiting toxicity. Citation Format: Colette Shen, Yara Abdou, Linda Chen, Xianming Tan, Gaorav Gupta, Mina Lobbous, Filipa Lynce, Erica Stringer-Reasor, Carey Anders. Phase I/II study of stereotactic radiosurgery with concurrent olaparib followed by adjuvant durvalumab and physician’s choice systemic therapy in subjects with breast cancer brain metastases [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-20-03.

ROS1 Positive Non-Small Cell Lung Cancer Patient with Brain Metastases Who Overcame Crizotinib Resistance with Lorlatinib: Case Report

Background: ROS1-positive patients account for 1-2% of non small cell lung cancer (NSCLC) cases. Crizotinib is the first tyrosine kinase inhibitor (TKI) indicated in first line treatment of ROS1-rearranged NSCLC. However, crizotinib resistance is frequent within the first 12 months of treatment. Lorlatinib is a novel tyrosine kinase inhibitor of ROS-1 recently indicated for metastatic or locally advanced crizotinib-resistant NSCLC. Case report: We report a case of a 43-year-old female patient with no medical history, diagnosted with stage IVB NSCLC including asymptomatic brain metastasis, and harboring ROS1 rearrangement. Within the first three months of starting crizotinib, the patient showed on CT scan evaluation new bone and brain metastases. Lorlatinib in the second line revealed a noteworthy improvement in metastasis and primary lesion. Conclusion: Brain metastases frequently occur in ROS1-rearranged NSCLC at the time of diagnosis and treatment course. However the efficacy of crizotinib might not translate to intracranial control of the disease, one of the cause of resistance to this drug.

Clinical outcomes of melanoma brain metastases treated with nivolumab and ipilimumab alone versus nivolumab and ipilimumab with stereotactic radiosurgery.

Upfront dual checkpoint blockade with immune checkpoint inhibitors (ICI) has demonstrated efficacy for treating melanoma brain metastases (MBM) in asymptomatic patients. Whether the combination of stereotactic radiosurgery (SRS) with dual checkpoint blockade improves outcomes over dual-checkpoint blockade alone is unknown. We evaluated clinical outcomes of patients with MBM receiving ICI with nivolumab and ipilimumab, with and without SRS. 49 patients with 158 MBM receiving nivolumab and ipilimumab for untreated MBM between 2015 and 2022 were identified at our institution. Patient and tumor characteristics including age, Karnofsky Performance Status (KPS), presence of symptoms, cancer history, MBM burden, and therapy course were recorded. Outcomes measured from initiation of MBM-directed therapy included overall survival (OS), local control (LC), and distant intracranial control (DIC). Time-to-event analysis was conducted with the Kaplan-Meier method. 25 patients with 74 MBM received ICI alone, and 24 patients with 84 MBM received concurrent SRS. Median follow-up was 24months. No differences in age (p = 0.96), KPS (p = 0.85), presence of symptoms (p = 0.79), prior MBM (p = 0.68), prior MBM-directed surgery (p = 0.96) or SRS (p = 0.68), MBM size (p = 0.67), or MBM number (p = 0.94) were seen. There was a higher rate of nivolumab and ipilimumab course completion in the SRS group (54% vs. 24%; p = 0.029). The SRS group received prior immunotherapy more often than the ICI alone group (54% vs. 8.0%; p < 0.001). There was no significant difference in 1-year OS (72% vs. 71%, p = 0.20) and DIC (63% v 51%, p = 0.26) between groups. The SRS group had higher 1-year LC (92% vs. 64%; p = 0.002). On multivariate analysis, LC was improved with combination therapy (AHR 0.38, p = 0.01). In our analysis, patients who received SRS with nivolumab and ipilimumab had superior LC without increased risk of toxicity or compromised immunotherapy treatment completion despite the SRS cohort having higher rates of prior immunotherapy. Further prospective study of combination nivolumab and ipilimumab with SRS is warranted.

Converging survival trends in non-small cell lung cancer patients with and without brain metastasis receiving state-of-the-art treatment

IntroductionHistorically, patients with brain metastasis (BM) have been excluded from clinical trials investigating treatments for non-small cell lung cancer (NSCLC) due to their unfavorable prognosis. Advanced treatments have increased survival prospects for NSCLC patients with BM. This study evaluated the life expectancy of NSCLC patients with and without BM in the context of contemporary treatments.MethodsOutcome data were collected for patients with advanced NSCLC attending a tertiary medical center between 2015 and 2020. Patients were stratified according to BM status and compared for overall survival (OS) using log-rank and Cox regression analyses.ResultsThe cohort included 360 patients with NSCLC of whom 134 (37.2%) had BM. Most (95%) of cases of BM developed within the first two years: 63% at diagnosis, 18% during the first year, 14% during the second year. There was no significant difference in OS between patients without BM and those with BM (median 23.7 vs. 22.3 months, HR = 0.97, p = 0.82); patients with BM and a targetable or non-targetable mutation (40.2 vs. 31.4 months, HR = 0.93, p = 0.84, and 20.7 vs. 19.87 months, HR = 0.95, p = 0.75, respectively); and patients with symptomatic BM (23.7 vs. 19.8 months, HR = 0.95, p = 0.78). Treatment for BM (95% of patients) consisted of stereotactic radiosurgery or tyrosine kinase inhibitors, with corresponding intracranial control rates of 90% and 86%.ConclusionThe results imply that the presence of BM has no impact on the prognosis of NSCLC. The practice of excluding NSCLC patients with BM from clinical trials warrants reconsideration.

Entrectinib in the treatment of ROS1-positive lung cancer

The possibilities in the treatment of patients with non–small cell lung cancer are constantly expanding – thanks to high-performance genomic profiling methods, we are discovering new targets in the tumor for drug action, as a result, new targeted drugs appear, some of them have several application points. Multipurpose drugs have a number of advantages and therefore have become the main direction of drug development. Entrectinib is an oral low molecular weight multikinase inhibitor that blocks three targets at once – the receptors of tyrosine kinases ROS1, NTRK1/2/3 and ALK, in 2023 was approved by the Ministry of Health of the Russian Federation for the treatment of adult patients with ROS1-positive metastatic non-small cell lung cancer. This form of lung cancer is classified as a rare orphan disease, which usually occurs in younger people (about 50 years old), more often in women and non-smokers. Until recently , we had the only active targeted drug – crizotinib. It provided a sufficiently high immediate effect and long-term control of the disease. However, his intracranial activity was not evaluated prospectively, and a retrospective analysis showed modest results. Entrectinib is distinguished from its competitor by high intracranial activity, and, as is known, metastatic brain damage in patients with activating mutations is quite common. With comparable indicators of objective response, its duration and time to progression, entrectinib provides a high level of intracranial control and reduces the risks of progression in the central nervous system in patients who did not have brain metastases at the beginning of therapy. In addition, entrectinib demonstrates good tolerability.

Long-Term Intracranial Outcomes With Combination Dual Immune-Checkpoint Blockade and Stereotactic Radiosurgery in Patients With Melanoma and Non-Small Cell Lung Cancer Brain Metastases

The intracranial benefit of offering dual immune-checkpoint inhibition (D-ICPI) with ipilimumab and nivolumab to patients with melanoma or non-small cell lung cancer (NSCLC) receiving stereotactic radiosurgery (SRS) for brain metastases (BMs) is unknown. We hypothesized that D-ICPI improves local control compared with SRS alone. Patients with melanoma or NSCLC treated with SRS from 2014 to 2022 were evaluated. Patients were stratified by treatment with D-ICPI, single ICPI (S-ICPI), or SRS alone. Local recurrence, intracranial progression (IP), and overall survival were estimated using competing risk and Kaplan-Meier analyses. IP included both local and distant intracranial recurrence. Two hundred eighty-eight patients (44% melanoma, 56% NSCLC) with 1,704 BMs were included. Fifty-three percent of patients had symptomatic BMs. The median follow-up was 58.8 months. Twelve-month local control rates with D-ICPI, S-ICPI, and SRS alone were 94.73% (95% CI, 91.11%-96.90%), 91.74% (95% CI, 89.30%-93.64%), and 88.26% (95% CI, 84.07%-91.41%). On Kaplan-Meier analysis, only D-ICPI was significantly associated with reduced local recurrence (P = .0032). On multivariate Cox regression, D-ICPI (hazard ratio [HR], 0.4003; 95% CI, 0.1781-0.8728; P = .0239) and planning target volume (HR, 1.022; 95% CI, 1.004-1.035; P = .0059) correlated with local control. One hundred seventy-three (60%) patients developed IP. The 12-month cumulative incidence of IP was 41.27% (95% CI, 30.27%-51.92%), 51.86% (95% CI, 42.78%-60.19%), and 57.15% (95% CI, 44.98%-67.59%) after D-ICPI, S-ICPI, and SRS alone. On competing risk analysis, only D-ICPI was significantly associated with reduced IP (P = .0408). On multivariate Cox regression, D-ICPI (HR, 0.595; 95% CI, 0.373-0.951; P = .0300) and presentation with >10 BMs (HR, 2.492; 95% CI, 1.668-3.725; P < .0001) remained significantly correlated with IP. The median overall survival after D-ICPI, S-ICPI, and SRS alone was 26.1 (95% CI, 15.5-40.7), 21.5 (16.5-29.6), and 17.5 (11.3-23.8) months. S-ICPI, fractionation, and histology were not associated with clinical outcomes. There was no difference in hospitalizations or neurologic adverse events between cohorts. The addition of D-ICPI for patients with melanoma and NSCLC undergoing SRS is associated with improved local and intracranial control. This appears to be an effective strategy, including for patients with symptomatic or multiple BMs.

RADT-07. CLINICAL OUTCOMES OF MELANOMA BRAIN METASTASES TREATED WITH NIVOLUMAB AND IPILIMUMAB ALONE VERSUS NIVOLUMAB AND IPILIMUMAB WITH STEREOTACTIC RADIOSURGERY

Abstract BACKGROUND Upfront dual checkpoint blockade has demonstrated efficacy in new melanoma brain metastases (MBM) of asymptomatic patients. Whether combination stereotactic radiosurgery (SRS) with dual checkpoint blockade improves outcomes over dual checkpoint blockade alone is unknown. We evaluated clinical outcomes of new MBM receiving nivolumab and ipilimumab, with and without SRS. METHODS 52 patients with 171 MBM receiving nivolumab and ipilimumab for untreated MBM between 2015 and 2022 were identified at our institution. Patient and tumor characteristics including age, Karnofsky Performance Status (KPS), presence of symptoms, cancer history, MBM burden, and toleration of therapy were recorded. Outcomes measured from initiation of MBM-directed therapy included overall survival (OS), local control (LC), distant intracranial control (DIC), and intracranial control (ICC). Time-to-event analysis was conducted with the Kaplan-Meier method. RESULTS 25 patients with 74 MBM received nivolumab and ipilimumab alone. 27 patients with 97 MBM received concurrent SRS. No differences in age (p = 0.72), KPS (p = 0.94), presence of symptoms (p = 0.87), prior MBM (p = 0.90), prior MBM-directed surgery (p = 0.77) or SRS (p = 0.65), MBM size (p = 0.36), MBM number (p = 0.36), or treatment completion (p = 0.12) were seen. Median follow-up was 22.7 months. There was a trend towards higher rates of nivolumab and ipilimumab course completion in the combination group (44% vs. 24%; p = 0.12). The combination therapy group received prior immunotherapy more often than the monotherapy group (52% vs. 8.0%; p = 0.0003). OS, DIC, and ICC were similar (p = 0.16, p = 0.32, p = 0.57, respectively) with overall 12-month OS 70.7%, DIC 56.8%, and ICC 49.4%. The combination therapy group had higher 12-month LC compared to the monotherapy group (91% vs. 64%; p = 0.001). CONCLUSION In our analysis, SRS with nivolumab and ipilimumab shows superior LC compared to nivolumab and ipilimumab alone despite our combination cohort being more advanced with higher rates of prior immunotherapy. Further prospective study of combination nivolumab and ipilimumab with SRS is warranted.

CTIM-01. NIVOLUMAB AND STEREOTACTIC RADIOSURGERY (SRS) FOR PATIENTS WITH BREAST CANCER BRAIN METASTASES: LONG TERM RESULTS AND CELL FREE DNA (CFDNA) ASSESSMENT FROM A NON-RANDOMIZED, OPEN-LABEL, PHASE IB STUDY

Abstract BACKGROUND We hypothesized treatment with nivolumab and SRS would be feasible and well tolerated and may improve intracranial tumor control over SRS alone for breast cancer brain metastases. METHODS The study is a phase Ib trial of nivolumab and SRS for breast cancer brain metastases. Clinical trial information: NCT03807765. Key eligibility criteria include breast cancer brain metastases of all subtypes, age ≥ 18, ECOG ≤ 2 with ≥ 10 brain metastases. Treatment was initiated with a dose of nivolumab (480 mg IV) that was repeated every 4 weeks. The initial dose of nivolumab was followed 1 week later by SRS. Blood was collected at baseline and q4 weeks. RESULTS A total of 12 patients were treated to 17 brain metastases. Breast cancer subtypes included triple negative (50%), HR+/HER2- (33%), and HR-/HER2+ (17%). Median follow-up from start of protocol therapy is 44 months. Two lesions were noted to undergo local failure, both pathologically confirmed, for a 12-month local control of 94%. Median distant intracranial control was 7.4 months with a 12 month control rate of 33%. Median systemic progression free survival was 7.7 months with a 12 month rate of 42%. Median overall survival (OS) was 24.7 months with a 12 month OS of 75%. No cases of radionecrosis were noted. Most patients were noted to have an increase in cfDNA throughout study treatment, at week 5 compared to baseline (83%), week 25 compared to baseline (89%), and 100% at first follow-up. An increase in cfDNA 4 weeks post SRS was found to predict worse intracranial control (HR: 4.4; 95% CI: 1.1-18.5; p = 0.04). CONCLUSIONS Nivolumab and SRS is a safe and feasible treatment option in breast cancer brain metastases. An increase in cfDNA 4 weeks post SRS was found to predict worse intracranial control and was eventually seen in all patients.

RADT-20. STEREOTACTIC RADIOSURGERY FOR 15 OR MORE BRAIN METASTASES

Abstract BACKGROUND Patients with ≥ 15 brain metastases(BM) continue to be treated with whole brain radiation therapy(WBRT), despite poor neurocognitive outcomes. We analyzed our institutional experience of treating these patients with stereotactic radiosurgery(SRS), with the aim of evaluating safety, cognitive outcomes, and survival. METHODS Patients who received SRS for ≥ 15 BMs in 1-5 fractions from 2014-2022 using the previously described single isocenter multi-target technique were included. Cognitive outcomes were objectively evaluated using serial Patient-Reported Outcome Measurement Information System(PROMIS) scores. RESULTS A total of 124 patients treated with LINAC-based SRS were included. The mean and median number of lesions treated per patient was 24.8 and 20, respectively (range 15 – 94). Most common primary histologies were lung(47.6%), melanoma(21.0%), and breast(14.5%). The median SRS dose was 24 Gy(range 18 – 30 Gy). The rate of any grade radiation necrosis (RN) and ≥ grade 3 RN were 15.3% and 3.2% respectively. New onset seizures were seen in 2.4% and alopecia in 2.4%. Median follow-up was 5.1 months(m). When cognitive data were available, 25 of 31 patients had a stable or improved PROMIS score. The 12m local control was 97.6% while overall intracranial control was 20.8%. One-year freedom from neurological death, leptomeningeal disease, and salvage WBRT were 85.6%, 87.6% and 71.7% respectively. Median overall survival(OS) from brain metastases diagnosis was 11.3m(95% CI 7.2m – 15.3m). On univariate analysis, no prior WBRT(p = 0.038), higher KPS(p = 0.002) and systemic therapy after SRS(p &amp;lt; 0.001) predicted for improved OS. CONCLUSIONS We present here the largest study evaluating SRS for patients with ≥ 15 BMs. We found that SRS was safe, had favorable cognitive outcomes, and comparable survival outcomes to contemporary studies evaluating WBRT in this patient population. Our study supports further randomized studies comparing SRS and memory avoidance WBRT approaches for patients with ≥ 15 BMs.