Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Median survival for all patients with breast cancer with brain metastases (BCBMs) has increased in the era of targeted therapy (TT) and with improved local control of intracranial tumors using stereotactic radiosurgery (SRS) and surgical resection. However, detailed characterization of the patients with long-term survival in the past 5 years remains sparse. The aim of this article is to characterize patients with BCBM who achieved long-term survival and identify factors associated with the uniquely better outcomes and to find predictors of mortality for patients with BCBM. METHODS:We reviewed 190 patients with breast cancer with 931 brain tumors receiving SRS who were followed at our institution with prospective data collection between 2012 and 2022. We analyzed clinical, molecular, and imaging data to assess relationship to outcomes and tumor control. RESULTS:The median overall survival from initial SRS and from breast cancer diagnosis was 25 months (95% CI 19-31 months) and 130 months (95% CI 100-160 months), respectively. Sixteen patients (17%) achieved long-term survival (survival ≥5 years from SRS), 9 of whom are still alive. Predictors of long-term survival included HER2+ status ( P = .041) and treatment with TT ( P = .046). A limited number of patients (11%) died of central nervous system (CNS) causes. A predictor of CNS-related death was the development of leptomeningeal disease after SRS ( P = .025), whereas predictors of non-CNS death included extracranial metastases at first SRS ( P = .017), triple-negative breast cancer ( P = .002), a Karnofsky Performance Status of <80 at first SRS ( P = .002), and active systemic disease at last follow-up ( P = .001). Only 13% of patients eventually needed whole brain radiotherapy. Among the long-term survivors, none died of CNS progression. CONCLUSION/CONCLUSIONS:Patients with BCBM can achieve long-term survival. The use of TT and HER2+ disease are associated with long-term survival. The primary cause of death was extracranial disease progression, and none of the patients living ≥5 years died of CNS-related disease.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Advances in targeted therapies and wider application of stereotactic radiosurgery (SRS) have redefined outcomes of patients with brain metastases. Under modern treatment paradigms, there remains limited characterization of which aspects of disease drive demise and in what frequencies. This study aims to characterize the primary causes of terminal decline and evaluate differences in underlying intracranial tumor dynamics in patients with metastatic brain cancer. These fundamental details may help guide management, patient counseling, and research priorities. METHODS:Using NYUMets-Brain-the largest, longitudinal, real-world, open data set of patients with brain metastases-patients treated at New York University Langone Health between 2012 and 2021 with SRS were evaluated. A review of electronic health records allowed for the determination of a primary cause of death in patients who died during the study period. Causes were classified in mutually exclusive, but collectively exhaustive, categories. Multilevel models evaluated for differences in dynamics of intracranial tumors, including changes in volume and number. RESULTS:Of 439 patients with end-of-life data, 73.1% died secondary to systemic disease, 10.3% died secondary to central nervous system (CNS) disease, and 16.6% died because of other causes. CNS deaths were driven by acute increases in intracranial pressure (11%), development of focal neurological deficits (18%), treatment-resistant seizures (11%), and global decline driven by increased intracranial tumor burden (60%). Rate of influx of new intracranial tumors was almost twice as high in patients who died compared with those who survived (P < .001), but there was no difference in rates of volume change per intracranial tumor (P = .95). CONCLUSION/CONCLUSIONS:Most patients with brain metastases die secondary to systemic disease progression. For patients who die because of neurological disease, tumor dynamics and cause of death mechanisms indicate that the primary driver of decline for many may be unchecked systemic disease with unrelenting spread of new tumors to the CNS rather than failure of local growth control.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Dose selection for brain metastases stereotactic radiosurgery (SRS) classically has been based on tumor diameter with a reduction of dose in the settings of prior brain irradiation, larger tumor volumes, and critical brain location. However, retrospective series have shown local control rates to be suboptimal with reduced doses. We hypothesized that lower doses could be effective for specific tumor biologies with concomitant systemic therapies. This study aims to report the local control (LC) and toxicity when using low-dose SRS in the era of modern systemic therapy. METHODS:We reviewed 102 patients with 688 tumors managed between 2014 and 2021 who had low-margin dose radiosurgery, defined as ≤14 Gy. Tumor control was correlated with demographic, clinical, and dosimetric data. RESULTS:The main primary cancer types were lung in 48 (47.1%), breast in 31 (30.4%), melanoma in 8 (7.8%), and others in 15 patients (11.7%). The median tumor volume was 0.037cc (0.002-26.31 cm3), and the median margin dose was 14 Gy (range 10-14). The local failure (LF) cumulative incidence at 1 and 2 years was 6% and 12%, respectively. On competing risk regression analysis, larger volume, melanoma histology, and margin dose were predictors of LF. The 1-year and 2-year cumulative incidence of adverse radiation effects (ARE: an adverse imaging-defined response includes increased enhancement and peritumoral edema) was 0.8% and 2%. CONCLUSION/CONCLUSIONS:It is feasible to achieve acceptable LC in BMs with low-dose SRS. Volume, melanoma histology, and margin dose seem to be predictors for LF. The value of a low-dose approach may be in the management of patients with higher numbers of small or adjacent tumors with a history of whole brain radio therapy or multiple SRS sessions and in tumors in critical locations with the aim of LC and preservation of neurological function.

BACKGROUND:Brain metastases (BM) have long been considered a terminal diagnosis with management mainly aimed at palliation and little hope for extended survival. Use of brain stereotactic radiosurgery (SRS) and/or resection, in addition to novel systemic therapies, has enabled improvements in overall and progression-free (PFS) survival. OBJECTIVE:To explore the possibility of extended survival in patients with non-small-cell lung cancer (NSCLC) BM in the current era. METHODS:During the years 2008 to 2020, 606 patients with NSCLC underwent their first Gamma Knife SRS for BM at our institution with point-of-care data collection. We reviewed clinical, molecular, imaging, and treatment parameters to explore the relationship of such factors with survival. RESULTS:The median overall survival was 17 months (95% CI, 13-40). Predictors of increased survival in a multivariable analysis included age <65 years (P < .001), KPS ≥80 (P < .001), absence of extracranial metastases (P < .001), fewer BM at first SRS (≤3, P = .003), and targeted therapy (P = .005), whereas chemotherapy alone was associated with shorter survival (P = .04). In a subgroup of patients managed before 2016 (n = 264), 38 (14%) were long-term survivors (≥5 years), of which 16% required no active cancer treatment (systemic or brain) for ≥3 years by the end of their follow-up. CONCLUSION/CONCLUSIONS:Long-term survival in patients with brain metastases from NSCLC is feasible in the current era of SRS when combined with the use of effective targeted therapeutics. Of those living ≥5 years, the chance for living with stable disease without the need for active treatment for ≥3 years was 16%.

PURPOSE/OBJECTIVE:New therapies for melanoma have been associated with increasing survival expectations, as opposed to the dismal outcomes of only a decade ago. Using a prospective registry, we aimed to define current survival goals for melanoma patients with brain metastases (BM), based on state-of-the-art multimodality care. METHODS:We reviewed 171 melanoma patients with BM receiving stereotactic radiosurgery (SRS) who were followed with point-of-care data collection between 2012 and 2020. Clinical, molecular and imaging data were collected, including systemic treatment and radiosurgical parameters. RESULTS:SRS were predictors of long-term survival ([Formula: see text] 5 years) from initial SRS (p = 0.023 and p = 0.018, respectively). Five patients (16%) of the long-term survivors required no active treatment for [Formula: see text] 5 years. CONCLUSION/CONCLUSIONS:Long-term survival in patients with melanoma BM is achievable in the current era of SRS combined with immunotherapies. For those alive [Formula: see text] 5 years after first SRS, 16% had been also off systemic or local brain therapy for over 5 years. Given late recurrences of melanoma, caution is warranted, however prolonged survival off active treatment in a subset of our patients raises the potential for cure.

OBJECTIVE:In the era in which more patients with greater numbers of brain metastases (BMs) are being treated with stereotactic radiosurgery (SRS) alone, it is critical to understand how patient, tumor, and treatment factors affect functional status and overall survival (OS). The authors examined the survival outcomes and dosimetry to critical structures in patients treated with Gamma Knife radiosurgery (GKRS) for ≥ 25 metastases in a single session or cumulatively over the course of their disease. METHODS:A retrospective analysis was conducted at a single institution. The institution's prospective Gamma Knife (GK) SRS registry was queried to identify patients treated with GKRS for ≥ 25 cumulative BMs between June 2013 and April 2020. Ninety-five patients were identified, and their data were used for analysis. Treatment plans for dosimetric analysis were available for 89 patients. Patient, tumor, and treatment characteristics were identified, and outcomes and OS were evaluated. RESULTS:The authors identified 1132 patients with BMs in their institutional registry. Ninety-five patients were treated for ≥ 25 cumulative metastases, resulting in a total of 3596 tumors treated during 373 separate treatment sessions. The median number of SRS sessions per patient was 3 (range 1-12 SRS sessions), with nearly all patients (n = 93, 98%) having > 1 session. On univariate analysis, factors affecting OS in a statistically significant manner included histology, tumor volume, tumor number, diagnosis-specific graded prognostic assessment (DS-GPA), brain metastasis velocity (BMV), and need for subsequent whole-brain radiation therapy (WBRT). The median of the mean WB dose was 4.07 Gy (range 1.39-10.15 Gy). In the top quartile for both the highest cumulative number and highest cumulative volume of treated metastases, the median of the mean WB dose was 6.14 Gy (range 4.02-10.15 Gy). Seventy-nine patients (83%) had all treated tumors controlled at last follow-up, reflecting the high and durable control rate. Corticosteroids for tumor- or treatment-related effects were prescribed in just over one-quarter of the patients. Of the patients with radiographically proven adverse radiation effects (AREs; 15%), 4 were symptomatic. Four patients required subsequent craniotomy for hemorrhage, progression, or AREs. CONCLUSIONS:In selected patients with a large number of cumulative BMs, multiple courses of SRS are feasible and safe. Together with new systemic therapies, the study results demonstrate that the achieved survival rates compare favorably to those of larger contemporary cohorts, while avoiding WBRT in the majority of patients. Therefore, along with the findings of other series, this study supports SRS as a standard practice in selected patients with larger numbers of BMs.

OBJECTIVE:Patients with non-small cell lung cancer (NSCLC) metastatic to the brain are living longer. The risk of new brain metastases when these patients stop systemic therapy is unknown. The authors hypothesized that the risk of new brain metastases remains constant for as long as patients are off systemic therapy. METHODS:A prospectively collected registry of patients undergoing radiosurgery for brain metastases was analyzed. Of 606 patients with NSCLC, 63 met the inclusion criteria of discontinuing systemic therapy for at least 90 days and undergoing active surveillance. The risk factors for the development of new tumors were determined using Cox proportional hazards and recurrent events models. RESULTS:The median duration to new brain metastases off systemic therapy was 16.0 months. The probability of developing an additional new tumor at 6, 12, and 18 months was 26%, 40%, and 53%, respectively. There were no additional new tumors 22 months after stopping therapy. Patients who discontinued therapy due to intolerance or progression of the disease and those with mutations in RAS or receptor tyrosine kinase (RTK) pathways (e.g., KRAS, EGFR) were more likely to develop new tumors (hazard ratio [HR] 2.25, 95% confidence interval [CI] 1.33-3.81, p = 2.5 × 10-3; HR 2.51, 95% CI 1.45-4.34, p = 9.8 × 10-4, respectively). CONCLUSIONS:The rate of new brain metastases from NSCLC in patients off systemic therapy decreases over time and is uncommon 2 years after cessation of cancer therapy. Patients who stop therapy due to toxicity or who have RAS or RTK pathway mutations have a higher rate of new metastases and should be followed more closely.

PURPOSE/OBJECTIVE(S): Multiple brain metastases (BM) from non-small cell lung cancer (NSCLC) historically has a dismal prognosis. Advances in systemic therapy for NSCLC have significantly improved survival, but the effect on prognosis in patients with NSCLC and BM is poorly understood. Stereotactic radiosurgery (SRS) may result in local control even with higher numbers of BM. We report survival outcomes of upfront SRS for >=5 BM from metastatic NSCLC. MATERIALS/METHODS: Review of our registry identified 177 patients treated for >=5 BM from NSCLC between 2012 and 2020, and did not undergo prior intracranial radiation or resection.
RESULT(S): Adenocarcinoma was found in 129 patients (73%). EGFR/ALK mutations were identified in 54 patients (31%). The median number of tumors at initial SRS were 8 (range 5-35). 121 patients (68%) were treated for 5-10 BM, 31 patients (18%) for 11-15 BM, and 25 patients (14%) for > 15 BM. The median overall survival (OS) from initial SRS for all patients was 15.1 months (95% CI 11.5-18.7). Survival at 1, 2, and 3 years was 57%, 39%, and 28% respectively. Adenocarcinoma was associated with improved survival compared to non-adenocarcinoma (P < 0.001), median OS 17.1 months (95% CI 11.4-22.9) and median OS 5.7 months (95% CI 2.8-8.6), respectively. Patients with EGFR/ALK mutations had a significantly greater survival time compared to those without (P=0.008), and median OS of 26.3 months (95% CI 19.1-33.6) versus 10.4 months (95% 6.2-14.6). Treatment of 5-10, 11-15, or > 15 tumors at initial GK were not associated with differences in survival (P=0.48). On multivariate analysis, survival benefit remained significant in patients with adenocarcinoma (HR 0.42, 95% CI 0.24-0.72, P=0.002), and patients with EGFR/ALK mutations (HR 0.58, 95% CI 0.37-0.91, P=0.02).
CONCLUSION(S): Patients treated with initial SRS for multiple BM from NSCLC in the modern era demonstrate longer survival as compared with historical reports. Adenocarcinoma subtype, particularly in the setting of EGFR/ALK mutation is associated with improved prognosis, even in patients with higher number of metastases. AUTHOR DISCLOSURE: J. Gurewitz: None. D. Patel: None. C. Benjamin: None. B.R. Donahue: None. J. Silverman: None. M. Mureb: None. K. Bernstein: None. D. Kondziolka: None.
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PURPOSE/OBJECTIVES/OBJECTIVE:To report our dosimetric analysis of the hippocampi (HC) and the incidence of perihippocampal tumor location in patients with≥25 brain metastases who received stereotactic radiosurgery (SRS) in single or multiple sessions. Materials/Methods Analysis of our prospective registry identified 89 patients treated with SRS for ≥ 25 brain metastases. HC avoidance regions (HA-region) were created on treatment planning MRIs by 5mm expansion of HC. Doses from each session were summed to calculate HC dose. The distribution of metastases relative to the HA-region and the HC was analyzed. RESULTS:Median number of tumors irradiated per patient was 33 (range 25-116) in a median of 3 (range1-12) sessions. Median bilateral HC Dmin (D100), D40, D50, Dmax, and Dmean (Gy) was 1.88, 3.94, 3.62, 16.6, and 3.97 for all patients, and 1.43, 2.99, 2.88, 5.64, and 3.07 for patients with tumors outside the HA-region. Multivariate linear regression showed that the median HC D40, D50, and Dmin were significantly correlated with the tumor number and tumor volume (p <0.001). Of the total3059 treated tumors,83 (2.7%) were located in the HA-region in 57% evaluable patients; 38 tumors (1.2%) abutted or involved the HC itself. CONCLUSIONS:Hippocampal dose, is higher in patients with tumors in the HA-region; however, even for patients with a high burden of intracranial disease and tumors located in the HA-regions, SRS affords hippocampal sparing. This is particularly relevant in light of our finding of eventual perihippocampal metastases in more than half of our patients.