Salvage Stereotactic Radiosurgery for Recurrent WHO Grade 2 and 3 Meningiomas: A Multicenter Study (STORM).

PURPOSE: The role of stereotactic radiosurgery (SRS) in the management of grade 2 and 3 meningiomas is not well elucidated. Unfortunately, local recurrence rates are high, and guidelines for management of recurrent disease are lacking. To address this knowledge gap, we conducted STORM, a multicenter retrospective cohort study of patients treated with primary SRS for recurrent grade 2 and 3 meningiomas. METHODS AND MATERIALS: Data on patients with recurrent grade 2 and 3 meningioma treated with SRS at first recurrence were retrospectively collected from eight academic centers in the United States. Patients with multiple lesions at the time of initial diagnosis or more than two lesions at the time of first recurrence were excluded from this analysis. Patient demographics and treatment parameters were extracted at time of diagnosis, first recurrence, and second recurrence. Oncologic outcomes including progression-free survival (PFS) and overall survival (OS) as well as toxicity outcomes were reported at the patient level. RESULTS: From 2000-2022, 108 patients were identified (94% grade 2, 6.0% grade 3). 106 patients (98%) had upfront surgical resection (60% gross-total resection) with 18% receiving adjuvant radiotherapy (RT). Median time to first progression was 2.5 years (IQR 1.34-4.30). At first recurrence, patients were treated with single or fractionated SRS to a median marginal dose of 16 Gy to a maximum of two lesions (87% received single fraction SRS). Median follow-up time after SRS was 2.6 years. 1-, 2-, and 3-year PFS was 90%, 75%, and 57%, respectively after treatment with SRS. 1-, 2-, and 3-year OS was 97%, 94%, and 92%, respectively. On multivariable analysis, grade 3 disease (HR 6.80; 95% CI 1.61-28.6), male sex (HR 3.48; 95% CI 1.47-8.26), and receipt of prior RT (HR 2.69; 95% CI 1.23-5.86) were associated with worse PFS. SRS dose and tumor volume were not correlated with progression. Treatment was well-tolerated, with a 3.0% incidence of grade 2+ radiation necrosis. CONCLUSIONS: This is the largest multi-center study to evaluate salvage SRS in recurrent grade 2 and 3 meningiomas. In this select cohort of patients with primarily grade 2 meningioma with potentially more favorable natural history of delayed, localized first recurrence amenable to salvage SRS, local control rates and toxicity profiles were favorable, warranting further prospective validation.

The role of radiotherapy in immunotherapy strategies in the central nervous system.

The clinical efficacy and relative tolerability of adverse effects of immune checkpoint immunotherapy have led to its increasingly routine use in the management of multiple advanced solid malignancies. Radiation therapy (RT) is well-known to have both local and distant immunomodulatory effects, which has led to extensive investigation into the synergism of these 2 therapies. While the central nervous system (CNS) has historically been thought to be a sanctuary site, well-protected by the blood-brain barrier from the effects of immunotherapy, over the last several years studies have shown the benefits of these drugs, particularly in metastatic disease involving the CNS. This review explores current progress and the future of combination therapy with immune checkpoint inhibitors and RT.

Brain metastases from renal cell carcinoma: Effects of novel systemic agents on brain metastasis outcomes.

OBJECTIVE: The objective of this study was to examine survival outcomes in 136 patients with renal cell carcinoma with metastases to the brain who were treated with radiation combined with immunotherapy or tyrosine kinase inhibitor compared to those who were treated with radiation therapy alone. METHODS: The Wake Forest Gamma Knife prospective database was searched for all patients with renal cell carcinoma brain metastases. Outcome measurements included overall survival, determined via the Kaplan-Meier Method, and cumulative incidence of local and distant failure, determined using the Fine Gray competing risks analysis with death as a competing risk for the 136 patients included. RESULTS: Overall survival for the entire population at 6 months, 12 months, and 24 months was 67%, 47% and 30%, respectively. For the TKI (non-immunotherapy-treated) population (n = 37), overall survival was 75%, 61%, and 40% at 6 months, 12 months, and 24 months, respectively. For the immunotherapy-treated population (n = 35), overall survival was 85%, 64%, and 50% at 6 months, 12 months, and 24 months, respectively. Overall survival was significantly increased for patients who received radiation with either immunotherapy or TKI (p < 0.0001). CONCLUSION: Prior series of patients with brain metastases of multiple histologies have demonstrated an improvement in the local efficacy of stereotactic radiosurgery when combined with systemic agents. We found that patients treated with targeted agents and patients treated with immunotherapy demonstrated a trend towards improvement over patients treated in the era prior to the advent of either classes of novel therapies.

Delayed Imaging Changes 18 Months or Longer After Stereotactic Radiosurgery for Brain Metastases: Necrosis or Progression.

OBJECTIVE: Imaging changes after stereotactic radiosurgery (SRS) can occur for years after treatment, although the available data on the incidence of tumor progression and adverse radiation effects (ARE) are generally limited to the first 2 years after treatment. METHODS: A single-institution retrospective review was conducted of patients who had >18 months of imaging follow-up available. Patients who had ≥1 metastatic brain lesions treated with Gamma Knife SRS were assessed for the time to radiographic progression. Those with progression ≥18 months after the initial treatment were included in the present study. The lesions that progressed were characterized as either ARE or tumor progression based on the tissue diagnosis or imaging characteristics over time. RESULTS: The cumulative incidence of delayed imaging radiographic progression was 35% at 5 years after the initial SRS. The cumulative incidence curves of the time to radiographic progression for lesions determined to be ARE and lesions determined to be tumor progression were not significantly different statistically. The cumulative incidence of delayed ARE and delayed tumor progression was 17% and 16% at 5 years, respectively. Multivariate analysis indicated that the number of metastatic brain lesions present at the initial SRS was the only factor associated with late radiographic progression. CONCLUSIONS: The timing of late radiographic progression does not differ between ARE and tumor progression. The number of metastatic brain lesions at the initial SRS is a risk factor for late radiographic progression.

Use of comprehensive genomic profiling for biomarker discovery for the management of non-small cell lung cancer brain metastases.

Background: Clinical biomarkers for brain metastases remain elusive. Increased availability of genomic profiling has brought discovery of these biomarkers to the forefront of research interests. Method: In this single institution retrospective series, 130 patients presenting with brain metastasis secondary to Non-Small Cell Lung Cancer (NSCLC) underwent comprehensive genomic profiling conducted using next generation circulating tumor deoxyribonucleic acid (DNA) (Guardant Health, Redwood City, CA). A total of 77 genetic mutation identified and correlated with nine clinical outcomes using appropriate statistical tests (general linear models, Mantel-Haenzel Chi Square test, and Cox proportional hazard regression models). For each outcome, a genetic signature composite score was created by summing the total genes wherein genes predictive of a clinically unfavorable outcome assigned a positive score, and genes with favorable clinical outcome assigned negative score. Results: Seventy-two genes appeared in at least one gene signature including: 14 genes had only unfavorable associations, 36 genes had only favorable associations, and 22 genes had mixed effects. Statistically significant associated signatures were found for the clinical endpoints of brain metastasis velocity, time to distant brain failure, lowest radiosurgery dose, extent of extracranial metastatic disease, concurrent diagnosis of brain metastasis and NSCLC, number of brain metastases at diagnosis as well as distant brain failure. Some genes were solely associated with multiple favorable or unfavorable outcomes. Conclusion: Genetic signatures were derived that showed strong associations with different clinical outcomes in NSCLC brain metastases patients. While these data remain to be validated, they may have prognostic and/or therapeutic impact in the future. Statement of translation relevance: Using Liquid biopsy in NSCLC brain metastases patients, the genetic signatures identified in this series are associated with multiple clinical outcomes particularly these ones that lead to early or more numerous metastases. These findings can be reverse-translated in laboratory studies to determine if they are part of the genetic pathway leading to brain metastasis formation.

Single-cell sequencing reveals the landscape of the human brain metastatic microenvironment.

Brain metastases is the most common intracranial tumor and account for approximately 20% of all systematic cancer cases. It is a leading cause of death in advanced-stage cancer, resulting in a five-year overall survival rate below 10%. Therefore, there is a critical need to identify effective biomarkers that can support frequent surveillance and promote efficient drug guidance in brain metastasis. Recently, the remarkable breakthroughs in single-cell RNA-sequencing (scRNA-seq) technology have advanced our insights into the tumor microenvironment (TME) at single-cell resolution, which offers the potential to unravel the metastasis-related cellular crosstalk and provides the potential for improving therapeutic effects mediated by multifaceted cellular interactions within TME. In this study, we have applied scRNA-seq and profiled 10,896 cells collected from five brain tumor tissue samples originating from breast and lung cancers. Our analysis reveals the presence of various intratumoral components, including tumor cells, fibroblasts, myeloid cells, stromal cells expressing neural stem cell markers, as well as minor populations of oligodendrocytes and T cells. Interestingly, distinct cellular compositions are observed across different samples, indicating the influence of diverse cellular interactions on the infiltration patterns within the TME. Importantly, we identify tumor-associated fibroblasts in both our in-house dataset and external scRNA-seq datasets. These fibroblasts exhibit high expression of type I collagen genes, dominate cell-cell interactions within the TME via the type I collagen signaling axis, and facilitate the remodeling of the TME to a collagen-I-rich extracellular matrix similar to the original TME at primary sites. Additionally, we observe M1 activation in native microglial cells and infiltrated macrophages, which may contribute to a proinflammatory TME and the upregulation of collagen type I expression in fibroblasts. Furthermore, tumor cell-specific receptors exhibit a significant association with patient survival in both brain metastasis and native glioblastoma cases. Taken together, our comprehensive analyses identify type I collagen-secreting tumor-associated fibroblasts as key mediators in metastatic brain tumors and uncover tumor receptors that are potentially associated with patient survival. These discoveries provide potential biomarkers for effective therapeutic targets and intervention strategies.

Brain Metastasis Incidence and Patterns of Presentation After Definitive Treatment of Locally Advanced Non-Small Cell Lung Cancer: A Potential Argument for Brain Magnetic Resonance Imaging Surveillance.

Purpose: Brain metastases (BMs) are a common source of morbidity and mortality. Guidelines do not advise brain surveillance for locally advanced non-small cell lung cancer (LA-NSCLC). We describe the incidence, time to development, presentation, and management of BMs after definitive chemoradiotherapy (CRT). Methods and Materials: We reviewed records of patients with LA-NSCLC treated with CRT within the period from 2013 to 2020. Descriptive statistics were used to characterize the population and the Kaplan-Meier method was used to estimate time to BM. Fisher exact tests and Wilcoxon rank-sum tests were used to compare outcomes between symptomatic and asymptomatic patients. Results: A total of 219 patients were reviewed including 96 with squamous cell carcinoma, 88 with adenocarcinoma, and 35 with large cell/not otherwise specified (LC/NOS). Thirty-nine patients (17.8%) developed BMs: 35 (90%) symptomatic and 4 (10%) asymptomatic. The rate of BM was highest in LC/NOS (34.3%) and adenocarcinoma (23.9%). Ninety percent of BMs occurred within 2 years. All asymptomatic patients underwent stereotactic radiosurgery alone, compared with 40% of symptomatic patients (P = .04). Symptomatic patients were more likely to require hospitalization (65.7% vs 0%, P = .02), craniotomy (25.7% vs 0%, not significant), and steroids (91.4% vs 0%, P < .001). Cumulative BM volume was higher for symptomatic patients (4 vs 0.24 cm3, P < .001) as was median greatest axial dimension (2.18 vs 0.52 cm, P < .001). Conclusions: We identified a high rate of BMs, particularly in LC/NOS and adenocarcinoma histology NSCLC. The majority were symptomatic. These results provide rationale for post-CRT magnetic resonance imaging brain surveillance for patients at high risk of BM.

Comparison of first-line radiosurgery for small-cell and non-small cell lung cancer brain metastases (CROSS-FIRE).

INTRODUCTION: Historical reservations regarding stereotactic radiosurgery (SRS) for small-cell lung cancer (SCLC) brain metastases include concerns for short-interval and diffuse central nervous system (CNS) progression, poor prognoses, and increased neurological mortality specific to SCLC histology. We compared SRS outcomes for SCLC and non-small cell lung cancer (NSCLC) where SRS is well established. METHODS: Multicenter first-line SRS outcomes for SCLC and NSCLC from 2000 to 2022 were retrospectively collected (n = 892 SCLC, n = 4785 NSCLC). Data from the prospective Japanese Leksell Gamma Knife Society (JLGK0901) clinical trial of first-line SRS were analyzed as a comparison cohort (n = 98 SCLC, n = 814 NSCLC). Overall survival (OS) and CNS progression were analyzed using Cox proportional hazard and Fine-Gray models, respectively, with multivariable adjustment for cofactors including age, sex, performance status, year, extracranial disease status, and brain metastasis number and volume. Mutation-stratified analyses were performed in propensity score-matched retrospective cohorts of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) positive NSCLC, mutation-negative NSCLC, and SCLC. RESULTS: OS was superior for patients with NSCLC compared to SCLC in the retrospective dataset (median OS = 10.5 vs 8.6 months; P < .001) and in the JLGK0901 dataset. Hazard estimates for first CNS progression favoring NSCLC were similar in both datasets but reached statistical significance in the retrospective dataset only (multivariable hazard ratio = 0.82, 95% confidence interval = 0.73 to 0.92, P = .001). In the propensity score-matched cohorts, there were continued OS advantages for NSCLC patients (median OS = 23.7 [EGFR and ALK positive NSCLC] vs 13.6 [mutation-negative NSCLC] vs 10.4 months [SCLC], pairwise P values < 0.001), but no statistically significant differences in CNS progression were observed in the matched cohorts. Neurological mortality and number of lesions at CNS progression were similar for NSCLC and SCLC patients. Leptomeningeal progression was increased in patients with NSCLC compared to SCLC in the retrospective dataset only (multivariable hazard ratio = 1.61, 95% confidence interval = 1.14 to 2.26, P = .007). CONCLUSIONS: After SRS, SCLC histology was associated with shorter OS compared to NSCLC. CNS progression occurred earlier in SCLC patients overall but was similar in patients matched on baseline factors. SCLC was not associated with increased neurological mortality, number of lesions at CNS progression, or leptomeningeal progression compared to NSCLC. These findings may better inform clinical expectations and individualized decision making regarding SRS for SCLC patients.

c-Met Mediated Cytokine Network Promotes Brain Metastasis of Breast Cancer by Remodeling Neutrophil Activities.

The brain is one of the most common metastatic sites among breast cancer patients, especially in those who have Her2-positive or triple-negative tumors. The brain microenvironment has been considered immune privileged, and the exact mechanisms of how immune cells in the brain microenvironment contribute to brain metastasis remain elusive. In this study, we found that neutrophils are recruited and influenced by c-Met high brain metastatic cells in the metastatic sites, and depletion of neutrophils significantly suppressed brain metastasis in animal models. Overexpression of c-Met in tumor cells enhances the secretion of a group of cytokines, including CXCL1/2, G-CSF, and GM-CSF, which play critical roles in neutrophil attraction, granulopoiesis, and homeostasis. Meanwhile, our transcriptomic analysis demonstrated that conditioned media from c-Met high cells significantly induced the secretion of lipocalin 2 (LCN2) from neutrophils, which in turn promotes the self-renewal of cancer stem cells. Our study unveiled the molecular and pathogenic mechanisms of how crosstalk between innate immune cells and tumor cells facilitates tumor progression in the brain, which provides novel therapeutic targets for treating brain metastasis.

Prognostic Mutational Signatures of NSCLC Patients treated with chemotherapy, immunotherapy and chemoimmunotherapy.

Different types of therapy are currently being used to treat non-small cell lung cancer (NSCLC) depending on the stage of tumor and the presence of potentially druggable mutations. However, few biomarkers are available to guide clinicians in selecting the most effective therapy for all patients with various genetic backgrounds. To examine whether patients' mutation profiles are associated with the response to a specific treatment, we collected comprehensive clinical characteristics and sequencing data from 524 patients with stage III and IV NSCLC treated at Atrium Health Wake Forest Baptist. Overall survival based Cox-proportional hazard regression models were applied to identify mutations that were "beneficial" (HR < 1) or "detrimental" (HR > 1) for patients treated with chemotherapy (chemo), immune checkpoint inhibitor (ICI) and chemo+ICI combination therapy (Chemo+ICI) followed by the generation of mutation composite scores (MCS) for each treatment. We also found that MCS is highly treatment specific that MCS derived from one treatment group failed to predict the response in others. Receiver operating characteristics (ROC) analyses showed a superior predictive power of MCS compared to TMB and PD-L1 status for immune therapy-treated patients. Mutation interaction analysis also identified novel co-occurring and mutually exclusive mutations in each treatment group. Our work highlights how patients' sequencing data facilitates the clinical selection of optimized treatment strategies.

Five-year survivors from brain metastases treated with stereotactic radiosurgery: Biology, improving treatments, or just plain luck?

Background: Improvements in therapies have led to an increasing number of long-term survivors of brain metastases. The present series compares a population of 5-year survivors of brain metastases to a generalized brain metastases population to assess for factors attributable to long-term survival. Methods: A single institution retrospective review was performed to identify 5-year survivors of brain metastases who received stereotactic radiosurgery (SRS). A historical control population of 737 patients with brain metastases was used to assess similarities and differences between the long-term survivor population and the general population treated with SRS. Results: A total of 98 patients with brain metastases were found to have survived over 60 months. No differences between long-term survivors and controls were identified with regards to the age at first SRS (P = .19), primary cancer distribution (P = .80), and the number of metastases at first SRS (P = .90). Cumulative incidence of neurologic death at 6, 8 and 10 years for the long-term survivor cohort was 4.8%, 16%, and 16% respectively. In the historical controls, cumulative incidence of neurologic death reached a plateau at 40% after 4.9 years. A significant difference in the distribution of burden of disease at the time of the first SRS was found between the 5-year survivors and the control (P = .0049). 58% of 5-year survivors showed no evidence of clinical disease at the last follow-up. Conclusion: Five-year survivors of brain metastases represent a diverse histologic population, suggesting a small population of oligometastatic and indolent cancers exist for each cancer type.

Bridging the Communication Gaps: A Prospective Single-Arm Pilot Study Testing the Feasibility of Interdisciplinary Radiotherapy Planning in Locally Advanced Lung Cancer.

RATIONALE AND OBJECTIVES: The treatment of locally advanced lung cancer (LALC) with radiotherapy (RT) can be challenging. Multidisciplinary collaboration between radiologists and radiation oncologists (ROs) may optimize RT planning, reduce uncertainty in follow-up imaging interpretation, and improve outcomes. MATERIALS AND METHODS: In this prospective clinical treatment trial (clinicaltrials.gov NCT04844736), 37 patients receiving definitive RT for LALC, six attending ROs, and three thoracic radiologists were consented and enrolled across four treatment centers. Prior to RT plan finalization, representative computed tomography (CT) slices with overlaid outlines of preliminary irradiation targets were shared with the team of radiologists. The primary endpoint was to assess feasibility of receiving feedback no later than 4 business days of RT simulation on at least 50% of plans. RESULTS: Thirty-seven patients with lung cancer were enrolled, and 35 of 37 RT plans were reviewed. Of the 35 patients reviewed, mean age was 69 years. For 27 of 37 plans (73%), feedback was received within 4 or fewer days (interquartile range 3-4 days). Thirteen of 35 cases (37%) received feedback that the delineated target potentially did not include all sites suspicious for tumor involvement. In total, changes to the RT plan were recommended for over- or undercoverage in 16 of 35 cases (46%) and implemented in all cases. Radiology review resulted in no treatment delays and substantial changes to irradiated volumes: gross tumor volume, -1.9 to +96.1%; planning target volume, -37.5 to +116.5%. CONCLUSION: Interdisciplinary collaborative RT planning using a simplified workflow was feasible, produced no treatment delays, and prompted substantial changes in RT targets.

Modulation of oxidative phosphorylation and mitochondrial biogenesis by cigarette smoke influence the response to immune therapy in NSCLC patients.

The treatment regimen of non-small cell lung cancer (NSCLC) has drastically changed owing to the superior anti-cancer effects generated by the immune-checkpoint blockade (ICB). However, only a subset of patients experience benefit after receiving ICBs. Therefore, it is of paramount importance to increase the response rate by elucidating the underlying molecular mechanisms and identifying novel therapeutic targets to enhance the efficacy of IBCs in non-responders. We analyzed the progression-free survival (PFS) and overall survival (OS) of 295 NSCLC patients who received anti-PD-1 therapy by segregating them with multiple clinical factors including sex, age, race, smoking history, BMI, tumor grade and subtype. We also identified key signaling pathways and mutations that are enriched in patients with distinct responses to ICB by gene set enrichment analysis (GSEA) and mutational analyses. We found that former and current smokers have a higher response rate to anti-PD-1 treatment than non-smokers. GSEA results revealed that oxidative phosphorylation (OXPHOS) and mitochondrial related pathways are significantly enriched in both responders and smokers, suggesting a potential role of cellular metabolism in regulating immune response to ICB. We also demonstrated that all-trans retinoic acid (ATRA) which enhances mitochondrial function significantly enhanced the efficacy of anti-PD-1 treatment in vivo. Our clinical and bioinformatics based analyses revealed a connection between smoking induced metabolic switch and the response to immunotherapy, which can be the basis for developing novel combination therapies that are beneficial to never smoked NSCLC patients.

Collagen deposition within brain metastases is associated with leptomeningeal failure after cavity-directed radiosurgery.

Background: Leptomeningeal failure (LMF) represents a devastating progression of disease following resection of brain metastases (BrM). We sought to identify a biomarker at time of BrM resection that predicts for LMF using mass spectrometry-based proteomic analysis of resected BrM and to translate this finding with histochemical assays. Methods: We retrospectively reviewed 39 patients with proteomic data available from resected BrM. We performed an unsupervised analysis with false discovery rate adjustment (FDR) to compare proteomic signature of BrM from patients that developed LMF versus those that did not. Based on proteomic analysis, we applied trichrome stain to a total of 55 patients who specifically underwent resection and adjuvant radiosurgery. We used competing risks regression to assess predictors of LMF. Results: Of 39 patients with proteomic data, FDR revealed type I collagen-alpha-1 (COL1A1, P = .045) was associated with LMF. The degree of trichrome stain in each block correlated with COL1A1 expression (ß = 1.849, P = .001). In a cohort of 55 patients, a higher degree of trichrome staining was associated with an increased hazard of LMF in resected BrM (Hazard Ratio 1.58, 95% CI 1.11-2.26, P = .01). Conclusion: The degree of trichrome staining correlated with COL1A1 and portended a higher risk of LMF in patients with resected brain metastases treated with adjuvant radiosurgery. Collagen deposition and degree of fibrosis may be able to serve as a biomarker for LMF.

Outcomes of radiation-induced meningiomas treated with stereotactic radiosurgery.

PURPOSE: Data on the efficacy and safety of stereotactic radiosurgery (SRS) for treatment of radiation-induced meningiomas (RIMs) are limited. METHODS: A single institution database of Cobalt-60 SRS cases from 08/1999 to 10/2020 was reviewed. Radiation-induced meningiomas were identified using Cahan's criteria. Endpoints included overall survival (OS), progression free survival (PFS), local control (LC), treatment failure, and treatment toxicity. Univariate and multivariate analyses were performed using cox proportional hazard models. RESULTS: A total of 29 patients with 86 RIM lesions were identified. Median follow-up after SRS was 59 months. The median dose prescribed to the 50% isodose line was 14 Gy (range 12-20 Gy). The actuarial 5-yr OS and PFS were 96% and 68%, respectively. Patients treated for recurrent RIMs had a significantly lower PFS (45% vs 94% at 3 yr, p < 0.005) than patients treated in the upfront setting. Patients with presumed or WHO grade I RIMs had a significantly greater PFS (3-year PFS 96% vs 20%) than patients with WHO grade II RIMs (p < 0.005). On a per-lesion basis, local control (LC) at 1-, 3-, and 5-yrs was 82%, 76%, 74%, respectively. On multivariate analysis, female gender was associated with improved LC (p < 0.001), while marginal doses > 14 Gy were associated with worse local control (p < 0.001). Grade I-III toxicity following treatment was 9.0%. CONCLUSIONS: Stereotactic radiosurgery is a safe and effective treatment option for radiographic RIMs, WHO grade I RIMs, or lesions treated in the upfront setting. WHO grade II lesions and recurrent lesions are at increased risk for disease progression.

A transformer-based deep-learning approach for classifying brain metastases into primary organ sites using clinical whole-brain MRI images.

Treatment decisions for brain metastatic disease rely on knowledge of the primary organ site and are currently made with biopsy and histology. Here, we develop a deep-learning approach for accurate non-invasive digital histology with whole-brain magnetic resonance imaging (MRI) data. Contrast-enhanced T1-weighted and fast spoiled gradient echo brain MRI exams (n = 1,582) were preprocessed and input to the proposed deep-learning workflow for tumor segmentation, modality transfer, and primary site classification into one of five classes. Tenfold cross-validation generated an overall area under the receiver operating characteristic curve (AUC) of 0.878 (95% confidence interval [CI]: 0.873,0.883). These data establish that whole-brain imaging features are discriminative enough to allow accurate diagnosis of the primary organ site of malignancy. Our end-to-end deep radiomic approach has great potential for classifying metastatic tumor types from whole-brain MRI images. Further refinement may offer an invaluable clinical tool to expedite primary cancer site identification for precision treatment and improved outcomes.

Long term survivors of stereotactic radiosurgery for brain metastases: do distant brain failures reach a plateau and what factors are associated with a brain metastasis velocity of zero?

PURPOSE: Life expectancy continues to increase for patients with brain metastases treated with stereotactic radiosurgery (SRS). The present study sought to retrospectively analyze brain metastasis patients who have survived 2 years or more, and assess for what factors may predict for a final brain metastasis velocity (BMV) of zero. METHODS: This was a single-institution retrospective study of 300 patients treated with SRS from 2001 to 2019 for brain metastases who survived greater than 2 years after first SRS. Final BMV is calculated by summing all metastases through the observed time divided by the total time in years. A BMV of zero is defined as at least 2 years of imaging follow-up without distant brain failure (DBF). RESULTS: Median age at first SRS is 61 (IQR: 53, 70). Kaplan-Meier estimated median overall survival is 4.9 years and time to DBF is 1.5 years (95% CI 1.2, 2.0). Twenty-eight (9.3%) patients underwent subsequent WBRT. One hundred and one (33.7%) patients never had any further brain metastases (BMV = 0) at a median follow-up time of 3.3 years. Median BMV is 0.4 (IQR: 0, 1.4). Distant brain failures reach a plateau at 4 years where the cumulative incidence of DBF is 82%. 70% of first time DBFs have occurred by 2 years. Factors significantly associated with a BMV of zero include fewer brain metastases at first SRS (HR 1.1; p = 0.0004) and Caucasian race (HR 1.5; p = 0.03). CONCLUSION: Approximately one third of brain metastasis patients who live beyond 2 years after initial SRS have a BMV of zero. DBFs appear to reach a plateau at 4 years. Factors significantly associated with a BMV of zero include Caucasian race and having had a single brain metastasis at first SRS.

Upfront immunotherapy leads to lower brain metastasis velocity in patients undergoing stereotactic radiosurgery for brain metastases.

Background: While immunotherapy has been shown to improve survival and decrease neurologic death in patients with brain metastases, it remains unclear whether this improvement is due to prevention of new metastasis to the brain. Method: We performed a retrospective review of patients presenting with brain metastases simultaneously with the first diagnosis of metastatic disease and were treated with upfront immunotherapy as part of their treatment regimen and stereotactic radiosurgery (SRS) to the brain metastases. We compared this cohort with a historical control population (prior to the immunotherapy era) who were treated with pre-immunotherapy standard of care systemic therapy and with SRS to the brain metastases. Results: Median overall survival time was improved in the patients receiving upfront immunotherapy compared to the historical cohort (48 months vs 8.4 months, p=0.001). Median time to distant brain failure was statistically equivalent (p=0.3) between the upfront immunotherapy cohort and historical control cohort (10.3 vs 12.6 months). Brain metastasis velocity was lower in the upfront immunotherapy cohort (median 3.72 metastases per year) than in the historical controls (median 9.48 metastases per year, p=0.001). Cumulative incidence of neurologic death at one year was 12% in the upfront immunotherapy cohort and 28% in the historical control cohort (p=0.1). Conclusions: Upfront immunotherapy appears to improve overall survival and decrease BMV compared to historical controls. While these data remain to be validated, they suggest that brain metastasis patients may benefit from concurrent immunotherapy with SRS.

Clinical outcomes of dose-escalated re-irradiation in patients with recurrent high-grade glioma.

Background: Re-irradiation for recurrent gliomas is a controversial treatment option with no clear standard dose or concurrent systemic therapy. Methods: This series represents a single-institution retrospective review of patients treated with re-irradiation for recurrent high-grade glioma. After 2012, patients were commonly offered concurrent bevacizumab as a cytoprotective agent against radiation necrosis. Kaplan-Meier method was used to estimate overall survival and progression-free survival. Cox proportional hazards regression was used to identify factors associated with overall survival and progression-free survival. Results: Between 2001 and 2021, 52 patients underwent re-irradiation for a diagnosis of recurrent high-grade glioma. 36 patients (69.2%) had a histologic diagnosis of glioblastoma at the time of re-irradiation. The median BED10 (biological equivalent dose 10 Gy) of re-irradiation was 53.1 Gy. Twenty-one patients (40.4%) received concurrent bevacizumab with re-irradiation. Median survival for the entire cohort and for glioblastoma at the time of recurrence patients was 6.7 months and 6.0 months, respectively. For patients with glioblastoma at the time of recurrence, completing re-irradiation (HR 0.03, P < .001), use of concurrent bevacizumab (HR 0.3, P = .009), and the BED10 (HR 0.9, P = .005) were predictive of overall survival. Nine patients developed grade 3-5 toxicity; of these, 2 received concurrent bevacizumab and 7 did not (P = .15). Conclusion: High dose re-irradiation with concurrent bevacizumab is feasible in patients with recurrent gliomas. Concurrent bevacizumab and increasing radiation dose may improve survival in patients with recurrent glioblastoma.

Intensity-modulated radiotherapy with planned Gamma Knife radiosurgery boost for head and neck cancer with extensive disease in proximity to critical structures.

BACKGROUND: To describe intensity-modulated radiotherapy (IMRT) with Gamma Knife Radiosurgery (GKRS) boost for locally advanced head and neck cancer (HNC) with disease near dose-limiting structures. METHODS: Patients with HNC treated with IMRT/GKRS as part of a combined modality approach between 2011 and 2021 were reviewed. Local control, overall survival and disease-specific survival were estimated using the Kaplan Meier method. RESULTS: Twenty patients were included. Nineteen patients had T3-4 tumors. Median follow-up was 26.3 months. GKRS site control was 95%. Two patients progressed at the treated primary site, one patient failed at the edge of the GKRS treatment volume, with no perineural or intracranial failure. 2-year OS was 94.7% (95% CI: 85.2%-100%). Concurrent chemotherapy was given in nine patients (45%). One patient (5%) received induction/concurrent chemotherapy. Brain radionecrosis occurred in three patients, one of which was biopsy-proven. CONCLUSIONS: IMRT plus GKRS boost results in excellent disease control near critical structures with minimal toxicity.