Leptomeningeal metastases of solid cancer

Different genetic profiles contribute to worse overall survival in patients with leptomeningeal metastases of non-small-cell lung cancer

BACKGROUND

To assess the genetic characteristics of central nervous system (CNS) metastases from non-small-cell lung cancer (NSCLC), we gathered the genetic profiles of brain metastases (BM) and leptomeningeal metastases (LM). Our objective was to identify genetic factors contributing to poorer overall survival (OS) in NSCLC patients with LM.

METHODS

This study included 25 consecutive patients with BM and 52 patients with LM from Guangdong Sanjiu Brain Hospital. All participants underwent 168-target panel sequencing.

RESULTS

Among the 25 patients with BM, TP53 was the most frequently mutated gene (44%), followed by driver genes such as EGFR and BRAF (40% and 20%, respectively). In patients with BM, EGFR_amp and CDK4 were also frequently mutated, with rates of 20% and 16%, respectively. The genetic landscape of patients with LM differed, with the top mutated genes being EGFR, TP53, EGFR_amp, CDKN2A, CCNE1, CDK4, PMS2, and PIK3CA, with mutation rates of 77%, 69%, 31%, 29%, 13%, 13%, 13%, and 12%, respectively. In our study, patients with LM exhibited significantly worse OS compared to those with BM (p = 0.029). The mutation rates of TP53, EGFR_amp, and CDKN2A varied between patients with LM and those with BM, at 69.23% vs. 44%, 30.77% vs. 20%, and 28.85% vs. 12%, respectively. Further exploration revealed that patients with BM with TP53 mutations had a shorter OS than patients without TP53 mutations (p = 0.014). Similarly, patients with LM and TP53 mutations presented with worse OS than those without TP53 mutations (p = 0.0067). LM patients with CDKN2A deletions had worse OS than those without CDKN2A deletions (p = 0.037). Additionally, patients with EGFR_amp had a shorter OS than those without EGFR_amp (p = 0.044).

CONCLUSIONS

Patients with LM exhibited significantly worse OS than those with BM. Gene signatures, such as TP53, EGFR_amp, and CDKN2A, may account for shorter outcomes in patients with LM.

Comparative evaluation of the diagnostic and prognostic performance of CNSide™ versus standard cytology for leptomeningeal disease

Background

This retrospective study compares the real-world performance of cerebrospinal fluid (CSF) CNSide™ versus cytology in leptomeningeal disease (LMD).

Methods

Consecutive patients with suspected LMD who underwent lumbar punctures for CSF cytology and CNSide™ from January 2020 to December 2022 were reviewed. LMD was classified by EANO criteria. Descriptive statistics, confusion matrix, Kaplan-Meier curves, and Cox proportional regression were used.

Results

Median age for 87 evaluable patients was 63 years (range: 23-93); 82 (94%) met EANO criteria for possible/probable/confirmed LMD (EANO/LMD). The commonest primary cancers were breast (36,44.0%) and lung (34,41.5%). Primary lung harbored actionable mutations in 18 (53.0%); primary breast expressed hormone receptors in 27 (75%), and HER2 amplification in 8 (22%). Uncontrolled systemic disease was detected in 35 (40%), while 25 (46%) received systemic therapy with medium/high CNS penetrance at LMD diagnosis. The median time from initial cancer to LMD diagnosis was 31 months (range: 13-73). LMD was confirmed by CSF cytology in 23/82 (28%), all identified by CNSide™. CNSide™ identified 13 additional cases (36/82, 43.9%), increasing diagnostic yield by 56.5%. Median overall survival (mOS) was 31 weeks (95%CI: 21-43), significantly worse for CNSide™ positive versus negative: 4.0 versus 16.0 weeks, respectively (HR = 0.50, P = .010). While survival since LMD diagnosis did not differ by histology, time to LMD diagnosis from initial cancer diagnosis was longer for breast (48.5 months, IQR: 30.0-87.5) versus lung (8 months, IQR:0.5-16.0) cohorts. mOS was longer for patients eligible for intrathecal chemotherapy (HR: 0.189, 95%CI: 0.053-0.672, P = .010).

Conclusions

This retrospective, real-world analysis of CNSide™ showed increased sensitivity versus cytology and provided clinically relevant molecular CSF analyses.

Spectrum of EEG Findings in Patients with Leptomeningeal Carcinomatosis and Seizures: Correlation with Neurodiagnostic Results and Outcome

Purpose: Leptomeningeal carcinomatosis (LC) is a devastating condition in patients with systemic malignancies or primary brain tumors. Although much is known about neuro-radiologic investigations, there is very little information about EEG findings in these patients. Whether EEG is correlated with cranial magnetic resonance imaging (MRI) results and survival has not been investigated. Methods: Medical records of 2340 adult patients with the diagnosis of brain tumor, either metastatic (Group 1) or primary (Group 2), between 2000-2021 were reviewed for the presence of LC and seizures. Demographic and clinical features, laboratory results and Karnofsky performance scores of included patients were noted. Available routine EEG recordings were re-evaluated. Any possible correlation between EEG findings-MRI and EEG findings-survival were investigated statistically. Results: Sixty-six patients with LC and seizures were identified. The most common malignancies were lung cancer and glioblastoma multiforme. Twenty-six EEG recordings of 17 patients in Group 1, and 13 EEGs of 9 patients in Group 2 were available for final analysis. The most common EEG characteristic was background slowing (73%). The most frequent findings were rhythmic periodic patterns or spike wave activity (27%). Sporadic epileptiform discharges (8%) or ictal recordings (4%) were very rare. None of the EEG features correlated with MRI results or survival. Conclusion: There are various EEG patterns in patients with LC and seizures. The most common findings are related to background activity, with rhythmic periodic patterns or spike wave activity being observed less commonly. EEG characteristics do not predict MRI findings or survival.

Building Team Medicine in the Management of CNS Metastases

CNS metastases are often terminal for cancer patients and occur at an approximately 10-fold higher rate than primary CNS tumors. The incidence of these tumors is approximately 70,000-400,000 cases annually in the US. Advances that have occurred over the past two decades have led to more personalized treatment approaches. Newer surgical and radiation techniques, as well as targeted and immune therapies, have enanled patient to live longer, thus increasing the risk for the development of CNS, brain, and leptomeningeal metastases (BM and LM). Patients who develop CNS metastases have often been heavily treated, and options for future treatment could best be addressed by multidisciplinary teams. Studies have indicated that patients with brain metastases have improved survival outcomes when cared for in high-volume academic institutions using multidisciplinary teams. This manuscript discusses a multidisciplinary approach for both parenchymal brain metastases as well as leptomeningeal metastases implemented in three academic institutions. Additionally, with the increasing development of healthcare systems, we discuss optimizing the management of CNS metastases across healthcare systems and integrating basic and translational science into our clinical care to further improve outcomes. This paper summarizes the existing therapeutic approaches to the treatment of BM and LM and discusses novel and emerging approaches to optimizing access to neuro-oncologic care while simultaneously integrating multidisciplinary teams in the care of patients with BM and LM.

Determining plasma and cerebrospinal fluid concentrations of EGFR-TKI in lung cancer patients

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are commonly used to treat advanced non-small cell lung cancer (NSCLC). A rapid and reliable method for measuring plasma and cerebrospinal fluid (CSF) concentrations of EGFR-TKIs is needed for therapeutic drug monitoring. By using UHPLC‒MS/MS with multiple reaction monitoring mode, we developed a method for rapidly determining the plasma and CSF concentrations of gefitinib, erlotinib, afatinib, and osimertinib. Protein precipitation was employed to remove protein interference for plasma and CSF matrix. The LC‒MS/MS assay was validated to be satisfactory in terms of linearity, precision, and accuracy. This method was successfully applied to measure plasma (n = 44) and CSF (n = 6) concentrations of EGFR-TKIs in NSCLC patients. The chromatographic separation was achieved by a Hypersil Gold aQ column within 3 minutes. The median plasma concentrations were 325.76, 1981.50, 42.62, 40.27, and 340.92 ng/ml for gefitinib erlotinib, afatinib 30 mg/day, afatinib 40 mg/day, and osimertinib, respectively. The CSF penetration rates were 2.15% for the patients receiving erlotinib therapy, 0.59% for afatinib, 0.08-1.12% for osimertinib 80 mg/day, and 2.18% for those receiving osimertinib 160 mg/day. This assay helps to predict the effectiveness and toxicities of EGFR-TKIs in the pursuit of precision medicine for lung cancer patients.

Complete Cerebrospinal Fluid Response to T-DM1 in HER2 Positive Metastatic Breast Cancer: A Case Report

Leptomeningeal carcinomatosis is a rare but serious consequence of pre-existing tumors, such as breast, lung, and gastrointestinal carcinomas. Further, leptomeningeal carcinomatosis is more frequently diagnosed with breast cancers, if only because breast cancers are diagnosed far more often than any other carcinomas. In this paper, we present the case of a leptomeningeal carcinomatosis patient who experienced complete remission following therapy targeted at the Her-2 (human epidermal growth factor receptor 2-positive) receptor. This patient’s diagnosis was complicated by the fact that brain and column MRI imaging were clear, but analysis of the cerebrospinal fluid led to the conclusion of leptomeningeal carcinomatosis. The tests were requested because the patient, under chemotherapy for advanced breast cancer at the time, reported some neurological symptoms. Following the diagnosis of leptomeningeal carcinomatosis and subsequent T-DM1 Her-2 receptor therapy, the patient showed a complete response to leptomeningeal carcinomatosis within 30 days and survived for another 16 months. This case offers compelling evidence that the effect TDM1 Her-2 receptor therapy has on a patient’s remission and long-term survivability is considerably better than other therapies for similar pre-existing conditions diagnosed with leptomeningeal carcinomatosis. Further prospective studies should confirm these findings.

Genotyping of cerebrospinal fluid in lung cancer patients with leptomeningeal metastasis

Background

The prognosis of non–small‐cell lung cancer (NSCLC) with leptomeningeal metastasis (LM) is poor. Detection of cell‐free DNA (cfDNA) by next generation sequencing (NGS) in cerebrospinal fluid (CSF) may facilitate diagnosis of LM and identification of drug resistance mechanisms, yet its clinical use needs to be further verified.

Methods

We performed a retrospective cohort study to assess the genetic profiles of paired CSF and plasma samples in lung cancer patients with LM. Of 17 patients screened, a total of 14 patients with LM and paired NGS tests were enrolled.

Results

All patients harbor driver gene mutations, including 12 epidermal growth factor receptor (EGFR) activating mutations, 1 anaplastic lymphoma kinase (ALK) rearrangement, and 1 ROS‐1 fusion. Genetic mutations were detected in CSF cfDNA from 92.9% patients (13/14), which was significantly higher than that from the plasma (9/14, 64.2%). The mutations were highly divergent between CSF and plasma cfDNA, with a concordance rate of 24.38% and 10 mutations shared by the two media. CSF cfDNA could also benefit the analysis of resistance mechanisms to targeted therapies. In five patients who experienced progression on 1st or 2nd generation EGFR‐tyrosine kinase inhibitors (TKIs), RB1 mutation, and amplification of MET and EGFR were detected in CSF cfDNA only. In eight patients with LM progression on osimertinib resistance, EGFR amplification was detected in CSF cfDNA from four patients, whereas no CNVs were detected in the matched plasma samples.

Conclusions

In conclusion, CSF could be superior to plasma in providing a more comprehensive genetic landscape of LM to find out drug resistance mechanisms and guide subsequent treatments.

Influence of the Timing of Leptomeningeal Metastasis on the Outcome of EGFR-Mutant Lung Adenocarcinoma Patients and Predictors of Detectable EGFR Mutations in Cerebrospinal Fluid

Simple Summary

Leptomeningeal metastasis (LM) is a devastating complication of lung cancer, with a generally poor outcome. We conduct the present study to evaluate the association between clinical presentations, brain images, tumor cell counts of the cerebrospinal fluid (CSF), and the epidermal growth factor receptor (EGFR) mutation detection rate in CSF among EGFR-mutant lung adenocarcinoma patients with LM and accessed the influence of the timing of LM occurrence on patient outcomes. Tumor cell numbers were semi-quantified according to tumor cells per high power field of CSF cytological slides. Radiological burden was assessed using a four-point scoring system, which evaluated LM-involved areas on brain magnetic resonance imaging. Our results suggest the association between the radiological severity score of LM, CSF tumor cell counts, and EGFR mutation detection rate in CSF. Furthermore, LM prior to first-line EGFR-tyrosine kinase inhibitor treatment was associated with an independently worse outcome.

Abstract

Background: We aim to evaluate the influence of the timing of leptomeningeal metastasis (LM) occurrence on the outcome of EGFR-mutant lung adenocarcinoma and to explore the predictors of detectable EGFR mutation in the cerebrospinal fluid (CSF). Methods: EGFR-mutant lung adenocarcinoma patients with cytologically confirmed LM were included for analysis. EGFR mutation in CSF was detected by MALDI-TOF MS plus PNA. Results: A total of 43 patients was analyzed. Of them, 8 (18.6%) were diagnosed with LM prior to first-line EGFR-TKI treatment (early onset), while 35 patients (81.4%) developed LM after first-line EGFR-TKI treatment (late onset). Multivariate analysis suggested that both late-onset LM (aHR 0.31 (95% CI 0.10–0.94), p = 0.038) and a history of third-generation EGFR-TKI treatment (aHR 0.24 (95% CI 0.09–0.67), p = 0.006) independently predicted a favorable outcome. EGFR mutation detection sensitivity in CSF was 81.4%. The radiological burden of LM significantly correlated with CSF tumor cell counts (p = 0.013) with higher CSF tumor cell counts predicting a higher detection sensitivity of EGFR mutation (p = 0.042). Conclusions: Early onset LM was an independently poor prognostic factor. A higher radiological severity score of LM could predict higher tumor cell counts in CSF, which in turn were associated with a higher detection rate of EGFR mutation.

Advances in the Diagnosis and Treatment of Leptomeningeal Disease

PURPOSE OF REVIEW

Leptomeningeal disease (LMD) is a rare, late complication of systemic cancer and is associated with significant neurological morbidity and high mortality. Here we provide an overview of this condition, summarizing key recent research findings and clinical practice trends in its diagnosis and treatment. We also review current clinical trials for LMD.

RECENT FINDINGS

Improved molecular diagnostic tools are in development to enable more sensitive detection of LMD, including circulating tumor cells and circulating tumor DNA. The use of targeted and CNS-penetrant therapeutics has shown survival improvements with tyrosine kinase inhibitors, antibody-drug conjugates, and select chemotherapy. However, these studies have primarily been phase I/II and retrospective analyses. There remains a dearth of clinical trials that include LMD patients. The combination of patient-specific molecular information and novel therapeutic approaches holds significant promise for improving outcomes in patients with LMD.

The joint detection of CEA and ctDNA in cerebrospinal fluid: an auxiliary tool for the diagnosis of leptomeningeal metastases in cancer

BACKGROUND

Leptomeningeal metastases (LMs) are highly invasive which leads to poor prognosis, but the accurate diagnosis of LM is challenging. It is necessary to investigate more advanced diagnostic methods to realize precision medicine. The main purpose of this study was to select a more effective method for the auxiliary diagnosis of LM by comparing various detection methods. The secondary purpose was to explore the value of cerebrospinal fluid (CSF) tumor markers (TMs) and circulating tumor DNA (ctDNA) testing in guiding clinical treatment.

METHODS

TMs in serum and CSF of patients were detected by chemiluminescence. The ctDNA of CSF and plasma were detected by the next-generation sequencing (NGS) technology.

RESULTS

In total, 54 tumor patients participated in this study, in which 39 with LM and 15 without LM (8 with parenchymal tumor and 7 without brain metastasis). The results showed that the sensitivity and accuracy of CSF cytology isolated during the first lumbar puncture were 0.31 (95% CI 0.17-0.48) and 0.50 (95% CI 0.36-0.64), respectively. The sensitivity and accuracy of CSF_CEA were 0.71 (95% CI 0.54-0.85) and 0.78 (95% CI 0.64-0.89), which were better than those of CSF_NSE and CSF_CFRA-211. The sensitivity and accuracy of CSF_ctDNA were 0.92 (95% CI 0.79-0.98) and 0.91 (95% CI 0.80-0.97), significantly higher than that of CSF cytology (P < 0.01). The sensitivity and accuracy of CSF_CEA combined with CSF_ctDNA were 0.97 (95% CI, 0.87-1.00) and 0.94 (95% CI 0.85-0.99), which were significantly higher than the traditional methods CSF cytology (P < 0.01). For LM patients with hydrocephalus, the sensitivity of CSF ctDNA even achieved 100% (14/14).

CONCLUSION

CSF_CEA combined with CSF_ctDNA could be used to accurately distinguish patients with LM from those with no brain metastasis and from those with parenchymal tumors. CSF_ctDNA testing reveals a unique mutation profile for patients with LM. Dynamic detection of CSF TM and ctDNA can better predict the efficacy and reveal the cause of drug resistance to guide subsequent treatment.

CLINICAL TRIAL REGISTRATION

Clinical trial registration number: NCT03029065.

Deciphering Biomarkers for Leptomeningeal Metastasis in Malignant Hemopathies (Lymphoma/Leukemia) Patients by Comprehensive Multipronged Proteomics Characterization of Cerebrospinal Fluid

Simple Summary

The early diagnosis of leptomeningeal disease is a challenge because it is asymptomatic in the early stages. Consequently, it is important to identify a panel of biomarkers to help in its diagnosis and/or prognosis. For this purpose, we explored a multipronged proteomics approach in cerebrospinal fluid (CSF) to determine a potential panel of biomarkers. Thus, a systematic and exhaustive characterization of more than 300 CSF samples was performed by an integrated approach by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) and functional proteomics analysis to establish protein profiles, which were useful for developing a panel of biomarkers validated by in silico approaches.

Abstract

In the present work, leptomeningeal disease, a very destructive form of systemic cancer, was characterized from several proteomics points of view. This pathology involves the invasion of the leptomeninges by malignant tumor cells. The tumor spreads to the central nervous system through the cerebrospinal fluid (CSF) and has a very grim prognosis; the average life expectancy of patients who suffer it does not exceed 3 months. The early diagnosis of leptomeningeal disease is a challenge because, in most of the cases, it is an asymptomatic pathology. When the symptoms are clear, the disease is already in the very advanced stages and life expectancy is low. Consequently, there is a pressing need to determine useful CSF proteins to help in the diagnosis and/or prognosis of this disease. For this purpose, a systematic and exhaustive proteomics characterization of CSF by multipronged proteomics approaches was performed to determine different protein profiles as potential biomarkers. Proteins such as PTPRC, SERPINC1, sCD44, sCD14, ANPEP, SPP1, FCGR1A, C9, sCD19, and sCD34, among others, and their functional analysis, reveals that most of them are linked to the pathology and are not detected on normal CSF. Finally, a panel of biomarkers was verified by a prediction model for leptomeningeal disease, showing new insights into the research for potential biomarkers that are easy to translate into the clinic for the diagnosis of this devastating disease.

Leptomeningeal carcinomatosis and breast cancer: a systematic review of current evidence on diagnosis, treatment and prognosis

Leptomeningeal carcinomatosis (LC) is a rare but challenging manifestation of advanced breast cancer with a severe impact on morbidity and mortality. We performed a systematic review of the evidence published over the last two decades, focusing on recent advances in the diagnostic and therapeutic options of LC. Lobular histology and a triple-negative intrinsic subtype are well-known risk factors for LC. Clinical manifestations are diverse and often aspecific. There is no gold standard for LC diagnosis: MRI and cerebrospinal fluid cytology are the most frequently used modalities despite the low accuracy. Current standard of care involves a multimodal strategy including systemic and intrathecal chemotherapy in combination with brain radiotherapy. Intrathecal chemotherapy has been widely used through the years despite the lack of data from randomized controlled trials and conflicting evidence on patient outcomes. No specific chemotherapeutic agent has shown superiority over others for both intrathecal and systemic treatment. Although endocrine therapy was heuristically considered unable to exert significant control on central nervous system metastatic disease, retrospective data suggest a favourable toxicity profile and even a possible positive impact on survival. In recent years, encouraging data on the use of targeted agents has emerged but further research in this field is required. Palliative treatment in the form of whole brain or stereotactic radiotherapy is associated with improvement in clinical manifestations and quality of life, with no proven impact on survival. The most investigated prognostic factors include performance status, non-triple-negative disease and multimodal treatment. Validation of prognostic scores is necessary to aid clinicians in the identification of patient subgroups that are most likely to benefit from an intensive therapeutic approach.

Lorlatinib Therapy for Rapid and Dramatic Control of Brain and Spinal Leptomeningeal Metastases From ALK-Positive Lung Adenocarcinoma

We report a patient with severe neurological deterioration due to leptomeningeal metastases involving brain and spinal cord from anaplastic lymphoma kinase (ALK)-positive lung adenocarcinoma, managed rapidly and successfully with lorlatinib therapy. A 48-year-old male patient presented with acute mental deterioration, severe headache, and weakness of both legs. The patient’s previous medical history included cerebral metastases from ALK-positive lung adenocarcinoma, which had been successfully managed via whole brain radiation therapy and gamma knife radiosurgery one year and three months before, respectively. Physical examination revealed neck stiffness and paraparesis with motor grade I. Gadolinium-enhanced brain MRI showed newly developed leptomeningeal enhancement along cerebellar folia, and whole spine MRI revealed similar leptomeningeal metastasis along the whole spinal axis. Lorlatinib was started orally with a dose of 100 mg/day. The patient showed rapid clinical improvement after one week. The patient was alert and the headache disappeared, while the paraparesis improved to normal ambulatory status. Two months of lorlatinib treatment resulted in almost complete disappearance of previous leptomeningeal enhancement of brain and spinal cord, and absence of newly developed metastatic lesions in the central nervous system, based on MRI results. The patient had been regularly followed with ongoing lorlatinib therapy for 5 months without any systemic complications or neurological abnormality. Conclusively, lorlatinib could be a rapid and effective treatment for patients with central nervous system leptomeningeal metastases arising from ALK-positive lung cancer.

Neoplastic meningitis in solid tumours: updated review of diagnosis, prognosis, therapeutic management, and future directions

Neoplastic meningitis (NM) is a relatively frequent metastatic complication of cancer associated with high levels of neurological morbidity and generally poor prognosis. It appears in 5%-15% of patients with solid tumours, the most frequent being breast and lung cancer and melanoma. Symptoms are caused by involvement of the cerebral hemispheres, cranial nerves, spinal cord, and nerve roots, and are often multifocal or present with signs and symptoms of intracranial hypertension. The main diagnostic tools are the neurological examination, brain and spinal cord contrast-enhanced magnetic resonance imaging, and cerebrospinal fluid analysis including cytology, although studies have recently been conducted into the detection of tumour cells and DNA in the cerebrospinal fluid, which increases diagnostic sensitivity. With the currently available therapies, treatment aims not to cure the disease, but to delay and ameliorate the symptoms and to preserve quality of life. Treatment of NM involves a multimodal approach that may include radiotherapy, intrathecal and/or systemic chemotherapy, and surgery. Treatment should be individualised, and is based mainly on clinical practice guidelines and expert opinion. Promising clinical trials are currently being conducted to evaluate drugs with molecular and immunotherapeutic targets. This article is an updated review of NM epidemiology, clinical presentation, diagnosis, prognosis, management, and treatment; it is aimed at general neurologists and particularly at neurologists practicing in hospital settings with oncological patients.

Paraneoplastic sensorimotor neuropathy and ventral cauda equina nerve root enhancement as initial presentation of small cell lung carcinoma: a case study

BACKGROUND

Paraneoplastic neurologic syndromes (PNS) are rare, however, are important to recognize as oftentimes they precede the detection of an occult malignancy. Our case highlights a rare circumstance of paraneoplastic radiculoneuropathy and the importance of recognizing PNS in antibody negative disease, as is the case in up to 16% of sensory neuronopathies, and the process of excluding other etiologies.

CASE PRESENTATION

We discuss a 51-year-old man who presented with asymmetric subacute sensorimotor deficits in the lower limbs. Initial clinical examination showed weakness throughout the right lower limb and normal strength on the left with objective numbness in a mixed dermatomal and stocking-glove distribution. Electrophysiology was consistent with axonal sensorimotor neuropathy. Cerebrospinal fluid showed pleocytosis and elevated protein. Intravenous immunoglobulin treatment was given with some improvement in pain symptoms but no measurable motor improvement. Following clinical and electrophysiologic deterioration the patient was transferred to a tertiary centre. Magnetic resonance imaging of the spine showed smooth enhancement of the ventral caudal nerve roots. Chest computed tomography revealed left lower vascular scarring. Further positron emission tomography scan imaging identified fluorodeoxyglucose avid right lung lymphadenopathy. Bronchoscopy-guided biopsy revealed small cell lung carcinoma. Onconeural and antiganglioside antibodies were negative. The patient was then transferred to a medical oncology ward where he underwent chemoradiotherapy and subsequently experienced improvement in his motor function, supporting that his neurological condition was indeed secondary to a paraneoplastic process.

CONCLUSIONS

Onconeural negative paraneoplastic radiculoneuropathy can precede diagnosis of small cell lung carcinoma. If considered early and adequately investigated, it can allow earlier diagnosis and treatment of underlying malignancy, improving overall and neurological prognosis.

Leptomeningeal Metastases from Solid Tumors: Recent Advances in Diagnosis and Molecular Approaches

Leptomeningeal metastases (LM) from solid tumors represent an unmet need of increasing importance due to an early use of MRI for diagnosis and improvement of outcome of some molecular subgroups following targeted agents and immunotherapy. In this review, we first discussed factors limiting the efficacy of targeted agents in LM, such as the molecular divergence between primary tumors and CNS lesions and CNS barriers at the level of the normal brain, brain tumors and CSF. Further, we reviewed pathogenesis and experimental models and modalities, such as MRI (with RANO and ESO/ESMO criteria), CSF cytology and liquid biopsy, to improve diagnosis and monitoring following therapy. Efficacy and limitations of targeted therapies for LM from EGFR-mutant and ALK-rearranged NSCLC, HER2-positive breast cancer and BRAF-mutated melanomas are reported, including the use of intrathecal administration or modification of traditional cytotoxic compounds. The efficacy of checkpoint inhibitors in LM from non-druggable tumors, in particular triple-negative breast cancer, is discussed. Last, we focused on some recent techniques to improve drug delivery.

Health care resource utilization and treatment of leptomeningeal carcinomatosis in the United States

Background

The economic burden of cancer in the United States is substantial, and better understanding it is essential in informing health care policy and innovation. Leptomeningeal carcinomatosis (LC) represents a late complication of primary cancer spreading to the leptomeninges.

Methods

The IBM MarketScan Research databases were queried for adults diagnosed with LC from 2001 to 2015, secondary to 4 primary cancers (breast, lung, gastrointestinal, and melanoma). Health care resource utilization (HCRU) and treatment utilization were quantified at baseline (1-year pre-LC diagnosis) and 30, 90, and 365 days post-LC diagnosis.

Results

We identified 4961 cases of LC (46.3% breast cancer, 34.8% lung cancer, 13.5% gastrointestinal cancer, and 5.4% melanoma). The median age was 57.0 years, with 69.7% female and 31.1% residing in the South. Insurance status included commercial (71.1%), Medicare (19.8%), and Medicaid (9.1%). Median follow-up was 66.0 days (25th percentile: 24.0, 75th percentile: 186.0) and total cumulative costs were highest for the gastrointestinal subgroup ($167 768) and lowest for the lung cancer subgroup ($145 244). There was considerable variation in the 89.6% of patients who used adjunctive treatments at 1 year, including chemotherapy (64.3%), radiotherapy (57.6%), therapeutic lumbar puncture (31.5%), and Ommaya reservoir (14.5%). The main cost drivers at 1 year were chemotherapy ($62 026), radiation therapy ($37 076), and specialty drugs ($29 330). The prevalence of neurologic impairments was 46.9%, including radiculopathy (15.0%), paresthesia (12.3%), seizure episode/convulsive disorder not otherwise specified (11.0%), and ataxia (8.0%).

Conclusions

LC is a devastating condition with an overall poor prognosis. We present the largest study of LC in this real-world study, including current treatments, with an emphasis on HCRU. There is considerable variation in the treatment of LC and significant health care costs.

Knockdown of IKKβ Inhibits Tumor Development in a Leptomeningeal Metastasis Mouse Model and Proliferation of Lung Cancer Cells

Objective

This study will explore the role of IKKβ in the leptomeningeal metastasis (LM) of lung cancer cells.

Methods

In vitro studies were conducted in mouse Lewis lung carcinoma (LLC) cells with IKKβ knockdown. Cell proliferation was explored using CCK-8 and tumor colony-forming assays. The expression of the extracellular signal-regulated kinase (ERK) signaling pathway was detected by Western blot. Tumor cell apoptosis was identified through Western blot detection of Bax and Bcl-2. The migration of tumor cells was identified by a wound healing assay. In vivo studies used an LM mouse model developed by injecting LLC cells with or without IKKβ knockdown into the cisterna magna. Mouse brain and spinal samples were sectioned for hematoxylin and eosin staining.

Results

In vitro: IKKβ knockdown inhibits tumor cell proliferation, initiates apoptosis, and attenuates cell migration. In vivo: IKKβ knockdown inhibits tumor growth in the LM mouse model. In addition, the in vitro results showed that IKKβ knockdown attenuated the expression of ERK phosphorylation in LLC cells.

Conclusion

Blocking the NF-κB signaling pathway by IKKβ knockdown in LLC cells inhibited tumor growth in the LM mouse model. IKKβ supports leptomeningeal tumor progression by promoting cancer cell proliferation and migration and inhibiting cancer cell apoptosis, and these actions may be correlated to ERK signaling.

Leptomeningeal Metastases in Non-small Cell Lung Cancer: Optimal Systemic Management in NSCLC With and Without Driver Mutations

OPINION STATEMENT

As a devastating complication of non-small cell lung cancer (NSCLC), the incidence of leptomeningeal metastasis (LM) is rising, largely due to overall longer survival of NSCLC, especially in patients with targetable molecular driver mutations. There is no clear consensus on the optimal management of LM. This review will cover recent advances in diagnosis, monitoring, and treatment of LM in NSCLC. In LM without oncogene drivers, systemic chemotherapy, intrathecal therapy, and radiation have modestly improved the clinical outcomes. Emerging data have also suggested encouraging activity of immunotherapy. At the same time, in LM with sensitizing EGFR mutations, osimertinib should be considered regardless of T790M status. Pulse erlotinib, afatinib, and newer agents with improved CNS penetration have also shown benefits. Moreover, accumulating evidences support potential benefits of molecularly targeted therapy in ALK-rearranged and other oncogene-driven NSCLC with LM. Future studies are warranted to better define the underlying mechanism, to optimize the clinical management, and to improve patient outcomes.

A Porcine Model of Transvertebral Ultrasound and Microbubble-Mediated Blood-Spinal Cord Barrier Opening

Blood-spinal cord barrier opening, using focused ultrasound and microbubbles, has the potential to improve drug delivery for the treatment of spinal cord pathologies. Delivering and detecting ultrasound through the spine is a challenge for clinical translation. We have previously developed short burst, phase keying exposures, which can be used in a dual-aperture configuration to address clinical scale targeting challenges. Here we demonstrate the use of these pulses for blood-spinal cord barrier opening, in vivo in pigs.

Methods: The spinal cords of Yorkshire pigs (n=8) were targeted through the vertebral laminae, in the lower thoracic to upper lumbar region using focused ultrasound (486 kHz) and microbubbles. Four animals were treated with a combination of pulsed sinusoidal exposures (1.0-4.0 MPa, non-derated) and pulsed short burst, phase keying exposures (1.0-2.0 MPa, non-derated). Four animals were treated using ramped short burst, phase keying exposures (1.8-2.1 MPa, non-derated). A 250 kHz narrowband receiver was used to detect acoustic emissions from microbubbles. Blood-spinal cord barrier opening was assessed by the extravasation of Evans blue dye. Histological analysis of the spinal cords was used to assess tissue damage and excised vertebral samples were used in benchtop experiments.

Results: Ramped short burst, phase keying exposures successfully modified the blood-spinal cord barrier at 16/24 targeted locations, as assessed by the extravasation of Evans blue dye. At 4 of these locations, opening was confirmed with minimal adverse effects observed through histology. Transmission measurements through excised vertebrae indicated a mean transmission of (47.0 ± 7.0 %) to the target.

Conclusions: This study presents the first evidence of focused ultrasound-induced blood-spinal cord barrier opening in a large animal model, through the intact spine. This represents an important step towards clinical translation.

Neoplastic meningitis in solid tumours: Updated review of diagnosis, prognosis, therapeutic management, and future directions

Neoplastic meningitis (NM) is a relatively frequent metastatic complication of cancer associated with high levels of neurological morbidity and generally poor prognosis. It appears in 5%-15% of patients with solid tumours, the most frequent being breast and lung cancer and melanoma. Symptoms are caused by involvement of the cerebral hemispheres, cranial nerves, spinal cord, and nerve roots, and are often multifocal or present with signs and symptoms of intracranial hypertension. The main diagnostic tools are the neurological examination, brain and spinal cord contrast-enhanced magnetic resonance imaging, and cerebrospinal fluid analysis including cytology, although studies have recently been conducted into the detection of tumour cells and DNA in the cerebrospinal fluid, which increases diagnostic sensitivity. With the currently available therapies, treatment aims not to cure the disease, but to delay and ameliorate the symptoms and to preserve quality of life. Treatment of NM involves a multimodal approach that may include radiotherapy, intrathecal and/or systemic chemotherapy, and surgery. Treatment should be individualised, and is based mainly on clinical practice guidelines and expert opinion. Promising clinical trials are currently being conducted to evaluate drugs with molecular and immunotherapeutic targets. This article is an updated review of NM epidemiology, clinical presentation, diagnosis, prognosis, management, and treatment; it is aimed at general neurologists and particularly at neurologists practicing in hospital settings with oncological patients.

Venous Sinus Stenting for Transverse Sinus Stenosis Associated with Leptomeningeal Carcinomatosis in a Patient with Epidermal Growth Factor Receptor-Mutated Lung Cancer: A Case Report

Patient: Male, 57-year-old

Final Diagnosis: Leptomeningeal carcinomatosis

Symptoms: Headache • visual acuity loss

Medication: —

Clinical Procedure: Venous sinus stenting

Specialty: Oncology

Retrospective Analysis of Acute Rehabilitation Outcomes of Cancer Inpatients with Leptomeningeal Disease

OBJECTIVE

Evaluate Functional Independence Measure (FIM) changes and incidence of serious medical complications requiring return to the primary acute care service of acute rehabilitation cancer inpatients with leptomeningeal disease (LMD).

DESIGN

Retrospective chart review.

SETTING

Tertiary referral based comprehensive cancer center acute inpatient rehabilitation unit.

PARTICIPANTS

Thirty cancer patients admitted to acute inpatient rehabilitation between 8 January 2014 and 8 August 2018 with pathology confirmed LMD within 6 months.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

FIM and incidence of return to the primary acute care service.

RESULTS

Twenty five of 30 (83.3%) patients were noted to have neurologic impairments and 13/30 (43.3%) were noted to have cognitive impairments. Five of 30 patients (16.7%) received intrathecal chemotherapy and 4/30 (13.3%) received radiation during acute inpatient rehabilitation for LMD treatment. Median days in acute care prior to acute inpatient rehabilitation was 22.5. Median days from acute inpatient rehabilitation admission until death of the 23 deceased patients as of 1 January 2019 was 180.00. Twenty of 30 (66.7%) patients were discharged home, 9/30 (30%) transferred to the primary acute care service, and 1/30 (3.3%) discharged to a skilled nursing facility. Reasons for return to the primary acute care service included additional chemotherapy 3/9 (33%), neurologic decline 2/9 (22%), fever 2/9 (22%), altered mental status 1/9 (11%), and progressive polyarthritis 1/9 (11%). Of the 21 patients who completed acute inpatient rehabilitation without return to the primary acute care service, mean FIM subscore changes from admission to discharge for Activities of Daily Living, Mobility, and Motor were 5.1 (P < .001), 4.8 (P < .001) and 11.7 (P < .001), respectively (Wilcoxon signed rank test, significance P < .05).

CONCLUSION

LMD patients who completed acute inpatient rehabilitation made statistically significant improvements on the majority of FIM items. Most patients were discharged home. Our data suggest LMD should not be a reason for exclusion from acute inpatient rehabilitation.

LEVEL OF EVIDENCE

III.

The clinical characteristic and prognostic factors of leptomeningeal metastasis in patients with non-small-cell lung cancer-a retrospective study from one single cancer institute

Background

Leptomeningeal metastasis (LM) is a detrimental complication of advanced non‐small‐cell lung cancer (NSCLC), and the optimal therapeutic approach for LM patients is in shortage. This retrospective study aimed to investigate the clinical features and prognostic factors of NSCLC patients with LM.

Methods

We retrospectively reviewed the medical records of NSCLC patients with LM at the Shandong Cancer Hospital and Institute between July 2014 and March 2018. Identified cases had pathology‐proven NSCLC with either positive cerebrospinal fluid cytology or leptomeningeal enhancement by MRI.

Results

One hundred and thirty‐six NSCLC patients (58 men, 78 women) with LM were enrolled in the retrospective study; median age was 55 years (range, 29‐89 years). Fifty‐one patients harbored EGFR mutations, ALK rearrangement was detected in 6 patients. Treatment for LM consisted of EGFR‐TKIs alone in 11 patients, whole brain radiotherapy (WBRT) alone in 19 patients, Chemotherapy (ChT) alone in 12 patients, EGFR‐TKIs plus WBRT in 30 patients, WBRT plus ChT in 25 patients, and EGFR‐TKIs plus ChT in 24 patients. The median progression‐free survival was 3.9 months (95% confidence interval [CI]: 3.178‐4.622), and the median overall survival (OS_LM) was 9.8 months (95% CI:7.5‐12.1). Thirty patients who received WBRT plus EGFR‐TKIs achieved longer survival than those who only received WBRT (median 13.6 vs 8.8 months; P = 0.027), but did not add any survival benefit than those only received EGFR‐TKIs (median 13.6 vs 13.9 months; P = 0.352). A multivariate analysis indicated that KPS ≥ 80 (hazard ratio [HR] = 0.592, 95% CI:0.369‐0.95; P = 0.03) and EGFR‐TKIs (HR = 0.507, 95% CI:0.283‐0.908; P = 0.022) after LM diagnosis were independent favourable predictors of survival, whereas smoking (HR = 1.181, 95% CI:1.009‐3.246; P = 0.047) was an independent predictor of poor survival.

Conclusions

Our results suggest that patients with good performance statuses, non‐smoking patients, and the administration of EGFR‐TKIs might improve clinical outcomes in NSCLC patients with LM.

Leptomeningeal carcinomatosis in patients with breast cancer

Leptomeningeal carcinomatosis (LC) is defined as infiltration of the leptomeninges by metastatic carcinoma, a relatively uncommon but devastating complication of many malignancies. Although only 5% of patients with breast cancer develop leptomeningeal involvement, it remains the most common etiology of LC. It can occur as a late-stage complication of systemic progression or present as the first sign of metastatic disease, with or without parenchymal brain metastases. Lobular carcinomas have a higher propensity to metastasize into the meninges when compared to ductal carcinoma, especially the triple-negative subtype, which usually is associated with a shorter interval between metastatic breast cancer diagnosis and the development of LC. Prognosis remains poor, with median survival of 4 months for patients receiving state-of-the-art treatment. The main factors associated with survival are performance status at diagnosis, CSF protein level and triple-negative subtype. Headache is commonly the first clinical presentation of LC, and the diagnostic workup usually requires CSF-cytological analysis and or/MRI. The current management of LC consists of a combination of intra-CSF chemotherapy, systemic therapy, radiotherapy and/or best-supportive care. The standard intra-CSF chemotherapy regimen is methotrexate. Radiotherapy is used for relieving obstruction points on CSF-outflow channels due to ependymal nodules, tumor deposits or bulky disease. Objective responses have been reported with intrathecal administration of trastuzumab for HER2-positive disease, yet this strategy is still under investigation. Further prospective trials are needed to better address the impact of these treatment modalities on overall survival and quality of life.

Clinical Utility of Cerebrospinal Fluid Cell-Free DNA as Liquid Biopsy for Leptomeningeal Metastases in ALK-Rearranged NSCLC

INTRODUCTION

Leptomeningeal metastases (LMs) indicated a poor prognosis in NSCLC. LMs were more frequent in driver gene-mutated patients, and cerebrospinal fluid (CSF) cell-free DNA has shown unique genetic profiles of LM in EGFR-mutated LM. However, studies in patients with ALK receptor tyrosine kinase gene (ALK)-rearranged NSCLC with LMs are scarce.

METHODS

Patients with lung cancer with ALK rearrangement were screened from September 2011 to February 2018 at our institute. CSF and paired plasma were tested by next-generation sequencing.

RESULTS

LMs were diagnosed in 30 (10.3%) of 291 patients with ALK-rearranged lung cancer. A total of 11 paired CSF and plasma samples tested by next-generation sequencing were analyzed. Driver genes were detected in 81.8% of the CSF samples (9 of 11) and 45.5% of the plasma samples (5 of 11) (p = 0.183). The maximum allelic fractions were all higher in CSF than in plasma (p = 0.009). ALK and tumor protein p53 gene (TP53) were the two most frequently mutated genes in CSF. Gatekeeper gene ALK G1202R and C1156F mutations were identified in CSF after resistance to alectinib. Multiple copy number variants were mainly found in CSF, including in EGFR, cyclin D1 gene (CCND1), fibroblast growth factor 3 gene (FGF3), and fibroblast growth factor 4 gene (FGF4). Also found were v-myc avian myelocytomatosis viral oncogene homolog gene (MYC) copy number gains and TP53 and cyclin dependent kinase inhibitor 2A gene (CDKN2A) copy number deletions. Brigatinib seemed to be effective in controlling LM. One case showed that CSF could be used to monitor disease development of LM and longitudinally monitor tumor response.

CONCLUSION

Liquid biopsy of CSF is more sensitive than liquid biopsy of plasma to detect targetable alterations, characterizing resistance mechanisms on progression and monitoring tumor response in patients with ALK-rearranged NSCLC with LM. Thus, CSF might be promising as a medium of liquid biopsy in LM.

Leptomeningeal metastases in non-small-cell lung cancer

Leptomeningeal metastasis is a complication of advanced non-small-cell lung cancer (NSCLC). Diagnosis and monitoring of leptomeningeal metastasis are challenging, and are based on neurological, radiographic, and cerebrospinal fluid findings. Substantial progress has been made in several key aspects of management of leptomeningeal metastasis, including improved characterisation of the genetic profiles, generation of clinically relevant animal models, advances in cerebrospinal fluid liquid biopsy with improved cytology and genotyping analysis, and the development of therapeutic agents with greater CNS penetration. This Review discusses cumulative data on multiple treatment modalities with a particular focus on recent advances in molecularly targeted therapies in subtypes of patients with leptomeningeal metastasis from NSCLC. Future research is needed to further understand the biology of leptomeningeal metastasis and the mechanisms of resistance to treatment.

A model of breast cancer meningeal metastases: characterization with in vivo molecular imaging

Meningeal metastasis is a fatal complication of breast cancer which affects 8-15% of patients who experience severe neurological complications of cranial nerves, cerebrum, and spinal cord. Survival once diagnosed is less than 4 months. Currently there is no cure. Aggressive multimodal radiation, intra-CSF, or systemic chemotherapy is palliative. Investigation of urgently needed new treatment modalities is hindered by the lack of suitable animal models to effectively study tumor growth kinetics. We present a model of meningeal metastases where tumor growth and associated neurological symptoms have been characterized over 3 weeks by sequential molecular imaging, tumor growth kinetics, and histopathology. Meningeal metastases were induced by stereotaxic injection of human breast cancer cells (MDA-MB-231-Rluc) into the lateral ventricle. Tumor identified by Gd-MRI and Rluc-bioluminescence depict growth in 3 phases, namely lag, exponential, and plateau phase. Invasive tumor growth was highlighted by changes in contrast distribution in the meninges, ventricle and brain compartments over time where moderate contrast uptake in the early growth phase gave rise to a heavy tumor burden in the base of the brain in the latter phases. Tumor growth was accompanied with debilitating neurological symptoms and change in body mass. Tumor was confirmed by ex vivo histology. The reliability of the model to study novel therapeutics was confirmed by oncolytic virus delivered into the lateral ventricle showed potential for treatment. This effective and reliable model resembles human disease progression and is ideally suited to investigate novel treatments.

Characteristics and outcomes of non-Hodgkin's lymphoma patients with leptomeningeal metastases

BACKGROUND

Leptomeningeal metastasis is an uncommon but devastating complication. The incidence of non-Hodgkin's lymphoma has been increasing in recent decades, due to the poor central nervous system penetration of drugs and the prolonged overall survival of patients, leptomeningeal metastases has gradually increased over time. Patients with leptomeningeal metastases have short survival durations and poor quality of life; there are few studies about non-Hodgkin's lymphoma with leptomeningeal metastases. We investigated characteristics and outcomes of non-Hodgkin's lymphoma patients with leptomeningeal metastases.

METHODS

This study included 27 non-Hodgkin's lymphoma patients with leptomeningeal metastases diagnosed at Tianjin Medical University Cancer Institute and Hospital between 2013 and 2016. Statistical analysis was performed to investigate the overall survival of non-Hodgkin's lymphoma with leptomeningeal metastases.

RESULTS

Diffuse large B cell lymphoma was the most common cancer subtype (21/27, 78%), and more than half of the patients showed extranodal involvement (18/27, 67%). Survival analysis has shown extranodal involvement (P = 0.0205), International Prognostic Index (P = 0.0112), performance status (P < 0.0001), parenchymal involvement (P = 0.0330) and received radiotherapy (P = 0.0056) were predictive factors of prognosis for these patients with leptomeningeal metastases. Cox regression analysis has shown patients with concurrent parenchymal involvement and received radiotherapy are correlated with good prognosis.

CONCLUSIONS

Given the small number of patients who were included, this study exhibited limitations with respect to analytical power and the random selection of patients. Nevertheless, this investigation revealed characteristics of non-Hodgkin's lymphoma patients with leptomeningeal metastases and suggested that such patients could benefit from multimodal therapy.

Polymeric Micelle of A₃B-Type Lactosome as a Vehicle for Targeting Meningeal Dissemination

Polymeric micelle of the A₃B-type lactosome comprising (poly(sarcosine))₃-b-poly(l-lactic acid) was labeled with ¹¹¹In. The ¹¹¹In-labeled A₃B-type lactosome was administered to the model mice bearing meningeal dissemination and bone metastasis at mandible. With single-photon emission computed tomography (SPECT) imaging, the meningeal dissemination was identified successfully by ¹¹¹In-labeled A₃B-type lactosome, which was superior to ²⁰¹TlCl in regard of the imaging contrast. The ¹¹¹In-labeled A₃B-type lactosome was also potential in imaging selectively of bone metastasis at mandible, whilst a nonspecific imaging of the whole bone was obtained by the SPECT imaging using ^99mTc-HMDP. The polymeric micelle of the A₃B-type lactosome was therefore found to be effective as a vehicle of ¹¹¹In to be targeted to meningeal dissemination and bone metastasis.

Leptomeningeal Metastases

OPINION STATEMENT

Treatment options for leptomeningeal metastases are expanding with greater tolerability and efficacy than in the past. Improved knowledge of molecular subtypes of some cancers can guide in choosing more effective therapeutic options; however, physicians should be mindful that these molecular types can be different in the central nervous system compared to the rest of the body. This is particularly true in breast and lung cancer, in which some patients now can live for many months or even years after diagnosis of leptomeningeal metastases. Options for intrathecal therapies are expanding, but physicians should be mindful that this is a passive delivery system that relies on normal CSF flow, so therapies will not penetrate bulky or parenchymal disease sites, especially in the presence of abnormal CSF flow. When chemotherapeutic options are lacking or unsuccessful, focal radiosurgery which can provide symptomatic relief and proton craniospinal radiation remain effective options. Hopefully more formal studies will be conducted in the future to verify which treatments are indeed most effective for particular types of cancer.

Diagnosis and treatment patterns for patients with leptomeningeal metastasis from solid tumors across Europe

Leptomeningeal metastases are a late manifestation of systemic cancer which affects up to 10% of patients with solid tumors. Prognosis is poor, and overall survival at 1 year is only approximately 10%. Management depends mainly on general and neurological condition, primary tumor, and patterns of metastasis, notably absence or presence of concurrent systemic or solid brain metastases. Here we set out to characterize current practice patterns of diagnosis and treatment of patients with leptomeningeal metastasis in Europe. We prepared a web-based survey including 25 simple or multiple choices questions on best practice supplemented by eight case vignettes with various diagnosis and management options. The survey was sent to the membership of the European Association of Neuro-Oncology and the European Organisation for Research and Treatment of Cancer Brain Tumor Group. Between April 7, 2016 and August 8, 2016, 224 colleagues from 26 countries initiated the survey, 115 colleagues completed the whole survey. There were major differences both in the general diagnostic and therapeutic approach, e.g., regarding the use of cerebrospinal fluid (CSF) flow studies, intra-CSF chemotherapy, various types of radiotherapy, and even more so when selecting decisions on diagnostic and therapeutic measures for single case vignettes. Diagnosis and treatment decisions for patients with leptomeningeal metastasis from solid tumors vary widely across Europe. Standardization of diagnosis and evaluation tools as well as controlled studies to improve the level of evidence for all therapeutic approaches to LM are required.