Diagnosis, management, and survival of patients with leptomeningeal cancer based on cerebrospinal fluid-flow status

Radiation Therapy in the Management of Leptomeningeal Disease From Solid Tumors

Purpose

Leptomeningeal disease (LMD) is clinically detected in 5% to 10% of patients with solid tumors and is a source of substantial morbidity and mortality. Prognosis for this entity remains poor and treatments are palliative. Radiation therapy (RT) is an essential tool in the management of LMD, and a recent randomized trial demonstrated a survival benefit for proton craniospinal irradiation (CSI) in select patients. In the setting of this recent advance, we conducted a review of the role of RT in LMD from solid tumors to evaluate the evidence basis for RT recommendations.

Methods and Materials

In November 2022, we conducted a comprehensive literature search in PubMed, as well as a review of ongoing clinical trials listed on ClinicalTrials.gov, to inform a discussion on the role of RT in solid tumor LMD. Because of the paucity of high-quality published evidence, discussion was informed more by expert consensus and opinion, including a review of societal guidelines, than evidence from clinical trials.

Results

Only 1 prospective randomized trial has evaluated RT for LMD, demonstrating improved central nervous system progression-free survival for patients with breast and lung cancer treated with proton CSI compared with involved-field RT. Modern photon CSI techniques have improved upon historical rates of acute hematologic toxicity, but the overall benefit of this modality has not been prospectively evaluated. Multiple retrospective studies have explored the use of involved-field RT or the combination of RT with chemotherapy, but clear evidence of survival benefit is lacking.

Conclusions

Optimal management of LMD with RT remains reliant upon expert opinion, with proton CSI indicated in patients with good performance status and extra-central nervous system disease that is either well-controlled or for which effective treatment options are available. Photon-based CSI traditionally has been associated with increased marrow and gastrointestinal toxicities, though intensity modulated RT/volumetric-modulated arc therapy based photon CSI may have reduced the toxicity profile. Further work is needed to understand the role of radioisotopes as well as combined modality treatment with intrathecal or central nervous system penetrating systemic therapies.

Leptomeningeal metastasis from solid tumours: EANO-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

•This Clinical Practice Guideline provides recommendations for managing leptomeningeal metastases from solid tumours. •The guideline covers clinical, imaging and cytological diagnosis, staging and risk assessment, treatment and follow-up. •A treatment and management algorithm is provided. •The author panel encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion.

Multidisciplinary management of patients with non-small cell lung cancer with leptomeningeal metastasis in the tyrosine kinase inhibitor era

OBJECTIVE

Leptomeningeal metastasis (LM) is a challenging scenario in non-small cell lung cancer (NSCLC). Considering that outcomes of treatment modalities stratified by LM chronological patterns related to brain metastasis (BM) are lacking, the aim of this study was to evaluate outcomes and explore prognostic factors.

METHODS

The authors retrospectively collected data of patients with NSCLC undergoing Ommaya reservoir implantation, ventriculoperitoneal shunt implantation, or lumboperitoneal shunt implantation. Based on radiographic findings and time from diagnosis of NSCLC to LM, the authors divided them into subtypes of LM as follows: LM without BM; LM concurrent with BM; or LM after BM. The Kaplan-Meier method was applied to analyze overall survival (OS) and multivariate Cox regression for prognostic factors.

RESULTS

Sixty-one patients with LM were included, with a median OS of 8.1 (range 0.2-70.0) months. Forty-three (70.5%) patients had EGFR-mutant disease. Forty-two (68.9%) patients had 19-del or L858R mutation, and one (1.6%) patient had G719A mutation. Fifty-seven (93.4%) patients had hydrocephalus. Twenty-one (34.4%) patients received whole-brain radiotherapy before LM diagnosis, 3 (4.9%) patients underwent operation for BMs before LM diagnosis, and 42 (68.9%) patients received EGFR tyrosine kinase inhibitor (TKI) therapy before LM diagnosis. Eleven patients were treated with chemotherapy, 10 patients were treated with TKIs, and 32 patients were treated with chemotherapy combined with TKIs before LM diagnosis. Patients with LM after BM had lower Karnofsky Performance Status (KPS) scores (KPS score 50) than did those with LM without BM (KPS score 80) or LM concurrent with BM (KPS score 70; p = 0.003). More patients with LM after BM received intrathecal methotrexate than in the other subgroups (p < 0.001). The median OS was significantly shorter in the LM after BM than in the concurrent LM and BM and the LM without BM subgroups (5.4 vs 5.5 vs 11.6 months; p = 0.019). Cox regression revealed that a KPS score ≥ 70 (HR 0.51; p = 0.027) and shunt implantation (HR 0.41; p = 0.032) were favorable prognostic factors.

CONCLUSIONS

Patients with NSCLC who had LM without BM had better survival outcomes (11.6 months) compared with those who had LM after BM or concurrent LM and BM. Aggressive shunt implantation may be favored for LM.

Leptomeningeal Metastasis from Non-Small Cell Lung Cancer and Current Landscape of Treatments

Leptomeningeal metastasis (LM), also known as leptomeningeal carcinomatosis (LC), is a devastating complication of metastatic cancer that occurs when neoplastic cells invade the meningeal space. Diagnosis of LM remains challenging given the heterogeneous signs and symptoms at presentation and requires thorough neurological examination, cerebrospinal fluid (CSF) analysis, and MRI of the brain and spine with gadolinium. Detecting neoplastic cells in the CSF is the gold standard for diagnosing leptomeningeal metastases; however, it has low sensitivity and may require multiple CSF samples. New emerging technologies, such as liquid biopsy of CSF, have increased sensitivity and specificity for detecting circulating tumor cells in CSF. The management of LM in patients with NSCLC requires an individualized multidisciplinary approach. Treatment options include surgery for ventricular shunt placement, radiation therapy to bulky or symptomatic disease sites, systemic or intrathecal chemotherapy, molecularly targeted agents, and, more recently, immunotherapy. Targeting actionable mutations in LM from NSCLC, such as EGFR tyrosine kinase inhibitors or anaplastic lymphoma kinase gene rearrangement inhibitors, has shown encouraging results in terms of disease control and survival. Although there are limited data regarding the use of immunotherapy in LM, immunotherapy has produced promising results in several case reports. In this review, we focused on the epidemiology, pathophysiology, clinical presentation, diagnosis, and current treatment strategies, with a special emphasis on novel agents, including targeted therapies and immunotherapy of LM in patients with NSCLC.

Intrathecal Methotrexate Toxicity Resulting in Brain Death due to Generalized Cerebral Edema Case Report

Intrathecal methotrexate (IT MTX) resulting in severe adverse events including life-threatening cerebral edema is not well described. We report a rare case of death in a 37-year-old BRCA1+ woman with metastatic triple-negative breast cancer status post mastectomy following administration of IT MTX for leptomeningeal carcinomatosis. Within the 24 hours after intraoperative IT MTX delivery, she developed neurologically devastating diffuse cerebral edema leading to uncal and cerebellar tonsillar herniation. This case report highlights a rare but devastating side effect of IT MTX.

Radiotherapy for Leptomeningeal Carcinomatosis in Breast Cancer Patients: A Narrative Review

Simple Summary

Leptomeningeal carcinomatosis (LC) is a rare event in breast cancer (BC) patients that carries an abysmal prognosis. Little progress has been made in this field in the last few decades. Despite innovations in radiotherapy (RT), there is no univocal evidence of its impact on survival. Due to the rarity of the diagnosis, only a few prospective trials have evaluated the role of RT for LC in BC. Nonetheless, most BC patients with LC currently receive RT, depending on local protocols and individual convictions. This review presents the current knowledge on the indications and feasibility of RT for LC in BC, focusing on new technologies and perspectives.

Abstract

Leptomeningeal carcinomatosis (LC), defined as the infiltration of the leptomeninges by cancer cells, is a rare oncological event with the most common etiology being breast cancer (BC), lung cancer, and melanoma. Despite innovations in radiotherapy (RT), firm evidence of its impact on survival is lacking, and concerns are related to its possible neurotoxicity. Owing to a paucity of data, the optimal treatment strategy for LC remains unknown. This review discusses current approaches, indications, and contraindications for various forms of RT for LC in BC. A separate section is dedicated to new RT techniques, such as proton therapy. We also summarize ongoing clinical trials evaluating the role of RT in patients with LC.

Neuro-Ophthalmic Manifestations of Intracranial Malignancies

BACKGROUND

To describe the various neuro-ophthalmic presentations, key exam features, and clinical findings associated with 5 common primary and secondary intracranial malignancies.

EVIDENCE ACQUISITION

Retrospective PubMed search and review of published case reports, case series, observational studies, book chapters, and review articles examining the neuro-ophthalmic features of intracranial malignancies including primary glial neoplasms (e.g., glioblastoma multiforme), primary and secondary lymphoma, intracranial metastases, carcinomatous/lymphomatous meningitis, and intracranial germ cell tumors. The search strategy used to perform the retrospective review included the aforementioned tumor type (e.g., glioblastoma multiforme) and the following terms and Boolean operators: AND ("visual loss" OR "papilledema" OR "diplopia" OR "ophthalmoplegia" or "neuro-ophthalmology" OR "proptosis").

RESULTS

The rate of growth and the location of an intracranial tumor are essential factors in determining the neuro-ophthalmic presentation of certain intracranial malignancies. Primary malignant brain glial neoplasms commonly present with visual afferent complaints (e.g., unilateral or bilateral visual acuity or visual field defects, bitemporal or homonymous hemianopsia), pupil abnormalities (relative afferent pupillary defect), and optic atrophy or papilledema. Primary intraocular lymphoma (with or without central nervous system lymphoma) typically presents as a painless bilateral vitritis. Secondary intracranial malignancies have variable afferent and efferent visual pathway presentations. Carcinomatous/lymphomatous meningitis is associated with diplopia (e.g., multiple ocular motor cranial neuropathies with or without vision loss from papilledema or compressive/infiltrative optic neuropathy). Intracranial germ cell tumors can present with a chiasmal syndrome or dorsal midbrain syndrome.

CONCLUSION

Intracranial malignancies can present with neuro-ophthalmic symptoms or signs depending on topographical localization. Specific neuro-ophthalmic presentations are associated with different malignant intracranial tumors. Clinicians should be aware of the common malignant intracranial tumors and their associated clinical presentations in neuro-ophthalmology.

Cerebrospinal Fluid Profiles and Their Changes after Intraventricular Chemotherapy as Prognostic or Predictive Markers for Patients with Leptomeningeal Carcinomatosis

Objective

Here, we evaluated whether cerebrospinal fluid (CSF) profiles and their changes after intraventricular chemotherapy for leptomeningeal carcinomatosis (LMC) could predict the treatment response or be prognostic for patient overall survival (OS) along with clinical factors.

Methods

Paired 1) pretreatment lumbar, 2) pretreatment ventricular, and 3) posttreatment ventricular samples and their CSF profiles were collected retrospectively from 148 LMC patients who received Ommaya reservoir installation and intraventricular chemotherapy. CSF profile changes were assessed by calculating the differences between posttreatment and pretreatment samples from the same ventricular compartment. CSF cell counts were further differentiated into total and other based on clinical laboratory reports.

Results

For the treatment response, a decreased CSF ‘total’ cell count tended to be associated with a ‘controlled’ increase in intracranial pressure (ICP) (p=0.059), but other profile changes were not associated with either the control of increased ICP or the cytology response. Among the pretreatment CSF profiles, lumbar protein level and ventricular cell count were significantly correlated with OS in univariable analysis, but they were not significant in multi-variable analysis. Among CSF profile changes, a decrease in ‘other’ cell count showed worse OS than ‘no change’ or increased groups (p=0.001). The cytological response was significant for OS, but the hazard ratio of partial remission was paradoxically higher than that of ‘no response’.

Conclusion

A decrease in other cell count of CSF after intraventricular chemotherapy was associated with poor OS in LMC patients. We suggest that more specific CSF biomarkers of cancer cell origin are needed.

Neoplastic Meningitis and Paraneoplastic Syndromes

Neoplastic meningitis (NM) and paraneoplastic syndromes (PNSs) are a rare group of disorders present in patients with cancer. Clinical diagnosis of these conditions is challenging, and imaging and laboratory analysis play a significant role in diagnosing. Diagnosis of NM largely depends on documenting circulating tumor cells in the cerebrospinal fluid (CSF) and/or leptomeningeal and nodular enhancement on contrast-enhanced MR imaging of the brain or axial spine. PNSs encompass a variety of symptoms or syndromes. Paraneoplastic neuronal disorder diagnosis requires a multidimensional approach, high clinical suspicion, CSF and serum examination, and imaging. Neuroimaging is an integral part in the evaluation.

Impact of cerebrospinal fluid flow study in patients undergoing intrathecal chemotherapy via ventricular catheter reservoir

PURPOSE

Leptomeningeal carcinomatosis (LMC) is a form of CNS cancer metastasis with severe morbidity. Intrathecal chemotherapy (ITC) administration through an implanted ventricular catheter reservoir (IVCR) is often utilized. Additionally, a nuclear imaging flow study can be performed prior to ITC administration to assess cerebrospinal fluid (CSF) flow. The clinical impact of a CSF flow study is unclear.

METHODS

A retrospective chart review identified 31 patients with LMC that underwent IVCR placement between 2011 and 2019. Data extracted included patient demographics, nuclear imaging flow study, surgical complications, ITC toxicities and outcomes.

RESULTS

Potential drug-induced neurologic toxicities (headache, nausea/vomiting, altered mental status, etc.) were noted in (n = 4/16) 25% of patients who underwent a flow study prior to initiation of ITC, compared to (n = 1/15) 6.6% of patients who did not undergo a flow study. Median overall survival (OS) was 4.0 and 32.8 months for the patients that underwent a flow study versus patients who did not, respectively (p < 0.01). The mean interval from IVCR implantation to initiation of ITC was 15.2 ± 8.5 days and 3.3 ± 3.0 days in patients who underwent CSF flow study and patients that did not, respectively (p < 0.0001).

CONCLUSIONS

A flow study can provide information regarding CSF flow dynamics prior to initiation of ITC; however this might delay initiation of ITC which may negatively impact OS. Additionally, in our study patients that underwent a flow study had more ITC induced drug toxicity events compared to those that did not. Further studies are needed to clarify the role of CSF flow study in these patients.

Leptomeningeal malignancy of childhood: sharing learning between childhood leukaemia and brain tumour trials

Leptomeningeal malignancy complicates childhood cancers, including leukaemias, brain tumours, and solid tumours. In leukaemia, such malignancy is thought to invade leptomeninges via the vascular route. In brain tumours, dissemination from the primary tumour, before or after surgery, via CSF pathways is assumed; however, evidence exists to support the vascular route of dissemination. Success in treating leptomeningeal malignancy represents a rate-limiting step to cure, which has been successfully overcome in leukaemia with intensified systemic therapy combined with intra-CSF therapy, which replaced cranial radiotherapy for many patients. This de-escalated CNS-directed therapy is still associated with some neurotoxicity. The balanced benefit justifies exploration of ways to further de-escalate CNS-directed therapy. For primary brain tumours, standard therapy is craniospinal radiotherapy, but attendant risk of acute and delayed brain injury and endocrine deficiencies compounds post-radiation impairment of spinal growth. Alternative ways of treating leptomeninges by intensifying drug therapy delivered to CSF are being investigated-preliminary evidence suggests improved outcomes. This Review seeks to describe methods of intra-CSF drug delivery and drugs in use, and consider how the technique could be modified and additional drugs might be selected for this route of administration.

Breast leptomeningeal disease: a review of current practices and updates on management

PURPOSE

Leptomeningeal disease (LMD) is an advanced metastatic disease presentation portending a poor prognosis with minimal treatment options. The advent and widespread use of new systemic therapies for metastatic breast cancer has improved systemic disease control and extended survival; however, as patients live longer, the rates of breast cancer LMD are increasing.

METHODS

In this review, a group of medical oncologists, radiation oncologists, radiologists, breast surgeons, and neurosurgeons specializing in treatment of breast cancer reviewed the available published literature and compiled a comprehensive review on the current state of breast cancer LMD.

RESULTS

We discuss the pathogenesis, epidemiology, diagnosis, treatment options (including systemic, intrathecal, surgical, and radiotherapy treatment modalities), and treatment response evaluation specific to breast cancer patients. Furthermore, we discuss the controversies within this unique clinical setting and identify potential clinical opportunities to improve upon the diagnosis, treatment, and treatment response evaluation in the management of breast LMD.

CONCLUSIONS

We recognize the shortcomings in our current understanding of the disease and explore the future role of genomic/molecular disease characterization, technological innovations, and ongoing clinical trials attempting to improve the prognosis for this advanced disease state.

Association of MRI findings with clinical characteristics and prognosis in patients with leptomeningeal carcinomatosis from non-small cell lung cancer

PURPOSE

Magnetic resonance imagining (MRI) is helpful for diagnosis of leptomeningeal carcinomatosis (LMC) and localizing LMC symptoms. Goal of this study is how MRI findings of LMC are associated with clinical characteristics or prognosis in patients with non-small cell lung cancer (NSCLC).

METHODS

We retrospectively collected data on 283 patients with LMC from NSCLC, adenocarcinoma based on cerebrospinal fluid cytology. All patients had brain MRI with gadolinium enhancement at LMC diagnosis, and spinal MRI was performed at the physician's discretion. We evaluated the prognostic factors for overall survival (OS) of all patients and subgroup of patients with central nervous system cause of death.

RESULTS

Two-hundred sixteen patients (76%) had definite or suggestive LMC findings and 67 had negative findings on brain MRI. Of the 37 patients who presented with cauda equina syndrome, 35 (95%) exhibited typical spinal MRI findings. Median OS of all patients was 3.65 months (95% confidence interval, 3.06-4.18). There was no significant difference in median OS between MRI-negative and MRI-positive groups (4.31 vs. 3.48 months, p = 0.711), whereas negative MRI finding showed longer median OS significantly in a subgroup of 77 patients with a central nervous system cause of death (p = 0.035). Considering clinical characteristics, progressive systemic disease, and altered mentality were significant prognostic factors associated with poor OS, whereas presenting symptom of headache with nausea/vomiting, intra-CSF chemotherapy, WBRT after LMC diagnosis, and concurrent RTKi treatment were significant for favorable OS in multivariable analysis.

CONCLUSIONS

Positive MRI findings suggests heavier disease burden than negative MRI findings in patients with LMC who died of a central nervous system cause. Spinal MRI findings in patients with LMC correlate with cauda equina symptoms.

The Comparative Treatment of Intraventricular Chemotherapy by Ommaya Reservoir vs. Lumbar Puncture in Patients With Leptomeningeal Carcinomatosis

Object: Leptomeningeal Carcinomatosis (LCM) represents a state of systemic malignant disease with poor prognosis. The purpose of this study is to compare overall survival (OS) between intraventricular chemotherapy through Ommaya reservoir (OR) and chemotherapy through lumbar puncture (LP) in LCM.

Patients and Methods: Forty adult patients with LCM were included. All patients underwent lumbar puncture and Magnetic resonance imaging (MRI). Thirty patients received chemotherapy through LP and 10 undergone colocation of Ommaya reservoir for intraventricular chemotherapy.

Results: The most common symptom was headache (Present in 50%). The cranial nerves most affected were VI and VII. Leptomeningeal enhancement was the most frequent finding in MRI. The OS in the LP group was 4 months and Ommaya group was 9.2 months (p = 0.0006; CI:1.8-3), with statistical differences in favor to Intraventricular treatment. Proportional hazard regression showed that receiving chemotherapy through Ommaya reservoir was a protective factor (Hazard ratio = 0.258, Standard Error = 0.112, p = 0.002 and 95% CI 0.110-0.606). Using KPS as a factor did not affect the hazard ratio of Ommaya reservoir itself.

Conclusions: OS was significantly higher in patients with Ommaya reservoir in spite of Karnofsky Performance Status (KPS) previous to chemotherapy. Therefore, intraventricular chemotherapy should be preferred over lumbar puncture chemotherapy administration if there are resources available.

Leptomeningeal metastasis

Leptomeningeal metastasis (LM) results from dissemination of cancer cells to both the leptomeninges (pia and arachnoid) and cerebrospinal fluid (CSF) compartment. Breast cancer, lung cancer, and melanoma are the most common solid tumors that cause LM. Recent approval of more active anticancer therapies has resulted in improvement in survival that is partly responsible for an increased incidence of LM. Neurologic deficits, once manifest, are mostly irreversible, and often have a significant impact on patient quality of life. LM-directed therapy is based on symptom palliation, circumscribed use of neurosurgery, limited field radiotherapy, intra-CSF and systemic therapies. Novel methods of detecting LM include detection of CSF circulating tumor cells and tumor cell-free DNA. A recent international guideline for a standardization of response assessment in LM may improve cross-trial comparisons as well as within-trial evaluation of treatment. An increasing number of retrospective studies suggest that molecular-targeted therapy, such as EGFR and ALK inhibitors in lung cancer, trastuzumab in HER2+ breast cancer, and BRAF inhibitors in melanoma, may be effective as part of the multidisciplinary management of LM. Prospective randomized trials with standardized response assessment are needed to further validate these preliminary findings.

Neoplastic meningitis in solid tumors: from diagnosis to personalized treatments

Neoplastic meningitis (NM) is a devastating complication of solid tumors with poor outcome. Some randomized clinical trials have been conducted with heterogeneous inclusion criteria, diagnostic parameters, response evaluation and primary endpoints. Recently, the Leptomeningeal Assessment in Neuro-Oncology (LANO) Group and the European Society for Medical Oncology/European Association for Neuro-Oncology have proposed some recommendations in order to provide diagnostic criteria and response evaluation scores for NM. The aim of these guidelines is to integrate the neurological examination with magnetic resonance imaging and cerebrospinal fluid findings as well as to provide a framework for use in clinical trials. However, this composite assessment needs further validation. Since intrathecal therapy represents a treatment with limited efficacy in NM, many studies have been conducted on systemic therapies, including target therapies, with some encouraging results in terms of disease control. In this review, we have analyzed the clinical aspects and the most recent diagnostic tools and therapeutic options in NM.

Preclinical Modeling and Therapeutic Avenues for Cancer Metastasis to the Central Nervous System

Metastasis is the dissemination of cells from the primary tumor to other locations within the body, and continues to be the predominant cause of death among cancer patients. Metastatic progression within the adult central nervous system is 10 times more frequent than primary brain tumors. Metastases affecting the brain parenchyma and leptomeninges are associated with grave prognosis, and even after successful control of the primary tumor the median survival is a dismal 2-3 months with treatment options typically limited to palliative care. Current treatment options for brain metastases (BM) and disseminated brain tumors are scarce, and the improvement of novel targeted therapies requires a broader understanding of the biological complexity that characterizes metastatic progression. In this review, we provide insight into patterns of BM progression and leptomeningeal spread, outlining the development of clinically relevant in vivo models and their contribution to the discovery of innovative cancer therapies. In vivo models paired with manipulation of in vitro methods have expanded the tools available for investigators to develop agents that can be used to prevent or treat metastatic disease. The knowledge gained from the use of such models can ultimately lead to the prevention of metastatic dissemination and can extend patient survival by transforming a uniformly fatal systemic disease into a locally controlled and eminently more treatable one.

Cerebrospinal Fluid Dissemination and Neoplastic Meningitis in Primary Brain Tumors

BACKGROUND

Neoplastic meningitis, also known as leptomeningeal disease, affects the entire neuraxis. The clinical manifestations of the disease may affect the cranial nerves, cerebral hemispheres, or the spine. Because of the extent of disease involvement, treatment options and disease staging should involve all compartments of the cerebrospinal fluid (CSF) and subarachnoid space. Few studies of patients with primary brain tumors have specifically addressed treatment for the secondary complication of neoplastic meningitis. Therapy for neoplastic meningitis is palliative in nature and, rarely, may have a curative intent.

METHODS

A review of the medical literature pertinent to neoplastic meningitis in primary brain tumors was performed. The complication of neoplastic meningitis is described in detail for the various types of primary brain tumors.

RESULTS

Treatment of neoplastic meningitis is complicated because determining who should receive aggressive, central nervous system (CNS)-directed therapy is difficult. In general, the therapeutic response of neoplastic meningitis is a function of CSF cytology and, secondarily, of the clinical improvement in neurological manifestations related to the disease. CSF cytology may manifest a rostrocaudal disassociation; thus, consecutive, negative findings require that both lumbar and ventricular cytological testing are performed to confirm the complete response. Based on data from several prospective, randomized trials extrapolated to primary brain tumors, the median rate of survival for neoplastic meningitis is several months. Oftentimes, therapy directed at palliation may improve quality of life by protecting patients from experiencing continued neurological deterioration.

CONCLUSIONS

Neoplastic meningitis is a complicated disease in which response to therapy varies by histology. Thus, survival rates after CNS-directed therapy will differ by the underlying primary tumor. Optimal therapy of neoplastic meningitis is poorly defined, and few guidelines exist to guide clinicians on the most appropriate choice of therapy.

Retrospective Analysis of Cerebrospinal Fluid Profiles in 228 Patients with Leptomeningeal Carcinomatosis : Differences According to the Sampling Site, Symptoms, and Systemic Factors

Objective

Elevated cell counts and protein levels in cerebrospinal fluid (CSF) result from disease activity in patients with leptomeningeal carcinomatosis (LMC). Previous studies evaluated the use of CSF profiles to monitor a treatment response or predict prognosis. CSF profiles vary, however, according to the sampling site and the patient's systemic condition. We compared lumbar and ventricular CSF profiles collected before intraventricular chemotherapy for LMC and evaluated the association of these profiles with patients' systemic factors and LMC disease activity.

Methods

CSF profiles were retrospectively collected from 228 patients who underwent Ommaya reservoir insertion for intraventricular chemotherapy after a diagnosis of LMC. Lumbar samples taken via lumbar puncture were used for the diagnosis, and ventricular samples were obtained later at the time of Ommaya reservoir insertion. LMC disease activity was defined as the presence of LMC-related symptoms such as increased intracranial pressure, hydrocephalus, cranial neuropathy, and cauda equina syndrome.

Results

Cell counts (median : 8 vs. 1 cells/mL) and protein levels (median : 68 vs. 17 mg/dL) significantly higher in lumbar CSF than in ventricular CSF (p<0.001). Among the evaluated systemic factors, concomitant brain metastasis and previous radiation were significantly correlated with higher protein levels in the lumbar CSF (p=0.01 and <0.001, respectively). Among the LMC disease activity, patients presenting with hydrocephalus or cauda equina syndrome showed higher lumbar CSF protein level compared with that in patients without those symptoms (p=0.049 and p<0.001, respectively). The lumbar CSF cell count was significantly lower in patients with cranial neuropathy (p=0.046). The ventricular CSF cell counts and protein levels showed no correlation with LMC symptoms. Carcinoembryonic antigen (CEA), which was measured from ventricular CSF after the diagnosis in 109 patients, showed a significant association with the presence of hydrocephalus (p=0.01).

Conclusion

The protein level in lumbar CSF indicated the localized disease activity of hydrocephalus and cauda equina syndrome. In the ventricular CSF, only the CEA level reflected the presence of hydrocephalus. We suggest using more specific biomarkers for the evaluation of ventricular CSF to monitor disease activity and treatment response.

Molecular Targeted Therapies for the Treatment of Leptomeningeal Carcinomatosis: Current Evidence and Future Directions

Leptomeningeal carcinomatosis (LMC) is the multifocal seeding of cerebrospinal fluid and leptomeninges by malignant cells. The incidence of LMC is approximately 5% in patients with malignant tumors overall and the rate is increasing due to increasing survival time of cancer patients. Eradication of the disease is not yet possible, so the treatment goals of LMC are to improve neurologic symptoms and to prolong survival. A standard treatment for LMC has not been established due to low incidences of LMC, the rapidly progressing nature of the disease, heterogeneous populations with LMC, and a lack of randomized clinical trial results. Treatment options for LMC include intrathecal chemotherapy, systemic chemotherapy, and radiation therapy, but the prognoses remain poor with a median survival of <3 months. Recently, molecular targeted agents have been applied in the clinic and have shown groundbreaking results in specific patient groups epidermal growth factor receptor (EGFR)-targeted therapy or an anaplastic lymphoma kinase (ALK) inhibitor in lung cancer, human epidermal growth factor receptor 2 (HER2)-directed therapy in breast cancer, and CD20-targeted therapy in B cell lymphoma). Moreover, there are results indicating that the use of these agents under proper dose and administration routes can be effective for managing LMC. In this article, we review molecular targeted agents for managing LMC.

Leptomeningeal carcinomatosis as the primary presentation of relapse in breast cancer

Leptomeningeal metastasis (LM) is an uncommon presentation of relapse in breast cancer, which is associated with poor clinical outcomes and poor prognosis. Notably, LM most commonly occurs in breast cancer. The aim of the present review was to investigate the occurrence of LM as the primary presentation of relapse following remission in breast cancer patients and to determine whether specific histological subtypes are predisposed to meningeal metastases. In addition, the present review evaluated whether patients presenting with LM as the primary site of relapse exhibit differences in survival when compared with patients exhibiting metastasis to other sites. Cross-sectional studies have demonstrated that LM is commonly associated with other sites of distant metastasis including lung, liver and bone metastases. The histological breast cancer subtype most commonly associated with LM was invasive lobular carcinoma, while triple-negative breast cancer patients appear to be predisposed to the development of LM when considering the overall prevalence of histological breast cancer subtypes. At present, data regarding LM as the primary site of relapse are limited due to its rarity as the first site of metastasis in breast cancer. Case-controlled studies are required to investigate the incidence of LM as the primary site of recurrence in breast cancer patients as this would enable treatment standardization and identification of prognostic factors for improved survival.

Defining patients at risk for neoplastic meningitis: what parameters can be used to determine who should be treated?

While a growing body of clinical research is defining how better to treat neoplastic meningitis, questions regarding which parameters can be used to define who to treat remain. This discussion initiates the clinical core and practical components of the symposium.

[Carcinomatous meningitis: The radiation therapist's point of view]

Carcinomatous meningitis complicates 5 to 10% of cancers, essentially with breast cancers, lung cancers and melanomas. The incidence probably increased because of therapeutic advances in oncology. Treatment is based on external beam radiotherapy, systemic treatment, intrathecal chemotherapy and supportive care. The aim of this work was to review data on external radiation therapy and carcinomatous meningitis. There are few evidences on the subject, but it is a major topic of interest. A whole brain radiation therapy is indicated in case of brain metastases or clinical encephalitis. Focal radiation therapy is recommended on symptomatic, bulky or obstructive sites. The dose depends on performance status (20 to 40 Gy in five to 20 fractions), volume to treat and available techniques (classic fractionation or hypofractionation via stereotactic radiosurgery). The objective of radiation therapy is to improve quality of life. Association with systemic therapy improves overall survival. Administration of sequential intrathecal chemotherapy may also improve overall survival, but induces more toxicity. The use of new radiotherapy techniques and development of radiosensitizing molecules in patients with good performance status could improve survival in this frequent complication of cancer.

Development of the Metronomic Biofeedback Pump for leptomeningeal carcinomatosis: technical note

Patients with leptomeningeal carcinomatosis face a particularly grim prognosis. Current treatment consists of intrathecal delivery of methotrexate (MTX) or cytosine arabinoside (Ara-C) via Ommaya reservoir or lumbar puncture. Yet despite these interventions, the median survival after diagnosis is only 4–7 months. To address inherent shortcomings of current treatments and provide a more effective therapeutic approach, the Pharmaco-Kinesis Corporation has developed a novel type of implantable pump capable of delivering intrathecal chemotherapy (i.e., MTX) in a metronomic fashion with electronic feedback. The Metronomic Biofeedback Pump (MBP) consists of 3 components: 1) a 2-lumen catheter; 2) a microfluidic delivery pump with 2 reservoirs; and 3) a spectrophotometer monitoring MTX concentrations in the CSF. Using an animal model of intraventricular drug delivery, the authors demonstrate that the MBP can reliably deliver volumes of 500 μl/min, consistently measure real-time intrathecal MTX concentrations via CSF aspiration, and provide biofeedback with the possibility of instant control and delivery adjustments. Therefore, this novel approach to chemotherapy minimizes toxic drug levels and ensures continuous exposure at precisely adjusted, individualized therapeutic levels. Altogether, application of the MBP is expected to increase survival of patients with leptomeningeal carcinomatosis, and appropriate Phase I and II trials are pending.

Comprehensive neuraxis imaging in leptomeningeal metastasis: a retrospective case series

AIM

Quantify imaging abnormalities in a retrospective case series of patients with leptomeningeal metastasis (LM).

METHODS

A total of 240 adult patients with LM (125 nonbrain solid tumor patients with positive cerebrospinal fluid [CSF] cytology; 40 nonbrain solid tumor patients with negative CSF cytology and positive MRI; and 50 lymphoma and 25 leukemia patients with positive CSF-flow cytometry) underwent brain and entire spine MRI and radioisotope CSF-flow studies prior to treatment.

RESULTS

MRI was more often abnormal in solid tumors (40 CSF defined and 100% in MRI defined) compared with hematologic cancers (16-20%; p = 0.03). Similarly, CSF-flow studies was more often abnormal in solid tumors (25-28%) compared with hematologic cancers (10-20%; p = 0.04). MRI and flow-study abnormalities altered therapy in a third of solid tumors and 15% of hematologic cancers.

CONCLUSION

Although imaging abnormalities are less often seen in hematologic cancers compared with solid tumor LM, imaging abnormalities frequently result in treatment alteration.

Carcinomatous meningitis in non-small cell lung cancer: Palliation with intrathecal treatment

Carcinomatous meningitis or meningeal carcinomatosis is seen in up to 5% of patients of metastatic non-small cell lung cancer. However, isolated carcinomatous meningitis without brain parenchymal metastasis is less common. Patients with carcinomatous meningitis have limited treatment options. However, intrathecal therapy if used optimally along with targeted therapy when indicated result in good palliation with improvement in survival.

Treatment of leptomeningeal spread of NSCLC: a continuing challenge

OPINION STATEMENT

Leptomeningeal metastasis is a serious and frequently fatal complication of non-small cell lung cancer. Curative treatment remains elusive, but careful use of radiation, systemic chemotherapy, intrathecal chemotherapy, and symptoms management can greatly improve quality of life and survival. For most patients, we recommend a combination of skull-based radiation with focal radiation to any symptomatic spinal segments followed by systemic chemotherapy. For patients with EGFR mutations, erlotinib may be used as first-line therapy in a daily or high-dose regimen. Pemetrexed has promise for use in patients with brain and leptomeningeal metastases. Patients with multiple comorbidities or low performance status may tolerate intrathecal therapy better than systemic chemotherapy. The most commonly used intrathecal chemotherapies are methotrexate and liposomal cytarabine, although newer agents, such as topotecan and mafosfamide, may be more effective. Elevated intracranial pressure, which causes headaches, vertigo, nausea, and vomiting, should be treated with dexamethasone and acetazolamide. In select patients, cerebrospinal fluid shunting may be considered. The use of antidepressants, central nervous system stimulants, benzodiazepines, antiemetics, and pain medications can increase quality of life in patients with leptomeningeal metastases.

Carcinomatous meningitis: Leptomeningeal metastases in solid tumors

Leptomeningeal metastasis (LM) results from metastatic spread of cancer to the leptomeninges, giving rise to central nervous system dysfunction. Breast cancer, lung cancer, and melanoma are the most frequent causes of LM among solid tumors in adults. An early diagnosis of LM, before fixed neurologic deficits are manifest, permits earlier and potentially more effective treatment, thus leading to a better quality of life in patients so affected. Apart from a clinical suspicion of LM, diagnosis is dependent upon demonstration of cancer in cerebrospinal fluid (CSF) or radiographic manifestations as revealed by neuraxis imaging. Potentially of use, though not commonly employed, today are use of biomarkers and protein profiling in the CSF. Symptomatic treatment is directed at pain including headache, nausea, and vomiting, whereas more specific LM-directed therapies include intra-CSF chemotherapy, systemic chemotherapy, and site-specific radiotherapy. A special emphasis in the review discusses novel agents including targeted therapies, that may be promising in the future management of LM. These new therapies include anti-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors erlotinib and gefitinib in nonsmall cell lung cancer, anti-HER2 monoclonal antibody trastuzumab in breast cancer, anti-CTLA4 ipilimumab and anti-BRAF tyrosine kinase inhibitors such as vermurafenib in melanoma, and the antivascular endothelial growth factor monoclonal antibody bevacizumab are currently under investigation in patients with LM. Challenges of managing patients with LM are manifold and include determining the appropriate patients for treatment as well as the optimal route of administration of intra-CSF drug therapy.

Ocular symptoms secondary to meningeal carcinomatosis in a patient with lung adenocarcinoma: a case report

Background

Meningeal carcinomatosis (MC) is a rare complication associated with hematologic and solid tumors. MC develops when malignant cells gain access to the leptomeningeal space, producing several clinical symptoms. Loss of vision and ocular motility deficit are the most frequent ocular symptoms reported. Fundus examination usually appears normal, although optic nerve alterations like optic atrophy or papilledema have been described. MC diagnosis is usually completed by magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) analysis. Indicated treatment for MC usually involves intrathecal chemotherapy combined with radiotherapy, although survival rate is extremely low.

Case presentation

A 66-year old man with stage IV metastatic lung adenocarcinoma, presented to the Ophthalmology Department with a two-month history of double vision, soft headaches and dizziness episodes. The patient presented a best visual corrected acuity of 0.7 in his right eye and 0.8 in his left eye. Diplopia was corrected with 6-prism diopters base-out prism in right eye. Funduscopy showed a bilateral papilledema, juxtapapillary exudates and splinter hemorrhages. Brain MRI showed a diffuse leptomeningeal enhancement in cortical sulcus. Lumbar puncture was performed and cerebrospinal fluid (CSF) cytology revealed malignant cells compatible with a diagnosis of MC. Intrathecal chemotherapy was administered.

Conclusion

MC is a serious complication of systemic cancer patients, involving a poor prognosis. Early diagnosis is extremely important, although treatment is frequently aimed to reduce the symptoms and extend survival. Eye symptoms may be the chief complaint, so MC should be considered in any patient with vision loss or diplopia accompanied by neurologic symptoms and in the absence of an intraocular cause, especially in the context of systemic cancer.

Diagnosis and outcome measures in trials for neoplastic meningitis: a review of the literature and clinical experience

Innovative approaches to the treatment of neoplastic meningitis are being widely tested. Unfortunately, research on diagnostic strategies and outcome measures on which any advances in treatment ultimately depend, has not been avidly pursued. A critical review of the literature on neoplastic meningitis published since 1978 was undertaken by using MEDLINE and other English language databases. All articles addressing the issues of diagnostic or response criteria were included. Randomized clinical trials (RCTs) were emphasized. Prospectively collected data from the authors' institution correlating the results of cerebrospinal fluid (CSF) cytological examinations with Karnofsky Performance Scale (KPS) score are also discussed. Twenty-six studies (representing 1208 patients) fulfilled search criteria. Only three were RCTs. Cerebrospinal fluid cytology was the sole diagnostic criterion in two-thirds of studies. The results of CSF cytological examination alone or in combination with other clinical or laboratory endpoints constituted the primary outcome measure in 85%. Few studies attempted to address known deficiencies in the reliability and validity of these measures, and correlation between measures was poor. Quality of life was never used as a primary outcome measure. All currently available measurements, including CSF cytology, biochemistry, immunological, and molecular markers, neuroimaging studies, clinical examination, and survival, suffer from poor sensitivity and/or specificity, and often correlate poorly with each other. Although CSF cytological examination, performed according to a rigorous, research-supported protocol, may be the optimum diagnostic and outcome measure at this time, additional research is a prerequisite for any further advances in the clinical care of patients with neoplastic meningitis.

Occult Breast Cancer Presenting as Leptomeningeal Carcinomatosis

Leptomeningeal carcinomatosis (LC) is a rare and devastating metastatic manifestation of both liquid and solid tumors consisting of dissemination of malignant cells with invasion into the meninges. Few options exist in most clinical situations, especially when LC is the presenting sign of occult malignancy. The prognosis is often poor with limited survival. Aims of palliation must be considered the primary goal for most patients. We report a case in which occult metastatic breast cancer presented with neurological symptoms from LC. We discuss diagnosing the primary malignancy when LC is the presenting manifestation as well as treatment, both palliative and cytoreductive. We also focus on those patients with breast cancer that are at highest risk of developing LC.

Long-term survival of a patient with leptomeningeal involvement by nasopharyngeal carcinoma after treatment with high-dose intravenous methotrexate

BACKGROUND

Nasopharyngeal carcinoma with leptomeningeal involvement is rare and typically has poor prognosis.

METHODS AND RESULTS

We present a case report of a patient with nasopharyngeal carcinoma who was treated with high-dose intravenous methotrexate and remains asymptomatic and without clinical evidence of disease 6 years later.

CONCLUSIONS

Systemic high-dose methotrexate should be evaluated in the treatment of advanced nasopharyngeal carcinoma with central nervous involvement.

Leptomeningeal disease

Leptomeningeal metastasis (LMD) is a lethal complication caused by a variety of cancers, typically developing late in the disease course. It is associated with major neurologic disabilities and short survival. The incidence of LMD may increase because of longer survival of patients who have cancer, and because of the use of newer large-molecule therapies with poor central nervous system penetration. To achieve improved outcomes for patients who have LMD, new treatments need to reach the meninges and cerebrospinal fluid and interact with relevant molecular targets. Some of the agents currently in testing may contribute to this goal. To allow for better outcomes through earlier treatment, advances in diagnosis are needed. By using agents with higher therapeutic indices, in patients with a lower burden of disease (identified earlier with clinical or molecular markers) it should be possible to achieve gradual improvements in outcomes for patients suffering from this devastating disease.

Leptomeningeal Metastasis: Challenges in Diagnosis and Treatment

As therapeutic options and supportive care for the treatment of neoplastic disease have improved, there has been an associated increase in the incidence of leptomeningeal disease. In this review, the clinical presentation, natural history, diagnostic evaluation, and treatment options for this often devastating sequela of solid tumors, lymphoma, and leukemia will be summarized. The therapeutic efficacy of ionizing radiation, systemic agents, and intrathecal drugs will be examined from the existing literature. Additionally the pathophysiology, which in part defines the therapeutic limitations in approaching this patient population, will be discussed in order to assist in individualized clinical decision making.

Neoplastic meningitis resulting from hematological malignancies: pharmacokinetic considerations and maximizing outcome

Neoplastic meningitis, also known as leptomeningeal metastases, is a complication of various types of cancer that occurs when tumor cells enter the cerebrospinal fluid (CSF), travel along CSF pathways and grow. Treatment options include drug delivery directly into the CNS or systemic administration for targeted action in the CNS. CNS drug delivery is limited by the blood-brain barrier and the blood-CSF barrier. It may be possible to partially overcome this by using high-dose systemic therapy; however, this is done at the possible expense of increased systemic toxicity. Intra-CSF drug delivery bypasses the blood-brain barrier and allows direct access of the chemotherapeutic agent to the CSF. Because neoplastic meningitis occurs in an increasingly large percentage of all cancer patients, it is imperative to optimize drug delivery to the CSF and meninges. Both the pharmacokinetic profile of the chemotherapeutic agent and the site of administration influence therapeutic efficacy. Achieving prolonged therapeutic cytotoxic drug concentrations and even distribution in the CSF will improve efficacy. In this article we summarize data on the efficacy, safety and outcome of high-dose systemic and intra-CSF treatments.

Neoplastic meningitis

Neoplastic meningitis occurs in approximately 5%-10% of all patients with cancer, and aggressive supportive measures are a critical component of comprehensive care. A literature review of the current diagnostic methods, randomized controlled trials, and available treatments was undertaken; and a comprehensive discussion of best-practice supportive care measures is provided. Although the prognosis for those diagnosed with neoplastic meningitis is poor, treatment and supportive care may allow stabilization of neurologic symptoms and afford protection from further neurologic deterioration, allowing patients to maximize their function and independence and adjust their expectations of treatment from cure to palliation.

Novel approaches to treating leptomeningeal metastases

Leptomeningeal metastasis is a devastating complication of the central nervous system in patients with late-stage solid or hematological cancers. Leptomeningeal metastasis results from the multifocal seeding of the leptomeninges by malignant cancer cells. Although central nervous system metastasis usually presents in patients with widely disseminated and progressive late-stage cancer, malignant cells may spread to the cerebrospinal fluid during earlier disease stages in particularly aggressive cancers. Treatment of leptomeningeal metastasis is largely palliative but will often provide stabilization and protection from further neurological deterioration and improve quality of life. There is a need to raise awareness of the impact of leptomeningeal metastases on cancer patients and its known and putative biological basis. Novel diagnostic approaches include identification of biomarkers that may stratify the risk for developing leptomeningeal metastasis. Current therapies can be used more effectively while waiting for advanced treatments to be developed.

Neoplastic meningitis from solid tumors: new diagnostic and therapeutic approaches

Neoplastic meningitis is a result of the spread of malignant cells to the leptomeninges and subarachnoid space and their dissemination within the cerebrospinal fluid. This event occurs in 4%-15% of all patients with solid tumors and represents an important prognostic factor for poor survival. Neoplastic meningitis should be diagnosed in the early stages of disease to prevent important neurological deficits and to provide the most appropriate treatment. Despite new diagnostic approaches developed in recent years, such as positron emission tomography-computed tomography and new biological markers, the combination of magnetic resonance imaging without and with gadolinium enhancement and cytology still has the greatest diagnostic sensitivity. Recently, no new randomized studies comparing intrathecal (i.t.) with systemic treatment have been performed, yet there have been a few small phase II studies and case reports about new molecularly targeted substances whose successful i.t. or systemic application has been reported. Trastuzumab, gefitinib, and sorafenib are examples of possible future treatments for neoplastic meningitis, in order to better individualize therapy thus allowing better outcomes. In this review, we analyze the most recent and interesting developments on diagnostic and therapeutic approaches.

Benefit of ventriculoperitoneal cerebrospinal fluid shunting and intrathecal chemotherapy in neoplastic meningitis: a retrospective, case-controlled study

OBJECT

Neoplastic meningitis (NM) is a debilitating and increasingly frequent neurological complication of cancer characterized by infiltration of tumor cells into the leptomeninges and the subarachnoid space. Although NM is rarely curable, combined intrathecal chemotherapy and focal radiation can improve disease-related symptoms and survival. Hydrocephalus occurs in a significant proportion of patients, is associated with poor prognosis and reduced quality of life, and usually precludes the use of intrathecal therapy.

METHODS

Since January of 2005, the authors have used a combined treatment approach for patients with both NM and hydrocephalus that employs a subcutaneously placed reservoir connected in series to an on/off valve and a ventriculoperitoneal shunt for both diversion of CSF and injection of intrathecal chemotherapy. They conducted a retrospective, case-controlled study from 2 independent institutions to review their experience.

RESULTS

Twenty-four patients with NM and hydrocephalus underwent placement of a CSF reservoir-on/off valve-ventriculoperitoneal shunt (RO-VPS) construct. There was no perioperative mortality, and there were only 2 minor complications. One shunt failure and no shunt-associated infections were observed over a median of 28 weeks of follow-up. Symptomatic improvement and improved performance status were seen in 20 patients (83.3%) and were sustained over 6 months. Eighteen patients received intraventricular chemotherapy without unexpected toxicity, and cytological responses were found in 11 patients (61.1%). Median progression-free and overall survival was 14 and 31 weeks, respectively. Compared with a contemporaneous comparison group of 24 demographically matched patients with NM who underwent CSF reservoir placement only, those who received RO-VPS constructs (p = 0.02) and had primary diagnosis of breast cancer (p = 0.04) had significant advantage in overall survival.

CONCLUSIONS

A combined RO-VPS system is safe and practical to install, results in symptomatic improvement in most patients, and allows uncomplicated and effective administration of intrathecal chemotherapy in patients with NM. Cerebrospinal fluid diversion surgery should be considered in NM patients in conjunction with intrathecal and systemic treatments.

Leptomeningeal metastasis

PURPOSE OF REVIEW

Leptomeningeal metastasis occurs in approximately 5% of all patients with cancer. This review summarizes recent literature regarding methods of diagnosis and treatment of leptomeningeal metastasis.

RECENT FINDINGS

Staging of leptomeningeal metastasis should include contrast-enhanced brain and spine MRI, and though controversial, radionuclide cerebrospinal fluid (CSF) flow study. Treatment of leptomeningeal metastasis often requires involved-field radiotherapy to bulky or symptomatic disease sites as well as intra-CSF and systemic chemotherapy. The use of high-dose systemic therapy may benefit patients with leptomeningeal metastasis and obviate the need for intra-CSF chemotherapy. Intra-CSF drug therapy primarily utilizes one of three chemotherapeutic agents [i.e. methotrexate, cytosine arabinoside (both free and liposomal) and thio-tetraethylenepentamine] administered by a variety of schedules either by intralumbar or intraventricular drug delivery. Novel intra-CSF agents increasingly utilized in the treatment of leptomeningeal metastasis are targeted mAbs such as rituximab and trastuzumab.

SUMMARY

Although treatment of leptomeningeal metastasis is palliative with median patient survival of 2-3 months, treatment may afford stabilization and protection from further neurologic deterioration in patients with leptomeningeal metastasis.