Current diagnosis and treatment of leptomeningeal metastasis

Drug delivery in leptomeningeal disease: Navigating barriers and beyond

Leptomeningeal disease (LMD) refers to the infiltration of cancer cells into the leptomeningeal compartment. Leptomeninges are the two membranous layers, called the arachnoid membrane and pia mater. The diffuse nature of LMD poses a challenge to its effective diagnosis and successful management. Furthermore, the predominant phenotype; solid masses or freely floating cells, has altering implications on the effectiveness of drug delivery systems. The standard of care is the intrathecal delivery of chemotherapy drugs but it is associated with increased instances of treatment-related complications, low patient compliance, and suboptimal drug distribution. An alternative involves administering the drugs systemically, after which they must traverse fluid barriers to arrive at their destination within the leptomeningeal space. However, this route is known to cause off-target effects as well as produce subtherapeutic drug concentrations at the target site within the central nervous system. The development of new drug delivery systems such as liposomal cytarabine has improved drug delivery in leptomeningeal metastatic disease, but much still needs to be done to effectively target this challenging condition. In this review, we discuss about the anatomy of leptomeninges relevant for drug penetration, the conventional and advanced drug delivery methods for LMD. We also discuss the future directions being set by different clinical trials.

Revisiting intrathecal thiotepa: Efficacy and safety in secondary CNS malignancies

Treating metastatic malignancies to the central nervous system (CNS) is challenging because many drugs cannot cross the blood-brain-barrier (BBB). Direct intrathecal (IT) drug administration into the cerebrospinal fluid (CSF) is a strategy to overcome this problem. Thiotepa has effective CNS penetration but its popularity has waned over the last two decades due to concerns about its efficacy and potential systemic toxicity. This review evaluates the available evidence for the use of IT thiotepa in hematologic malignancies and non-CNS solid tumors with leptomeningeal disease metastases (LMD). Our search shows that IT thiotepa is a reasonable alternative in hematologic malignancies and LMD due to solid organ malignancies. This suggests a potential role of IT thiotepa in second-or third-line treatment or a substitute role in cases of drug-shortages and adverse effects with other agents. Future research should focus on rigorous comparative trials to establish its definitive role in the evolving landscape of CNS-directed chemotherapy.

Direct Administration of Chemotherapy and Other Agents into the Fourth Ventricle to Treat Recurrent Malignant Brain Tumors in Children

Direct administration of chemotherapy and other agents into the fourth ventricle of the brain is a novel approach to treating recurrent malignant posterior fossa brain tumors in children. Candidates for this treatment approach include patients with recurrent medulloblastoma, ependymoma, atypical teratoid/rhabdoid tumor, and potentially other neoplasms that originate in the fourth ventricle or elsewhere in the posterior fossa. In this chapter, the authors first explain the rationale for considering fourth ventricular drug infusions in patients with recurrent malignant posterior fossa tumors. We then summarize the results of translational experiments conducted in piglets and non-human primates that demonstrated safety and favorable pharmacokinetics. These translational experiments led to several pilot human clinical trials, and the results of these trials are reviewed. Finally, currently open clinical trials testing infusion of various agents into the fourth ventricle are discussed, and thoughts about potential future directions are shared.

Cytopathological differential diagnosis of malignant tumor cells in the cerebrospinal fluid: A retrospective analysis

Leptomeningeal metastasis is the spread of cancer to the leptomeninges and subarachnoid space and represents a dreadful complication of cancer. The most commonly responsible neoplasms are high-grade lymphomas, leukemias, and some solid tumors, chiefly breast and lung cancer as well as melanoma. Herein we report our ten-year retrospective experience on 715 cases of cerebrospinal fluid cytology, 21 (2.9%) of which were positive for leptomeningeal metastasis. Sample collection and processing, clinical history, interdisciplinary dialog, and ancillary techniques such as immunocytochemistry and flow cytometry are all fundamental in reaching the correct diagnosis and thus optimally caring for patients with leptomeningeal metastasis.

Leptomeningeal Carcinomatosis: A Rare Presentation of Perforated Gastric Cancer

Leptomeningeal carcinomatosis (LMC) or leptomeningeal metastasis is defined as metastasis to the pia mater, arachnoid, and subarachnoid space. Only very few patients with cancer have LMC. In the practice of general surgeons, this diagnosis is rarely, if ever, encountered. We present a rare case of a patient presenting to ED with worsening headaches over several months that developed acute-onset abdominal pain while being evaluated. Further workup showed free air, and the patient was taken emergently to the OR, where a perforated gastric ulcer was identified and biopsied. Pathology revealed gastric adenocarcinoma and subsequent MRI pointed to suspected LMC. Unfortunately, till today there is no effective treatment for advanced-stage gastric cancer, and aggressive intrathecal chemotherapy is only available to mitigate leptomeningeal involvement.

Intradural Extramedullary Tumors and Associated Syndromes

Most intradural tumors are located within the intradural extramedullary compartment, and the most common tumors are schwannomas and meningiomas. Other less common neoplasms include neurofibroma, solitary fibrous tumor, myxopapillary ependymoma, lymphoma, metastatic leptomeningeal disease, malignant peripheral nerve sheath tumor, and paraganglioma. Patients usually present with gait ataxia, radicular pain, and motor and sensory deficits due to chronic compressive myelopathy or radiculopathy. MRI is the modality of choice for detecting and evaluating intradural extramedullary spinal tumors. This imaging technique helps narrow the differential diagnosis and therefore decide treatment.

The autopsy is not dead: ongoing relevance of the autopsy

Background

Autopsy requests have been trending downward for a variety of factors. There are differences between pre- and postmortem diagnoses. Autopsies remain a tool for education, public health research, quality control, and closure for families.

Objective

We report two cases that illustrate the utility of autopsy for uncovering contributing factors in the death of these patients and highlight their ongoing importance.

Design

Clinical and autopsy investigation of two individuals and illustration of the importance of autopsy findings which, had they been diagnosed premortem, could have changed the outcome. Cases were evaluated using the Goldman criteria for discrepancies between premortem clinical diagnoses and postmortem autopsy findings.

Results

In the first case, the patient had been previously admitted due to a non-ST elevation myocardial infarction months before the fatal event. The autopsy showed an undiagnosed clear cell carcinoma of the ovary. She expired due to a massive myocardial infarction secondary to neoplasm induced hypercoagulable state. The degree of pre-mortem/postmortem diagnostic discrepancy makes this a Goldman Class I error.In the second case, the patient presented to the emergency department with symptoms of Guillain-Barré Syndrome (GBS), for which he was treated. Abdominal masses were discovered; however, the patient decompensated before workup was completed. A high-grade B-cell lymphoma was confirmed but would not have altered the outcome, making this a Goldman class II error.

Conclusions

The autopsy remains a relevant and necessary tool for physicians and society. It assists in the establishment of diagnoses, measurement of treatment quality, the providence of public health metrics, and closure to the survivors.

A Rare Case of Metastasis of Gastric Adenocarcinoma to the Leptomeninges

Leptomeningeal carcinomatosis (LMC) is defined as the diffuse infiltration of malignant cells throughout the pia and arachnoid membrane. LMC is commonly observed in patients with leukemia, lymphoma, and breast and lung cancer. The prevalence of LMC spread in patients with primary gastric malignancy is very rare. Due to its devastating neurological complications and high mortality, it is difficult to assess the associated clinical features, treatment outcomes, and prognostic factors. Current treatment options include intra-thecal chemotherapy, radiotherapy, and supportive care with a median survival of three to four months. LMC is a rare manifestation of gastric cancer and is an extremely fatal disease. Therefore, it is difficult to distinguish LMC from other neurological etiologies. We present a unique case of an individual who presented with headaches and was found to have LMC.

Novel Therapeutic Approaches in Neoplastic Meningitis

Central nervous system (CNS) metastasis from systemic cancers can involve the brain parenchyma, leptomeninges, or the dura. Neoplastic meningitis (NM), also known by different terms, including leptomeningeal carcinomatosis and carcinomatous meningitis, occurs due to solid tumors and hematologic malignancies and is associated with a poor prognosis. The current management paradigm entails a multimodal approach focused on palliation with surgery, radiation, and chemotherapy, which may be administered systemically or directly into the cerebrospinal fluid (CSF). This review focuses on novel therapeutic approaches, including targeted and immunotherapeutic agents under investigation, that have shown promise in NM arising from solid tumors.

Intrathecal delivery and its applications in leptomeningeal disease

Intrathecal delivery (IT) of opiates into the cerebrospinal fluid (CSF) for anesthesia and pain relief has been used clinically for decades, but this relatively straightforward approach of bypassing the blood-brain barrier has been underutilized for other indications because of its lack of utility in delivering small lipid-soluble drugs. However, emerging evidence suggests that IT drug delivery be an efficacious strategy for the treatment of cancers in which there is leptomeningeal spread of disease. In this review, we discuss CSF flow dynamics and CSF clearance pathways in the context of intrathecal delivery. We discuss human and animal studies of several new classes of therapeutic agents-cellular, protein, nucleic acid, and nanoparticle-based small molecules-that may benefit from IT delivery. The complexity of the CSF compartment presents several key challenges in predicting biodistribution of IT-delivered drugs. New approaches and strategies are needed that can overcome the high rates of turnover in the CSF to reach specific tissues or cellular targets.

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.

Inhibition of Jumonji Histone Demethylases Selectively Suppresses HER2+ Breast Leptomeningeal Carcinomatosis Growth via Inhibition of GMCSF Expression

HER2⁺ breast leptomeningeal carcinomatosis (HER2⁺ LC) occurs when tumor cells spread to cerebrospinal fluid-containing leptomeninges surrounding the brain and spinal cord, a complication with a dire prognosis. HER2⁺ LC remains incurable, with few treatment options. Currently, much effort is devoted toward development of therapies that target mutations. However, targeting epigenetic or transcriptional states of HER2⁺ LC tumors might efficiently target HER2⁺ LC growth via inhibition of oncogenic signaling; this approach remains promising but is less explored. To test this possibility, we established primary HER2⁺ LC (Lepto) cell lines from nodular HER2⁺ LC tissues. These lines are phenotypically CD326⁺CD49f^-, confirming that they are derived from HER2⁺ LC tumors, and express surface CD44⁺CD24^-, a cancer stem cell (CSC) phenotype. Like CSCs, Lepto lines showed greater drug resistance and more aggressive behavior compared with other HER2⁺ breast cancer lines in vitro and in vivo. Interestingly, the three Lepto lines overexpressed Jumonji domain-containing histone lysine demethylases KDM4A/4C. Treatment with JIB04, a selective inhibitor of Jumonji demethylases, or genetic loss of function of KDM4A/4C induced apoptosis and cell-cycle arrest and reduced Lepto cell viability, tumorsphere formation, regrowth, and invasion in vitro. JIB04 treatment of patient-derived xenograft mouse models in vivo reduced HER2⁺ LC tumor growth and prolonged animal survival. Mechanistically, KDM4A/4C inhibition downregulated GMCSF expression and prevented GMCSF-dependent Lepto cell proliferation. Collectively, these results establish KDM4A/4C as a viable therapeutic target in HER2⁺ LC and spotlight the benefits of targeting the tumorigenic transcriptional network. SIGNIFICANCE: HER2⁺ LC tumors overexpress KDM4A/4C and are sensitive to the Jumonji demethylase inhibitor JIB04, which reduces the viability of primary HER2⁺ LC cells and increases survival in mouse models.

Ventricular apparent diffusion coefficient measurements in patients with neoplastic leptomeningeal disease

Background

To test the hypothesis that intraventricular ADC values can be used to determine the presence of neoplastic leptomeningeal disease (LMD).

Materials and methods

ADC values were measured at multiple sites in the ventricular system in 32 patients with cytologically-proven LMD and 40 control subjects. Multiple linear regression analysis was used to determine the mean difference of ADCs between the LMD and control groups after adjusting for ventricle size and tumor type. Receiver operating characteristics (ROC) analysis was performed and optimal ADC value cut-off point for predicting the presence of LMD. ADC was compared to T1 enhancement and FLAIR signal hyperintensity for determining the presence of LMD.

Results

After adjusting for ventricular volume and tumor type, the mid body of lateral ventricles showed no significant difference in ventricular volume and a significant difference in ADC values between the control and LMD groups (p > 0.05). In the mid-body of the right lateral ventricle the AUC was 0.69 (95% CI 0.57–0.81) with an optimal ADC cut off point of 3.22 × 10^− 9 m²/s (sensitivity, specificity; 0.72, 0.68). In the mid-body of left lateral ventricle the AUC was 0.7 (95% CI 0.58–0.82) with an optimal cut-off point of 3.23 × 10^− 9 m²/s (0.81, 0.62). Using an average value of HU measurements in the lateral ventricles the AUC was 0.73 (95% CI 0.61–0.84) with an optimal cut off point was 3.11 × 10^− 9 m²/s (0.78, 0.65). Compared to the T1 post-contrast series, ADC was predictive of the presence of LMD in the mid-body of the left lateral ventricle (p = 0.036).

Conclusion

Complex interactions affect ADC measurements in patients with LMD. ADC values in the lateral ventricles may provide non-invasive clues to the presence of LMD.

Leptomeningeal metastasis in a marginal zone lymphoma, presenting as a delirium: case report

Background

Hematologic malignancies can spread to the central nervous system (CNS), either as focal lesions or as leptomeningeal disease. Marginal zone lymphoma (MZL) is a low-grade non-Hodgkin lymphoma and generally presents as an indolent disease. This case report illustrates an unexpected diagnosis of leptomeningeal metastasis in an MZL, presenting as a delirium without B symptoms, pronounced hematologic progression or abnormalities on cerebral imaging.

Case presentation

An 80-year-old patient with a medical history of monoclonal B-cell lymphocytosis (MBL) with a clone indicative for an MZL, presented to the emergency and the geriatric departments with a recent cognitive deterioration and behavioral changes. MMSE score was 18/30. After excluding the most common etiologies through classical work-up including a normal head magnetic resonance imaging, a lumbar puncture was performed. In the cerebrospinal fluid an elevated protein level and increased lymphocyte count were identified, whereas beta-amyloid and tau protein levels were normal. Immunophenotyping of the lymphocytes confirmed CNS invasion by the MZL clone. Staging revealed mild splenomegaly. Prednisolone, intrathecal and systemic chemotherapy were initiated, leading to quick cognitive improvement with a final MMSE score of 28/30.

Conclusions

To the best of our knowledge a delirium in an older patient due to leptomeningeal disease in MZL has never been described. To date, rare reports of CNS invasion by MZL describe focal intracranial lesions. After exclusion of common etiologies, physicians should remain vigilant when confronted with a patient with history of MBL presenting neurological symptoms. This case illustrates the importance of low threshold for lumbar punctures in this population, also for those patients with normal imaging studies.

Intradural Extramedullary Spinal Neoplasms: Radiologic-Pathologic Correlation

While intradural extramedullary spinal disease varies widely, identification of tumors in this location and their radiologic manifestations greatly facilitates narrowing of the diagnostic considerations. Meningioma and schwannoma are the two most common intradural extramedullary tumors, and both are associated with neurofibromatosis. Meningiomas are most common in the thoracic spine and show a strong female predilection and a clinical manifestation related to compression of the spinal cord or nerve roots. Schwannomas typically are associated with radicular pain and other sensory symptoms. Melanotic schwannoma frequently shows T1 hyperintensity at MRI related to the presence of paramagnetic free radicals in melanin. Neurofibroma, known for its T2 hyperintensity, frequently involves the cervical spine, where it may make surgical resection challenging. Less commonly, malignant peripheral nerve sheath tumor commonly mimics the imaging appearance of a schwannoma but has decidedly more aggressive biologic behavior. In the cauda equina, myxopapillary ependymoma and paraganglioma are believed to arise from the filum terminale and have characteristic imaging manifestations based on their underlying pathologic features. Recent identification of a common genetic marker has led to reclassification of what had previously been regarded as separate tumors and are now known as solitary fibrous tumor/hemangiopericytoma. In the proper clinical setting, the presence of nodular intradural enhancement strongly suggests the presence of leptomeningeal metastatic disease, even when results of cerebrospinal fluid analysis are negative. This article highlights the characteristic neuroimaging manifestations of these neoplasms, with emphasis on radiologic-pathologic correlation. See Illumination by Frazier .

Cauda equina syndrome in an ovarian malignant-mixed müllerian tumor with leptomeningeal spread

Leptomeningeal metastasis is extremely rare in patients with ovarian cancer, but should be considered in patients presenting with neurologic deficits such as cauda equine syndrome. Given its poor prognosis and lack of data currently on management, additional studies are needed to optimize treatment regimens and improve outcomes.

Radiotherapy in Leptomeningeal Disease: A Systematic Review of Randomized and Non-randomized Trials

Background: Leptomeningeal disease (LMD), also known as neoplastic meningitis, leptomeningeal carcinomatosis, or carcinomatous meningitis, is a rare cancer complication occurring in ~5% of cases and ultimately leads to significant morbidity and mortality. In the modern era, incidence of this condition continues to rise with longer survival of patients with advanced and even metastatic disease due to continued improvements in systemic therapies that are providing prolonged control of distant disease, but with limited effect in the central nervous system (CNS). Typical treatment strategies include optimal systemic therapy for the primary disease, as well as neuroaxis directed therapies, which may include intrathecal chemotherapy (ITC) or radiotherapy (RT). Methods: A systematic review of radiotherapy for LMD was performed. Medline, EMBASE, and Cochrane databases were searched from 1946 to 2018 for clinical trials, retrospective/prospective reviews, and case series with ≥2 human subjects that used radiation therapy techniques in the treatment of LMD. The outcome measures of interest included: characteristics of trial participants, inclusion/exclusion criteria, study type, number of participants, primary cancer histology, type of intervention for LMD, survival results if reported, length of follow up, and study conclusion. Results: Of 547 unique citations, 62 studies met the pre-specified eligibility criteria. These studies included 36 retrospective cohorts, 11 prospective series, 12 case series, and a single citation of guidelines, NCDB analysis, and a randomized control trial. Owing to study heterogeneity, meta-analyses of the endpoint data could not be performed. Conclusions: LMD is a devastating complication of cancer with reported survivals ranging from 2 to 4 months. Based on this systematic review, the recommendation for the treatment of LMD is for multimodality discussion of cases and treatment, including the use of radiotherapy, for LMD. However, with continued advances in systemic therapy as well as imaging advances, the landscape of LMD is evolving rapidly and the role of RT will likely also continue to evolve and advance. There is limited high-quality evidence to guide the optimal use of RT for the treatment of LMD, and there is a great need for prospective, histology specific investigation of the role of radiotherapy for LMD in the era of modern systemic therapies.

Diffuse large B-cell lymphoma recurrence presenting as multiple, progressive cranial neuropathies

A 58-year-old man with a history of rheumatoid arthritis and stage IV diffuse large B-cell lymphoma, in complete remission with no evidence of residual disease on positron emission tomography/CT after completing six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone chemotherapy, presented with acute onset of dysphagia to solids and liquids. On further evaluation, his dysphagia was attributed to a vagus nerve palsy, and later during his admission, he developed rapidly progressing left facial and vestibulocochlear nerve palsies. Imaging studies displayed pathological enhancement of bilateral seventh and eighth cranial nerves, concerning for leptomeningeal recurrence of lymphoma. Cerebrospinal fluid analysis and flow cytometry were confirmatory, revealing markedly atypical monotypic CD19 positive B cells.

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.

Management of hydrocephalus in patients with leptomeningeal metastases: an ethical approach to decision-making

PURPOSE

Leptomeningeal metastases (LM) are a rare, but often debilitating complication of advanced cancer that can severely impact a patient's quality-of-life. LM can result in hydrocephalus (HC) and lead to a range of neurologic sequelae, including weakness, headaches, and altered mental status. Given that patients with LM generally have quite poor prognoses, the decision of how to manage this HC remains unclear and is not only a medical, but also an ethical one.

METHODS

We first provide a brief overview of management options for hydrocephalus secondary to LM. We then apply general ethical principles to decision making in LM-associated hydrocephalus that can help guide physicians and patients.

RESULTS

Management options for LM-associated hydrocephalus include shunt placement, repeated lumbar punctures, intraventricular reservoir placement, endoscopic third ventriculostomy, or pain management alone without intervention. While these options may offer symptomatic relief in the short-term, each is also associated with risks to the patient. Moreover, data on survival and quality-of-life following intervention is sparse. We propose that the pros and cons of each option should be evaluated not only from a clinical standpoint, but also within a larger framework that incorporates ethical principles and individual patient values.

CONCLUSIONS

The decision of how to manage LM-associated hydrocephalus is complex and requires close collaboration amongst the physician, patient, and/or patient's family/friends/community leaders. Ultimately, the decision should be rooted in the patients' values and should aim to optimize a patient's quality-of-life.

Leptomeningeal metastasis from systemic cancer: Review and update on management

Leptomeningeal metastasis is an uncommon and typically late complication of cancer with a poor prognosis and limited treatment options. Diagnosis is often challenging, with nonspecific presenting symptoms ranging from headache and confusion to focal neurologic deficits, such as cranial nerve palsies. Standard diagnostic evaluation involves a neurologic examination, magnetic resonance imaging of the brain and spine with gadolinium, and cytologic evaluation of the cerebral spinal fluid. Therapy entails a multimodal approach focused on palliation with surgery, radiation, and/or chemotherapy, which may be administered systemically or directly into the cerebral spinal fluid. Limited trial data exist to guide treatment, and current regimens are based primarily on expert opinion. Although newer targeted and immunotherapeutic agents are under investigation and have shown promise, an improved understanding of the biology of leptomeningeal metastasis and treatment resistance as well as additional randomized controlled studies are needed to guide the optimal treatment of this devastating disease. Cancer 2018;124:21-35. © 2017 American Cancer Society.

Overview of metastatic disease of the central nervous system

In 2016, the American Society of Clinical Oncology reported that 1.7 million Americans were diagnosed with cancer; this number will rise to 2.3 million in the United States and 22 million worldwide in 2030. This rising need is being met by an explosion of new cancer therapies, including: immune checkpoint inhibitors, T-cell therapies, tumor vaccines, antiangiogenic therapies, and various targeted therapies. This armamentarium of targeted therapies has led to better systemic control of disease and longer patient overall survival (OS). The incidence of metastatic disease to the central nervous system (CNS) is rising as patients are living longer with these more effective systemic therapies. Prolonged OS allows increased time to develop CNS metastases. The CNS is also a sanctuary for metastatic tumor cells that are protected from full exposure to therapeutic concentrations of most anticancer agents by the blood-brain barrier, the tumor microenvironment, and immune system. In addition, CNS metastases often develop late in the course of the disease, so patients are frequently heavily pretreated, resulting in drug resistance. Although genomic profiling has led to more effective therapies for systemic disease, the same therapy may not be effective in treating CNS disease, not only due to failure of blood-brain barrier penetration, but from discordance between the molecular profile in systemic and CNS tumor.

Chemical meningitis related to intra-CSF liposomal cytarabine

Therapeutic options of leptomeningeal metastases include intra-cerebrospinal fluid (CSF) chemotherapy. Among intra-CSF agents, liposomal cytarabine has advantages but can induce specific toxicities. A BRAF-V600E-mutated melanoma leptomeningeal metastases patient, treated by dabrafenib and liposomal cytarabine, presented after the first injection of liposomal cytarabine with hyperthermia and headaches. Despite sterile CSF/blood analyses, extended intravenous antibiotics were given and the second injection was delayed. The diagnosis of chemical meningitis was finally made. Dose reduction and appropriate symptomatic treatment permitted the administration of 15 injections of liposomal cytarabine combined with dabrafenib. A confirmation of the diagnosis of chemical meningitis is essential in order (1) not to delay intra-CSF or systemic chemotherapy or (2) to limit the administration of unnecessary but potentially toxic antibiotics.

Most common sites on MRI of intracranial neoplastic leptomeningeal disease

Neoplastic leptomeningeal disease (LMD) represents infiltration of the leptomeninges by tumor cells. Knowledge of the frequencies of locations of LMD on MRI may assist in early detection, help elucidate the process of leptomeningeal spread of cancer and understand how LMD affects the central nervous system. Our goal was to identify intracranial sites of neoplastic LMD predilection on MRI in patients with cytologically-proven LMD. The presence of FLAIR signal hyperintensity and T1-weighted post-contrast enhancement in the sulci of the supratentorial compartment and cerebellum and enhancement of the cranial nerves (CNs), basal cisterns, pituitary stalk, and ependymal surface of the lateral ventricles, as well as the presence of parenchymal metastasis were recorded. Within each imaging sequence, sites were ordered by prevalence and compared using McNemar's test. The study included 270 patients. Positive MRI findings were present in 185/270 (68.5%) patients. FLAIR signal hyperintensity was significantly more common (p≤0.003) in the cerebellum (n=96) and occipital lobe (n=92) relative to the other lobes. Leptomeningeal enhancement was also significantly more common (p≤0.009) in the cerebellum (n=82) and occipital lobe (n=67) relative to the other lobes. Enhancement was most commonly found involving CN VII/VIII and the ependymal surface of the lateral ventricles compared to other sites. Parenchymal metastases were present in 110 (40.1%) of the patients. In conclusion, neoplastic LMD predominantly involves the cerebellum and occipital lobes, CN VII/VIII, and the ependymal lining of the lateral ventricles. Parenchymal metastases are frequently present in patients with neoplastic LMD.

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.

Gamma Knife radiosurgery for brain metastases from gastrointestinal primary

INTRODUCTION

In this study, we assessed clinical outcomes of patients with brain metastases from a gastrointestinal (GI) primary cancer and patterns of failure after stereotactic radiosurgery including failure within the radiosurgical volume, distant failure and leptomeningeal failure (LMF). We also assessed other factors associated with the patients' neurologic and extraneuraxial disease that may affect clinical outcomes.

METHODS

We reviewed our institutional series of 62 consecutive patients with brain metastases treated with stereotactic radiosurgery, which included 17 patients with oesophageal, 44 patients with colorectal and one patient with anal canal primary. The median marginal dose to the radiosurgery volume was 17 Gy (range 10-24 Gy). Thirteen patients were treated with whole-brain radiotherapy (WBRT) prior to GKS.

RESULTS

The median dose delivered to the margin of the tumour was 17 Gy (range: 10-24 Gy). The median largest tumour diameter was 2.7 cm (range: 0.60-6.1 cm). The median overall survival (OS) was 7.1 months with a median follow-up of 6.1 months and a range of 0-31.7 months. Freedom from local failure was 86.5% and 62.2% at 6 and 12 months respectively. Freedom from distant failure was 73.2% and 42.2% at 6 and 12 months, respectively, and 40% of patients died of neurologic death. LMF occurred in seven patients, all of whom had colorectal primaries. Multivariate analysis revealed that craniotomy for resection of brain metastasis (HR = 2.63, P < 0.02), an absence of extracranial disease (HR = 2.28, P < 0.03), and prolonged time to distant brain failure (HR = 2.85, P < 0.01) predicted for improved survival.

CONCLUSIONS

Colorectal cancer metastases tend to have a higher rate of leptomeningeal failure than other types of GI cancer metastases. Radiosurgical management of brain metastases from GI primary represents an acceptable management option. Neurologic death remains problematic.

Methotrexate administration directly into the fourth ventricle in children with malignant fourth ventricular brain tumors: a pilot clinical trial

We hypothesize that chemotherapy can be safely administered directly into the fourth ventricle to treat recurrent malignant brain tumors in children. For the first time in humans, methotrexate was infused into the fourth ventricle in children with recurrent, malignant brain tumors. A catheter was surgically placed into the fourth ventricle and attached to a ventricular access device. Cerebrospinal fluid (CSF) flow was confirmed by CINE MRI postoperatively. Each cycle consisted of 4 consecutive daily methotrexate infusions (2 milligrams). Disease response was monitored with serial MRI scans and CSF cytologic analysis. Trough CSF methotrexate levels were sampled. Five patients (3 with medulloblastoma and 2 with ependymoma) received 18, 18, 12, 9, and 3 cycles, respectively. There were no serious adverse events or new neurological deficits attributed to methotrexate. Two additional enrolled patients were withdrawn prior to planned infusions due to rapid disease progression. Median serum methotrexate level 4 h after infusion was 0.04 µmol/L. Range was 0.02–0.13 µmol/L. Median trough CSF methotrexate level 24 h after infusion was 3.18 µmol/L (range 0.53–212.36 µmol/L). All three patients with medulloblastoma had partial response or stable disease until one patient had progressive disease after cycle 18. Both patients with ependymoma had progressive disease after 9 and 3 cycles, respectively. Low-dose methotrexate can be infused into the fourth ventricle without causing neurological toxicity. Some patients with recurrent medulloblastoma experience a beneficial anti-tumor effect both within the fourth ventricle and at distant sites.

Meningeal melanomatosis: a challenge for timely diagnosis

Neoplastic meningitis is a central nervous system complication that occurs in 3–5% of patients with cancer. Although most commonly seen in patients with disseminated disease, in a small percentage of patients, it may be the initial manifestation of cancer or even primitive in origin. In the absence of cancer history, the diagnosis of neoplastic meningitis may be challenging even for expert neurologists. Prognosis is poor, with a median overall survival of weeks from diagnosis. In the retrospective study herein, we described three cases of meningeal melanomatosis in patients without previous cancer history. The patients were diagnosed with significant delay (17 to 47 weeks from symptom onset) mainly due to the deferral in performing the appropriate testing. Even when the diagnosis was suspected, investigations by MRI, cerebrospinal fluid, or both proved at times unhelpful for confirmation. Prognosis was dismal, with a median survival of 4 weeks after diagnosis. Our observations are a cue to analyze the main pitfalls in the diagnosis of neoplastic meningitis in patients without cancer history and emphasize key elements that may facilitate early diagnosis.

Leptomeningeal metastasis: a Response Assessment in Neuro-Oncology critical review of endpoints and response criteria of published randomized clinical trials

PURPOSE

To date, response criteria and optimal methods for assessment of outcome have not been standardized in patients with leptomeningeal metastasis (LM).

METHODS

A Response Assessment in Neuro-Oncology working group of experts in LM critically reviewed published literature regarding randomized clinical trials (RCTs) and trial design in patients with LM.

RESULTS

A literature review determined that 6 RCTs regarding the treatment of LM have been published, all of which assessed the response to intra-CSF based chemotherapy. Amongst these RCTs, only a single trial attempted to determine whether intra-CSF chemotherapy was of benefit compared with systemic therapy. Otherwise, this pragmatic question has not been formally addressed in patients with solid cancers and LM. The methodology of the 6 RCTs varied widely with respect to pretreatment evaluation, type of treatment, and response to treatment. Additionally there was little uniformity in reporting of treatment-related toxicity. One RCT suggests no advantage of combined versus single-agent intra-CSF chemotherapy in patients with LM. No specific intra-CSF regimen has shown superior efficacy in the treatment of LM, with the exception of liposomal cytarabine in patients with lymphomatous meningitis. Problematic with all RCTs is the lack of standardization with respect to response criteria. There was considerable variation in definitions of response by clinical examination, neuroimaging, and CSF analysis.

CONCLUSION

Based upon a review of published RCTs in LM, there exists a significant unmet need for guidelines for evaluating patients with LM in clinical practice as well as for response assessment in clinical trials.

CSF CA 15-3 in breast cancer-related leptomeningeal metastases

The sensitivity of CSF cytology, the standard method for diagnosis of leptomeningeal metastases (LM), is low. Serum cancer antigen 15-3 (CA 15-3) is frequently used for the monitoring of patients with breast cancer (BC) and is a laboratory test available in most centers. The aim of the current study was to determine the feasibility of measuring CSF CA 15-3 and CA 15-3 CSF/serum ratio in patients with BC-related LM. Serum and CSF CA 15-3 values were evaluated in 20 BC patients with LM (Group 1), 20 patients with LM from other primary cancers (Group 2), 20 BC patients with parenchymal brain metastases only (Group 3) and 20 controls (Group 4). CSF and serum were collected on the same day. Serum and CSF CA 15-3 were assessed by an automatized immuno-enzymatic technology (TRACE(®) technology, KRYPTOR Automate, Brahms Society, France). In univariate analysis, BC patients with LM (Group 1) compared to other groups, a significantly elevated serum CA 15-3 (median 51 U/ml, range 12-2819) and CSF CA 15-3 (median 8.7 U/ml, range 0.1-251) was observed. Additionally, the CSF/serum ratio of CA 15-3 was significantly higher in this group of patients (median 0.18, range 0.002-4.40). Multivariate analysis identified a cut-off for CSF CA15-3 with 80 % sensitivity and 70 % specificity.

CONCLUSIONS

The current study confirms the feasibility of determining CSF CA 15-3 using a widely available technology. Evaluation of the CSF CA 15-3 may be useful in the diagnosis and management of BC-related LM but further studies are needed.

Leptomeningeal carcinomatosis from gastric cancer: single institute retrospective analysis of 9 cases

PURPOSE

The aim of this study is to investigate the clinical features and outcomes of 9 consecutive patients who suffered with leptomeningeal carcinomatosis (LMC) originating from gastric cancer.

METHODS

Between January 1995 and December 2010, we retrospectively reviewed the medical records of 9 patients with gastric LMC who had been treated at St. Vincent's Hospital, The Catholic University of Korea.

RESULTS

With the exception of 1 patient, the primary gastric cancer was Borrmann type III or IV, and 5 cases had poorly differentiated or signet ring cell histology. TNM stage of the primary gastric cancer was III in 6 patients. The median interval from diagnosis of the primary malignancy to the diagnosis of LMC was 9 months. Headache (6 cases), altered mental status (4 cases), and dysarthria (3 cases) were presenting symptoms of LMC. Computed tomography findings were abnormal in 4 of 7 cases, while magnetic resonance imaging revealed abnormality in 4 of 5 cases. Radiation therapy was administered to 5 patients and intrathecal chemotherapy was administered to only 1 patient. Median overall survival duration from the diagnosis of LMC was 3 months.

CONCLUSION

LMC originating from gastric cancer had a fatal clinical course and treatment strategies remain challenging.

Survival of breast cancer patients with meningeal carcinomatosis treated by intrathecal thiotepa

Treatment of breast cancer meningeal carcinomatosis (MC) relies on intrathecal chemotherapy. Thiotepa is one of the few drugs approved in this setting, although no large cohort has been reported. The aim of our retrospective study is to describe survival and prognostic factors of breast cancer patients treated by intrathecal thiotepa. A search in the electronic database of the Institut Curie was performed and retrieved the patients diagnosed with breast cancer MC from 2000 to 2012 and who received at least one intrathecal injection of thiotepa. The standard regimen was intrathecal thiotepa (10 mg) and methylprednisolone (40 mg), repeated every other week. Clinical data were retrieved from the computerized medical file of each patient. Sixty-six patients have been treated with intrathecal thiotepa either as first line or second line of treatment for breast cancer MC. The median overall survival was 4.5 months (range 0.1-50). There was no significant survival difference between patients treated as first or second line. In multivariate analysis, main adverse prognostic factors at diagnosis were performance status >2 (p = 0.001, RR = 3.4, 95 % CI 1.6-7.2) and history of more than 3 previous systemic chemotherapy lines (p = 0.002, RR = 2.90, 95 % CI 1.50-5.65). After start of the treatment, high primary tumor grade, elevated Cyfra 21-1 levels in the cerebrospinal fluid, and lack of clinical improvement were also independent adverse prognostic factors in multivariate analysis. This is the largest retrospective cohort of breast cancer MC treated by intrathecal thiotepa ever reported. The median overall survival was short but some patients clearly benefited from this treatment, even used as second line.

Three cases of neoplastic meningitis initially diagnosed with infectious meningitis in emergency department

Neoplastic meningitis (NM) is diagnosed by the presence of malignant cells in the cerebrospinal fluid (CSF). We report 3 patients with NM, who were misdiagnosed with infectious meningitis in emergency department (ED). Case 1. A 68-year-old man visited our ED with a 3-month history of headache. With MRI and CSF study, he was diagnosed with tuberculous meningitis. After 20 days, repeated CSF cytology showed malignant cells. His diagnosis was lung cancer with NM. Case 2. A 57-year-old man visited regional hospital ED with a 3-week history of headache and diplopia. Brain MRI was not contributory. With CSF examination, his diagnosis was aseptic meningitis. With worsening headache, he was referred to our ED. Repeated CSF showed malignant cells. His diagnosis was stomach cancer with NM. Case 3. A 75-year-old man visited a regional hospital with headache lasting for 4 months. His diagnosis was sinusitis. Persistent symptom brought him back, and he developed recurrent generalized seizures. Brain MRI showed diffuse leptomeningeal enhancement suggesting meningitis, and he was transferred to our ED. CSF exam showed malignant cells. His diagnosis was NM with unknown primary focus. When evaluating the patients with headache in ED, NM should be kept in mind as a differential diagnosis of meningitis.

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.

Neoplastic meningitis from solid tumors: a prospective clinical study in lombardia and a literature review on therapeutic approaches

Neoplastic dissemination to the leptomeninges is an increasingly common occurrence in patients with both haematological and solid tumors arising outside the central nervous system. Both refinement of diagnostic techniques (Magnetic resonance imaging) and increased survival in patients treated with targeted therapies for systemic tumors account for this increased frequency. Cerebrospinal fluid cytological analysis and MRI confirm clinical diagnosis based on multifocal central nervous system signs/symptoms in a patient with known malignancy. Overall survival in patients with leptomeningeal neoplastic dissemination from solid tumors is short, rarely exceeding 3-4 months. However, selected patients may benefit from aggressive therapies, Apart from symptomatic treatment, intrathecal chemotherapy is used, with both free (methotrexate, Thiotepa, AraC) and liposomal antitumor agents (liposomal AraC). Palliative radiotherapy is indicated only in cases of symptomatic bulky disease, surgery is limited to positioning of Ommaya recervoirs or C5F shunting. We report clinical data on a cohort of 26 prospectively followed patients with neoplastic leptomeningitis followed in Lombardia, Italy, in 2011. Prognostic factors and pattern of care are reported.

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.

Incidence and risk factors for leptomeningeal carcinomatosis in breast cancer patients with parenchymal brain metastases

OBJECTIVE

The objective of study is to evaluate the incidence of leptomeningeal carcinomatosis (LMC) in breast cancer patients with parenchymal brain metastases (PBM) and clinical risk factors for the development of LMC.

METHODS

We retrospectively analyzed 27 patients who had undergone surgical resection (SR) and 156 patients with whole brain radiation therapy (WBRT) as an initial treatment for their PBM from breast cancer in our institution and compared the difference of incidence of LMC according to clinical factors. The diagnosis of LMC was made by cerebrospinal fluid cytology and/or magnetic resonance imaging.

RESULTS

A total of 27 patients (14%) in the study population developed LMC at a median of 6.0 months (range, 1.0-50). Ten of 27 patients (37%) developed LMC after SR, whereas 17 of 156 (11%) patients who received WBRT were diagnosed with LMC after the index procedure. The incidence of LMC was significantly higher in the SR group compared with the WBRT group and the hazard ratio was 2.95 (95% confidence interval; 1.33-6.54, p<0.01). Three additional factors were identified in the multivariable analysis : the younger age group (<40 years old), the progressing systemic disease showed significantly increased incidence of LMC, whereas the adjuvant chemotherapy reduce the incidence.

CONCLUSION

There is an increased risk of LMC after SR for PBM from breast cancer compared with WBRT. The young age (<40) and systemic burden of cancer in terms of progressing systemic disease without adjuvant chemotherapy could be additional risk factors for the development of LMC.

Chemotherapy administration directly into the fourth ventricle in a nonhuman primate model

OBJECT

The authors hypothesized that chemotherapy infusions directly into the fourth ventricle might potentially play a role in treating malignant fourth ventricular tumors. The study tested the safety and pharmacokinetics of short- and long-term infusions of methotrexate into the fourth ventricle in a new nonhuman primate model.

METHODS

Six rhesus monkeys underwent posterior fossa craniectomy and catheter insertion into the fourth ventricle. In Group I (3 animals), catheters were externalized, and lumbar drain catheters were placed simultaneously to assess CSF distribution after short-term methotrexate infusions. In 2 animals, methotrexate (0.5 mg) was infused into the fourth ventricle daily for 5 days. Serial CSF and serum methotrexate levels were measured. The third animal had a postoperative neurological deficit, and the experiment was aborted prior to methotrexate administration. In Group II (3 animals), catheters were connected to a subcutaneously placed port for subsequent long-term methotrexate infusions. In 2 animals, 4 cycles of intraventricular methotrexate, each consisting of 4 daily infusions (0.5 mg), were administered over 8 weeks. The third animal received 3 cycles, and then the experiment was terminated due to self-inflicted wound breakdown. All animals underwent detailed neurological evaluations, MRI, and postmortem histological analysis.

RESULTS

No neurological deficits were noted after intraventricular methotrexate infusions. Magnetic resonance images demonstrated catheter placement within the fourth ventricle and no signal changes in the brainstem or cerebellum. Histologically, two Group I animals, one of which did not receive methotrexate, had several small focal areas of brainstem injury. Two Group II animals had a small (≤ 1-mm) focus of axonal degeneration in the midbrain. Intraventricular and meningeal inflammation was noted in 4 animals after methotrexate infusions (one from Group I and all three from Group II). In all Group II animals, inflammation extended minimally into brainstem parenchyma. Serum methotrexate levels were undetectable or negligible in both groups, ranging from 0.00 to 0.06 μmol/L. In Group I, the mean peak methotrexate level in fourth ventricle CSF exceeded that in the lumbar CSF by greater than 10-fold. Statistically significant differences between fourth ventricle and lumbar AUC (area under the concentration-time curve) were detected at peaks (p = 0.04) but not at troughs (p = 0.50) or at all time collection points (p = 0.12). In Group II, peak fourth ventricle CSF methotrexate levels ranged from 84.62 to 167.89 μmol/L (mean 115.53 ± 15.95 μmol/L [SD]). Trough levels ranged from 0.06 to 0.55 μmol/L (mean 0.22 ± 0.13 μmol/L).

CONCLUSIONS

Methotrexate can be infused into the fourth ventricle in nonhuman primates without clinical or radiographic evidence of injury. Observed inflammatory and other histological changes had no clinical correlate. This approach may have pharmacokinetic advantages over current treatment paradigms. Further experiments are warranted to determine if fourth ventricular chemotherapy infusions may benefit patients with malignant fourth ventricular tumors.

Risk for leptomeningeal seeding after resection for brain metastases: implication of tumor location with mode of resection

Object

Surgical spillage has been one of the causative factors for the development of leptomeningeal seeding (LMS) after resection of brain metastases. In this paper, the authors' goal was to define the factors related to the development of LMS and to evaluate the difference according to tumor location.

Methods

The authors retrospectively analyzed 242 patients who had undergone resection for brain metastases. The factors investigated included tumor location with proximity to the CSF pathway (that is, contacting, involved with, or separated from the CSF pathway), the method of resection, and the use of the Cavitron Ultrasonic Surgical Aspirator (CUSA).

Results

A total of 39 patients (16%) developed LMS at a median of 6.0 months (range 1–42 months) after resection. The risk of developing LMS was significantly higher in patients whose tumors were resected piecemeal than in those whose tumors were removed en bloc, with a hazard ratio (HR) of 4.08 (p < 0.01). The incidence of LMS was significantly higher in patients in whom the CUSA was used, and the HR was 2.64 (p < 0.01). The proximity of tumor to the CSF pathway in the involved group conferred an increased risk of LMS compared with the separated group (HR 11.36, p < 0.01). The risk of piecemeal resection for LMS was significant only in involved lesions (p < 0.01), and the use of the CUSA in both contact and involved lesions increased the incidence of LMS (p < 0.01 and p < 0.03, respectively).

Conclusions

The authors suggest that piecemeal resection using the CUSA should be limited because of the risk of postsurgical LMS, especially when the tumor is in contact with the CSF pathway.