Intrathecal cytosine arabinoside for the treatment of meningeal metastases from malignant brain tumors and systemic 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.

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.

Symptomatic Leptomeningeal and Intramedullary Metastases from Intracranial Glioblastoma Multiforme: A Case Report

Background

Glioblastoma multiforme infrequently metastasizes to the leptomeninges and even more rarely to the spinal cord. Moreover, very few patients with intracranial glioblastoma develop symptoms from spinal dissemination, with most patients not surviving long enough for spinal disease to become clinically evident.

Case Report

We present a rare case of symptomatic diffuse spinal leptomeningeal metastases simultaneously to an intramedullary lesion from an intracranial glioblastoma multiforme. After the diagnosis of spinal metastases the patient was treated with limited-field spinal radiotherapy (30 Gy in 3-Gy fractions).

Results

Radiotherapy on the main spinal lesions provided either relief from pain or mild improvement of neurological deficits. The patient died due to intracranial progression 4 months after diagnosis of spinal seeding and 17 months after diagnosis of the primary disease. We analyzed leptomeningeal and spinal metastases from glioblastoma multiforme with reference to the literature.

Conclusions

Radiotherapy for spinal disease may provide important symptom relief but the prognosis of these patients remains dramatically poor. As the local control of primary glioblastoma multiforme has improved with recent therapeutic advances, distant metastasis from high-grade gliomas is likely to become a more common clinical problem and such patients need to be included in clinical trials to evaluate new therapeutic approaches.

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.

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.

Challenges in drug delivery to tumors of the central nervous system: an overview of pharmacological and surgical considerations

The majority of newly diagnosed brain tumors are treated with surgery, radiation, and the chemotherapeutic temozolomide. Development of additional therapeutics to improve treatment outcomes is complicated by the blood-brain barrier (BBB), which acts to protect healthy tissue from chemical insults. The high pressure found within brain tumors adds a challenge to local delivery of therapy by limiting the distribution of bolus injections. Here we discuss various drug delivery strategies, including convection-enhanced delivery, intranasal delivery, and intrathecal delivery, as well as pharmacological strategies for improving therapeutic efficacy, such as blood-brain barrier disruption.

Cisplatin and temozolomide combination in the treatment of leptomeningeal carcinomatosis from ethmoid sinus intestinal-type adenocarcinoma

Intestinal-type adenocarcinoma of the nasal cavities and paranasal sinuses is a relatively rare tumor. Standard therapeutic modalities include surgery followed by radiotherapy, sometimes with chemotherapy treatment. Despite these treatments, the outcome is poor due to frequent local recurrences constituting the main cause of death among patients; leptomeningeal carcinomatosis is not a frequent event, and its presence indicates short expected survival. The therapy of neoplastic meningitis includes cranial irradiation, intrathecal chemotherapy and high-dose systemic chemotherapy. However, these approaches report important side effects with only modest efficacy. Thus, it is important to discover better treatment for this cancer complication. We present, for the first time, a case of leptomeningeal carcinomatosis from invasive intestinal-type adenocarcinoma treated with temozolomide and cisplatin chemotherapy obtaining a prolonged reduction and stabilization of the lesion improving the clinical condition of the patient.

Intrathecal chemotherapy for treatment of leptomeningeal dissemination of metastatic tumours

Neoplastic meningitis consists of diffuse involvement of the leptomeninges by infiltrating cancer cells, and can be caused by systemic or primary CNS tumours, such as solid cancers or lymphoproliferative malignant disease. Neoplastic meningitis is characterised by multifocal neurological signs and symptoms. Thus, careful neurological examination is needed for diagnosis of secondary diffuse involvement. Survival of patients with neoplastic meningitis is short (3-4 months), although some patients have long-lasting remission. Because most patients with neoplastic meningitis have diffuse systemic disease, treatment is typically palliative. However, more aggressive treatments are available to low-risk patients, which could increase survival. Therefore, identification of low-risk patients is important. Intrathecal chemotherapy is currently the main treatment for patients with neoplastic meningitis, but optimum anticancer chemotherapy is being studied.

Evaluation of osmolality and pH of various concentrations of methotrexate, cytarabine, and thiotepa prepared in normal saline, sterile water for injection, and lactated Ringer's solution for intrathecal administration

Background. Neurotoxicity of intrathecal (IT) chemotherapy has been variously attributed to the preservatives, volume, osmolality, and pH of the preparations. There has been little evaluation of how different drug concentrations or diluents can affect the osmolality and pH of the final solution. We conducted a three-part study: survey of cancer centers regarding the drug concentrations and diluent used in preparing IT chemotherapy; review of the literature on common practice of preparing IT chemotherapy; evaluation of the pH and osmolality of commonly used chemotherapy preparations for IT.

Method. We surveyed selected cancer centers to provide information on their standard volume, drug concentrations, and choice of diluents. MEDLINE was searched for clinical reports using the MeSH terms of `cytarabine,' `methotrexate,' or `thiotepa' with the subheading `Cerebrospinal fluid' and combined with `intrathecal' in all database fields. Data retrieved included the choice of diluent, volume, and/or drug concentration. We evaluated the pH and osmolality of methotrexate (1, 2, 5, and 10 mg/mL), cytarabine (2, 5, 10, and 25 mg/mL), and thiotepa (1, 2, and 5 mg/mL) in normal saline, sterile water for injection (SWFI), and lactated Ringer's solution.

Results. Nine centers were surveyed (seven in Canada, one in Australia, one in United Kingdom). Most centers used 5mL of preservative-free normal saline, irrespective of the drug or drug concentration used. Forty-four reports in the literature were reviewed. Most reported 5 mL of preservative-free normal saline. Most information on drug concentrations was provided for methotrexate, with an average concentration of about 1—2.5 mg/ mL. Cytarabine 0.4—20 mg/mL and thiotepa 1 mg/mL were also reported. In our in vitro evaluation, there was a trend of increased pH associated with increasing concentration of methotrexate and cytarabine. There was no apparent impact of thiotepa concentration on the pH values of the final preparations, irrespective of the diluent used. Except for cytarabine 10 and 25 mg/mL, all the tested solutions have pH within 10% of the physiologic range of CSF. There was a concentration-dependent change in osmolality with methotrexate and cytarabine preparations. Osmolality was increased with increased concentrations in all except methotrexate mixed in SWFI and thiotepa mixed in normal saline and lactated Ringer's solution. Except for some thiotepa solutions, all the tested solutions have osmolality within 10% of the physiologic range of CSF.

Conclusions. There is limited published literature on the potential impact of diluent and drug concentration on the pH and osmolality of IT chemotherapy preparation. Most cancer centers conventionally prepare IT chemotherapy with 5mL of preservative diluent normal saline, irrespective of the specific drug or dose used. The conventional practice means that most methotrexate preparations are likely to have comparable pH and osmolality to CSF. In contrast, cytarabine preparations may show significantly higher pH than the CSF, while thiotepa preparations generally have lower osmolality than the CSF. J Oncol Pharm Practice (2009) 15: 45—52.

Phase II trial of intracerebrospinal fluid etoposide in the treatment of neoplastic meningitis

BACKGROUND

The purpose of the current study was to determine the toxicity and response of a fixed dose intracerebrospinal fluid (CSF) etoposide in the treatment of patients with newly diagnosed neoplastic meningitis (NM). NM reportedly occurs in 1% to 5% of patients with known cancer. Currently available treatment options are limited and provide only modest benefit.

METHODS

Twenty-seven patients (median age, 55 yrs) with clinically and cytologically documented NM received intra-CSF etoposide. Tumor histologies included lung (8 patients), breast (5 patients), primary brain tumor (4 patients), non-Hodgkin lymphoma (4 patients), melanoma (4 patients), colon (1 patient), and prostate (1 patient). Concurrent involved-field radiotherapy (19 of 27 patients) or systemic chemotherapy (17 of 27 patients) was administered based on clinical indications. Etoposide was administered at a fixed dose (0.5 mg every day given 5 days per week every other week for 8 weeks [induction]). Patients were evaluated by CSF cytology and neurologic examination at the conclusion of induction therapy. Responding patients continued to receive etoposide (5 consecutive days every 4 weeks) with monthly evaluations.

RESULTS

Seven of 27 patients (26%) treated with etoposide had a cytologic response and either stable or improved neurologic status at the conclusion of induction. Eight patients (30%) developed disease progression during induction therapy and did not complete the 8-week induction course of therapy. At the conclusion of induction therapy, 12 patients (44%) had persistently positive CSF cytology, although they were clinically stable. In responding patients, time to neurologic disease progression ranged from 8 weeks to 40 weeks (median, 20 wks). Toxicity manifested as transient chemical arachnoiditis (5 of 27 patients; 13% of all treatment cycles). The 6-month neurologic disease progression-free survival was 11%.

CONCLUSIONS

Etoposide appears to have modest activity against NM and easily managed toxicity.

The treatment of neoplastic meningitis

Neoplastic meningitis (NM) is a debilitating complication of cancer that occurs when tumour cells infiltrate the leptomeninges. Treatment often includes direct installation of chemotherapy into the cerebrospinal fluid either by lumbar puncture or the use of a ventricular reservoir, radiation therapy, systemic chemotherapy or a combination of these modalities. The current standard chemotherapeutic agents for direct instillation into the cerebrospinal fluid include methotrexate, cytarabine and thiotepa. Other agents, such as topotecan, manfosfamide and IFNs, are undergoing evaluation in clinical trials. Despite active investigation of new therapies, the prognosis for patients with NM remains poor. However, some patients do demonstrate improvement of neurological function and prolongation of survival with treatment. Therefore, careful evaluation and treatment planning is warranted in order to avoid treatment-associated toxicities and to maximise the impact of the treatment on the disease process.

Combined-modality treatment of leptomeningeal gliomatosis

OBJECTIVE

Leptomeningeal gliomatosis (LG) is a clinically uncommon metastatic complication of high-grade gliomas (HGGs), for which there is no consensus regarding treatment. The goal of this study was to determine the toxicity and response rate of combined-modality therapy for the treatment of patients with HGGs and LG.

METHODS

Eighteen patients (10 men and 8 women), ranging in age from 28 to 70 years (median, 38 yr), with clinically, neuroradiologically, and cytologically documented LG received intraventricular chemotherapy. Tumor histological types included anaplastic astrocytoma (10 patients) and glioblastoma multiforme (8 patients). Concurrent radiotherapy (11 patients) or systemic chemotherapy (13 patients) was administered as clinically indicated. Methotrexate was administered initially, and treatment was continued for patients in stable or improved condition. For patients who experienced progression, cytosine arabinoside was administered as second-line therapy, followed by N,N',N"-triethylenethiophosphoramide as third-line therapy. Patients underwent bimonthly evaluations with cerebrospinal fluid cytological assessments and neurological examinations.

RESULTS

Four to 13 cycles (median, 5 cycles) of intraventricular chemotherapy were administered. Toxicity included aseptic meningitis (12 patients), radiation-induced enteritis (2 patients), and myelosuppression of Grade II or less (4 patients). No patient required hospitalization or transfusions, and no treatment-related deaths occurred. Partial responses were observed for 6 patients, and 12 patients demonstrated progressive disease. The median duration of response was 3 months (range, 2-4 mo). Survival times after the initiation of intraventricular chemotherapy ranged from 2 to 8 months (median, 3.5 mo). The cause of death was progressive LG (14 patients), combined LG and HGG (3 patients), and HGG (1 patient).

CONCLUSION

For this small cohort of patients, combined-modality therapy had modest toxicity but minimal palliative efficacy. For the majority of patients with LG, supportive care should be considered.

Current options for the treatment of neoplastic meningitis

Neoplastic meningitis, which is the diffuse involvement of the leptomeninges by infiltrating cancer cells, may be caused by many systemic tumors. The treatment options for neoplastic meningitis disease remain unsatisfactory. In this review article, we discuss the pathogenesis and cytology of neoplastic meningitis and the options for treatment, including intrathecal chemotherapy, systemic chemotherapy, and newer agents such as cytokines and monoclonal antibodies.

A phase II trial of intra-cerebrospinal fluid alpha interferon in the treatment of neoplastic meningitis

BACKGROUND

Neoplastic meningitis (NM), a metastatic complication of both primary central nervous system and systemic cancer, occurs in 1-5% of patients with known cancer. Currently available treatment options are limited and provide only modest benefit. The current study was performed to determine the toxicity and response rate of intra-cerebrospinal fluid (CSF) alpha interferon (alpha-IFN) in the treatment of patients with NM.

METHODS

Twenty two patients (median age, 56 years) with clinical and cytologically documented NM received intra-CSF alpha-IFN. Tumor histologies included: lung (five patients); brain (five patients); non-Hodgkin lymphoma (three patients); breast (three patients); melanoma (two patients); chronic myelogenous leukemia (two patients); colon (one patient); and prostate (one patient). Concurrent involved-field radiotherapy (12 out of 22 patients) or systemic chemotherapy (11 out of 22) was administered based on clinical indications. -alpha-IFN was administered at a fixed dose (1 x 10(6) IU every other day given three times per week for four weeks by induction). Patients were evaluated by CSF cytology and neurologic examination at the conclusion of induction therapy. Responding patients continued to receive alpha-IFN with monthly evaluations.

RESULTS

Ten out of 22 patients (45%) treated with alpha-IFN had a cytologic response and either stable or improved neurologic status at the conclusion of induction. Duration of response ranged from 8 to 40 weeks (median, 16 weeks). Toxicity was manifested as transient chemical arachnoiditis (16 out of 22 patients; 60% of all treatment cycles) and chronic fatigue (20 out of 22 patients). No treatment-related hospitalizations or deaths were seen.

CONCLUSIONS

alpha-IFN has modest activity against NM. However, it is associated with considerable toxicity at the dose and schedule used in the current study and, as a result, may prove difficult to administer.

Neoplastic meningitis: a guide to diagnosis and treatment

Neoplastic meningitis is a disease of the entire neuraxis and is pleomorphic in its clinical presentation. Diagnosis is achieved by recognition of the clinical manifestations of neoplastic meningitis followed by neuroradiography of the brain and spinal cord and examination of the cerebrospinal fluid. Treatment, if clinically warranted, includes irradiation of symptomatic or bulky disease and intracerebrospinal fluid chemotherapy following an assessment of the extent of metastatic disease treatment is based on the results of four randomized intracerebrospinal fluid chemotherapy trials.

Intrathecal chemotherapy with MX2 for treating glioma dissemination in vivo

We examined whether the intrathecal MX2 chemotherapy for treating dissemination of malignant glioma would be a feasible therapy. In the toxicity study, physiological and histological neurotoxicity was not observed in the rats treated with less than 100 microg/kg of MX2 administered intracisternally. But physiological side effects were observed in the treatment group of more than 200 microg/kg and histological brain toxicity was in the treatment group of more than 1000 microg/kg. Dissemination models were induced in rats by intracisternal inoculation of C6 glioma cells. The median survival times of the rats treated with 100 microg/kg of intrathecal MX2 on day 1, 3, or 7 after tumor inoculation were prolonged by 52.4% (p = 0.0006), 31.5% (p = 0.0007), and 7.1% (p = 0.0180), respectively, compared to that of untreated control animals. Intrathecal MX2 treatment also cured 33.6% of rats in the treatment group. These findings suggested that there was a possibility that intrathecal MX2 would be a safe and effective method for treating dissemination of malignant glioma.

Survival of patients with high grade glioma treated with intrathecal thiotriethylenephosphoramide for ependymal or leptomeningeal gliomatosis

BACKGROUND

The diagnosis of leptomeningeal dissemination of malignant glioma (meningeal gliomatosis) is associated with poor survival. Intrathecal (IT) chemotherapeutic agents used to achieve tumor control and improve survival include methotrexate, cytosine arabinoside (ara-C), thiotriethylenephosphoramide (thio-TEPA), neocarzinostatin, and 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitros ourea hydrochloride (ACNU). Little information exists about survival following administration of IT chemotherapy. The authors report survival data from a series of patients with supratentorial anaplastic astrocytoma (AA) or glioblastoma multiforme (GBM) treated for ependymal or leptomeningeal gliomatosis with IT thio-TEPA.

METHODS

The authors reviewed the records of 14 patients treated between 1991 and 1997 (GBM: n = 9; AA: n = 5). All patients were diagnosed with ependymal (n = 8) or leptomeningeal (n = 6) dissemination of tumor on the basis of clinical signs and symptoms, ependymal or leptomeningeal contrast enhancement on magnetic resonance imaging (MRI), and/or cerebrospinal fluid analysis. All 14 patients underwent placement of a ventricular reservoir system and subsequent instillation of IT thio-TEPA on a weekly basis for 6-12 weeks. Response to treatment was evaluated clinically and by MRI at intervals of 1-3 months and 3-6 months from the initiation of IT thio-TEPA. Data on survival from the time of diagnosis of dissemination was assessed.

RESULTS

The median survival, from the time of diagnosis of ependymal or leptomeningeal dissemination, of patients who received IT thio-TEPA was 10 months (AA = 19 months; GBM = 10 months). Five of 14 patients had a radiographic response to treatment within 6 months. The median survival of patients with a radiographic response was 15.5 months, compared with 10 months for nonresponders. No significant neurotoxicity or myelopathy was observed.

CONCLUSIONS

Early treatment with IT thio-TEPA may result in improved survival with minimal morbidity. Radiographic response may predict prolonged survival.

Lipid association increases the potency against primary medulloblastoma cells and systemic exposure of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) in rats

PURPOSE

To reduce the systemic toxicity and prolong the systemic presence of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), a lipid-based drug carrier was designed and characterized.

METHODS

The degree of CCNU association with lipid vesicles composed of 1, 2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) (1:1, m/m) was characterized and the drug decomposition rates of lipid-drug complexes were monitored. Effects of lipid association on drug potency against medulloblastoma cells and total systemic drug exposure in rats were determined.

RESULTS

At a CCNU:lipid molar ratio greater than 1:5, more than 90% of the drug was associated with the lipid vesicles. In aqueous suspensions, lipid association significantly reduced the first-order drug decomposition rate. In addition, lipid-associated CCNU exhibited a 4-fold increase in drug sensitivity with medulloblastoma cells. IC50 values for CCNU admixed and encapsulated with lipid vesicles were 18+/-4.9 and 14.0+/-2.2 microM, respectively, compared to 83+/-11.0 microM for free CCNU. When administered to rats, lipid-associated CCNU increased the AUC (area under the concentration-time curve) of CCNU by approximately 2-fold (20.46+/-2.15 compared to 39.59+/-1.87 microg x min/ml), and the terminal half-life (t1/2beta) by almost 9-fold (17+/-9 compared to 147+/-48 min) over free CCNU. Despite the increase in total systemic drug exposure, rats treated with lipid-associated CCNU exhibited a significantly lower frequency of acute neurotoxicity.

CONCLUSIONS

These data indicate that CCNU associated with lipid vesicles may increase drug stability, potency, and systemic exposure in rats.

Intrathecal mafosfamide therapy for pediatric brain tumors with meningeal dissemination

The treatment of childhood brain tumors with cerebrospinal fluid (CSF) dissemination is limited by the relative inaccessibility of the CSF to drugs administered systemically and the paucity of available agents for intrathecal therapy. Mafosfamide is a cyclophosphamide derivative, which does not require hepatic activation and thus can be utilized for regional therapy. Between May 1994 and December 1996, 16 patients 2 to 19 (median 12) years old with various disseminated brain tumors were treated with intraventricular mafosfamide via an indwelling subcutaneous reservoir. The patients received mafosfamide at a dose of 20 mg once or twice weekly until remission was achieved, followed by weekly administrations as consolidation therapy, and every 3 to 4 weeks thereafter for maintenance therapy. Except for transient headaches, nausea and vomiting during and immediately after mafosfamide administration no toxicities were observed. Nine of the 16 patients were evaluable for response by CSF cytology. Eight had complete responses and one patient did not respond. In addition to mafosfamide all patients received systemic chemotherapy as well. However, 4 of the 8 responding patients had developed CSF dissemination under concurrent systemic therapy and cleared their CSF only after administration of intrathecal mafosfamide. At a median follow-up of 21 months, 7 patients are in complete and 4 in partial remission, 2 have stable disease and 3 died of tumor progression. We conclude that mafosfamide at a dose of 20 mg can be safely administered into the CSF and may produce responses and prolong remission of the leptomeningeal disease.

Ventriculolumber perfusion of 3-[(4-amino-2-methyl-5-pyrimidinyl)-methyl]-1-(2-chloroethyl-1-nitrosou rea hydrochloride for subarachnoid dissemination of gliomas

The toxicity and therapeutic effect of the ventriculolumber perfusion of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl-1-1(2-chloroethyl)-1-nitros our ea hydrochloride (ACNU) against subarachnoid dissemination of gliomas were studied. Twenty-one patients (6 patients with anaplastic glioma, 7 with glioblastoma and 8 with medulloblastoma or PNET) received ventriculolumber perfusion of ACNU when they were diagnosed as having subarachnoid dissemination. The course of perfusion and cumulative dose of ACNU was 10 times and 95 mg on average, respectively. Most of the patients received systemic chemotherapy in combination with perfusion therapy and some patients with radiotherapy. Response rate was 17% and median survival time after the diagnosis of dissemination was 12 months for anaplastic gliomas, 29% and 12 months for glioblastoma, and 88% and over 25 months for medulloblastoma and PNET. The ventriculolumber perfusion of ACNU was performed for prophylactic purpose in 7 patients with high risk at the early postoperative period in combination with conventional adjuvant therapy. The course of perfusion and cumulative dose of ACNU was 2.3 times and 21 mg on average, respectively. One patient developed subarachnoid dissemination and died 22 months after surgery. Other 6 patients survived without dissemination on median over 29 months after surgery. Side effects encountered were headache in 4 patients, nausea and vomiting in 5, a convulsion in 2, right facial weakness in 1, fecal incontinence in 3 and meningitis in 2. They were all temporary except for facial weakness occurred in one patient. These data suggest that the ventriculolumber perfusion of ACNU is a safe and useful in the treatment and prophylaxis against the subarachnoid dissemination of gliomas.

Leptomeningeal metastases: a review of evaluation and treatment

Leptomeningeal metastases (LM) is a common problem in neuro-oncology occurring in approximately 5% of all patients with cancer. Notwithstanding frequent focal signs and symptoms in LM, LM is a disease affecting the entire neuraxis and therefore staging and treatment need encompass all cerebrospinal fluid (CSF) compartments. Central nervous system (CNS) staging of LM includes contrast enhanced cranial computerized tomography (CE-CT) or magnetic resonance imaging (MR-Gd), contrast enhanced spine magnetic resonance imaging (MR-S) or computerized tomographic myelography (CT-M) and radionuclide CSF flow study (FS). Treatment of LM involves involved-field radiotherapy of bulky or symptomatic disease sites and intra-CSF drug therapy. The inclusion of concomitant systemic therapy may benefit patients with LM and may obviate the need for intra-CSF chemotherapy. At present, intra CSF drug therapy is confined to three chemotherapeutic agents (i.e. methotrexate, cytosine arabinoside and thio-TEPA) administered by a variety of schedules either by intralumbar or intraventricular drug delivery. Although treatment of LM is palliative with an expected median patient survival of 6 months, it often affords stabilization and protection from further neurologic deterioration in patients with LM.

Complications associated with intraventricular chemotherapy in patients with leptomeningeal metastases

The authors studied complications associated with intraventricular chemotherapy in patients with leptomeningeal metastases (LM). One hundred twenty consecutive patients with LM (71 females and 49 males) ranging in age from 10 to 72 years (median 42 years) were treated with involved-field radiotherapy and intraventricular chemotherapy using an Ommaya reservoir and intraventricular catheter system. The diagnosis of LM was determined by a combination of clinical presentation (114 patients); cerebrospinal fluid cytological studies (100); or neuroradiographic studies (42). Systemic tumor histological findings included breast (34 patients); non-Hodgkin's lymphoma (22); melanoma (16); primitive neuroectodermal tumors including medulloblastoma (10); glial neoplasms, leukemia, small cell lung, nonsmall cell lung, and colon (six each); prostate and kidney (three each); and gastric cancers (two). Sixteen patients, all with non-Hodgkin's lymphoma, also had acquired immune deficiency syndrome. Patients received one to four (median two) chemotherapeutic drugs and underwent a total of 1110 cycles of intraventricular chemotherapy (median 10). Intraventricular chemotherapy administration and diagnostic Ommaya reservoir punctures totaled 4400, with a median of 46 per patient. Complications included aseptic/chemical meningitis (52 patients); myelosuppression due to intraventricular chemotherapy (21); catheter-related infections (nine); unidirectional catheter obstruction (six); intraventricular catheter malpositioning (two); Ommaya reservoir exposure (two); leukoencephalopathy (two); and chemotherapy-related myelopathy (one). There were no treatment-related deaths; however, seven patients (6%) required additional surgery for either catheter repositioning (two) or reservoir removal (five). Seven patients with catheter-related infections were treated successfully with intraventricular and systemic antibiotic drugs, thereby preserving the Ommaya system. The authors conclude that Ommaya reservoirs are convenient and pharmacologically rational systems for administering intraventricular chemotherapy. Overall, serious complications requiring surgery are infrequent (6%) and most often secondary to catheter infections, Ommaya reservoir exposure, or initial catheter malpositioning. In the majority of instances, catheter infections may be managed medically, as may the most common complications of intraventricular chemotherapy including aseptic meningitis (43% of patients) and myelosuppression (18%).

Pediatric leptomeningeal metastases: outcome following combined therapy

Fifteen children ranging in age from 4 to 18 years with leptomeningeal metastases were evaluated for extent of tumor and treated with radiotherapy or chemotherapy. Histologic diagnosis included: acute lymphoblastic leukemia (4); anaplastic astrocytoma (1); ependymoma (2); nonseminomatous germ cell tumor (1); non-Hodgkin's lymphoma (1); pineoblastoma (1); and primitive neuroectodermal tumor not otherwise specified (2). Pretreatment imaging studies demonstrated recurrent intracranial parenchymal disease in nine, spinal disease in four, and abnormal radioisotope ventriculography in six. Systemic disease was seen in four children (3 leukemia; 1 non-Hodgkin's lymphoma). All children were treated with systemic chemotherapy and intraventricular chemotherapy. Nine children received radiotherapy to bulky or symptomatic leptomeningeal disease. Median survival was 6 months (range, 4-18 months). Children with hematologic malignancies had superior outcomes compared to children with solid tumors. Three children with leukemic or lymphomatous meningitis are alive and disease free whereas all children with carcinomatous meningitis died. In conclusion, leptomeningeal metastases in children portends a limited survival, and therapies at this time remain palliative except in children with hematologic malignancies.

Carcinomatous meningitis in solid tumours

Carcinomatous meningitis (CM) is an uncommon but devastating complication of malignancy. The management is controversial and clear recommendations cannot be made because: 1) Most series include patients with CM that has arisen from different primary malignancies which are associated with different median survival intervals. 2) There have been no prospective randomised investigations of treatment modalities in patients with CM from a particular tumour type. 3) The definition of response varies from one report to another so that some response rates refer to cytological changes in the CSF while others take clinical, cytological and biochemical parameters into account. 4) Reports include patients with and without parenchymal metastases and the natural history of carcinomatous meningitis in the two situations may differ. The median survival of solid tumour carcinomatous meningitis (excluding leukaemia and lymphoma) is approximately 2-3 months and patients with breast cancer have the longest survival (median 3 months). Currently patients are treated with radiotherapy to part or all of the neuraxis with either intrathecal or intravenous chemotherapy but the relative contribution of these modalities to survival or quality of life remains unknown. Approximately 50% of patients with carcinomatous meningitis die from other causes, including systemic disease. The two most important endpoints for the patient, neurological improvement and overall survival, are seldom used in isolation in the literature. Many reports have focused on surrogate markers of response, namely biochemical and cytological data points but the correlation between clinical status and these parameters is poor because of differences between lumbar and ventricular CSF and disturbances of CSF flow in CM. The current literature does not provide clear guidelines for the treatment of this condition. Multicentre, prospective, randomised trials should be conducted that address questions of most relevance to the patient, namely neurological status and overall survival.

Meningeal carcinomatosis in patients with breast carcinoma. Clinical features, prognostic factors, and results of a high-dose intrathecal methotrexate regimen

BACKGROUND

This retrospective study evaluates the results of a regimen of high-dose intrathecal methotrexate and the prognostic factors for the response in patients with meningeal from breast carcinoma.

METHODS

From 1979 to 1994, 68 breast carcinoma patients were diagnosed with meningeal carcinomatosis at a mean age of 52 years. All but two had previous metastatic involvement. The proportion of lobular and ductal carcinomas was balanced. Malignant cells were present in cerebrospinal fluid (CSF) samples from 61 patients, whereas the 7 remaining patients had increased CSF protein associated with computerized tomographic scan evidence of meningeal metastases. From 1989, 41 of the patients received a regimen of high-dose intrathecal methotrexate with systemic folinic acid rescue (HD-MTX+FA): intrathecal MTX, 15 mg daily x 5 days, repeated every 2 weeks, and intrathecal hydrocortisone acetate, 125 mg on Day 1, and folinic acid, 10 mg intramuscularly 12 hours after each MTX injection. Systemic treatment and radiation therapy were usually associated. Patients treated before 1988 received intrathecal MTX in conventional doses (15 mg once a week).

RESULTS

Clinical objective response, defined as a neurological improvement for at least one month, was achieved in 17 patients (41%) and stabilization in 14 (34%) treated with the HD-MTX+FA regimen. The response rate was significantly higher compared with that of the group treated with the conventional doses (P = 0.03). Median survival was 14 weeks for patients treated with the HD-MTX+FA regimen, compared with 7 weeks for patients who received conventional doses of MTX (P = 0.01). Grade 3 or 4 neutropenia was the main toxicity that occurred in 16 16 patients (39%) treated with the HD-MTX+FA regimen, and in 7 patients (33%) treated with conventional doses of MTX. In a univariate analysis, three parameters were singled out as having a favorable prognostic value for response to therapy; controlled systemic disease at diagnosis (P < 0.05), low initial CSF protein level (P < 0.05), and concomitant systemic chemotherapy during intrathecal therapy (P < 0.02). Multivariate analysis was not performed because the sample size was too small.

CONCLUSIONS

Although this study was retrospective, the intrathecal HD-MTX+FA regimen appears to be a more efficient strategy than conventional doses of MTX to induce neurologic improvement and perhaps better survival. It should be recommended in combination with systemic chemotherapy for selected patients with meningeal carcinomatosis from breast carcinoma who are likely to benefit from intensive therapy, i.e., patients with a CSF protein level less than 5 g/L and in whom systemic disease has been controlled.

A review of leptomeningeal metastases in pediatrics

Leptomeningeal metastasis is an uncommon problem in pediatric neurology and oncology. It occurs primarily in children with acute lymphoblastic leukemia and primary brain tumors. Although leptomeningeal metastasis may present with focal neurologic signs and symptoms, leptomeningeal metastasis is a disease affecting the entire neuraxis and necessitating an extent-of-disease evaluation of both the brain and spinal cord. Neuroradiographic staging of leptomeningeal metastases includes contrast-enhanced cranial computed tomography, magnetic resonance imaging, contrast-enhanced spine magnetic resonance imaging or computed tomographic myelography, and radionuclide cerebrospinal fluid flow studies. As a consequence of global neuraxis involvement, the treatment of leptomeningeal metastases requires therapy directed at all cerebrospinal fluid compartments. The treatment of leptomeningeal metastases usually includes both radiotherapy and intra-cerebrospinal fluid drug therapy. Radiotherapy is directed to regions of bulky or symptomatic central nervous system disease. Intra-cerebrospinal fluid drug therapy, using one of three available chemotherapeutic agents (methotrexate, cytarabine, or triethylene thiophosphoramide), is administered by a variety of schedules and either by intralumbar or intraventricular drug delivery. Notwithstanding that the treatment of leptomeningeal metastases is palliative, with an expected patient survival of 6 months, it often affords stabilization and protection from further neurologic deterioration in children with leptomeningeal metastases in whom death is usually a consequence of progressive systemic or parenchymal brain disease.

Neurotoxicity and pharmacokinetics of ventriculolumbar perfusion of methyl 6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU) in dogs

Ventriculolumbar perfusion of methyl 6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU), a water soluble nitrosourea with log P -0.71, may be efficacious in the treatment of subarachnoid dissemination of malignant glioma. We used 2 dogs to study the neurotoxicity and pharmacokinetics of MCNU. MCNU (1 mg), dissolved in 10 ml of artificial CSF, was administered via the right lateral ventricle during a period of 18 to 42 min and the CSF was drained by lumbar puncture. The perfusion was repeated once a week for 10 consecutive weeks. No neurological and systemic symptoms were noted after perfusion. Histological examination of the brain and spinal cord showed local denudation of the ependyma and local subependymal spongy degeneration and gliosis in the lateral ventricle into which MCNU was administered in one dog and local denudation of the ependyma in the other. When administration was over a period of 21 to 38 min, the MCNU concentration in the lumbar CSF peaked at 11.11 to 50.67 micrograms/ml, in 28 to 78 min. The area under the drug concentration-time curve (AUC) was 1152 micrograms x min/ml on average, significantly larger than that of ACNU. The elimination phase followed linear kinetics and the half-time was 41.1 min on average, significantly longer than that of ACNU. These findings suggest that ventriculolumbar perfusion of MCNU may be effective in the treatment of subarachnoid dissemination of malignant glioma notwithstanding some local histological changes.

Pharmacokinetics of intrathecal 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride in rats

The pharmacokinetics of intrathecal 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) were studied in female Wistar rats by macroscopical autoradiography using 14C labeled ACNU. In normal rats, ACNU rapidly distributed in the subarachnoid space and ventricles after intracisternal administration. Diffusional transport into the brain tissue was limited to a depth of 1 or 2 mm from the cerebrospinal fluid (CSF) surface of the brain. Clearance of ACNU from the CSF space and brain was relatively fast and the half time of ACNU concentration at the cortical or ventricular surface was 10 min. In rats with leptomeningeal tumor induced by intracisternal inoculation of Walker 256 carcinosarcoma cells, the distribution pattern of ACNU after intracisternal administration was essentially the same as in normal rats until the tumor had grown in the subarachnoid space to form more than 10 or 20 layers of tumor cells. ACNU was distributed in the tumor as well. When the tumor had grown to form masses in the subarachnoid space, ACNU failed to penetrate to more than a depth of 1 or 2 mm from the tumor surface. Our results suggest that intrathecal ACNU administration may have no, or minor side effects on the brain and that it can eliminate floating or thin layered tumor cells in the subarachnoid space but not bulky tumors.

Ventriculolumbar perfusion of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitrosou rea hydrochloride

We report on the toxicity, intrathecal pharmacokinetics, and therapeutic effect of the ventriculolumbar perfusion of 3-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitros our ea hydrochloride (ACNU) against the subarachnoid dissemination of primary central nervous system tumors. Fifteen patients received ventriculolumbar perfusion of ACNU. One was treated with ventriculolumbar perfusion of ACNU alone, and the others underwent concomitant systemic chemotherapy; three of these patients received irradiation as well. ACNU was administered at an initial dose of 0.5 and was increased to 1.5 to 10.0 mg in six patients. Because of a lack of Level 2 or greater toxicity, the subsequent seven patients received 8.7 to 10.0 mg of ACNU dissolved in artificial cerebrospinal fluid (CSF) at a concentration of 0.1 mg/ml, from the start of the treatment. During ACNU administration, the lumbar CSF was drained at approximately the same rate as that of the infusion. Twelve patients received from 3 to 42 courses (average, 14 courses). The cumulative dose of ACNU ranged from 5 to 330.4 mg (average, 82.9 mg). One patient had a convulsion; two patients experienced transient headache, nausea, and vomiting; two others reported transient headache, nausea, vomiting, and fecal incontinence; and one experienced transient nausea, vomiting, and fecal incontinence. No side effects were noted in the other nine patients. When 9.0 to 9.5 mg of ACNU, dissolved in 90 to 95 ml of artificial CSF, was administered for 37 to 52 min, the maximum concentration of ACNU in the lumbar CSF was 9.86 to 12.79 micrograms/ml and the area under the drug concentration-time curve was 260.8 to 502.5 micrograms.min/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of intrathecally administered ACNU in mongrel dogs: pharmacokinetics and quantitative autoradiographic study

The pharmacokinetics of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) in the cerebrospinal fluid (CSF), were determined in dogs after ventriculolumbar perfusion (VLP, n = 6), and bolus injection into the ventricle (VB, n = 2), cisterna magna (MB, n = 5), and lumbar cistern (LB, n = 3), by high-performance liquid chromatography. The VLP method introduced effective amounts of ACNU into the lumbar cistern for cell kill in vitro. That is, the areas under the time concentration curve (AUC) of ACNU in the lumbar CSF for those receiving a 1.5 mg perfusion of ACNU were 481, 791, and 520 micrograms.min/ml and those receiving a 5 mg perfusion were 1,081, 2,048, and 1,215 micrograms.min/ml, respectively. These values were superior to 3-log cell kill condition of 9L gliosarcoma and 1.5-log cell kill of HU-126 human glioma cell line. Among the groups to which 5 mg of ACNU was administered, the VLP method attained significantly higher AUC values in the lumbar CSF than MB method. Quantitative autoradiography using an imaging plate system was performed in the VLP group (n = 2), VB group (n = 1), MB group (n = 2), and LB group (n = 2) using a 10 microCi/kg [ethylene-14C] ACNU dose which is thought to be related to the alkylating activity of ACNU. The VLP method attained a stable and abundant distribution of ACNU in the neural axis from the ventricular cavity to the lumbar cistern, but the cerebral convexity surface was devoid of a significant level of ACNU. When the MB method was used, the pharmacokinetic data varied in the cisterna magna and lumbar region, and again no significant level of ACNU was detected in the ventricular cavity. With the LB method, although a rich distribution was detected in the spinal cord, the concentration decreased abruptly at the upper cervical level. The VB method was unsatisfactory for obtaining an effective amount of ACNU in the lumbar region. The research and testing to date indicate that the VLP method is the procedure of choice in the treatment of meningeal dissemination.

Intrathecal chemotherapy with ACNU for meningeal gliomatosis

ACNU [1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride], one of the chloroethylnitrosoureas (CENUs), is believed to be effective against malignant glioma when intravenously or intrathecally administered. A rat model with meningeal gliomatosis (MG) induced by an intracisternal inoculation of rat C6 or 9L glioma cells was intrathecally and intravenously treated with ACNU in order to test the feasibility of intrathecal chemotherapy with ACNU in the treatment of meningeal gliomatosis. The median survival time (MST) of the animals was significantly prolonged when ACNU was intrathecally administered at dosages of 0.5 to 1.5 mg kg-1 in the early stages of MG, i.e. within 3 days after the tumour inoculation, whereas intravenous therapy with ACNU at a dose of 15 mg kg-1 did not exhibit any efficacy in the rats inoculated with C6 glioma cells (C6-MG). Intrathecal ACNU, however, at dosages of up to 1.5 mg kg-1 failed to demonstrate any therapeutic effect in the late stage of MG, i.e. 5 days after the tumour inoculation, except in the rats inoculated with 9L brain tumour cells (9L-MG). Intravenous chemotherapy with ACNU at a dose of 15 mg kg-1 extended the MST of the 9L-MG rats more significantly in the late stage of MG than in its early stage. This points to the feasibility of intrathecal ACNU in the treatment of meningeal gliomatosis in its early stages, but not in its late stages in which intravenous ACNU might be more effective than intrathecal treatment against MG of which the parenchyma has already been deeply invaded by the tumour.

Intrathecal chemotherapy with ACNU in a meningeal gliomatosis rat model

Intrathecal administration of ACNU ((1-4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitroso urea hydrochloride) had a remarkable chemotherapeutic effect in a rat model of meningeal gliomatosis. This effect was evaluated in rats with meningeal gliomatosis induced by an intracisternal inoculation of rat C6 glioma cells. The median survival time of the rats treated with a single dose of intrathecal ACNU (1 mg/kg) on Day 1 or Day 3 after tumor inoculation was significantly prolonged by 35.7% to 42.9% or 25.0% to 28.6%, respectively, as compared with that of the control animals. Meningeal gliomatosis rat models treated intrathecally with ACNU (1 mg/kg) 5 days after tumor inoculation or intravenously with ACNU (15 mg/kg) both failed to prolong the survival time of the animals. These findings suggest that intrathecal chemotherapy with a low dose of ACNU is effective in the early stages of meningeal gliomatosis, whereas intravenous chemotherapy with a high dose of ACNU is always ineffective.

Plasma and cerebrospinal fluid pharmacokinetics of cytosine arabinoside in dogs

Cytosine arabinoside (ara-C) is a component of many protocols for the treatment of CNS (central nervous system) leukemia and lymphoma in humans and dogs. It is also used for the prophylaxis of CNS metastasis in acute lymphoblastic leukemia. Although ara-C enters the cerebrospinal fluid (CSF) of human cancer patients after i.v. administration, it is unclear whether a similar CNS distribution occurs in humans whose blood-brain barrier has not been compromised by invasive disease. No information on the penetration of ara-C into the CSF in dogs is available. We studied the plasma and CSF pharmacokinetics of 600 mg/m2 ara-C in ten healthy male dogs after its administration as a rapid i.v. bolus (six dogs) or as a 12-h i.v. infusion (four dogs). Ara-C concentration in blood and CSF samples was determined by high-performance liquid chromatography (HPLC). After an i.v. bolus of ara-C, the mean plasma distribution half-life was 7.1 +/- 4.5 min and the mean elimination half-life was 69 +/- 28 min. The mean plasma clearance was 227 +/- 125 ml min-1 m-2. The peak concentration of ara-C in the CSF was 29 +/- 11 microM, which occurred at 57 +/- 13 min after the ara-C bolus. The CSF elimination half-life was 113 +/- 26 min. During a 12-h infusion of ara-C (50 mg m-2 h-1), the plasma steady-state concentration was 14.1 +/- 4.2 microM, the CSF steady-state concentration was 8.3 +/- 1.1 microM, and the CSF: plasma ratio was 0.62 +/- 0.14. The plasma elimination half-life was 64 +/- 19 min and the plasma clearance was 214 +/- 69 ml min-1 m-2. The CSF elimination half-life was 165 +/- 28 min. No clinically significant toxicity was observed over a 21-day period following drug administration in either of the treatment groups. Our data indicate that ara-C crosses the blood-brain barrier in normal dogs and that i.v. administration of this drug has potential as a treatment modality for neoplasia involving the CNS.

Phase I/II study of intraventricular and intrathecal ACNU for leptomeningeal neoplasia

A total of 27 patients with leptomeningeal neoplasia were treated with the water-soluble nitrosourea ACNU given intraventricularly or intrathecally in a phase I/II study. Patients were entered in the study if they showed evidence of either a positive CSF cytology or neurodiagnostic evidence of leptomeningeal disease, or both. Patients were evaluated for toxicity and efficacy; additionally, in 13 patients ACNU pharmacokinetic studies were carried out. A variety of tumor types were represented in the study group, including primary and metastatic CNS tumors. Toxicity was mild and included pain at the injection site (four patients), transient radicular symptoms at a short distance from the injection site (three patients), and nausea and vomiting (one patient). No myelotoxicity was seen. Of 21 patients who presented with positive cytology, 8 (38%) had a conversion from positive to negative cytology, with a range of response durations from 1 to 20+ months. Of the remaining six patients with negative cytology but other neurodiagnostic evidence of leptomeningeal disease, one patient showed an improvement seen on the myelogram and one underwent a brief reduction in CSF protein. ACNU elimination from the ventricular system is rapid, with a beta slope of 0.028 min-1 and a computed elimination constant, Ko of 13 min. The mean clearance was 3.8 ml/min (range, 1.0-6.2 ml/min). Peak ACNU levels varied between 108 and 620 micrograms/ml, with the AUC being 1.4-14.7 mg.min/ml. The total dose of ACNU given was between 9 and 104 mg, and the single dose range was 4-16.5 mg. We conclude that ACNU can be given safely with minimal toxicity as intra-CSF therapy, that it demonstrates efficacy in some patients with leptomeningeal disease, and that further studies are warranted to evaluate more fully alternative dosing and drug delivery approaches.

Intrathecal ACNU--a new therapeutic approach against malignant leptomeningeal tumors

Pharmacokinetics, toxicity and therapeutic efficacy of intrathecal ACNU, 3-[4-amino-2-methyl-5-pyrimidinyl)methyl)-1-(2-chloroethyl)-1-nitroso urea, were studied in rats to determine if it is a new and effective method for the treatment of malignant leptomeningeal tumors. Pharmacokinetics of intracisternally administered ACNU was studied by macroscopical autoradiography using 14C-labeled ACNU. It was demonstrated that intracisternally administered ACNU distributed in the subarachnoid space and subpial layer of the brain in high concentration and was rapidly eliminated into the systemic circulation. The diffusional transport of ACNU into the deeper part of the brain was limited. More than 3.0 mg/kg of intracisternal ACNU induced progressive loss of the weight of body in normal rats, and 80% of the rat given 6.0 mg/kg died. Increase of capillary permeability, neuronal loss and gliosis were observed in the marginal layer of the brain facing to the subarachnoid space in the rat given more than 3.0 mg/kg of ACNU. Systemic and local toxicity was not observed in the rat given less than 1.5 mg/kg. Therapeutic effect of intrathecal ACNU against leptomeningeal tumors was evaluated in the rat with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells. The median survival time of the rat treated with 1.5 mg/kg of intracisternal ACNU once on day 2 or on day 5 after tumor inoculation was significantly prolonged by 173%, and 214% at maximum, respectively, as compared with that of the untreated animal. These findings suggest that intrathecal ACNU may be of value for clinical trial against leptomeningeal tumors.

Extensive spinal necrosis with spinal leptomeningeal dissemination of cerebral astrocytoma. Case report

A 58-year-old male with malignant astrocytoma in the right parietal lobe developed ascending spinal dysfunction 15 months after subtotal resection of the primary lesion. He was treated by postoperative radiation and combined chemotherapy. Autopsy revealed extensive spinal necrosis affecting the level below the lower cervical region. Microscopic examination demonstrated diffuse leptomeningeal metastasis of glioma cells to the whole spine. There was no previous report in the literature of massive myelomalacia attributable to leptomeningeal dissemination an astrocytic supratentorial tumour. Clinical and neuropathological findings suggested that disturbance of venous drainage of the spinal cord might be responsible for myelomalacia in this case.

Exchange of cerebrospinal fluid in accidental intrathecal overdose of cytarabine

Intrathecal cytarabine (cytosine arabinoside) is included in many protocols for the treatment of acute lymphoblastic leukaemia of childhood. We report here the accidental administration of 200mg cytarabine intrathecally to a 4-year-old boy with CNS relapse. After the overdose the patient had dilated pupils during the first hour. One month later an unsteady gait and mild intention tremor in the hands were noted. By the exchange of cerebrospinal fluid with isotonic saline started 1 hour after overdose through a lumbar needle, about 27% of the administered dose was recovered. The estimated recovery in view of the time elapsed between overdose and start/end of the exchange procedure was 36%. This indicates that this procedure is of value in managing patients with heavy overdose of intrathecal cytarabine in hospitals without neurosurgical facilities.

Combined intraommaya methotrexate, cytosine arabinoside, hydrocortisone and thio-TEPA for meningeal involvement by malignancies

Twenty-three adult patients with meningeal involvement by a variety of malignancies were treated with the intra-Ommaya combination of methotrexate, hydrocortisone, cytosine arabinoside, and thio-TEPA. Whole brain irradiation was also administered to most patients who had not previously received it. Most patients demonstrated improvement of cerebrospinal fluid parameters, but only 50% of the patients experienced neurological improvement. Patients who did not receive cranial irradiation and performance status 4 patients were less likely to respond than were patients who did receive cranial irradiation as part of their treatment and patients who were performance status 0-3. Four patients developed possible and 2 patients developed probable or definite serious neurological complications. Another 4 patients developed less severe, reversible neurological toxicity. It is possible (but still uncertain) that this regimen is more toxic than other less intensive regimens, and further studies should be undertaken cautiously.

Pyrimidine pathways enzymes in human tumors of brain and associated tissues: potentialities for the therapeutic use of N-(phosphonacetyl-L-aspartate and 1-beta-D-arabinofuranosylcytosine

The activities of aspartate transcarbamylase (de novo pyrimidine biosynthesis pathway) and of deoxycytidine kinase as well as deoxycytidine deaminase (salvage pyrimidine biosynthesis pathway) were determined in extracts prepared from 40 brain tumors of different types in comparison with extracts from normal nervous tissues. Aspartate transcarbamylase, which is undetectable in normal brain tissue, is present in all tumor samples and in some cases rises to very high activities. Deoxycytidine kinase activity is present in all tissues but its level is generally higher in tumors. Deoxycytidine deaminase is present in all the tissues which were analyzed, although its activity is lower in some of the tumor samples. 1-beta-D-Arabinofuranosylcytosine is a substrate for both deoxycytidine kinase and deaminase in all the samples used except one. These results suggest some potential for the utilization of 1-beta-D-arabinofuranosylcytosine and N-(phosphonacetyl)-L-aspartate in the treatment of brain tumors.

Spinal metastases of cerebral glioblastoma: the value of computed tomographic metrizamide myelography in the diagnosis

Spinal metastases from cerebral glioblastoma via the cerebrospinal pathway are rarely detected when the primary tumors are under apparent control. The authors report two adult patients with cerebral glioblastoma who developed spinal symptoms referable to spinal seeding without neurological and computed tomographic findings of the recurrence of the primary tumors. Computed tomographic metrizamide myelography clearly revealed minute deposits of perispinal metastatic tumors that could not be detected by conventional myelography. Even perispinal mass lesions so minute that they are revealed only by computed tomographic metrizamide myelography can invade the spinal cord and cause clinical symptoms.

Improvement in survival produced by sequential therapies in the treatment of recurrent medulloblastoma

Thirty-six patients with recurrent medulloblastoma were treated with various combination chemotherapy protocols after initial treatment (usually irradiation) failed. Use of systemic chemotherapy was limited by depressed bone marrow reserves secondary to previous craniospinal irradiation. Intraventricular and intrathecal therapies included cytosine arabinoside (Ara-C), methotrexate, and thio-tepa given as single agents. Major systemic agents used alone or in combination included CCNU, procarbazine, vincristine, and the hexitol epoxides. Patients were reirradiated with or without misonidazole when there was definite tumor progression after all other therapies failed and/or because myelosuppression was so severe that further chemotherapy was not possible. Sequential systemic or intrathecal chemotherapy and reirradiation produced median survivals of two years and 25% quartile survivals of 2.9 years. The prognosis for patients harboring recurrent medulloblastoma has improved considerably over the years because of the therapeutic approaches reported here.