Limitations of high dose intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) chemotherapy for malignant gliomas

Treatment of Malignant Gliomas: A New Approach

The aim of this study is to describe the authors’ experience with intra-arterial ACNU chemotherapy of malignant gliomas. The prognosis of cerebral malignant gliomas remains poor, whatever traditional therapy is applied. ACNU is a well tolerated nitrosourea with a strong antimitotic effect on neurogenic cells both in vitro and in vivo; this drug has enhanced efficacy when used at high concentrations, particularly as an intraarterial infusion. Seventy-six patients have been studied to date, 68 of whom are evaluable; these patients were treated by intraarterial infusion of ACNU (100 mg/m2) every 6 weeks, with a mean of 2.5 courses per patient. The objective response (OR) was 28% and analysis of pretreatment factors revealed that survival was influenced by histological grade, other types of therapy applied, and age. In general IAC is well tolerated and the response and survival appear to be better than with systemic chemotherapy.

Ocular toxicity and cancer chemotherapy. A review

BACKGROUND

Systemic anticancer therapies can produce acute and chronic organ damage, but the eye is usually considered a protected site. Nonetheless, the oculo-visual system has a potentially high degree of sensitivity to toxic substances. Ocular toxicity induced by cancer chemotherapy includes a broad spectrum of disorders, reflecting the unique anatomic, physiologic, and biochemical features of this essential organ.

METHODS

A review of the literature regarding the ocular toxicity of chemotherapeutic agents, hormonal agents, biologic agents, and high dose chemotherapy with allogeneic and autologous bone marrow transplantation was conducted.

RESULTS

Ocular toxicity induced by anticancer chemotherapy is not uncommon. The development of more aggressive regimens as well as new agents and combination chemotherapies have resulted in a significant increase of reported cases of chemotherapy-induced ocular side effects. In most instances, the mechanisms of ocular toxicity continue to be poorly understood.

CONCLUSIONS

Ocular toxicities induced by chemotherapeutic agents are generally not preventable; therefore, clinicians must be aware of potential vision-threatening complications. Prompt consultation with an ophthalmologist can lead to early detection, proper diagnosis, and appropriate therapeutic measures. Dose reduction or discontinuation of incriminated drugs may help in reducing the severity and the duration of side effects.

A comparison of intraarterial carboplatin and ACNU for the treatment of gliomas

BACKGROUND

Intraarterial chemotherapy with carboplatin for malignant gliomas has been tried recently, but its therapeutic efficacy and toxicity have not yet been elucidated.

METHODS

We treated patients with malignant glioma by intraarterial chemotherapy using carboplatin, and compared the efficacy as well as the side effects with intraarterial ACNU.

RESULTS

Twenty patients were treated with carboplatin (300 mg/m2) and 22 patients were treated with ACNU (80-200 mg/m2). Response (complete remission+partial response) rate for carboplatin was 12.5% compared to 45% for ACNU. Despite higher response rate for ACNU, the difference in the survival curves of the two groups was not significant. Three patients who were treated with high dose (150-200 mg/m2) of ACNU developed hemiparesis and aphasia. Seven patients treated with carboplatin developed 10 incidences of neurotoxicities; two hemiparesis, one aphasia, one blindness, one visual field disturbance, three convulsions, and two developed incidences of disturbances of consciousness.

CONCLUSIONS

Intraarterial carboplatin was not superior to intraarterial ACNU in achieving remissions, and showed much greater tendency to produce neurotoxicities.

Delivery of a novel nitrosourea, MCNU, to the brain tissue in glioma-bearing rats. Intracarotid versus intravenous infusion

We observed the tissue delivery of a novel water-soluble nitrosourea, 1-(2-chloroethyl)-3-(methyl-alpha-D-glucopyranos-6-yl)-1-nitros our ea (MCNU) in rats bearing experimental brain tumors by conducting autoradiography on all. Prior to this study, the development of a streaming phenomenon was ascertained (and thus finding the optimum velocity for intra-arterial infusion) by 14C-iodoantipyrine (IAP) autoradiography. Furthermore, a single pass extraction value of MCNU was measured. At an arterial infusion rate of 0.2 ml/min., the streaming phenomenon was recognized but the tracer was fairly evenly distributed at a rate of 1.0 ml/min. On the other hand, the single pass extraction value for MCNU was 0.18 +/- 0.036 (mean +/- S.D., n = 3, under pentobarbital anesthesia). It was suggested that MCNU is very unlikely to be transported into the normal rat brain. We conducted 14C-MCNU autoradiography to observe tissue distribution of MCNU following its intra-arterial and intravenous infusions in a brain tumor model using rats. The normal side (the side where no infusions were given) and the cerebral cortex at the side affected by the tumor (the side where the infusion was given) showed hardly any uptake of 14C-MCNU in both the intra-arterial and intravenous infusion groups. The tumorous section was divided into the periphery and the center to measure tissue concentration of the tracer in each section. Compared against the cortical section, the periphery and the center showed significant increases in the concentration (approximately 11 to 15 times and 3 to 7 times, respectively, the figure for the cortical region) for both the intra-arterial and intravenous groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized comparison of intra-arterial versus intravenous BCNU, with or without intravenous 5-fluorouracil, for newly diagnosed patients with malignant glioma

This Phase III trial tested the efficacy and safety of intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) for the treatment of newly resected malignant glioma, comparing intra-arterial BCNU and intravenous BCNU (200 mg/sq m every 8 weeks), each regimen without or with intravenous 5-fluorouracil (1 gm/sq m three times daily given 2 weeks after BCNU). All patients also received radiation therapy. A total of 505 patients were randomly assigned within the study. Fifty-seven patients were excluded, primarily because of neuropathology error, and the remaining 448 patients constituted the Valid Study Group. Of the total 505 patients, 190 patients could not receive intra-arterial BCNU and 315 patients were randomly assigned to receive intra-arterial (167 patients) and intravenous (148 patients) BCNU. Actuarial analysis (log-rank) demonstrated reduced survival for the intra-arterial group (p = 0.03). Serious toxicity was observed in the intra-arterial group; 16 patients (9.5%) developed irreversible encephalopathy with computerized tomography evidence of cerebral edema, and 26 patients (15.5%) developed visual loss ipsilateral to the infused carotid artery. Administration of 5-fluorouracil did not influence survival. The survival rate between the intravenous and the intra-arterial BCNU patients with glioblastoma multiforme did not differ, but was worse for intra-arterial BCNU patients with anaplastic astrocytoma than for those receiving intravenous BCNU (p = 0.002). Neuropathologically, intra-arterial BCNU produced white matter necrosis. It is concluded that intra-arterial BCNU is neither safe nor effective in prolonging survival when administered by the methods used in this study of newly diagnosed patients with malignant glioma.

Alternating sequential intracarotid BCNU and cisplatin in recurrent malignant glioma

The authors entered 43 patients with recurrent malignant glioma in a trial of alternating sequential intracarotid BCNU and cisplatin. Protocol design was alternating courses of BCNU (2 doses, 300 to 400 mg each) and cisplatin (2 doses, 150 to 200 mg each) each at 4-week to 6-week intervals. Eight of 40 patients (20%) evaluable after the first course of BCNU showed partial or minor response. Only 18 patients were evaluable after the first course of cisplatin, and 5 were evaluable after the second course of BCNU. Median survival was 9 months (range, 2 weeks to 6 years). Cerebral or ocular toxicity unique to this method of chemotherapy administration and failure to show clinical improvement were the most common reasons for removal from study. Because of the high attrition rate, the authors were unable to determine a meaningful response to alternating sequential BCNU and cisplatin or to test the clinical degree of cross-resistance to these agents in human malignant glioma.

Intravascular streaming during carotid artery infusions. Demonstration in humans and reduction using diastole-phased pulsatile administration

Intra-arterial carotid artery chemotherapy for malignant gliomas is limited by focal injuries to the eye and brain which may be caused by poor mixing of the drug with blood at the infusion site. This inadequate mixing can be eliminated in animal models with diastole-phased pulsatile infusion (DPPI) which creates 1-ml/sec spurts during the slow blood flow phase of diastole. Before treatment with intracarotid cisplatin, 10 patients with malignant gliomas were studied to determine whether intravascular streaming occurs after intracarotid infusion in humans, and if so, if it is reduced with DPPI. Regional cerebral blood flow (rCBF) studies were performed by intravenous injection of H2(15)O and positron emission tomography. This was followed by supra- or infraophthalmic internal carotid artery (ICA) injections of H2(15)O with either continuous infusion or DPPI. Local H2(15)O concentration in the brain was determined and the images of radiotracer distribution in the continuous infusion and DPPI studies were compared to the rCBF images. Intravascular streaming of the infusate was identified by a heterogeneous distribution of the infused H2(15)O in brain compared to rCBF. Extensive and variable intravascular streaming occurred in three patients who received infusions into the supraophthalmic segment of the ICA. Some brain areas received up to 11 times the expected radiotracer delivery, while other regions received as little as one-tenth. This streaming pattern was markedly reduced or eliminated by DPPI. In the five patients who received infraophthalmic infusions, a minimally heterogeneous distribution of the infusate was detected. The authors conclude that extensive intravascular streaming accompanies supraophthalmic ICA infusions in patients. The magnitude of streaming can be substantially reduced or eliminated with DPPI. Those who perform intra-arterial infusion should consider using DPPI to assure uniform drug delivery to brain.

Ocular complications of systemic cancer chemotherapy

Cancer chemotherapy has changed rapidly in recent years. New agents are constantly being developed. Established agents are being used with increased frequency, in new combinations, at higher dosages, and via new routes of administration. Enhanced survival, as well as increased drug toxicity, has resulted. Ocular toxicity is not uncommon and can greatly impact on quality of life. Practitioners in all fields are increasingly caring for patients who are receiving cancer chemotherapy. The recognition of eye disease resulting from chemotherapy is essential to appropriate patient management. We provide a review of the rapidly growing body of literature on the ocular toxicity of systemic cancer chemotherapy with particular attention to context, clinical course, mechanism, prevention and treatment.

Mixing in the human carotid artery during carotid drug infusion studied with PET

The safety and efficacy of drug infusion into the carotid artery require adequate mixing of the infused solution with carotid blood. Using positron emission tomography (PET), we studied the mixing of solutions infused into the human carotid artery in seven patients by analyzing the distribution of [15O]H2O infused into the carotid artery and by vein. At four infusion rates ranging from 0.5 to 10 ml/min, the variability in distribution averaged 16.5-17.8% among the pixels in a large volume of interest, without dependence on the infusion rate. The overall correlation between [15O]H2O influx with arterial infusion and [15O]H2O influx with venous injection was 0.78-0.82 at the four infusion rates, with no trend toward higher correlations at the faster infusion rates. The distribution into the anterior, middle, and posterior cerebral artery territories differed from distribution throughout the entire carotid territory by an average of 6.2-9.6% at the four infusion rates, with no trend toward smaller differences at the faster infusion rates. Infusions performed into a vinyl tube simulating the carotid artery indicated that at 0.5 ml/min, the velocity of fluid exiting the catheter makes no apparent contribution to mixing. We conclude that with infusions at the carotid bifurcation, mixing in the human carotid artery is complete or nearly complete over a wide range of infusion rates. The mixing appears to result from the patterns of blood flow within the artery, and not from jet effects at the catheter tip.

Fatal necrotizing encephalopathy complicating treatment of malignant gliomas with intra-arterial BCNU and irradiation: a pathological study

We describe the neuropathologic findings at autopsy in six patients who developed a progressive encephalopathy complicating the treatment of malignant gliomas with combined intra-arterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and cerebral irradiation. Four brains were free of tumor and one contained a microscopic focus of residual glioma. In only one case was there evidence of tumor progression. A disseminated process characterized by miliary foci of necrosis with mineralizing axonopathy was present in all cases, restricted to the internal carotid distribution of the perfused hemisphere and involving primarily though not exclusively the white matter, which was diffusely and severely edematous. This was combined in 3 cases with a histologically dissimilar, massive necrotizing leukoencephalopathy indistinguishable from pure radionecrosis. Much of the toxicity of this therapy is mediated by vascular injury, but the disseminated necrotizing lesion probably reflects, at least in part, direct neural damage.

Pathology of high-dose intraarterial BCNU

Current radiotherapy and chemotherapy for high-grade and/or recurrent astrocytomas result in only moderate increases in survival time. In an attempt to improve this, high-dose intraarterial 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) was utilized on 41 patients with these neoplasms over a 4-year period at our institution. Eight of the 41 patients came to biopsy or autopsy at times sufficiently following intraarterial BCNU infusion and with adequate tissue samples to evaluate the histological changes induced by the drug. Two of the eight patients received no additional radiotherapy or chemotherapy. The other five received conventional whole brain irradiation, and one additionally received 50 mg of intravenous 2-deoxy-5-fluorouridine (FUdR). The eight patients showed mild to severe amounts of bland coagulative necrosis, vascular hyalinization, perithelial fibroblastic proliferation, and endothelial atypia. One of these patients had a recognized severe clinical leukoencephalopathy, and the pathological changes were maximal in this individual. Six patients had radiological evidence of increased necrosis and clinical deterioration prebiopsy or preautopsy, but, within this group, there were no distinguishing clinical features. Microscopic changes were severe in two of these patients. A final patient died of unrelated septic shock 5 days after a single infusion of intraarterial BCNU, and the microscopic changes were least extensive in her. This study suggests that high-dose intraarterial BCNU can cause a leukoencephalopathy, sometimes severe, either alone or in synergistic fashion with cranial irradiation. Occurrence of such leukoencephalopathy is not always predictable based on BCNU dosage and cannot always be reliably distinguished from tumor regrowth or tumor necrosis by radiological and clinical evaluation. Hence, caution most be exercised in continuation of high-dose intraarterial BCNU protocols.

Intracarotid cisplatin chemotherapy for recurrent gliomas

Forty patients with recurrent gliomas were treated with monthly intra-arterial infusions of cisplatin. Of the 35 evaluable patients, 12 (34%) responded with computerized tomography (CT) evidence of a decrease in tumor size; in 14 (40%) the tumor stabilized on CT scans, and in nine (26%) the disease progressed. The median survival period was 35.0 weeks for the responders and 27.5 weeks for all 35 patients. The primary toxicities were renal (reversible alterations in creatinine clearance), otological (severe hearing loss in one patient), and likely neurotoxicity in one patient who had received bilateral infusions following contralateral tumor progression. The authors are now using this form of regional chemotherapy sequentially before and following radiotherapy in newly diagnosed cases.

Ocular complications after intracarotid BCNU for intracranial tumors

112 patients with intracranial tumors treated with intracarotid BCNU to a cumulative dose of 370 mg/m2 body surface have been examined retrospectively for ocular complications. Average follow-up was 494 days (range 5 months-5 years). The rate of ocular complications was 2.7%. There was 1 case of hemorrhagic glaucoma with amaurosis and an accompanying oculomotor palsy, 1 case of retinal branch artery occlusion combined with third nerve paresis and 1 case of oculomotor palsy.

Intravascular streaming and variable delivery to brain following carotid artery infusions in the Sprague-Dawley rat

Intracarotid artery infusions in animals are commonly performed in studies of the blood-brain barrier and in chemotherapy trials. Implicit in the analysis of these experiments is that the infusate will be distributed to the territory of the internal carotid artery in a manner that is proportional to blood flow. Fifteen Sprague-Dawley rats were studied to determine if poor infusate mixing with blood due to intravascular streaming occurred during intracarotid artery drug infusions and if it could be eliminated with fast retrograde infusion. In three experimental groups, a radiolabeled flow tracer--14C-iodoantipyrine (IAP)--was infused retrograde through the external carotid artery into the common carotid artery at slow, medium, and fast rates (0.45, 1.5, and 5.0 ml/min). In a control group, IAP was injected intravenously (i.v.). Local isotope concentrations in the brain were determined by quantitative autoradiography, and the variability of isotope delivery was assessed in the frontoparietal cortex, temporal cortex, and caudate putamen of all animals. Streaming phenomena were manifest in all selected anatomic areas after the slow and medium rates of intraarterial infusion. After fast intracarotid infusion or i.v. injection, there was uniform distribution of isotope in the same brain regions.

Carotid artery mixing with diastole-phased pulsed drug infusion

Focal injury to the brain or retina is a frequent complication of drug delivery to the internal carotid artery (ICA) and may be due to poor mixing of the drug with blood at the infusion site. Rhesus monkeys were studied to determine whether phased drug delivery during diastole from a modified pulsatile angiographic injector would improve drug mixing in vivo. A radiolabeled flow tracer, carbon-14-iodoantipyrine (14C-IAP), was injected into the ICA of three monkeys in 80-msec pulses, each ending at least 50 msec before the end of local diastole. Local isotope concentration in the brain was determined by quantitative autoradiography. The ratio of highest to lowest concentration was 1.86 +/- 0.26 (mean +/- standard deviation) in the frontoparietal cortex, 1.65 +/- 0.42 in the frontoparietal white matter, 1.89 +/- 0.28 in the temporal cortex, and 1.39 +/- 0.17 in the basal ganglia. These results were similar to recordings in three control animals that received intravenous 14C-IAP to demonstrate complete drug mixing (1.37 +/- 0.12, 1.41 +/- 0.11, 1.70 +/- 0.08, 1.22 +/- 0.24, respectively), and contrasted to findings in five animals which received continuous intracarotid infusions to demonstrate standard ICA drug delivery (4.54 +/- 2.07, 2.94 +/- 1.45, 5.43 +/- 3.57, 3.60 +/- 2.90, respectively). Pulsed intra-arterial infusion during diastole provides a technically simple method for improving intravascular drug mixing, and results in drug delivery to tissue capillaries that is proportional to blood flow.

Randomized phase III trial of single versus multiple chemotherapeutic treatment following surgery and during radiotherapy for patients with anaplastic gliomas

In 81 patients with anaplastic supratentorial gliomas, single versus multiple chemotherapeutic agents were selected for treatment following surgery and during radiotherapy in a prospective randomized study. Time to treatment failure and survival were not significantly enhanced by multiple agent chemotherapy, as administered in this study.

Influence of modes of ACNU administration on tissue and blood drug concentration in malignant brain tumors

The water-soluble nitrosourea compound ACNU is also lipid-soluble at normal physiological pH levels. It lacks toxic effects on vision that nitrosoureas occasionally produce following intra-arterial administration. In 28 cases of both primary and secondary malignant brain tumors, ACNU was administered at surgery or angiography by three different modes: intravenous injection in Group I (10 cases), intra-arterial injection via the carotid artery in Group II (11 cases), and intra-arterial injection via the carotid artery after opening the blood-brain barrier (BBB) by means of mannitol in Group III (seven cases). Tumor tissue and blood samples were taken serially at various time intervals after ACNU injection, and ACNU was measured by high-performance liquid chromatography. The time-concentration curve for ACNU was calculated in each case by the two- and one-compartment open models for determination of ACNU levels in blood and tissue, respectively. Pharmacokinetic parameters including biological half-life, blood and tissue levels (0-t minutes and 0-infinity minutes), total plasma clearance, and distribution volume of the beta phase were compared. Statistical analysis of tissue ACNU levels at 0-t minutes revealed higher concentrations in Group III patients than in Groups II and I: levels in Group II were significantly higher than in Group I. Mean biological half-life was 30.3, 23.0, and 38.5 minutes in Groups I, II, and III, respectively. Levels of ACNU were significantly increased in tumor tissue as well as in peritumoral tissue in one Group III patient with multiple metastatic anaplastic adenocarcinoma. In this series, treatment of malignant brain tumor by intra-arterial administration of ACNU produced significantly higher tissue levels of ACNU than did the systemic intravenous route.

Central neurotoxicity following intracarotid BCNU chemotherapy for malignant gliomas

Central neurotoxicity is reported in 5 of 16 patients with recently diagnosed anaplastic gliomas, who received intra-arterial BCNU (200 mg/M2/course) and also 2 in a series of 26 patients with recurrent gliomas similarly treated. Neurotoxicity was usually delayed, commencing several weeks following the second or third course. CT scans during central neurotoxicity represented 1 or more of 3 patterns: no change; increased low density area(s); and/or ipsilateral gyral enhancement and punctate calcification in the middle cerebral artery territory. In one clinicopathological correlation, coagulative necrosis of the white matter was observed, identical histologically to those changes recognized as delayed vascular events following radiotherapy. Cautious exploration of the various clinical factors that may contribute to this toxicity seems appropriate, as exploration of the potential benefits of regional chemotherapeutic infusions is undertaken.

Maculopathy associated with combination chemotherapy and osmotic opening of the blood-brain barrier

Eleven patients with intracranial malignant neoplasms underwent hyperosmotic opening of the blood-brain barrier by rapid mannitol infusion via the internal carotid or vertebral artery. Cyclophosphamide was administered intravenously preceding the mannitol infusion and methotrexate was infused after the mannitol via the same artery. Both the mannitol and methotrexate delivered via the carotid artery have direct access to the ipsilateral choroidal and retinal circulations. In these patients, retinal pigment epithelial changes eventually developed ipsilateral to the carotid infusions. The changes probably represent the toxicity of intraarterial methotrexate possibly potentiated by mannitol-induced opening of the blood-retinal barrier. Functional visual loss was minimal and was not a limiting factor with this therapeutic modality.

Interspecies scaling of regional drug delivery

Calculation of the pharmacokinetic advantage of regional drug administration requires knowledge of the relevant intercompartment transport parameter. In a lumped model this is the blood (or plasma) flow rate for intra-arterial drug infusion or the permeability-area product for intraperitoneal or intrathecal administration. It is suggested that the perfusion of many tissues and the intrinsic permeability of the peritoneal surface or the brain-cerebrospinal fluid interface are similar among mammals. This provides a clear allometric basis for interspecies scaling based on organ size or surface areas. Intra-arterial or intrathecal treatment of the brain or meninges is a particularly interesting problem because of the relatively large brain of humans and because increased folding results in a cortical surface area that is almost proportional to brain size. Major unresolved issues remain concerning the distributed character of the processes such as streaming of drug infused into an artery and nonuniform mixing of cerebrospinal fluid.

Intracarotid BCNU leukoencephalopathy

Intracarotid 1,3-bis(2-chloroethyl)-1-nitrosurea (BCNU) is now a frequently used chemotherapeutic agent for high-grade glial neoplasms. The toxicity from such therapy has not been well-documented. A 50-year-old man with a left frontoparietal grade 4 astrocytoma received three injections of intracarotid BCNU, 400 mg each, over a 2-month period. No radiation or other chemotherapy was ever given. He tolerated the BCNU injections well, with some reduction of tumor bulk, until the third dose. After his last injection, his condition gradually deteriorated; he became obtunded, and died 5 weeks later. At autopsy, the brain showed extensive cavitation and coagulative necrosis, fibrinoid vascular necrosis, edema, swollen axons, and bizarre cellular morphologic features confined to the BCNU perfusion territory. Grade 4 astrocytoma remained in the right hemisphere and in the left occipital lobe, sites outside the area of BCNU perfusion. Intracarotid BCNU can result in a severe leukoencephalopathy similar to that seen with methotrexate or delayed radionecrosis.

Superselective intracerebral chemotherapy of malignant tumours with BCNU. Neuroradiological considerations

Early experience shows that: Superselective intra-arterial catheterization above the ophthalmic artery minimizes the orbital complications. Catheterization in a distal branch may lead to the non-infusion of a part of the tumor territory. A much higher concentration of the drug is achieved by superselective intra-arterial infusion than by intravenous injection. Longer infusions seem more efficacious than bolus injection. Early trapping of the drug appears to be essential for therapeutic efficacy.

Drug streaming during intra-arterial chemotherapy

Treatment of brain tumors by intra-arterial (IA) chemotherapy is occasionally complicated by sites of focal toxicity in the brain and retina. A possible cause of focal toxicity is non-uniform drug delivery due to intravascular drug streaming. To investigate this phenomenon in vivo, the authors examined the distribution of drug delivery after internal carotid artery (ICA) infusion in rhesus monkeys. Carbon-14 (14C)-labeled iodoantipyrine was delivered into the ICA of eight monkeys at slow infusion rates (1% to 2% of ICA flow) or at fast infusion rates (20% of ICA flow) combined with additional techniques to promote mixing with ICA blood. Two monkeys received intravenous (IV) 14C-antipyrine. Uniformity of delivery was assessed by comparing high-to-low ratios of isotope concentration in four brain regions evaluated by quantitative autoradiography. There was striking non-uniformity of drug delivery in the slow IA infusion group, with as much as 13-fold differences in drug concentration in anatomically contiguous areas. The values of high-to-low concentration ratios (mean +/- standard deviation) in individual autoradiographic planes were: 1) frontoparietal cortex: slow IA infusion 4.54 +/- 2.07, fast IA infusion 1.71 +/- 0.31, IV infusion 1.30 +/- 0.174; 2) frontoparietal white matter: slow IA infusion 2.94 +/- 1.45, fast IA infusion 1.59 +/- 0.41, IV infusion 1.34 +/- 0.21; 3) temporal cortex: slow IA infusion 5.43 +/- 3.57, fast IA infusion 1.69 +/- 0.24, IV infusion 1.67 +/- 0.25; 4) basal ganglia: slow IA infusion 3.6 +/- 2.9, fast IA infusion 1.18 +/- 0.10, IV infusion 1.09 +/- 0.04. Differences between concentration ratios after slow IA and fast IA infusion are significant (p less than 0.01); those between fast IA and IV infusion are not significant. Intra-arterial drug administration at infusion rates analogous to those currently used clinically results in drug streaming with markedly heterogeneous drug deposition in the perfused hemisphere. This may cause suboptimal drug levels in the tumor, and toxic levels at sites within the perfused hemisphere. This effect can be abrogated by techniques that eliminate drug streaming.

Supraophthalmic carotid infusion with low dose cisplatin and BCNU for malignant glioma

Arterial infusion of select chemotherapeutic agents has been shown to deliver increased drug concentration to brain tumors with reduced systemic toxicity. In this study, nine patients with histologically confirmed malignant glioma received cisplatin 110 mg and BCNU 300 mg fixed dose. All patients had received standard doses of cranial radiation after their initial surgical procedures. In three patients, intraoperative modification of the cerebral circulation was accomplished prior to the actual infusion because the vascular supply of the tumor arose from major arteries other than a single internal carotid artery. Supraophthalmic catheterization technique was employed. No neurological deficits occurred post infusion. The radiographic response rate was 25%. No responses were seen in patients who received less than 69 mg/M2 cisplatin this combination. The longest survival is 11+ months in a patient with anaplastic astrocytoma. Our first thirteen patients received cisplatin 150-200 mg and BCNU 300 mg for each infusion with a response rate of 83% in evaluable patients. Since modest reduction in cisplatin dose dramatically reduced the response rate, future studies should be directed at fine tuning the dose of this drug, or at neutralizing recirculating drug after its high dose first pass through the arterial circulation.

Vascular diversion in chemotherapy of brain tumors

Of the patients with malignant gliomas treated by arterial infusion of chemotherapeutic agents at one institution, tumor extension beyond the territory supplied by a single internal carotid artery was documented at operation or by computed tomography or angiography in 55%. In 47% of the patients, a surgical procedure was performed to modify the cerebral circulation so that the entire lesion could be treated by infusing a single internal carotid artery. This report examines the anatomical and radiological background for these procedures, and the surgical options, techniques, and complications in this series of patients.

Intraarterial 1,3-bis(2-chloroethyl)-1-nitrosourea chemotherapy for the treatment of malignant gliomas of the brain: a preliminary report

In a clinical trial, 10 patients with malignant gliomas underwent partial resection of their tumors and were treated by intraarterial 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) chemotherapy. The drug was given at least 1 month after the completion of postoperative radiotherapy in total doses of 270-280 mg/m2 in two sessions separated by a 48-hour interval (the two sessions with interval were equal to one course). This therapy was repeated every 8-10 weeks. Four patients had three courses and the other six patients had two courses of chemotherapy. This therapy was the only antitumor chemotherapy for this group of patients. Our preliminary results demonstrate the safety of this new procedure and suggest that intraarterial BCNU chemotherapy may be more effective, and has a better tolerance and less toxicity, than intravenous BCNU chemotherapy. Furthermore, it was demonstrated that, in the case of one patient, higher antitumor activity resulted from intraarterial BCNU chemotherapy as compared to intravenous BCNU therapy.

Applications of monoclonal antibodies in the diagnosis and treatment of primary brain tumors

The development of monoclonal antibodies has resulted in marked expansion in understanding the central nervous system (CNS). This has been especially true in the study of human neuroectodermal tumors where monoclonal antibodies have been used as physiological probes to define and characterize human neuroectodermal tumor-associated antigens. Utilizing monoclonal antibodies, neuroectodermal tumor-associated antigens have been described in four broad categories; biochemically defined markers, shared nervous system-lymphoid cell markers, shared neuroectodermal-oncofetal markers, and putative restricted tumor markers. Preliminary data have demonstrated the ability to localize animal and human tumors in vitro, ex vivo, and in vivo. Early application of monoclonal antibody technology to neuroimmunology and neuro-oncology has resulted in a new awareness of the complex relationships that exist within the CNS. Their specificity and reproducibility may provide the means to qualitatively and quantitatively define the phenotypic heterogeneity of human neuroectodermal tumors. Potentially, monoclonal antibodies, alone or as carriers of radionuclides, drugs, or toxins, may allow successful diagnosis and treatment of human neuroectodermal tumors.

Aspiration of blood from the jugular vein during intracarotid drug infusion in monkeys. Implications for extracorporeal drug removal

Circulation of blood in the ipsilateral jugular vein through an extracorporeal circuit for drug removal during intracarotid chemotherapy has recently been reported to decrease the systemic drug exposure. The reduced systemic exposure achieved by the use of this technique should permit a several-fold increase of the intracarotid dose of chemotherapy without increasing systemic toxicity. To determine the influence of the rate of blood removal from the jugular vein on the fraction of the blood flowing through the ipsilateral internal carotid artery (ICA) collected for extracorporeal drug removal, the authors aspirated blood from the jugular bulb into an extracorporeal circuit at varying rates during a constant infusion of the indicator dye, indocyanine green (ICG), into the ICA of rhesus monkeys. The fraction of the ipsilateral carotid blood channeled into the extracorporeal circuit increased linearly with the rate of aspiration of jugular blood. This suggests that the absence of valves in the intracranial venous system should permit increasing fractions of drug removal during intracarotid infusion by increasing the rate of collection of venous blood from the ipsilateral jugular bulb. The measurement of ICG concentrations in a similar manner in patients undergoing isolated perfusion may prove to be a clinically useful method for estimating the maximum safe dose in high-dose intra-arterial chemotherapy.

Ocular and orbital toxicity following intracarotid injection of BCNU (carmustine) and cisplatinum for malignant gliomas

Eleven patients treated with intracarotid BCNU, cisplatinum, or BCNU and cisplatinum in combination for recurrent malignant gliomas were followed with serial ophthalmologic examinations for 2 to 11 months. Eight patients developed significant visual loss ipsilateral to the side of infusion. Secondary glaucoma and internal ophthalmoplegia were new complications observed after BCNU treatment. An unusual pigmentary retinopathy, previously unreported, was seen in patients treated with cisplatinum. One patient also developed a cavernous sinus syndrome after the intracarotid administration of cisplatinum.

Intra-arterial BCNU chemotherapy for treatment of malignant gliomas of the central nervous system

Because of the rapid systemic clearance of BCNU (1,3-bis-(2-chloroethyl)-1-nitrosourea), intra-arterial administration should provide a substantial advantage over intravenous administration for the treatment of malignant gliomas. Thirty-six patients were treated with BCNU every 6 to 8 weeks, either by transfemoral catheterization of the internal carotid or vertebral artery or through a fully implantable intracarotid drug delivery system, beginning with a dose of 200 mg/sq m body surface area. Twelve patients with Grade III or IV astrocytomas were treated after partial resection of the tumor without prior radiation therapy. After two to seven cycles of chemotherapy, nine patients showed a decrease in tumor size and surrounding edema on contrast-enhanced computerized tomography scans. In the nine responders, median duration of chemotherapy response from the time of operation was 25 weeks (range 12 to more than 91 weeks). The median duration of survival in the 12 patients was 54 weeks (range 21 to more than 156 weeks), with an 18-month survival rate of 42%. Twenty-four patients with recurrent Grade I to IV astrocytomas, whose resection and irradiation therapy had failed, received two to eight courses of intra-arterial BCNU therapy. Seventeen of these had a response or were stable for a median of 20 weeks (range 6 to more than 66 weeks). The catheterization procedure is safe, with no immediate complication in 111 infusions of BCNU. A delayed complication in nine patients has been unilateral loss of vision secondary to a retinal vasculitis. The frequency of visual loss decreased after the concentration of the ethanol diluent was lowered.

BCNU solubility and toxicity in the treatment of malignant astrocytomas

Administration of BCNU into the carotid artery as treatment for malignant astrocytomas has produced retinal and brain toxicity. It is unclear whether the BCNU diluent, ethanol, is the cause of the toxicity, but the elimination of the ethanol is an attractive possibility. Clinically, decreasing the ethanol from 2.0 ml/100 mg BCNU to 0.75 ml/100 mg BCNU resulted in a marked decrease in eye toxicity. To simulate this clinical situation, three 500-mg solutions of BCNU, ethanol, and saline were prepared, decreasing the ethanol concentration from 3.0 ml to 2.0 ml to 0.75 ml/100 mg BCNU. The amount of BCNU recovered in vitro after simulated clinical administration of the three solutions decreased from 84.9% to 38.3% as the diluent decreased. Therefore, drug delivery at a fixed BCNU dose will decrease with the amount of ethanol diluent used. The clinical decrease in eye toxicity must be partly attributed to a decrease in the amount of BCNU delivered to the retina. Simulated administration of a solution of 500 mg BCNU/150 ml of 5% dextrose in water (D5W) gave 83.7% BCNU recovery. The D5W gives solubility comparable to that provided by 3.0 ml ethanol to each 100 mg BCNU, and its use eliminates ethanol as a potential retinal and brain toxin.

The pharmacology of diaziquone given in intravenous or intracarotid infusion to normal and intracranial tumor-bearing puppies

Diaziquone (also called "aziridinyl benzoquinone," or AZQ), an antitumor drug designed to penetrate the blood-brain barrier, has demonstrated activity against central nervous system (CNS) neoplasms. Four-hour infusions of carbon-14 (14C)-labeled AZQ (0.8 mg/kg) were given via the left common carotid artery or left brachial vein to two groups of puppies. A third group, harboring a transplantable canine glioma, received 14C-AZQ by intravenous infusion. Levels of chloroform (CHCl3)-extractable 14C (AZQ only) and total 14C (AZQ and metabolites) were determined in serial samples of plasma and cerebrospinal fluid (CSF). At the end of the infusion time, total and CHCl3-extractable 14C levels were determined in brain and tumor. Intra-arterial infusion of AZQ caused no histological abnormalities in the retina or brain. For the intravenous infusion group, the concentrations of CHCl3-extractable 14C (in nmol/ml or nmol/gm) were 0.68, 0.35, and 0.84 for plasma, brain, and CSF, respectively. For the intra-arterial infusion group, the concentrations were 0.25, 0.13, and 0.32 for plasma, brain, and CSF, respectively. Comparison of right and left hemispheres following intra-arterial infusion showed a slightly higher concentration of 14C in the ipsilateral (left) hemisphere, with concentrations (nmol/gm) of CHCl3-extractable 14C/total of 14C of 0.15/0.87 on the left and 0.12/0.65 on the right. Concentrations (nmol/gm) of CHCl3-extractable 14C/total 14C in brain and tumor were 0.60/1.24 and 0.58/1.65, respectively. In tumor-bearing animals, tumor and surrounding brain contained similar concentrations of AZQ, but there were higher concentrations of metabolites in tumor. This may reflect different metabolism of AZQ within brain and tumor or different permeability to metabolites. This study revealed that AZQ enters the CNS and brain-tumor tissue in substantial concentrations and that there is no significant advantage to intracarotid infusion of AZQ.

Phase-I Trial of Intracarotid BCNU and Cisplatin in Patients with Malignant Intracerebral Tumors

Eighteen patients with progressive or recurrent intracerebral malignant neoplasms after cranial radiation therapy were entered in a phase-I trial of intracarotid bis-chloroethylnitrosourea (BCNU) and cisplatin. Thirty-six courses of varying doses of BCNU and cisplatin were infused intraarterially via a percutaneous, trasfemoral approach. Courses were repeated every 4-6 weeks upon patients' recovery from toxicity. Intraarterial cisplatin or BCNU alone was administered if the blood counts were still subnormal. CT scans and neurologic examinations were performed monthly. Major toxic effects included ipsilateral retinal (amaurosis) in 4 patients and neurologic toxicity in 2 patients (minor focal seizure, reversible obtundation in one patient, and transient hemiparesis in one patient). One patient was infused by a catheter inserted into the supraclinoid internal carotid artery and had no further visual deterioration and no major side effects. Tumor regression was observed in patients previously treated with radiation and/or systemic chemotherapy, including 4 of 9 who had recurrent malignant gliomas, and 2 of 9 who had metastatic tumors. Recommended dose for phase-II trials is BCNU 100 mg/m2 and cisplatin 60 mg/m2 every 4-6 weeks. Retinal and neurologic toxicity are possible side effects.

Supraophthalmic carotid infusion for brain-tumor chemotherapy. Technical note

The ocular complications of intracarotid infusion of drugs for brain-tumor chemotherapy may be eliminated by infusion of the chemotherapeutic agent into the carotid artery above the origin of the ophthalmic artery. The authors have developed a catheter that can negotiate the carotid siphon. This catheter is not balloon-tipped but incorporates a flexible tip with an expanded end to facilitate drag by flowing blood. The exit hole is placed to allow remote manipulation of the tip by hydraulic forces. Using this catheter, the authors have been consistently able to infuse the supraophthalmic carotid artery.