Medulloblastoma in childhood: revisiting intrathecal therapy in infants and children

INTRODUCTION

Intrathecal chemotherapy is being explored in medulloblastoma in pre-school children as part of brain-sparing strategies and as an alternative to unacceptably neurotoxic cranio-spinal radiotherapy. The range of drugs suitable for this route of administration is restricted by the lack of research evidence of pharmacological suitability and efficacy of other drugs in medulloblastoma.

METHODS

Ideal clinical, biological, physicochemical and pharmaceutical properties for intrathecal administration were defined through literature review of pharmaceutical texts, Medline, Embase and consulting the manufacturers. A total of 126 chemotherapy agents were assessed against these criteria by searching the academic domain of pharmaceutical texts, computer databases and consultation with manufacturers.

RESULTS

Of the 126 candidate drugs, 99 were rejected because of documentation of their irritant nature, neurotoxicity and requirement for hepatic activation in standard pharmaceutical texts. Fifty were rejected for a single identifiable reason including, neurotoxicity (n = 24), irritant (n = 15), needs enzyme activation (n = 5), clinical evidence of intrathecal neurotoxicity (n = 4) and no evidence of tumour-specific efficacy (n = 2). Where two reasons were cited the justifications were: neurotoxic and irritant (n = 3) and needs activation and systemic administration results in equivalent concentration (n = 1). Twenty-seven drugs remained of which 12 were selected as eligible for further clinical investigation, and 15 were selected for further pre-clinical investigation.

CONCLUSIONS

The pre-determined criteria were not applicable, in their entirety, in the majority of drugs, due to lack of information in the academic domain, emphasising the importance of a more open approach for sharing basic drug information. The prioritised list of 12 candidate drugs for clinical trial and 15 for pre-clinical investigation justify that a concerted research effort in this area of practice is made.

Successful treatment of invasive mould infection affecting lung and brain in an adult suffering from acute leukaemia

We describe in detail a 67-yr-old woman who was treated with a cytostatic combination chemotherapy for newly diagnosed common-acute lymphoblastic leukaemia. At the end of induction therapy, the patient acquired invasive mould infection affecting lung and brain. The patient entered complete remission of her leukaemia. Treatment with liposomal amphotericin B was initiated along with surgical excision of the fungal brain abscess. Intrathecal instillation of amphotericin B deoxycholate was started using an Ommaya reservoir because of an anatomical connection between the postoperative cavity and the ventricle. Full dose cytostatic chemotherapy was continued with little delay. A computerised tomography scan of the chest performed 2 months later revealed no fungal abscesses. Magnetic resonance imaging of the brain did not reveal any fungal manifestation. During maintenance therapy/week 69, the patient relapsed from leukaemia. High doses of intravenous liposomal amphotericin B were administered prophylactically. The patient's leukaemia proved refractory to reinduction chemotherapy and the patient died from pneumonia 8 wk later. Post mortem microbiological investigation and histopathological examination of lung and brain tissue did not reveal any macroscopical or microscopical fungal manifestations. This case underlines the feasibility and successful application of combined antileukaemic, antifungal and surgical therapy in a patient with acute leukaemia.

Advanced ovarian dysgerminoma with cure of tumor persistent in meninges

Isolated meningeal recurrence of ovarian cancer is uncommon. It is generally assumed that such cases are not accompanied by prolonged survival. We report the cure of a patient with advanced ovarian dysgerminoma who developed febrile carcinomatous meningitis 2 weeks after receiving her fifth course of combination chemotherapy (5 months after initiation of chemotherapy). No parenchymal brain disease was identified. The persistence of disease in the leptomeninges is related to the ability of the blood-brain barrier to exclude chemotherapeutic agents. The patient responded to craniospinal radiation and remains free of disease 2 years after completion of treatment.

Ototoxicity of intracisternal gentamicin in cats

The intrathecal administration of gentamicin has been used to treat bacterial meningitis. However, the influence of this route of administration on the well-known ototoxic activity of gentamicin is unknown. This route of administration should facilitate access to the inner ear and should increase the ototoxic liability. The possible ototoxic and neurotoxic effects of intrathecally administered gentamicin (0.5, 1, 2, 4, 6, 10 mg/day) in cats were evaluated. Hearing thresholds were obtained by a noninvasive technique prior to and on the 7th and 21st days after the initiation of a seven-day dosage regimen. Histological examination of the organ of Corti was routinely done. Additionally, the vestibular organs of one animal on the 4 mg/day regimen were examined. The concentrations of gentamicin in the cerebrospinal fluid were also determined. The data indicate that the 2 mg/day dose may be very close to the threshold dose for ototoxicity when gentamicin is given by intracisternal administration.