VALUTAZIONE DELLA TOSSICITA OCULARE E STUDIO DELLE VIE OTTICHE. SU 13 PAZIENTI AFFETTI DA GLIOMA CEREBRALE MALIGNO SOTTOPOSTI A CHEMIOTERAPIA INTRAARTERIOSA CON CARBOPLATINO ED ETOPOSIDE

Early trials using selective intra-arterial drug administration for the chemotherapy of malignant brain gliomas caused unacceptable levels of neurological toxicity, with particular damage to the optic nerves. In vitro studies combining carboplatin, derived from cisplatin, with etoposide, a semi-synthetic derivative of podophyllotoxin, showed an elevated cytotoxicity to glial cells and synergy in reducing the intrinsic drug-resistance of glial tumour cells. There is considerable evidence of fewer systemic and neurological side effects of this combination given by selective intra-arterial route. This paper assesses specific damage to the optic nerves and central optic pathways caused by this chemotherapy. Thirteen patients with malignant brain glioma who received at least four cycles of subophthalmic intraarterial chemotherapy underwent full objective and subjective eye tests (visual field examination, ocular tonometry, examination of the fundus and intrinsic and extrinsic ocular motility; assessment of visual acuity, sensitivity to contrast and colour sense). All patients underwent MR imaging with paramagnetic contrast medium to disclose involvement of the optic pathways which would account for visual changes detected in the eye tests. Our findings show that carboplatin associated with etoposide do not affect the central and peripheral optic pathways. Chemotherapy can be administered by subophthalmic injection into the carotid arteries to perfuse large areas of brain tissue and enhance the possibility of the drugs reaching the infiltrating tumour cells at some distance from the tumour mass.