RADIATION RISKS TO PERSONNEL AND PUBLIC DURING THE TREATMENT OF MALIGNANT GLIOMA USING INTERSTITIAL BRACHYTHERAPY

I-125 seeds are used in brachytherapy for the treatment of malignant g liomas. The use of such radioactive sources is associated with a certa in radiological hazard to both personnel and members of the public. Th is hazard should be quantified so that the ALARA principle of radiolog ical protection may be implemented satisfactorily. A study was underta ken to derive isodose rate contours in the vicinity of an anthropomorp hic phantom with I-125 seeds positioned at typical tumour sites within the cranial cavity. These contours are illustrated for seed positions appropriate to deep and superficial temporal tumours. Results indicat e that the annual doses to personnel and public should not exceed thos e recommended by the International Commission on Radiological Protecti on.