Developments in a new system of brachytherapy for tumours of the eye are reported. This involves the use of 125I sources with special screens and filters to avoid irradiation of vital structures and to produce a homogeneous radiation field. Methods for the treatment of tumours of the lids, conjunctiva, retina, choroid and lachrymal gland have been developed. Sixteen out of 20 treatments appear to have been successful. This system would seem to be a material advance on those previously reported.
125I has an energy of 27-35 keV which permits highly effective screening and makes it eminently suitable for treating ophthalmic tumours. It was first used for this in 1974 (Sealy et al., 1976), and since then a flexible system has been developed to treat a variety of such tumours including localized retinoblastoma. A gold foil backed plaque is custom built to cover the tumour(s). The turned edges reduce the dose and thus protect vital adjacent structures such as the optic nerve and lens. The iodine seeds are sealed in the plaque in a predetermined position to give the required dose. A range of doses and times have been used but the authors now aim to give a TDF of 100 to the apex of the tumour in two to three days. Ten tumours in the remaining eye of seven patients with bilateral retinoblastoma were treated. The size ranged from 3 X 3 X 2 to 10 X 10 X 6 mm. There were nine complete responses from 17-90 months and a partial response in one patient who died of metastases at ten months. Vision was maintained in all. Eight recurrent tumours in seven patients were also treated together with a subsequent new tumour in one of the patients. There were three complete responses at 28-39 months and six tumours persisted. Vision was maintained in three of seven patients. The only complication was a vitreous haemorrhage which was mild in two patients, moderate in one patient and severe in three previously treated patients. These latter three patients subsequently had the eye enucleated and were found to have recurrent tumour.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.