OCULAR TUMOURS

Radiotherapy has made major advances in recent years in offering a viable treatment modality to patients with ocular tumours that were once deemed inoperable, according to Leonidas Zografos, who delivered this year’s EURETINA Medal Lecture as part of the official Opening Ceremony at the 13th EURETINA Congress. In a broad overview of the past, present and future of radiotherapy treatments in ocular oncology, Prof Zografos, Honorary Professor of Ophthalmology and consultant at the Jules-Gonin Eye Hospital, Lausanne, Switzerland, told delegates that technology has come a long way since the pioneering German ophthalmologist Richard Deutschmann’s first successful treatment of uveal melanoma in 1915 with seven episcleral applications of filtered mesothorium.

While the earliest treatment for uveal melanoma was removal of the eye, this has now been supplanted by radiotherapy as the standard of care for patients with uveal melanoma, offering preservation of an intact eye and, in many cases, preservation of visual function, said Prof Zografos. Discussing other key moments in the history of the development of radiotherapy for ocular tumours, Prof Zografos highlighted the research of R Foster Moore, H B Stallard, and Martin and Reese, among others, in ushering in the modern treatment of ocular tumours.

While ocular brachytherapy has made major strides in recent years, there are still treatment limitations in terms of tumour height, position and shape, said Prof Zografos. Much of Prof Zografos’ lecture focussed on the breakthrough provided by proton beam irradiation of intraocular tumours. At present there are more than 10 major units worldwide performing this type of therapy, with an estimated 25,000 to 30,000 cases of uveal melanoma now performed. Over 6,000 cases have now been carried out at the Swiss treatment centres alone, said Prof Zografos.

Survival rates with this type of therapy are excellent. After 10 years, local tumour control is 98.8 per cent and eye retention probability around 95.6 per cent, he said. The broad aim of the treatment is to prevent the recurrence of the tumour, said Prof Zografos. “If the recurrence occurs during the first two years, the mortality rate is almost 75 per cent, and if the recurrence occurs after the first two years the mortality rate is about 40 per cent, much more than the normal mortality rate without recurrence. So recurrence of the tumour is an extremely serious complication. With proton beam irradiation we have succeeded in reducing the recurrence rate to 1.2 per cent which is extremely low,” he said.

While proton beam irradiation represents a step forward in the treatment of uveal melanoma, there is always scope for further progress, said Prof Zografos. “The key challenges are the reduction of tumour-related mortality rate, the reduction of the irradiation-induced side-effects and the preservation of a low tumour recurrence rate,” he said. Putting the evolution of radiotherapy in the treatment of ocular tumours over the past century into context, Prof Zografos quoted the Greek statesman and orator Demosthenes: “Bad things of the past benefit the future and this applies to our patients as well,” he concluded.