Aj. Churchill et al., AN ALTERNATIVE AND MORE COST-EFFECTIVE METHOD OF DELIVERY OF RADIOTHERAPY IN AGE-RELATED MACULAR DEGENERATION, British journal of ophthalmology, 82(4), 1998, pp. 373-375
Aims/background-In the past 5 years there has been a dramatic increase
in the use of radiotherapy to treat subfoveal neovascular membranes (
NVMs) in both Europe and the USA despite the high cost. An alternative
, more cost effective method of delivery using x ray simulation and bi
te block head fixation is described. Method-15 patients were recruited
with classic subfoveal NVMs. Head fixation was achieved with a custom
ised Perspex mask for eight patients and a bite block for seven. An x
ray simulator was used to check the field of irradiation. No computeri
sed tomography (CT) was performed. All patients received a total dose
of 13.3 Gy ionising radiation. Visual acuities were charted before and
after treatment over a 24 month period. Results-After 24 months, 5/8
(67%) in the mask group showed stable visual acuities (less than two l
ine change on Snellen chart) compared with 3/7 (43%) in the bite block
group. This difference may be attributed to a variation in the pretre
atment visual acuities in the two groups. From several studies it has
been estimated that 24 months after diagnosis 28% untreated individual
s would have stable vision compared with 53% patients in this study. C
onclusions-These results compare favourably with other studies and sho
w that teletherapy can be a safe and effective form of treatment for s
ubfoveal NVMs. The authors have described an alternative method of hea
d fixation and shown that CT scanning is not essential. This method of
delivery is considerably less costly than that traditionally used and
may allow greater numbers of patients to benefit from radiotherapy tr
eatment.