Abstract
Abstract: :
Purpose: Stereotactic fractionated radiotherapy (SFR) with a linear accelerator is an innovative and important option in the treatment strategy for patients with brain tumors. The method is characterized by a high precision in the delivery of the irradiation dose (total dose 50–56 Gy, single dose 1,8 Gy, 5x/week) and achieves a high local tumor control with a low rate of side effects. This study will show changes of ophthalmological functions in patients with benign brain tumors following SFR. Methods: We observed a total of 70 patients with brain tumors, 50 of them passed a mean follow–up time of 25 months after SFR. 49 patients (70%) had a meningioma, 14 (20%) a pituitary adenoma, 5 (7%) a craniopharyngioma and 2 (3%) other tumors. 51 patients (72%) underwent surgery prior to SFR, 19 (27%) did not. On every visit, best corrected visual acuity, perimetry (30° Humphrey, Goldmann outer margins), electrophysiology (VEP) and ophthalmoscopy (optic disc) were carried out. Results: 100 eyes from 50 patients passed a mean follow–up time of 25 months. Visual acuity was unchanged in 59 eyes (59%), improved in 24 eyes (24%) and got worse in 17 eyes (17%). At baseline, visual field was normal in 57 out of 140 eyes (41%) and pathological in 83 eyes (59%). During follow–up, perimetry revealed stable results in 74 eyes (74%), improvement in 24 eyes (24%) and deterioration in 2 eyes (2%). Visual evoked potentials were normal in 94 eyes at baseline (67%) and pathological in 46 eyes (33%). In 83 eyes (83%), VEP was unchanged after SFR, got better in 16 eyes (16%) and worse in just 1 case (1%). Optic disc was normal in 92 eyes (66%) and atrophic in 48 eyes (34%). This did not change during follow–up. Conclusions: Ophthalmological functions like visual field and visual evoked potentials were affected in just a few cases following treatment (2% respectively 1%). Involvement of optic disc did not change during follow–up, visual acuity was unchanged or improved in 83 eyes (83%). Thus, stereotactic fractionated radiotherapy represents a safe treatment option of benign brain tumors also regarding possible ophthalmological side effects even independent of prior surgeries.
Keywords: visual impairment: neuro-ophthalmological disease • electrophysiology: clinical • perimetry