Keywords:
Eyes, CNS, MR, Stereotactic radiotherapy, Radiation therapy / Oncology, Neoplasia
Authors:
G. Ratnayake, T. Oh, R. Mehta, T. Hardy, K. Woodford, R. Haward, J. Ruben, M. Dally; VIC/AU
DOI:
10.26044/ranzcr2019/R-0013
Results
Patient and Treatment Characteristics
26 patients with ONSM treated with SRT met the criteria for inclusion in the study. All patients had unilateral diseases and were diagnosed based on characteristic radiological appearance of ONSM on MRI. The median duration of clinical follow-up was 68 months post-SRT (range 20 to 134 months).
Visual Outcomes
In the 10 patients with proptosis on presentation, 4 had a reduction in proptosis measured on exophthalmometry, 2 remained stable and 6 had no post-treatment data to assess response. In the three patients who presented initially with diplopia, all had an improvement in their symptoms.
Good vision was defined as BCVA 6/18 or better and poor vision as BCVA 6/24 or worse. A greater proportion of patients with good vision pre-SRT had stable or improved vision
Visual acuity improved in 10 patients (38.4%), remained stable in 10 patients (38.4%) and was reduced in 6 (23.1%) patients following treatment. In the patients that had good vision pre-SRT, 46.2% (6/13) had improved VA, 46.2% (6/13) had stable VA and only 7.6% (1/13) had a deterioration in VA recorded. However, in patients that had poor vision pre-SRT, 30.8% (4/13) had some improvement in VA, 30.8% (4/13) demonstrated stable VA and 38.5% (5/13) continued to have deterioration in their VA. Therefore a greater proportion of patients with good vision had stable or improved VA compared to poor vision (92.3% vs 61.5%).
Radiological Outcomes
There were no cases of radiological disease progression. The majority of tumours (96.1%) remained stable in size and one (3.8%) demonstrated a mild reduction in size.
Toxicity Analysis
14 patients (53.8%) reported acute toxicity during treatment all of which were Grade 1. The reported acute toxicities in order of frequency were fatigue (23.1%), headaches (19.2%), alopecia (3.8%) and dizziness (3.8%). Late toxicities include grade 1 dry eye in 11.6% of patients. One patient developed late grade 2 radiation retinopathy requiring treatment with an intravitreal VEGF inhibitor.
One patient developed multiple intracranial meningiomas which were identified on imaging 10.9 years post completion of radiotherapy, and while unlikely, may have been radiation induced.