Prospective assessment of patient-reported dry eye syndrome after whole brain radiation

Abstract Purpose Dry eye is not typically considered a toxicity of whole brain radiation (WBRT). We analyzed dry eye syndrome as part of a prospective study of patient-reported outcomes after WBRT. Methods Patients receiving WBRT to 25-40 Gy were enrolled on a study with dry mouth as the primary endpoint and dry eye syndrome as a secondary endpoint. Patients received 3-dimensional WBRT using opposed lateral fields. Per standard practice, lacrimal glands were not prospectively delineated. Patients completed the Subjective Evaluation of Symptom of Dryness (SESoD, scored 0-4, higher representing worse dry eye symptoms) at baseline, immediately after WBRT (EndRT), one month (1M), three months (3M), and six months. Patients with baseline SESoD ≥3 (moderate dry eye) were excluded. The endpoints analyzed were ≥1 point and ≥2 point increase in SESoD score at 1M. Lacrimal glands were retrospectively delineated with fused MRI’s. Results 100 patients were enrolled, 70 were eligible for analysis, and 54 were evaluable at 1M. Median bilateral lacrimal V20Gy was 79%. At 1M, 17 patients (32%) had a ≥1 point increase in SESoD score, and 13 (24%) a ≥2 point increase. Lacrimal doses appeared to be associated with an increase in SESoD score of both ≥1 point (V10Gy: p=0.042, OR 1.09/Gy, V20Gy: p=0.071, OR 1.03/Gy) and ≥2 points (V10Gy: p=0.038, OR 1.15/Gy, V20Gy: p=0.063, OR 1.04/Gy). The proportion with increase in dry eye symptoms at 1M for lacrimal V20Gy ≥79% vs. Conclusions Dry eye appears to be a relatively common, dose/volume-dependent acute toxicity of WBRT. Minimization of lacrimal gland dose may reduce this toxicity, and patients should be counseled regarding the existence of this potential side effect and treatments for dry eye.