External beam radiotherapy of choroidal metastases--final results of a prospective study of the German Cancer Society (ARO 95-08)

Abstract

Purpose: In 1994 a prospective study of the 'Arbeitsgemeinschaft Radiologische Onkologie' of the German Cancer Society was initiated to examine the results of a standardized radiation therapy for choroidal metastases with 40 Gy. Recommendations in the literature vary from 21 to 50 Gy of total dose and from 2 to 5 Gy per single fraction. To date, no larger series treated with both a standardized technique and dose has been reported.

Patients and methods: Between 1994 and 1998, 56 patients were enrolled and 50 patients with 65 involved eyes were available for analysis. Thirty-five patients (70%) had unilateral and 15 patients (30%) had bilateral choroidal metastases. Fifty eyes (77%) were symptomatic and 15 eyes (23%) were asymptomatic. Thirty-one patients (62%) had breast cancer and 13 patients (26%) lung cancer as the primary tumor. Patients were treated with 40 Gy in 20 fractions with bilateral asymmetric fields for bilateral or a unilateral field for unilateral choroidal metastasis. Seventeen patients had additional chemotherapy after radiotherapy for general tumor progression.

Results: With a median follow-up of 5.8 months (1-44 months) 41 out of 50 patients were dead. The median survival of all patients was 7 months and for patients with breast cancer 10 months. Of the 50 symptomatic eyes visual acuity increased for two or more lines in 36% (18/50), was stabilized in 50% (25/50 eyes), and decreased in 14% (7/50). No patient with asymptomatic metastasis (n = 15 eyes) developed ocular symptoms during follow-up. No patient with unilateral tumor and unilateral irradiation developed contralateral metastasis. Severe side effects, possibly related to tumor progression, occurred in three eyes (5%).

Conclusion: Radiation therapy with 40 Gy is an effective and safe palliative treatment for symptomatic and asymptomatic choroidal metastases to preserve vision in the majority of the patients. A unilateral field for unilateral metastasis seems to be sufficient to prevent contralateral disease. Side effects of radiotherapy are acceptable: 50% of patients developed a mild skin erythema and conjunctivitis (RTOG I). Late side effects were seen in three eyes (5%).