Plaque radiotherapy for the management of uveal metastasis

Abstract

Background: Radiotherapy is effective for the management of most uveal metastases, and standard external beam radiotherapy is generally administered during a 3-In 4-week period. For those patients in whom external beam radiotherapy or other methods fail or those patients with solitary uveal metastases, plaque radio therapy may be an alternative method. Objective: To determine the effectiveness of plaque ra-diotherapy for the management of uveal metastasis. Methods: A retrospective review o f 36 patients with uveal metastases who were examined at the Oncology Service at Wills Eye Hospital, Philadelphia, Pa, and treated with plaque radiotherapy. The clinical findings and follow-up data of the primary tumor and the uveal metastasis were analyzed. Results: Of the 36 patients, 27 (75%) received plaque treatment as primary therapy for the uveal metastasis and 9 (25%) received plaque treatment as secondary therapy after failure of the uveal tumor to respond to external beam radiotherapy, chemotherapy, or hormonal therapy. During treatment, 22 patients (61%) had no other systemic metastasis and 14 (39%) had controlled systemic metastasis. No patients had active metastasis elsewhere. The uveal metastasis was solitary and well circumscribed in all but I patient; it measured a mean of 11 mm in basal dimension and 4 mm in thickness. The mean time for treatment was 86 hours, and the mean therapeutic dose was 68.80 Gy to the tumor apex and 235.64 Gy to the tumor base. Regression of the uveal metastasis was documented in 34 patients (94%) during a mean follow-up of 11 months. As early as 3 months after treatment, the mean tumor thickness had decreased to 2 mm. Plaque radiotherapy salvaged 5 of the 6 eyes that had failed prior external beam radiotherapy. Radiation retinopathy, radiation papillopathy, or both were found in 3 patients (8%) and occurred at a mean of 8 months after treatment. At the last examination, 18 patients (50%) were alive (11 with and 7 without active systemic metastasis) and 18 (50%) were dead from systemic metastasis. Conclusions: Plaque radiotherapy is an effective method for treating selected solitary uveal metastasis. It offers a high degree of tumor control, especially for those eyes in which other methods have failed. Plaque treatment is provided during a short period, minimizing the time demand for these patients with a limited life expectancy.