Photodynamic Therapy for Choroidal Melanoma: What is the response rate?
To determine the response rate of choroidal melanoma following primary photodynamic therapy we conducted a meta-analysis of published studies. A total of 7 studies reporting photodynamic therapy (PDT) as primary treatment of choroidal melanoma in 162 patients with a mean tumor height of 2.8 mm (1.4 to 4.2) were identified. 46% of tumors were amelanotic, 48% were fully pigmented, and 6% had partial pigmentation. The PDT parameters in all studies included 10 minute intravenous infusion of verteporfin (6mg/m), but varied in number of sessions (1 to 3), fluence (1x to 19x), and number of spots (single or multiple). The response was defined as tumor regression (partial or total) or lack of growth after initial treatment. The response to PDT was predominantly observed as regression (126 [78%]). Overall response rate was 80% (mean) with a wide range among studies (58%- 100%) over a period of 50 months (mean) with variable follow up (range, 1-156 months). None of the studies reported progression or recurrence free survival. However, the recurrence rate was not related to the follow up duration. Favorable prognostic factors were smaller size and lack of pigmentation. The overall response rate of 80% suggests that PDT may be an effective primary treatment for small choroidal melanoma, especially in cases without pigmentation. Artifacts in study design (inclusion criteria and outcome measure) may have contributed to the variable observed response rate. Further studies with uniform inclusion criteria, standardized treatment parameters, well defined outcome measures, and long follow up are needed.Copyright © 2020 Elsevier Inc. All rights reserved.