Purpose
Evaluate the incidence and management of scleral necrosis (SNEC) in posterior uveal melanomas treated by radiation (I-125 plaque or Stereotactic Radiation Therapy [SRT]) and evaluated by transcleral fine needle aspiration biopsy (tsFNAB) prior to treatment.
Methods
We reviewed all of our posterior melanomas treated by focal radiation from July 2006 to July 2013 and selected those evaluated by tsFNAB prior to focal radiation treatment. Statistical analysis included computation of conventional descriptive statistics; cross-tabulation and Chi-square test of factors possibly related to the development of SNEC and summarization of management approaches and results. Incidence of SNEC was calculated using the Kaplan-Meier method.
Results
A total of 435 patients with posterior uveal melanoma were treated during the 7-year study interval. Eighty-eight of them were evaluated by tsFNAB and subsequent focal radiation treatment. Fifty-one percent of patients were females and median patient age was 62.3 years (± 13.9). Median largest basal diameter was 13.3 mm (±2.7) and tumor thickness was 6.8 mm (±2.4). Nine patients (10.2%) developed SNEC, 8 after I-125 plaque and 1 after SRT (p=0.3). Thicker tumors (>6.5mm) were more likely to develop SNEC (n=7) than thinner tumors (p=0.05). In the studied group, the cumulative probability of developing radiation induced SNEC was 6.2% at 6 months, 7.4% at 12 months, 10.1% at 18 months, and 14.3% at 24 months remaining stable after that (14.3% at 42 months). Meanwhile the cumulative probability of developing radiation induced SNEC among thicker tumors was 23.5% at 45 months. Five patients were treated by implantation of a scleral patch graft, 3 (with limited SNEC) were managed by observation (33.3%), and 1 was enucleated. The mean follow-up time among patients who did not develop SNEC was 22.1 months (±14.0). The overall cumulative probability of survival in this group was 77.3%.
Conclusions
In our series, tsFNAB appeared to have a role in the development of radiation induced SNEC in patients evaluated treated by focal radiation. Patients with thicker tumors seem to be more likely to develop SNEC after focal radiation treatment for posterior uveal melanoma. Observation has been our choice for limited SNEC, but scleral patch graft is an alternative for eye preservation in cases of extensive SNEC.
Keywords: 589 melanoma •
745 uvea •
671 radiation therapy