Abstract
Purpose: :
To report the ocular response of ciliochoroidal melanoma with monosomy 3 versus disomy 3 after iodine-125 brachytherapy.
Design: :
Retrospective, comparative cohort study.
Methods: :
We evaluated patients with ciliochoroidal melanoma treated with fine needle aspiration biopsy (FNAB) immediately prior to plaque application of iodine-125 brachytherapy between January 1, 2005 and December 31, 2008. Patients with (1) cytopathologic diagnosis of melanoma, (2) melanoma chromosome 3 status confirmed by fluorescence in situ hybridization (FISH) and (3) six or more months of follow-up after brachytherapy were sorted by monosomy 3 versus disomy 3 and compared by analysis of variance.
Results: :
Preliminary results from a subset of patients showed that monosomy 3 melanoma had a median greatest basal diameter of 12 mm and a median tumor thickness of 6.69 mm prior to brachytherapy; at a median of 1.75 years after brachytherapy, median thickness was 3.10 mm. Median percentage decrease in tumor thickness was 48.3%. Disomy 3 melanoma had a median greatest basal diameter of 10 mm and median tumor thickness of 3.19 mm before brachytherapy; at a median of 2.0 years after brachytherapy, median tumor thickness was 2.37 mm. The median percentage decrease in tumor thickness was 22.7%. Prior to brachytherapy, monosomy 3 melanoma was statistically greater in size than disomy 3 melanoma (p=0.0008) and showed a greater decrease in tumor thickness after brachytherapy (p=0.006). At 1.75 years after brachytherapy, monosomy 3 melanomas had a greater incidence of clinically diagnosed metastasis than disomy 3 melanomas.
Conclusions: :
Prior to brachytherapy, ciliochoroidal melanomas with monosomy 3 were significantly greater in size than disomy 3 melanomas and showed a significantly greater decrease in thickness approximately 1.75 years after brachytherapy. The greater decrease in monosomy 3 melanoma thickness after brachytherapy and the greater incidence of clinically diagnosed metastases are consistent with other malignancies in which more aggressive pathology is often associated with a greater initial response to treatment.
Keywords: melanoma • radiation therapy • clinical (human) or epidemiologic studies: outcomes/complications