Purpose: To evaluate the positive dual-modality positron emission tomography/computed tomography (PET/CT) of choroidal melanoma with chromosome 3 loss and tumor size.
Methods: Thirty-seven consecutive patients with choroidal melanoma with known chromosome 3 status who underwent whole-body PET/CT imaging were retrospectively reviewed. Cytology and chromosome 3 loss were identified by fine-needle aspiration biopsy. Fluorescent in situ hybridization and whole genome microarray by single-nucleotide polymorphism were used to evaluate the chromosome 3 status. Metabolic activity of primary choroidal melanoma by PET/CT imaging was evaluated.
Results: Thirteen of 37 (35%) primary choroidal melanomas had loss of chromosome 3; 7 of the 13 (54%) melanomas were positive for metabolic activity identified by PET/CT imaging. All 24 of 37 melanomas without chromosome 3 loss were inactive for metabolic activity. There was a statistically significant association between positive metabolic activity and chromosome 3 loss (P = 0.00017 Fisher exact test); positive PET/CT imaging was 54% sensitive and 100% specific for loss of chromosome 3. Seven of 37 (19%) choroidal melanomas with positive metabolic activity by PET/CT were statistically significantly larger in size than the 30 metabolically inactive melanomas (P < 0.001, Kruskal-Wallis test).
Conclusion: Positive metabolic activity of choroidal melanoma identified by PET/CT imaging was statistically significantly associated with chromosome 3 loss and larger tumor size.