Estimating choroidal melanoma volume: comparison of methods.

PURPOSE: To evaluate published methods of estimating choroidal melanoma volume.
DESIGN: Prospective consecutive case series. PARTICIPANTS: Ten consecutive patients with primary choroidal melanoma.
METHODS: After determination of tumor dimensions (largest tumor basal diameter, basal perpendicular diameter, and height), tumor volume was calculated for each tumor by using the 5 published methods. Percent differences in tumor volume were determined for each tumor as calculated by different methods. MAIN OUTCOME MEASURE: Choroidal melanoma volume.
RESULTS: The mean variation in estimated tumor volume expressed as a ratio was 2.33 (range, 1.64-3.84).
CONCLUSIONS: Choroidal melanoma volume calculation methods are inconsistent and caution is needed when volume measures are used for prognostic classification.