R Rask1, P K Jensen. 1. Department of Ophthalmology, Arhus University Hospital, Nørrebrogade 55, DK-8000 Arhus C, Denmark. kommrr@aau.dk
Abstract
BACKGROUND: Important prognostic information may be gained from knowledge of the volume and, over time, the change in volume of intraocular tumors such as choroidal melanomas. METHODS: The precision and time consumption of three different ultrasonographic methods were evaluated. Seven choroidal melanomas were analysed after placement of a ruthenium plaque and again after tumor regression had occurred. Perpendicular ultrasound B-scans were printed and analysed by overlay grid counting or outline tracing of tumor structures to calculate the volume. These two methods, using only two perpendicular scans, were compared with a micro-computer-controlled ultrasonographic three-dimensional rotation scanning system, where each tumor was manually outlined in 20 revolving scan planes RESULTS: The three-dimensional volume scanning method was the most precise, but also the most demanding in hardware and time consumption. CONCLUSION: Increased precision and less observer-dependent estimation of shrinkage rate after radiotherapy is available at the cost of sophisticated equipment.
BACKGROUND: Important prognostic information may be gained from knowledge of the volume and, over time, the change in volume of intraocular tumors such as choroidal melanomas. METHODS: The precision and time consumption of three different ultrasonographic methods were evaluated. Seven choroidal melanomas were analysed after placement of a ruthenium plaque and again after tumor regression had occurred. Perpendicular ultrasound B-scans were printed and analysed by overlay grid counting or outline tracing of tumor structures to calculate the volume. These two methods, using only two perpendicular scans, were compared with a micro-computer-controlled ultrasonographic three-dimensional rotation scanning system, where each tumor was manually outlined in 20 revolving scan planes RESULTS: The three-dimensional volume scanning method was the most precise, but also the most demanding in hardware and time consumption. CONCLUSION: Increased precision and less observer-dependent estimation of shrinkage rate after radiotherapy is available at the cost of sophisticated equipment.