Room: ePoster Forums
Purpose: Trans-rectal Ultrasound (TRUS) guided brachytherapy for prostate cancer has become a popular treatment option due to its benefits for patient recovery, dose localisation and conformity. The ability to delineate the prostate from surrounding tissue; the contrast resolution, is vital for treatment planning. This study will present the objective image quality assessment of TRUS systems used in the brachytherapy procedure using a novel contrast-detail (C-D) phantom, with task-specific and clinically relevant contrast and target sizes.
Methods: Clinical prostate data was used to determine the relevant contrasts for the C-D phantom, and arrays of small spherical agar tissue mimicking material targets were produced at the chosen contrasts ranging from 2-10mm diameter (Figure 1). Images were acquired on both probe arrays, of each of the target sizes at each contrast, on the clinical pre-set and on a pre-set THI setting for each of the five TRUS systems evaluated. A Matlab program was developed to objectively measure the contrast-detectability in terms of the lesion-signal-to-noise ratio (LSNR) over a range of depths for each contrast level.
Results: Preliminary data from the systems that were evaluated indicated that there is a decrease in contrast-detectability at depth in the phantom. For both the sagittal array and the transverse array the BK systems had better LSNR for the most superficial targets, but the C-D decreased to a similar level for all systems at the deeper target depths (Figure 2). With further data analysis the objective comparison of these systems may indicate optimum settings for TRUS imaging.
Conclusion: Preliminary data from TRUS systems evaluated, demonstrated the efficacy of the device as an image quality evaluation tool. The Matlab program allows for objective comparison of these systems which has the potential to determine optimised imaging parameters that could be as part of a standard imagining protocol for this application.
Not Applicable / None Entered.