Matteo Maspero1, Cornelis AT van den Berg1, Frank Zijlstra1, Hans C de Boer1,2, Gert J Meijer1,2, Max A Viergever1, Jan JW Lagendijk1,2, Linda GW Kerkmeijer1,2, and Peter R Seevinck1
1Center for Image Sciences, UMC Utrecht, Utrecht, Netherlands, 2Cancer Center, UMC Utrecht, Utrecht, Netherlands
A novel approach aiming at automatic localization of gold Fiducial Markers (FMs) used in prostate radiotherapy to accurately perform patient positioning is presented and evaluated. The proposed method correctly detected 49/51 FMs in 17 patients when compared to FMs locations manually detected on MR. The spatial accuracy (median) and precision (STD) achieved were 0.2 mm, and 1.2 mm, respectively, when compared to relative FMs locations obtained with CT. When combined with a manual check, this approach could be a safe way to eliminate CT during radiotherapy planning, facilitating an MR-only workflow.