Simple method for correcting imperfectly placed fiducial markers for image-guided radiotherapy technologies of the prostate cancer.

One of the main method of treating prostate cancer is radiotherapy . Contemporary techniques as IGRT concentrate on proper delivery and exact delineation of the target. We present the simple method of correction the visualisation of gold markers implanted before radiotherapy . In the case when one or two seeds were located imperfectly or were lost with stool or urine we implant additional seeds which create the spatial figure recognised in CT and MRI . Implantation of additional seeds is safe and very simple method which can "rescue" sense of image guided procedure in the case of unfavourable primary fiducial seeds location.