In order to increase the accuracy and speed of catheter reconstruction in surgical procedures such as an HDR prostate implant procedure, an automatic tracking system is provided preferably using an electromagnetic tracking device. The system uses a transmitter with a sensor used for catheter position. Due to substantial interference in the electromagnetic field from the surgical table, implant stepper/stabilizer etc, a calibration algorithm using a scattered data interpolation scheme is implemented to correct tracking location errors. The invention includes methods and systems used to carry out the methods.
