The present invention provides a system for immobilization of a patient body part for radiotherapy applications comprising: a device comprising at least one flanged support member which is suitable to be mounted to a fixation surface and is adapted to receive and retain at least two sheets a first sheet for covering the anatomical contours of a first area of said body part, and a second sheet for covering the anatomical contours of a second area of said body part which is not covered by the first sheet whereby the system is adapted for supporting the immobilized body part free from the fixation surface by the two sheets and the device.