Sarcomas often affect limbs which provides a challenge for radiotherapy positioning. Limbs are difficult to position accurately each day as the range of movement is far greater that the torso. If possible, the lymphatic drainage of the limbs should be preserved in order to reduce the risk of Oedema in the future. Thermo-Plastic Immobilisation devices are sometimes employed in order to hold the limb into position although this doesn’t provide the ideal solution. Since the limb separation is not great, the dose to the skin surface is usually high. Added a layer of plastic to the surface increases the dose to the skin and can lead to potential problems. AlignRT allows the radiographer or therapist to position the limb in the same position as their CT scan in order to ensure lymphatics are spared and skin doses are as low as possible.