A method of using a shielding device with an applicator includes inserting the distal portion of the shielding device to a treatment site of a patient, the shield being made of plastic, imaging the treatment site, planning treatment of the treatment site based on the imaging, setting up the patient for treatment, imaging the treatment site, removing the distal portion of the shielding device from the treatment site, exchanging the shield made of plastic with a shield made of tungsten, inserting the distal portion of the shielding device to the treatment site, the shield being made of tungsten, imaging the treatment site, and performing the treatment.