Preventing complications from high-dose rate brachytherapy when treating mobile tongue cancer via the application of a modular lead-lined spacer

Purpose: To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients. Methods: First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations. Results: With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant) distances to the source. Conclusions: The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT.