New device for precision tumor localization with MR imaging in radiation therapy treatment planning: Experimental data and clinical experience with the translatable

As MR imaging may more accurately define tumor soft-tissue extension as compared with previous modalities, a unique device for the design of irradiation portals based on MR imaging data has been constructed. This system utilizes a flat patient bed compatible with both MR and radiation equipment in concert with a custom mold for precise patient repositioning. An internal reference, based on established principles similar to those used for CT stereotactic biopsy, employs Gd-DPTA-filled tubes, which allow compensation for magnetic field fluctuations while defining tumor in three-dimensional space. Experimental data demonstrating improved target volume determination and potential future applications are presented