Radiation therapy or radiotherapy (RT) is a powerful treatment where precision and accuracy is crucial. Image Guided Radiotherapy (IGRT) facilitates more accurate position verification, correcting for anatomic changes related to internal organ movement. IGRT thereby helps reduce toxicity of radiotherapy and increases relapse-free survival. Currently, the most frequently used imaging-technique for IGRT is Computed Tomography (CT). However, CT- based target delineation of soft tissue tumors tends to only improve the precision and not the accuracy of treatment due to its relatively low soft tissue resolution. In some tumors ∼40% larger volumes are defined on CT compared to MRI, a technique with submillimeter soft tissue resolution. Therefore, it is advantageous to apply both CT and MRI in planning of soft tissue tumor radiotherapy. An inter-correlation point with a fixed position and volume (a marker) can be applied to indicate the point of treatment clearly in both imaging modalities and to localize and track tumors in real time. In this study, we present the development of a marker based on lactose octaacetate:octapropionate 1 :1 containing 3 mM PLA-DTPA(Gd), 40% triglyceride, 5% propylene carbonate and 10% XSAIB (sucrose based CT-contrast agent). The injectable marker had high CT contrast (>1000 HU) and displayed clearly visible, stable Ti contrast enhancement (T1 ∼900 ms) in the rim over at least 3 weeks with clinically observable resolution. Key words: Fiducial marker, MRI, CT, Image Guided Radiotherapy
|IPC||A61K47/26; A61K49/00; A61K49/04; A61K49/08; A61K49/10; A61K49/12; A61K49/14; A61K49/18|
|Country||International Bureau of the World Intellectual Property Organization (WIPO)|
|Publication status||Published - 2019|
Andresen, T. L., Jølck, R. I., & Bruun, L. M. (2019). IPC No. A61K47/26; A61K49/00; A61K49/04; A61K49/08; A61K49/10; A61K49/12; A61K49/14; A61K49/18. Development of injectable fiducial markers for image guided radiotherapy with dual mri and ct visibility. (Patent No. WO2018215595 ).