89 / 1544
è
Effectiveness of Tracking relies on a stable relationship
between the marker and tumor
l
Changes in tumor geometry (long-course RT)
l
Migration between CT and radiation delivery (bronchofiberscopy)
è
Ideal location Visicoil:
l
in the center of the lesion
l
not in the same axial-CT image plane (e.g. 45 degree angle)
è
Time interval between marker placement and CT for
‘scarring in’
è
Lung and liver: percutaneous insertion under CT-
fluoroscopic guidance
21