1097 / 1835
Involved Site Radiotherapy
(ISRT)
o
ISRT accomomodates cases in which optimal prechemotherapy imaging is
not available to the radiation oncologist
o
In these situations, it is not possible to reduce the CTV to the same extent
as with INRT, because the prechemotherapy GTV information may not be
optimal
o
In ISRT, clinical judgment in conjunction with the best available imaging
is used to contour a larger CTV that will be accommodate the uncertainties
in defining the prechemotherapy GTV