Users Manual Part 1
Clinical User’s Guide
IBA | 6-5|
Volume 1 - Treatment Session
|Part II
- Using Treatment Room Equipment Elementary Notions on Patient Positioning
|
IEC Gantry Coordinate System (g)
The IEC 61217 gantry coordinate system is stationary with respect to the gantry. It
is defined as a daughter of the FRS, as follows:
the origin is the origin of the FRS
X
g
is orthogonal to the beam axis, directed downwards when the gantry angle
is 90°
Y
g
is coincident with Y
f
Z
g
is aligned with the beam axis, directed towards the beam source
Figure 6-2. IEC Gantry Coordinate System
IEC Table Top Coordinate System (t)
The IEC 61217 table top coordinate system (TTCS) is stationary with respect to the
table.
In case of a couch (which presents a rectangular planar surface):
X
t
is parallel to the table small side and directed on the left of a patient in head-
first supine position on the table
Y
t
is parallel to the table longitudinal axis (long side) and directed towards the
head of a patient lying head-first on the table
Z
t
is normal to the table surface and directed upwards
Z
g
X
g