more accuracy in stereotactic radiosurgery
more accuracy in stereotactic radiosurgery

ESTRO 2017, Vienna Austria: Visit the virtual isocenter with RPS automatic, stand 2200

For more accuracy in stereotactic radiosurgery: presentation by gKteso on ESTRO 2017, Stand 2200


gKteso presents the virtual isocenter with RPS automatic:
For more accuracy in stereotactic.

„Synchronization of the gantry and couch movement allows the definition of a virtual isocenter. The distance between the patient and the radiation device can be altered in this manner. The system behaves as though there were an decreased distance between the radiation source and the isocenter.”

Stereotactic irradiation and
“source to virtual isocentre distance” (SVID)

Radial dose depending from SVID, using a 5 mm MLC.
Radial dose distribution for MLC at SVID 70 cm (continuous) and 50 cm (thin dashed), normalized to the distribution for MLC at SID 100 cm.

Shaded area: (Circular) PTV, Quasi-isotropic irradiation in 2π geometry.

Left: PTV Æ 1.0 cm; middle: PTV Æ 1.3 cm; right: PTV Æ 1.7 cm.
Prescriptions: top: D70%; middle: D80%; bottom: D90%. S(V)ID: SID or SVID.*


Varying “source to virtual
isocentre distance” (SVID):

Measured and calculated beam edges.

Source to isocentre distance (SID) 100 cm (continuous line) and source to virtual isocentre distance (SVID) 70 cm (dashed line):

Beam edges are set to 50% point for beams of effective 10 x 10 mm² (nominally 10 x 10 mm² for SID 100 cm, 14 x 14 mm² for SVID 70 cm, respectively). Left side (a+c): planned in TPS. Right side (b+d): film measurements.

Upper row L (a+b): leaf direction; lower row J (c+d): jaw direction.

Depth 10 cm, central axis dose is normalized to 1.0.*

*K.Bratengeier, submitted to ‘Radiation Oncology‘

RPS automatic– presented by gKteso – is a robot couch system with almost
unlimited possibilities and consequent advantages:

At a glance:

• exact positioning
• 6 degrees of freedom for optimized  positioning
• motion with extremely gentle movements
• perfect base for stereotactic radiosurgery