AbstractID: 8005 Title: Stereotactic IMRT using the GTC, HNL and TLC frames: The Radionics System
Intensity modulated radiation therapy utilizes non-uniform radiation intensity
patterns to deliver higher doses to tumors while providing a sharp fall off of dose into
normal tissue and critical structures. IMRT results in improved conformity, reduced
toxicity, improved tumor control and dose escalation. However, patient immobilisation
plays a crucial role to achieve these gains.
The Radionics (Tyco Healthcare) stereotactic system, although traditionally
consisting of XKnife and circular fields, has grown to include the XPlan treatment
planning system together with the mini-multileaf collimator (MMLC), the mode of
delivery being multiple static fields. It now utilizes the Head and Neck Localizer in
addition to the CRW, GTC and pediatric TLC frames. An IMRT module (KonRad) is
also integrated with the XPlan and is therefore usable with all the stereotactic frames.
As a premier site to implement clinically the HNL frame as a stereotactic device
together with the stereotactic IMRT on a Varian linear accelerator, a total of 44 patients
have been treated using the HNL alone for targets in the head and neck, 7 using the GTC
for CNS and one pediatric using the TLC frame since March 2001. The accuracy of day
to day set up as verified by comparing portal images with DRRs has been within the
tolerance of 3 mm for the HNL and 2 mm for the GTC and TLC. The presentation will
provide details of the experience gained with the system together with two specific
clinical examples of immobilisation, planning and treatment delivery.