Patient Workflow For Multisession Radiosurgery With Extend Positioning System : Preliminary Experience

Picozzi Piero1, Antonella Del Vecchio2, Alberto Franzin3, Patrizia Signorotto1, Angelo Bolognesi1, Tullio Toti1, Riccardo Calandrino1, Pietro Mortini1

1San Raffaele Scientific Institute, Milan, Italy 2Milan, Italy 3Mi, Italy

Keywords: gamma knife, Fractionated radiosurgery, Extend, technique, stereotactic frame

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     Radiosurgery is usually a single session treatment. Multi session treatments using Leksell G Frame requires that patient must have the frame fixed for three to five days.
     The introduction of Extend positioning system allows performance of these treatments with more patient comfort and an equally acceptable accuracy.
     In the period September – December 2009, 4 patients have been treated with multisession radiosurgery utilizing the Extend system. Patients underwent MRI scan for pre-planning few days before radiosurgery. Then they had a complete dental examination and dental imprinting with a special device for mouth fixation. Set up was completed positioning the patient on the PerfexionTM couch and during this phase we control the adherence of the mouth fixation piece under vacuum and we perform the first measurement set up. A similar set up was reproduced in the CT scan (GE LightSpeed VCT64) and stereotactic imaging was obtained. These images were co-registrated with pre-planning MRI and the treatment plan was checked before the export to the Perfexion. Three to five sessions were delivered to the patients. Before each session the position check of the patients was performed in order to assure the correct repositioning. The error was calculated by the system
     The timing of each phase was measured and the patients comfort assessed utilizing an analogical scale. Duration of each session of treatment ranges between 40 – 57 minutes depending on the complexity of the treatment, the value of the dose and the number of fractions. Two patients had no problems in tolerating mouth fixation, few problems in the other two cases because of bad dental conditions.
     This is a retrospective study.
     This preliminary experience suggests that Extend system is comfortable for the patients.
     It requires a careful preparation and the dental conditions may limit the applicability of the system.


Project Roles:

P. Piero (), A. Del Vecchio (), A. Franzin (), P. Signorotto (), A. Bolognesi (), T. Toti (), R. Calandrino (), P. Mortini ()