Pre-treatment computerized tomography

Post-treatment computerized tomography

Recently, with a variant of stereotactic radiotherapy, high doses of radiation can be targeted at body areas other than the brain. This new technique is called 'dynamic micro-multileaf stereotactic radiotherapy'.
It was difficult to apply the stereotactic technique to other areas of the body because of various problems (e.g. breathing movements, and the impossibility of applying high doses of radiation because of radiosensitive organs near the target).

With the micro-multileaf technique it is possible to irradiate volumes up to 12 cm in diameter by 'customizing' the technique. Anatomic structures that must not receive radiation are shielded by leafs fitted on the linear accelerator. Once the gross tumor volume (GTV) has been identified with CT and planning 3D, treatment can be targeted on that volume plus a small surrounding area, thereby sparing healthy structures and tissue. To overcome the problem of reproducibility, we use immobilization systems consisting of thermoplastic masks, polyurethane body templates and a device in the treatment bunker, called 'patient tracking system' whereby three TV cameras reproduce on a monitor the position assumed by the patient during simulation CT.
If necessary, the 'static' system can be transformed into the 'dynamic' system. The leafs can move even during therapy, in synchrony with the linear accelerator that moves in concentric arcs. Thus, we can reduce the dose to volumes surrounding the GTV and to use even higher doses in one or more sessions. 'Dynamic' radiotherapy is used to treat single peripheral lung lesions, also metastatic, primary or metastatic liver tumors, pancreatic tumors and practically anywhere the tumor size is sufficiently small for treatment, which is administered in the outpatient clinic.

Before Pet

After Pet