Accelerator

The linear accelerators create ionising beams - photons or ultra-hard X-ray beams or electrons. Depending on the requested entry depth into the tissue that is to be irradiated, we can choose between electron energies of  6 - 18 MeV and photon energies of 6 or 10 MV. The Millenium multi-leaf collimators with 120 leaves allow us to restrict the radiation volumes very precisely. Both our accelerators are equipped with Portal Imager, On-Board-Imaging System, Cone beam CT. We can carry out Intensity-Modulated Radiation Therapy (IMRT) and Rapid-Arc Radio Therapy (VMAT). These techniques allow for high-precision irradiation (stereotactic radiotherapy).

Since we have two identical accelerators (Tandem), we can use the respective other device if there is a technical malfunction or shut down due to maintenance. This way, we avoid long waiting times or  treatment interruptions.

Computer tomograph

A computer tomogram is required as the basis for modern treatment-planning. To create our planning-CT, we can use a Multislice computer tomograph from the Institute for Diagnostic and Interventional Radiology of Klinikum Schwabing, which is otherwise used for diagnostics. The data of the CT are directly transferred to our planning computer, which is why we can't use any foreign CT-recordings. With special issues, we additionally use MRI or PET/CT (CT and MRT resp. PET/CT are merged).

Radiation planning

We use the planning system Eclipse to provide modern, 3-dimensional radiation resp. IMRT planning.

The planning physician will conture the desired target on every CT-layer. He or she will also mark 'organs at risk', i.e. healthy tissue that is to be protected. Then, the medical physicist together with the physician will create a 3-dimensional radiation plan.

 

The radiation-treatment is usually carried out from different directions which, by overlaying, encompass the desired target (multi field technique). By using Intensity-Modulated Radiation Therapy (IMRT) we can precisely adapt the dose to the target and give better protection to surrounding organs. In the Rapid-Arc technique, the gantry circulates the target while irradiating it. These methods allow for highly precise and highly conformal irradiation of even very small targets.

 

 

Three-dimensional (3-D) plan for irradiating a vertebral body (Here, the target is irradiated from three different directions).

IMRT plan for irradiating an ENT tumour

Rapid-Arc plan for irradiating an anal tumour

High-precision irradiation of a lung tumour

Afterloading device

Afterloader GammaMed 3/24 iX

For irradiations of hollow organs of the human body we use an afterloading device GammaMed Plus 3/24 iX with the planning system Brachyvision. In Afterloading or brachytherapy, the encapsulated radionuclide Iridium-192 is brought into close contact with the tumour resp. the area to be irradiated. Once the specific applicator is positioned in the organ, e.g. the esophagus or the vagina, the radioactive probe can be moved within the organ, controlled by the computer (Afterloading method). After the irradiation is completed, which takes only a few minutes due to the high dose-rate of the iridium, the radiation source is automaticly retracted to the treatment-device.

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