Narrow beam for proton radiation therapy

The fixed narrow proton beam

The narrow beam for proton radiation therapy has a maximum diameter of 7 cm and the beam is fixed. To perform different irradiations the patients must be moved around. The beam is modified by a range modulator, collimator and bolus. So far proton energies up to 180 MeV have been used for radiotherapy.

Seated patients

For arterio-venous malformation(AVM) treatments and other intracranial targets the patients are treated in a seated position(see picture below)with the head immobilized by an individually formed bite-block and a plastic helmet covering the head. Targets located deeper than 4.5-5 cm in the brain require proton energies of at least 160 MeV.

To allow fields from various directions and to different targets, the chair can be moved in X-Y-Z-directions and turned around its own axis.

 Proton patient

Picture: Normal setup of seated patient for irradiation with proton beams.

Lying prostate patients

The first patient with Prostate cancer was treated in late 2002, with 180 MeV.

A special couch/platform was built for this purpose (see picture below), allowing a half lying patient. The couch is mounted on top of the chassie for the chair used for seated patients.

To allow fields from various directions and to different targets, the couch (eg the chair chassie) can be moved in X-Y-Z-directions and turned around its own axis.

lying prostate patient

Picture: An adjustable platform can be attached to the treatment chair in order to adapt it for prostate irradiations.

Lying child patients

In 2008 Barncancerfonden (The Swedish Childhood Cancer Foundation) funded construction of an adjustable treatment couch adapted for lying child patients (see picture below)and adjustement of software used for treatments.

Also this couch is mounted on top of the chassie for the chair used for seated patients. To allow fields from various directions and to different targets, the couch (eg the chair chassie) can be moved in X-Y-Z-directions and turned around its own axis.
 

 Child couch

Picture: the constructor of the special child couch tries it out before painting and final finish.

 

Beam line drawing

beamlines bio hall

Picture: The narrow beam project uses the G-line.

 

Optical bench

optical bench for proton therapy

In this picture we see the optical bench where the beam leaves the vacuum pipe to the left and passes through ion chambers, degraders and collimator and then just outside the picture to the right it is interacting with the target, i.e. the tumour in the patient.