TSL G-line : Proton Radiotherapy
Proton Radiotherapy
The proton beam extracted from the cyclotron may have exclusive advantages in treatment of certain human malignant tumours and some other disorders where conventional radiotherapy or surgery is not feasible. The depth dosedistribution, with "the Bragg-peak", and the relatively sharp penumbra, enables the concentration of radiation to the target volume and minimizes the dose to normal tissue surrounding the target. Proton beam irradiation may lead to cure or shrinkage of tumour burden in cases whereother treatment modalities fail.All patients are carefully investigated by computerized tomography and/or magnetic resonance imaging in order to obtain a detailed knowledge of the position and size of the tumour. Angiography and positron emission termography will be used in certain cases. Before the treatments, careful doseplanning is performed to ensure an optimal dose distribution.
The medical projects may be divided into the following groups:
- the fixed narrow proton beam (info follows further down)
- the scanned broad proton beam (info on this page)
The fixed narrow proton beam
So far proton energies of upto 180 MeV have been used for radiotherapy. 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. The maximum diameter of the proton beam is 7 cm. The beam is modified by a range modulator, collimator and bolus. Targets located deeper than 4.5-5 cm in the brain require proton energies of at least 160 MeV
Picture: Normal setup of seated patient for irradiation with proton beams.
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.
Picture: An adjustable platform can be attached to the treatment chair
in order to adapt it for prostate irradiations.
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.
Picture: the constructor of the special child couch tries it out before
painting and final finish.
Treatments
1. Eye melanomas. The first patient was treated in April 1989 with a modified
72 MeV beam to 54,5 Gy in 4 fractions using a single field technique.
2. Arterio-venous malformation of the brain. The first patient with superficially
located inoperabel AVM:s was treated in April 1991 with a modified 100 MeV
beam utilizing two portals to a total dose of 20 Gy in two fractions.
3. Therapy with protons beams in patients with Uveal melanomas and meningeomas
in the brain.
4. Proton beam therapy as a boost to photon beam therapy in patients with
malignant tumours.
5. Malignant gliomas. Patients with astrocytomas grade III and IV have received
irradiation treatment with photons and protons.
6. Meningeomas of the brain. Patients with partially resected meningeomas,
WHO grade I, in the brain have been treated since 1994. The treatment is generally
given four fractions to a total dose of 24 Gy.
7. Tumours in the head-and-neck region, tumours in the base of the skull and
adenomas in the pituitary. Most patients have received a combined therapy
with photons and protons.
8. 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 above).
9. In 2008 Barncancerfonden (The Swedish Childhood Cancer Foundation) funded construction of an adjustable treatment couch adapted for lying child patients (see picture above) and adjustement of software used for treatments.
| Proton treatments are arranged by the Akademiska
Hospital's Oncology clinic. Let your local doctor send inquires to the
Akademiska Hospital, ph +46-(0)18-611 00 00, http://www.akademiska.se. The Svedberg Laboratory have no possibility handling inquiries from patients. |
| Protonbehandlingar ordnas av Akademiska sjukhusets
onkologklinik. Din lokala läkare måste skicka remiss. Kontakta Akademiska
Sjukhuset, 018-611 00 00, http://www.akademiska.se
för mer information. The Svedberg-laboratoriet har ingen möjlighet att ta emot patientförfrågningar. |
Beam line drawing:
In this drawing the different beamlines can be seen, they host:
- G-line: the fixed narrow proton beam
- N-line: the scanned broad proton beam (info on this page)
- C-line: biological research experiments (info on this page)
Optical bench:
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.
Links to relevant information:
- Strålning inom medicin/Radiation in medical applications in swedish, from KSU.
- Gunnar Lundqvist - a patient treated at TSL, in swedish, from http://www.prostatacancer.nu