Stereotactic radiotherapy of malignancies in the abdomen. Methodological aspects.
A method for stereotactic high-dose radiotherapy of malignancies in the abdomen has been developed. A stereotactic frame for the body has been developed and a method for fixation of the patient in the frame is described. The reproducibility in the stereotactic system of tumours in the liver and the lung was found to be within 5-8 mm for 90% of the patient set-ups. The diaphragmatic movements were reduced to 5-10 mm, by applying a pressure on the abdomen. An analytical method is used to calculate dose distributions for a continuum of beams in an isocentric treatment technique. The advantage of a heterogeneous target dose is demonstrated and proposed for the present application. A non-coplanar treatment technique, using eight individually shaped beams is proposed and has been used for patient treatments. The dose distribution for a patient with a metastasis in the liver is shown as well as dose volume histograms for the target and the liver.
Lax
I
I
Department of Hospital Physics, Karolinska Hospital, Stockholm, Sweden.
Blomgren
H
H
Näslund
I
I
Svanström
R
R
D000008:Abdominal Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008113:Liver Neoplasms / Q000532:radiotherapy*; D008961:Models, Structural; D008962:Models, Theoretical; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D013238:Stereotaxic Techniques