Development of a translating bed for total body irradiation.
Total body irradiation is used to prepare a patient for bone marrow transplantation. Traditional techniques often sacrifice dose uniformity for patient comfort and ease of treatment. A method has been developed using a translational bed under a Cobalt 60 photon beam. The bed and controller were designed and built on site. A bolused patient lying in the bed is moved at constant speed through the beam. Using this technique, dose homogeneity is optimized by the use of bolus, extended source-skin distance, adequate field size and use of anterior/posterior fields. The dose rate represents a compromise between a value high enough to keep treatment times tolerable by the patient and one that is sufficiently low to avoid treatment complications. The value of 50 cGy/min which was used meets these requirements. Extensive phantom measurements have shown that the dose homogeneity can be obtained to within an acceptable limit of +/- 5%.
Connors
S
S
Dept. of Medical Physics, Cross Cancer Institute, Edmonton, Canada.
Scrimger
J
J
Logus
W
W
Johnson
L
L
Schartner
E
E
D001513:Beds; D016026:Bone Marrow Transplantation; D002648:Child; D003037:Cobalt Radioisotopes / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D014916:Whole-Body Irradiation
D003037:Cobalt Radioisotopes