A concave tray with divergent block for desired dose distribution around shielded region in megavoltage radiation therapy.
In clinical situations large numbers of rectangular divergent blocks are required at different off-axis positions from central axis to shield sensitive organs. Superiority of divergent blocks over non-divergent blocks on a flat tray lies in improving the dose homogeneity. A method has been developed to minimize the number of divergent shielding blocks by using a concave tray at the collimator. The results of use of a single divergent block are similar to that of the use of several divergent blocks, each to match at different off-axis positions in the radiation beam. This type of single concave tray thus provides a considerable ease of handling divergent blocks in a busy radiotherapy centre.
Department of Medical Physics, Tata Memorial Hospital, Bombay, India.
J S
JS
Avadhani
A S
AS
Pradhan
A
A
Sankar
P S
PS
Viswanathan
D001729:Bismuth; D002104:Cadmium; D004867:Equipment Design; D006801:Humans; D007854:Lead; D008961:Models, Structural; D011835:Radiation Protection / Q000295:instrumentation*; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000295:instrumentation*; D013499:Surface Properties
D002104:Cadmium; D007854:Lead; D001729:Bismuth