Dosimetric properties of MacroMedics products
MacroMedics develops dedicated state-of-the-art carbon fiber products for radiotherapy departments using the latest production techniques. Usability, functionality, hygiene and strength for the more and more heavy patient become more important, while the influence of build-up effect decreases by the use of multi-beam techniques.
MacroMedics has asked the radiotherapy department of the UMC Utrecht (University Medical Center Utrecht) to perform measurements on dosimetry, the transmission factor and skindose.
Test set-up and equipment:
The transmission factors are determined under 2 different gantry angles (0 and 45 degrees) and at 4 different fieldsizes. (3x3, 5x5 and 10x10 cm) These measurements are performed in a cylindrical perspex phantom at a depth of 5 cm. By choosing a cylindric phantom, measurements can be performed from different angles and the path length in the phantom will stay the same.
The dose build-up on the skin is determined by measuring the dose in a solid water RW3- phantom on a large number of depths (0, 1, 2, 3, 5, 7, 10, 15, 20, 30, 50, 100 mm).
From this a percentage depth dose (PDD) graph is made. By creating this PDD-graph without material and with material on a phantom block, the influence of the material on the dose on the skin (depth 0 mm) can be determined.
A summary of the results can be found below.
The specified numbers for absorption factors are measured at a perpendicular radiation and where of importance valid for the thicker part of the material.
The specified buildup of the skindose is an average of the values for 6 and 10 MV.
December 2013, Department of Radiotherapy, UMC Utrecht, The Netherlands
Provided values are for reference only. For more information about the measurements and results, please contact us: firstname.lastname@example.org
Note 1: To complete the overview, we have added measurement results of other MacroMedics devices from other hospitals
Note2: Use the provided values only as a guidance. Perform measurements in your hospital and equipment to verify these results.