There are three ways to reduce exposure to radiation - time, distance and shielding. Since time and distance to some of the staff in the department are constant, to keep the dose to within acceptable limits within a relatively small sized radiation cancer center, shielding provides an important barrier. Shielding calculations for a radiation oncology department is a complex process, which involves taking into account building design, machine energy, Linac orientation, material used for construction, etc. In addition, these calculations also need to take into consideration different particles like gamma rays, x rays, neutrons, etc.
Depending on the modality and energies of radiation producing sources, there are different recommendations on how to calculate the thickness of different shielding materials required in vault construction. Incorrect calculation of the necessary wall thickness with the shielding materials used results in significantly increased cost and unnecessary delays. We, as a group, have multiple licensed physicists who are experienced in these calculations, and have been responsible in successful design and implementation of the same for various cancer centers.
Using nationally accepted standards and criteria, detailed step-by-step calculations are performed thereby conforming to the guidelines set by the regulating authorities. We have in the past successfully designed vaults for operation of radiation producing equipment such as Linear accelerators, HDR after loaders, PET/CT, and CT scanners.