Stereotactic radiosurgery delivery verification using tetrazolium salt-based gel as a dosimeter

The recently made available ClearView (R) tetrazolium salt-based gel dosimeter, encapsulated in a vial, was tested to determine feasibility in use as an end-to-end dosimeter for stereotactic radiosurgery commissioning and quality assurance. A fabricated adaptor enabled direct attachment of the gel vial lid to a rod extension. The rod was inserted into a water-filled head phantom at the open neck location and locked into position. Once quality assurance testing of the linear accelerator was completed, a stereotactic plan was deployed. Optical scanning software enabled a direct comparison of the measured positional isocenter and dose distribution to the intended plan. Delivery accuracy was verified as line-dose profile plots of measured data coincide with the planned dose location and distribution. It has been demonstrated here that ClearView (R) gel contained in a vial is a suitable dosimeter for verifying stereotactic radiation therapy delivery accuracy. The end-to-end testing provided is geared to work identically for any small field study, including stereotactic radiosurgery and radiotherapy, volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy.