Development of a phantom for dose distribution verification in Stereotactic Radiosurgery.
A geometric acrylic phantom was designed and built for dose distribution verification in Stereotactic Radiosurgery. Acrylic objects representing the tumor tissue, (target volume (TV)), and the organ at risk (OAR), the brainstem, were inserted inside this phantom. The TV is represented by two semi-spheres of acrylic with a diameter of 13.0 mm, both having a central cavity for accommodation of a TLD-100 detector and a small radiochromic Gafchromic EBT film. The OAR is represented by the two parts of a 38.0 mm length acrylic cylinder with a diameter 18.0 mm and cavities along the cylinder central axis able to accommodate 5 TLD - 100 detectors and another of EBT film between the two cylinder parts. This experimental setup was submitted to a radiosurgical treatment, after which the TL dosimeters were evaluated and their responses were compared with the planned dose values. The radiochromic EBT films showed the dose distributions. The linear accelerator used was a Varian 2300 C/D, generating a 6 MV photon beam. The investigated phantom system was able to check the accuracy of dose delivery to predetermined points and the dose distribution due to stereotactic radiosurgery treatments and proved to be a good tool for quality control in these situations.
Instituto de Radioproteção e Dosimetria, CNEN, Av. Salvador Allende Barra da Tijuca, 22783-127 Rio de Janeiro, Brazil.
Nilseia Aparecida
NA
Barbosa
Luiz Antonio Ribeiro
LA
da Rosa
Delano Valdivino Santos
DV
Batista
Arnaldo Rangel
AR
Carvalho
D005373:Film Dosimetry / Q000295:instrumentation*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D016634:Radiosurgery; D011880:Radiotherapy Planning, Computer-Assisted; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation*
Geometric phantom; Quality assurance; Radiochromic EBT film; Stereotactic Radiosurgery