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208   Nuclear Science and Technology | Progress Report





               The comparison between Varian AAA              try uncertainties below 2 %, validating the re-
               and ACUROS XB dose calculation                 sults. Figure 9 presents the anthropomorphic
               algorithms for VMAT treatment planning         skull 3D printed phantom.
               of brain multiple metastases
                                                              3D Phantoms
                                             Figure 9-  Landauer
                                             nanoDot
                                             dosimeters and   Attenuation coefficient determination
                                             anthropomorphic
                                             skull 3D printed   of printed ABS and PLA samples in
                                             phantom.         diagnostic radiology standard beams



                                                              IAEA code of practice TRS-457 states that stan-
                                                              dard phantoms should offer the same primary
               The Optically Stimulated Luminescence dosim-   attenuation and scatter production as relevant
               etry has become one of most used techniques    body section of a representative patient. Mate-
               for radiation dosimetry nowadays. The “Ala-    rial cost, availability and dimensional stability
               bama Technique” demonstrates plan quality      must also be considered. The goal of this study
               and provides a practical, systematic approach   was to determine the attenuation coefficient
               to the treatment planning technique for single   of printed ABS and PLA samples in standard
               isocenter cranial radiosurgery with volumetric   X-ray beams, verifying if phantoms printed
               modulated arc therapy (VMAT) used in meta-     with these materials could be an easier-han-
               static carcinoma treatments. An anthropomor-   dle substitute for PMMA, enabling the creation
               phic skull 3D printed phantom was submitted    of different designs in an easier and cheaper
               to a CT scan and planed five target volumes. In   way. Results show that PMMA presents higher
               order to compare, two dose calculations were   attenuation coefficient, followed by PLA and
               performed in the Varian Eclipse with VMAT      ABS, which means that thinner PMMA layer
               planning with “Alabama technique” using        creates higher radiation attenuation.
               the Varian’s AAA and Acuros XB algorithms.
               The treatment was delivered with a VARIAN      Equivalence between Solid Water and printed
               True Beam linear accelerator with Multileaf    PLA plates for 6 MV clinical photon beam – An
               Collimator HD and 6 MV photon beam was         assessment using thermoluminescent dosimetry
               used. Landauer nanoDot dosimeters were po-
               sitioned inside each of the five target volumes    Three dimensional models of anatomical
               planned and the experimental dosimetry re-     structures, produced by rapid prototyping are
               sults were compared with the two calculation   being adopted for medical application as he-
               algorithms. The experimental results using the   modynamics studies and maxillofacial surgery
               OSLDs show agreement of 97.26 %, 99.12 %,      planning. Models with geometrical accuracy
               99.99 %, 95.94 % and 98.79 % for the targets 1   can be achieved using medical images as MRI
               to 5 respectively for the ACUROS XB calculated   or CT and produced using polyurethane, poly-
               doses. The findings of this work indicate that   lactic acid and epoxy resins. By changing ma-
               ACUROS XB calculates more accurate doses       terials and densities, it is possible to achieve
               compared with AAA, with all the experimen-     the desired tissue-equivalence[1]. This work
               tal agreements better than 96 %. The intrinsic   was developed in order to analyze the equiv-
               precision and uncertainty of the InLight sys-  alence between the printed PLA and the Solid
               tem device is sufficient to sustain the dosime-  Water plates by using the thermoluminescence





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