Akademik Veri Yönetim Sistemi
EMERGENT MATERIALS, 2024 (ESCI)
In radiotherapy applications, with the aim of accurately delivering the prescribed dose in-patient treatments, a wide variety of organic and/or inorganic materials can be utilized as bolus material. In recent years, polymer materials have become a wide range of scientific research in radiotherapy. Especially, PLA (polylactic acid) and acrylonitrile butadiene styrene (ABS) materials are widely utilized in various applications within the field of radiotherapy. While three-dimensional (3D) printing, especially using fused deposition modeling (FDM) technology, was among the first techniques adopted, plastic injection molding (IM) has also been a well-established manufacturing method for many years. Initially, ABS and PLA materials were 3D-printed on an FDM 3D printer as square prisms measuring 12 x 12 x 1 cm3. These were specifically designed for use as measurement instruments in radiation assessments. Subsequently, identical test materials were produced through IM in an ISO D2-type mold made of S235JR steel (material number 1.0038) with the same dimensions. In radiotherapy applications, it is important for clinical use to evaluate the material of dosimetric properties as well as tissue equivalence. The goal was to dosimetrically evaluate the response of these materials to radiation produced by both FDM and IM techniques. Hounsfield units (HU) values were determined with the CT simulator device for all materials. Dosimetric measurements were performed using a 6-MV nominal photon energy. Percentage depth doses, dose profiles, and radio transmittance measurements of the materials were conducted in a water phantom and solid water phantom. All measurements were also conducted for commercially available bolus materials used in patients. Commercial bolus was used as a reference due to its routine use in the clinic. Although the dosimetric parameters for materials produced through 3D printing and plastic injection molding yielded similar results among themselves and with bolus material, it is advisable to evaluate the material dosimetrically before its use as a personal material on a patient due to printing characteristics and material variability.