Tannin-Bonded Rhizophora spp. Particleboards as Water Equivalent Phantom Material for High Energy Photons and Electrons

Phantom materials are important tools for quality control and dosimetry works in medical physics. The tannin-bonded Rhizophora spp. particleboards in were fabricated as phantom and the dosimetric properties at high energy photons and electrons were evaluated. The particleboards were fabricated at dimensions of 30 x 30 x 1 cm3 and target density of 1.0 g/cm3 based on the commonly used solid water phantoms in radiotherapy. The effective atomic number of the particleboard was determined based on the elemental compositions measured using energy dispersive x-ray analysis (EDXA). The mass attenuation coefficients at high energy photon were measured at 16.59-25.26 keV photons and 60Co and 137Cs gamma energies. The percentage depth dose and beam parameters of the particleboards were measured at 6 MV photons and 6 MeV electrons using Gafchromic EBT2 film and treatment planning system (TPS) software. The results showed that the effective atomic number and electron density of the particleboards were close to the value of water. The mass attenuation coefficient at high energy photons were close to the XCOM value of water. The percentage depth dose at high energy photons and electrons showed an agreement to the value in water and solid water phantom within 10% at all measured depths. The overall results indicated the suitability of tannin-bonded Rhizophora spp. as phantom material for high energy photons and electrons.