Enhancing Radiotherapy Bolus Characteristics through Comparative Analysis of Added Sawdust and Bagasse Powder: A Comprehensive Study of Physical and Mechanical Properties
Authors: Sianturi Herty Afrina , Ginting Junedi , Azhari  , Rianna Martha , Marbun Renisa Gunar AP , Sinaga Anggi Pratiwi , Siregar Rumatar Yan Monri , Sidauruk Lincewati , Silalahi Montesqieu , Tampubolon Hendra , Manik Perdana 
Published: April 2024

Abstract
Research has been successfully conducted on the manufacture of synthetic bolus for radiotherapy made of silicone rubber containing polydimethyl siloxane and alginate as well as the addition of bagasse and wood sawdust. The purpose of this study was to determine the characterization of radiotherapy bolus by analyzing the comparison of the addition of bagasse and wood sawdust through its physical and mechanical properties. The methods used in this research are bolus sample preparation, characterizations of physical and mechanical properties and analysis of characterizations results. From the physical properties, the results of the characterizations of this research obtained that in the density test the bolus synthesis with the addition of bagasse at a thickness of 1.5 cm and 2 cm was 0.6 g/cm3 and 0.55 g/cm3 respectively, while the bolus synthesis with the addition of wood sawdust at a thickness of 1.5 cm and 2 cm had a density of 0.86 g/cm3 and 0.75 g/cm3 respectively. In porosity testing, the 1.5 cm thick synthetic bolus with the addition of bagasse and wood sawdust has a porosity of 6.6% while the bolus with a thickness of 2 cm in the addition of bagasse and wood sawdust has a porosity of 5%. In the water absorption test, the synthetic bolus in the addition of bagasse with a thickness of 1.5 cm and 2 cm has a water absorption of 11.11% and 9.09%, respectively. Bolus synthesis with the addition of wood sawdust with a thickness of 1.5 cm and 2 cm had a water absorption of 7.69% and 6.66%, respectively. From the mechanical properties, tensile strength testing of the synthesized bolus of 1.5 cm and 2 cm thickness with the addition of bagasse has a tensile strength value of 0.56 MPa and 0.38 MPa, respectively. while the tensile strength of the synthesized bolus with the addition of wood sawdust of 1.5 cm and 2 cm thickness is 0.42 MPa and 0.33 MPa, respectively. In the elongation at break test, the synthesis bolus with the addition of bagasse at a thickness of 1.5 cm and 2 cm was 92.33%, 52.69% respectively and the bolus with the addition of wood sawdust at a thickness of 1.5 cm and 2 cm had a large elongation at break of 93.49% and 106%. And in the elastic modulus test, the synthesis bolus in the addition of bagasse with a thickness of 1.5 cm and 2 cm is 0.611 MPa and 0.723 MPa respectively while the elastic modulus in the synthesis bolus with the addition of wood sawdust with a thickness of 1.5 cm and 2 cm is 0.465 MPa and 0.319 MPa respectively. From the physical and mechanical tests that have been carried out, the synthetic bolus with the addition of bagasse and wood sawdust at a thickness of 1.5 cm given the codes A1 and B1 can be said to have good material and has high elasticity compared to the synthetic bolus with a thickness of 2 cm both from the addition of bagasse and wood sawdust given the codes A2 and B2.