Bacterial nanocellulose membrane as bolus in radiotherapy: "proof of concept".

Boluses characterize materials with an electromagnetic radiation attenuation coefficient similar to biological tissue and used to restrict the penetration of high energy photons and electrons used in radiotherapy for the treatment of superficial tumors. The development of new materials, mainly from sustainable biotechnological routes, will contribute to increase efficiency and expand the use of these technologies. The objective of this research was to develop the "proof of concept" regarding the use of the bacterial nanocellulose membrane (BNCm) as a bolus. For this purpose, BNCm were produced, purified and subjected to the physical–chemical characterization. The radiological density (RD) and radiation attenuation potential (RAP) of the BNCm were established and compared to a commercial bolus (CB). The moldability of BNCm was established and compared to the virtual bolus of dosimetric planning. The physical–chemical analysis demonstrated the constitution of a pure, highly hydrated, homogeneous and nanostructured network of cellulose fibers. BNCm showed superiority in relation to RD and similar RAP values when compared to CB. Moldability analysis showed a profile identical to a virtual bolus. The results validate the concept of using BNCm as a highly efficient biotechnological device, aligned with the idea of sustainability, as a bolus for use in radiotherapy. [ABSTRACT FROM AUTHOR]