Dosimetry for small fields of high-energy electrons using radiographic films

Abstract

In our institution there are a considerable number of patients with skin carcinomas, for whom radiotherapy treatment with small high-energy electron fields is one of the most common treatment options. Dosimetry using an ionization chamber in small high-energy electron fields, as specified by international dosimetry protocols, requires ionization chambers with special characteristics; equipment that we do not have in our institution. This makes it necessary to use an alternative method to perform these measurements. The linear behavior of films in electrons of energies greater than 250 keV makes film dosimetry one of the best options to perform measurements in small high-energy electron fields; both for its quality of results, available information and low cost. This work aims to provide the radiotherapy department of the National Institute of Neoplastic Diseases "Dr. Eduardo Cáceres Graciani" (INEN) with a practical, safe and economical method to perform dosimetry of small high-energy electron fields; so that the international recommendations for high-energy electron dosimetry using film are applied taking into account the resources we have available, without implying that the quality of the results obtained is adversely affected.