title: In vivo dose evaluation during gynaecological radiotherapy using L-alanine/ESR dosimetry.
abstract: The dose delivered by in vivo 3-D external beam radiation therapy (EBRT) was verified with L-alanine/electron spin resonance (ESR) dosimetry for patients diagnosed with gynaecological cancer. Measurements were performed with an X-band ESR spectrometer. Dosemeters were positioned inside the vaginal cavity with the assistance of an apparatus specially designed for this study. Previous phantom studies were performed using the same conditions as in the in vivo treatment. Four patients participated in this study during 20-irradiation sessions, giving 220 dosemeters to be analysed. The doses were determined with the treatment planning system, providing dose confirmation. The phantom study resulted in a deviation between -2.5 and 2.1 %, and for the in vivo study a deviation between -9.2 and 14.2 % was observed. In all cases, the use of alanine with ESR was effective for dose assessment, yielding results consistent with the values set forth in the International Commission on Radiation Units and Measurements (ICRU) reports.
authors.affiliation: Departamento de Física, FFCLRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil amandarech@pg.ffclrp.usp.br.
authors.forename: Amanda Burg
authors.initials: AB
authors.lastname: Rech
authors.affiliation: Serviço de Radioterapia, HCFMRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Gustavo Lazzaro
authors.initials: GL
authors.lastname: Barbi
authors.affiliation: Serviço de Radioterapia, HCFMRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Luiz Henrique Almeida
authors.initials: LH
authors.lastname: Ventura
authors.affiliation: Serviço de Radioterapia, HCFMRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Flavio Silva
authors.initials: FS
authors.lastname: Guimarães
authors.affiliation: Serviço de Radioterapia, HCFMRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil Departamento de Clínica Médica, FMRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Harley Francisco
authors.initials: HF
authors.lastname: Oliveira
authors.affiliation: Departamento de Física, FFCLRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil.
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Baffa
mesh_terms: D000409:Alanine / Q000737:chemistry*; D001918:Brachytherapy; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005260:Female; D005831:Genital Diseases, Female / Q000532:radiotherapy*; D006801:Humans; D019047:Phantoms, Imaging; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D000409:Alanine