Functional Assessment of Cancer Therapy-Brain questionnaire: translation and linguistic adaptation to Brazilian Portuguese

context and objective: quality of life assessment among patients with brain tumors is important, given that new treatments have increased patient survival. the aim of this study was to translate the functional assessment of cancer therapy-brain (fact-br) questionnaire (version 4) into portuguese, carry out cross-cultural adaptation and assess its reproducibility. design and setting: cohort at the universidade federal de s？o paulo (unifesp). methods: forty patients with a brain tumor seen at the neuro-oncology outpatient clinic participated in the study. the process of translation and back-translation was carried out, along with adaptation to the portuguese language and brazilian culture. the intraclass correlation coefficient (icc) was used to test the reproducibility of the fact-br (version 4). results: the reproducibility of the questionnaire was excellent (icc = 0.95; 95% confidence interval, ci: 0.89-0.97). the icc with a mean interval of 15 days between applications of the questionnaire was very good in all domains (icc = 0.87 to 0.95). the mean time taken to answer the questionnaire was 6.27 ± 2.26 minutes, ranging from 3 to 11 minutes. conclusion: the translated version of the fact-br questionnaire (version 4) adapted to the portuguese language and brazilian culture proved to be easily understood and achieved very good reproducibility among patients with diagnoses of brain tumors.