Page 412 - 2014 Printable Abstract Book
P. 412
at community hospitals and subsequent phantom dosimetry experiments. Among subjects of the Life
Span Study (LSS), a field survey and a phantom dosimetry experiment were performed during 1981-84 to
investigate organ dose from radiation therapy. To obtain further and updated information on medical
radiation exposures in the LSS subjects, a mail survey was conducted in 2008. Methods: This survey used
a self-administered questionnaire, which was mailed to the LSS subjects who were alive as of July 1, 2007
and who had responded to the 1991 mail survey. Questions regarding exposure to CT, fluoroscopy,
angiography and radiotherapy were administered. The association between dose from A-bomb and
exposure from these four outcome measures were analyzed. Results: Questionnaires were sent to 24,640
subjects, with 14,090 responses (57%). Among the respondents, 73% of those had undergone CT scan,
68% fluoroscopy, 20% angiography, and 7% had received radiotherapy. While no clear trends of exposures
to CT and fluoroscopy with A-bomb radiation dose were found (P for trend > 0.05), significant upward
trends of exposures to angiography (P for trend 0.029) and radiotherapy (P for trend 0.013) were observed
with the atomic-bomb radiation dose. Older subjects were more likely to experience CT and younger
males GI fluoroscopies. Conclusions: A substantial proportion of LSS subjects were exposed to medical
radiation. Dose from atomic-bomb was not associated with exposures to screening-like diagnostic
procedures, but associated with exposures to procedures which aim to confirm diagnosis of cancers and
to radiotherapy, indicating the consequence of increased risk of cancers related to A-bomb radiation dose.
These findings can be used for future analysis after taking some limitations into account. Medical radiation
exposures in the LSS subjects will be evaluated by using findings not only from the present survey, but
also from previous studies.
(PS7-61) Computed tomography usage in Brazil: Trend, pattern, dose and risk assessment Lene H.S.
2
1
1
1
1
Veiga, PhD ; Ana C.M. Dovales, Msc ; Tainá Chaves, Msc ; Marina Mello, Msc ; Luiz Rosa, PhD ; John Hunt,
4
1
1
3
1
PhD ; Pedro Queiroz, PhD ; Dunstana Melo, PhD ; Marcelo Valente, PhD ; Andreas Jahnen, PhD ; Choonsik
6
1
5
7
Lee, PhD ; Amy Berrington de Gonzaléz, PhD ; Ausrele Kesminiene, PhD ; and Mark Pearce, PhD ; Institute
1
of Radiation Protection and Dosimetry, Rio de Janeiro, Brazil ; Rede D'Or São Luiz Hospital Network, Rio
2
3
de Janeiro, Brazil ; University of São Paulo Medical School, São Paulo, Brazil ; Centre de Recherche Public
5
4
Henri Tudor, Luxembourg, Belgium ; National Cancer Institute, Rockville, MD ; International Agency for
6
7
Research on Cancer, Lyon, France ; and Newcastle University, Newcastle upon Tyne, United Kingdom
Computed tomography (CT) usage has increased in most of developed world. Despite its
unquestionable value as a medical diagnostic tool, its increasing use coupled with empirical findings from
recently published studies in the UK and Australia has raised concern about potential cancer risks
associated with the radiation exposure. Nevertheless, while doses, pattern and trend of CT usage are well
documented in developed countries, and initiatives have been established to reduce unnecessary
exposure, relatively little is known about CT usage in developing countries, such as Brazil. In 2013, a
national project was launched in Brazil with the objectives of: 1) Describing nationwide trends and
patterns of CT scan use and associated radiation doses in the Brazilian population; 2) Evaluating CT
referrals among pediatric patients; and 3) Conducting a pilot study to assess the feasibility of establishing
a cohort study of cancer risk after pediatric CT in São Paulo, Brazil. The aim of this work is to present the
scope of this national project, including methodology and some preliminary results of CT usage in both
public and privately-funded health care systems in Brazil. Our study will provide information about doses,
trend and pattern of CT usage in Brazil that can possibly reflect differences in clinical practice between
developed and developing world. Also, the Brazilian cohort study can provide empirical quantitative
Span Study (LSS), a field survey and a phantom dosimetry experiment were performed during 1981-84 to
investigate organ dose from radiation therapy. To obtain further and updated information on medical
radiation exposures in the LSS subjects, a mail survey was conducted in 2008. Methods: This survey used
a self-administered questionnaire, which was mailed to the LSS subjects who were alive as of July 1, 2007
and who had responded to the 1991 mail survey. Questions regarding exposure to CT, fluoroscopy,
angiography and radiotherapy were administered. The association between dose from A-bomb and
exposure from these four outcome measures were analyzed. Results: Questionnaires were sent to 24,640
subjects, with 14,090 responses (57%). Among the respondents, 73% of those had undergone CT scan,
68% fluoroscopy, 20% angiography, and 7% had received radiotherapy. While no clear trends of exposures
to CT and fluoroscopy with A-bomb radiation dose were found (P for trend > 0.05), significant upward
trends of exposures to angiography (P for trend 0.029) and radiotherapy (P for trend 0.013) were observed
with the atomic-bomb radiation dose. Older subjects were more likely to experience CT and younger
males GI fluoroscopies. Conclusions: A substantial proportion of LSS subjects were exposed to medical
radiation. Dose from atomic-bomb was not associated with exposures to screening-like diagnostic
procedures, but associated with exposures to procedures which aim to confirm diagnosis of cancers and
to radiotherapy, indicating the consequence of increased risk of cancers related to A-bomb radiation dose.
These findings can be used for future analysis after taking some limitations into account. Medical radiation
exposures in the LSS subjects will be evaluated by using findings not only from the present survey, but
also from previous studies.
(PS7-61) Computed tomography usage in Brazil: Trend, pattern, dose and risk assessment Lene H.S.
2
1
1
1
1
Veiga, PhD ; Ana C.M. Dovales, Msc ; Tainá Chaves, Msc ; Marina Mello, Msc ; Luiz Rosa, PhD ; John Hunt,
4
1
1
3
1
PhD ; Pedro Queiroz, PhD ; Dunstana Melo, PhD ; Marcelo Valente, PhD ; Andreas Jahnen, PhD ; Choonsik
6
1
5
7
Lee, PhD ; Amy Berrington de Gonzaléz, PhD ; Ausrele Kesminiene, PhD ; and Mark Pearce, PhD ; Institute
1
of Radiation Protection and Dosimetry, Rio de Janeiro, Brazil ; Rede D'Or São Luiz Hospital Network, Rio
2
3
de Janeiro, Brazil ; University of São Paulo Medical School, São Paulo, Brazil ; Centre de Recherche Public
5
4
Henri Tudor, Luxembourg, Belgium ; National Cancer Institute, Rockville, MD ; International Agency for
6
7
Research on Cancer, Lyon, France ; and Newcastle University, Newcastle upon Tyne, United Kingdom
Computed tomography (CT) usage has increased in most of developed world. Despite its
unquestionable value as a medical diagnostic tool, its increasing use coupled with empirical findings from
recently published studies in the UK and Australia has raised concern about potential cancer risks
associated with the radiation exposure. Nevertheless, while doses, pattern and trend of CT usage are well
documented in developed countries, and initiatives have been established to reduce unnecessary
exposure, relatively little is known about CT usage in developing countries, such as Brazil. In 2013, a
national project was launched in Brazil with the objectives of: 1) Describing nationwide trends and
patterns of CT scan use and associated radiation doses in the Brazilian population; 2) Evaluating CT
referrals among pediatric patients; and 3) Conducting a pilot study to assess the feasibility of establishing
a cohort study of cancer risk after pediatric CT in São Paulo, Brazil. The aim of this work is to present the
scope of this national project, including methodology and some preliminary results of CT usage in both
public and privately-funded health care systems in Brazil. Our study will provide information about doses,
trend and pattern of CT usage in Brazil that can possibly reflect differences in clinical practice between
developed and developing world. Also, the Brazilian cohort study can provide empirical quantitative
