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ST 3.2 –
Protección radiológica en radiodiagnóstico
(orientada a la tomografía computada)
PATIENT DOSIMETRY IN DIGITAL MAMMOGRAPHY
IN BRAZIL AND COSTA RICA
Xavier, Aline
1*
; Villachan, Beatriz
1
; Andrade, Marcos
1
;
Alves, Fátima
2
; Pires, Silvio
2
; Bitelli, Regina
2
; Mora, Patrícia
3
;
Barros, Vinícius
1
; Khoury, Helen
1
1
Universidade Federal de Pernambuco. Brasil.
2
Universidade Federal de São Paulo. Brasil.
3
Centro de Investigación en Ciencias Atómicas, Nucleares y Moleculares. Costa Rica.
* Responsible author, email: alinecx90@gmail.com
Digital mammography systems are spreading across Latin America in the last years, but their
use is not always followed by the irradiation protocols’ optimization. This may result in higher
radiation absorbed doses to the mammary gland. Regarding this, it is important to know the
radiation doses delivered to patients due to these procedures. The objective of this work is to
estimate the mean glandular dose to patients undergoing digital mammograms in Costa Rica
and two regions of Brazil. Mammographic examinations were performed using four CR and four
DR systems, as follows: Siemens Mammomat 3000 Nova with Carestream Kodak DirectView
(CR) and Hologic Lorad Selenia (DR), located in Recife, Brazil; Hologic Lorad MIV and GE
Performa with Carestream Kodak Direct View Elite (CR) and GE Senographe DS (DR), located
in São Paulo, Brazil; Agfa Healthcare (CR) MM3.0 and Planmed Nuance (DR), located in Costa
Rica. The irradiation parameters (kVp, mAs and anode/filter combination), compressed breast
thickness and the patient age were collected during the examinations. Tube output and half-
value layer for several kVp values were measured using ionization chambers calibrated at
mammography radiation quality. Mean glandular dose (MGD) for each mammogram was
determined on the basis of the conversion factors estimated by Dance and the incident air
kerma calculated from the tube output. The results showed that the MGD values for breasts with
thickness from 4 cm to 6 cm varied from 1.08 mGy to 6.75 mGy at CR systems and from 1.09
mGy to 8.80 mGy at DR systems. The MGD values are included within the CEC reference
levels, but some MGD values are higher than the European reference levels, indicating the
need to optimize the irradiation protocols.