Radiation dose to conceptus resulting from tangential breast irradiation.
OBJECTIVE
To estimate the radiation dose to the conceptus resulting from tangential breast irradiation.


METHODS
Conceptus radiation doses were measured in anthropomorphic phantoms simulating the geometry of a pregnant woman at the first, second, and third trimesters of gestation. Medial and lateral field irradiations were generated using a 6-MV X-ray beam. Dose measurements were performed with thermoluminescent dosimeters.


RESULTS
For a treatment course delivering 50 Gy to the tumor, conceptus dose at the first trimester of gestation was found to be 2.1-7.6 cGy, depending on the field size used and the distance between conceptus and primary irradiation field. The corresponding dose ranges to the conceptus during the second and third trimesters of gestation were 2.2-24.6 cGy and 2.2-58.6 cGy, respectively. Dose data and formulas are presented to estimate conceptus dose for individual patients undergoing breast radiotherapy during the entire pregnancy.


CONCLUSIONS
This study may be of value in the management of pregnant women needing tangential breast irradiation, because it provides the required information to estimate conceptus dose.
Mazonakis
Michael
M
Department of Medical Physics, University Hospital of Iraklion, Crete, Greece.
Varveris
Haris
H
Damilakis
John
J
Theoharopoulos
Nikos
N
Gourtsoyiannis
Nikos
N
D000328:Adult; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D005333:Fetus; D006801:Humans; D008875:Middle Aged; D019047:Phantoms, Imaging; D011247:Pregnancy; D011264:Pregnancy Trimesters; D011829:Radiation Dosage