Radiation dose to the fetus during CyberKnife radiosurgery for a XXXX in pregnancy.

@entity1 @entity851 @entity1313 @entity5 @entity600 @entity11
PURPOSE: Pregnancy during radiosurgery is extremely rare in clinical practice. We report fetal dose results during CyberKnife radiosurgery for a @entity1313 in pregnancy. METHODS AND MATERIALS: A 26 year old pregnant @entity1 with a rapidly growing deep-seated @entity11 was treated during the third trimester of gestation using CyberKnife. Ultrasound imaging was used to determine the position of the embryo prior to treatment. A dose of 1400   cGy was prescribed aiming to control @entity5 growth until delivery of the @entity1 . Prior to radiosurgery, the treatment was simulated on an anthropomorphic phantom. Radiation dose to the embryo was measured using a Farmer chamber and EBT3 films. RESULTS: Fetal doses of 4.4   cGy and 4.1   cGy were measured for the embryo's head and legs, lying at 56   cm and 72   cm from the isocenter, respectively, using the Farmer chamber situated at 8.5   cm depth beneath the phantom surface. Dose results of 4.4   cGy, 3.5   cGy and 2.0   cGy were measured with the films situated at depths of 6.5   cm, 9.5   cm and 14.5   cm, respectively. An average dose of 4.2   cGy to the fetus was derived from the above values. A corresponding dose of 3.2   cGy was also calculated based on results obtained using EBT3 films situated upon the @entity1 skin. CONCLUSIONS: The measured fetal doses are below the threshold of 10   cGy for @entity600 , mental and @entity851 effects. The radiogenic @entity5 risk to the live-born embryo was estimated less than 0.3% over the normal incidence. The treatment was administered successfully, allowing the @entity1 to deliver a healthy @entity1 .
