Evaluation of fetal dose from megavoltage irradiation of the knee and neonate followup.

A 24-yr-old female patient who was to undergo radiation therapy management for a recurrent low-grade fibrosarcoma on her right knee was found to be 9 weeks pregnant. The patient and her relatives insisted on carrying the pregnancy to maturity, despite undergoing irradiation of her right knee for local control of her disease and to take the teratological risk, if any, that it entails. This paper discusses the measurement of scattered dose in water, fetal dose estimation in an Alderson-Rando human phantom and possible ways of minimizing it.