Tissue doses from radiotherapy of cancer of the uterine cervix

Abstract

For use in an epidemiologic study of subsequent tumors, absorbed doses from brachytherapy and external beam radiotherapy were measured and calculated for various tissues of patients treated for cancer of the uterine cervix. External beams included orthovoltage x rays (1.9 and 3.0 mm Cu half-value layer), cobalt-60 gamma rays, 2 MV x rays, and 25 MV x rays. The brachytherapy sources were encapsulated radium. Measurements were made in an Alderson anthropomorphic phantom and a water phantom; calculations were made using a Monte Carlo technique or standard radiotherapy methods. Depending upon stage of disease and radiation energy, the absorbed doses (cGy) from typical treatment regimes to tissues of interest were: ovaries, 1400-5200; stomach, 130-320; kidneys, 120-310; pancreas, 100-260; lungs, 22-48; breasts, 19-52; thyroid, 6-17; salivary glands, 4-11; brain, 2-7, and total active bone marrow, 320-1100. The lower values of each range were for stage I of the disease.