Measurement of Scattered Radiation Dose to the Eyes, Breasts and Gonads of Patients During External Beam Radiation

Abstract

In Nigeria data on radiation doses to critical organs outside primary radiation beams during radiotherapy is sparse therefore the extent to which other parts of patient’s body are protected during treatment could not be quantified. In clinical studies on measurement of radiation dose to critical structures, even though the doses are relatively low, have been associated with cardiac toxicity and increased risk of secondary cancer. This study is aimed at measuring scattered radiation to the eyes, breasts and gonads, of patients during Cobalt-60 external beam radiotherapy. Thirty patients with malignancy in the abdomen, breast, cervix and head and neck who consented to participate were studied. Scattered radiation was measured with thermoluminescence dosimetry (TLD) using calibrated Lithium Fluoride (LiF) phosphor and TLD Reader, Harshaw 4500. Scattered radiation dose to the eyes, breast and gonads from the treatment fields considered are: Abdomen (0.46 ± 0.10 Gy, 0.52 ± 0.10 Gy and 0.76 ± 0.50 Gy); Breast (0.58 ± 0.10 Gy, 1.10 ± 0.40 Gy and 0.50 ± 0.10 Gy); Head and neck (1.42 ± 1.10 Gy, 0.45 ± 0.10 Gy and 0.49 ± 0.10 Gy); Pelvis (0.50 ± 0.10 Gy, 0.48 ± 0.10 Gy and Nil). Gonads were not measured during irradiation of pelvic region. In this preliminary study, the scattered doses to the critical organs were found to be higher than the radiation level (0.1 Gy) at which cancer risk is considered unlikely. Further study is aimed at exploring treatment approach that would reduce scattered dose to the bearest minimum. [Elumelu-Kupoluyi T. N., Akinlade B. I., Abdus-salam A. A. and Adenipekun A. A. Measurement of Scattered Radiation Dose to The Eyes, Breasts and Gonads of Patients During External Beam Radiation Therapy.