Dose and secondary cancer-risk estimation of patients undergoing high dose rate intracavitary gynaecological brachytherapy

Dose and secondary cancer risk of the breast and thyroid during high dose rate (HDR) brachytherapy for 100 gynaecological cancer patients have been estimated. The organ doses were measured using LiF thermoluminescence dosimeters LiF (TLD-100). Patient demographic data (i.e. age and body mass index (BMI)) were also collected and analyzed. Statistical significance (p-value = 0.04; 0.01; 0.01) was observed for the correlation between age and breast dose; body mass index (BMI) and breast dose as well as BMI and thyroid dose. The average breast dose for cervical, vaginal and endometrial cancers were 7.44, 8.03 and 10.72 mGy, respectively. The average thyroid dose for cervical, vaginal and endometrial cancers were 2.32, 2.95 and 3.02 mGy, respectively. Excess absolute risk of the breast increased with attainable age and excess relative risk of the thyroid decreased with age at exposure. It is recommended to intensify post-treatment follow-ups and optimize the doses to the breast and thyroid.