Minimizing urinary bladder radiation dose during brachytherapy for carcinoma of the cervix using balloon inflation technique.

Purpose: Radiotherapy is effective in treating cancer of the cervix. However, its success is associated with significant morbidity of the urinary bladder. This study has been designed to reduce the radiotherapy dose from the brachytherapy component of cervical cancer treatment to the urinary bladder to minimize radiation-induced morbidity.
Materials and Methods: By inflating the balloon of a Foley catheter at the anterior fornix region, attempts were made to displace the urinary bladder in patients undergoing gynecological intracavitary brachytherapy. The radiation dose to the urinary bladder was then studied in 12 insertions without and 31 insertions with balloon inflation.
Results: The increase in the distance from the intrauterine tandem source to a reference point in the base of the bladder and the resultant decrease in the radiation dose have been determined. A highly significant reduction in the radiation dose with an increase in distance between the source applicator and bladder base were achieved (p < 0.01 in both cases).
Conclusion: A significant reduction in radiation dose to the bladder base can be achieved by the technique described in this study. A three-dimensional plan generated using CT images can demonstrate the drawback of ICRU-38 bladder reference point. The technique is simple consistent and reproducible within an acceptable range.