Introduction
The standard of care for treatment of advanced cervical cancer is the combination of concurrent chemotherapy with external beam radiation therapy (EBRT) followed by an intracavitary brachytherapy (ICBT) boost1-4. This comprehensive treatment achieves a favorable outcome for cervical cancer patients5-7, but for patients with bulky irregular shaped tumors, the local recurrence rate remainedl relatively high 8-10.
ICBT plays a crucial role in the radiotherapy for cervical cancer. It has been shown in large patient series that omission of brachytherapy results in a dramatic reduction of the curative chance11-14. Conventional ICBT is typically prescribed to a defined point based on the Manchester system 15, in which the individual tumor size or shape is not taken into account. Several studies have demonstrated that the dose distribution of conventional ICBT often fails to cover the entire target volume, especially in patients with large irregular tumors16, 17, which result in a relatively high relapse rate 18.
3D image-guided brachytherapy has been demonstrated to improve outcomes in comparison to conventional BT-planning, and the combination of IC/IS applicators can be incorporated into planning for bulky tumors19, 20. In locally advanced cervical cancer, tumors tend to spread laterally along the cardinal ligament. Therefore, in order to improve the dose coverage of the entire target volume, previous investigators have made many efforts to develop novel brachytherapy techniques such as trans-perineal interstitial BT (ISBT) and trans-cervical interstitial BT with ICBT (IC/ISBT)21, 22. Previously, the concept of supplementary IMRT based on conventional ICBT (IC/IMRT) has been introduced 23. Furthermore, proof of principle with IC/IMRT demonstrated that IC/IMRT is able to supplement radiation dose to the parametrial tumor extension where ICBT optimized based on image guidance is unable to cover the target volume 24 25.
To date, clinical outcomes with IC/IMRT have not been reported. In the present study, we retrospectively analyzed the local control (LC), survival rates and side effects of 76 patients treated with IC/IMRT in order to further clarify the present and future clinical impact of this technique.