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.