[Dose Distribution Optimization in Combined Intracavitary and Interstitial Brachytherapy for Cervical Cancer].

PURPOSE

Hybrid inverse treatment planning optimization (HIPO) is a new optimization tool for brachytherapy. We verified its utility using treatment plans for combined intracavitary and interstitial brachytherapy in cervical cancer.

MATERIALS & METHODS: We compared the manually optimized plan and the plan optimized using HIPO. The plan using HIPO was optimized with three different methods: needle only, tandem and needle, and all applicators. The dose volume histogram (DVH) parameters such as D of high risk clinical target volume (HR-CTV) and D of OAR (rectum, sigmoid colon and bladder) were used to evaluate each treatment plan.

RESULTS

The D of HR-CTV in most plans was received more than 600 cGy. In addition, the D of OAR also was less than the tolerance dose on the average of all plans. However, the D of the rectum and bladder treatment plans optimized only with needles was significantly higher than other plans.

CONCLUSIONS

The treatment plans used in clinical practice and obtained by HIPO have similar dose distributions and DVH parameters. Moreover, the time needed to create treatment plan was reducing by HIPO. We suggest that HIPO will be an effective tool in treatment planning.