Imaging-Based Surgical Navigated 125i Interstitial Brachytherapy for Locally Advanced Salivery Gland Carcinoma

Abstract

The precise placement of the needles and seeds is mandatory in interstitial brachytherapy. This study is to explore the practice of accurate positioning of imaging-based surgical navigated 125i interstitial brachytherapy for treatment of locally advanced salivery gland carcinoma. Seventeen patients with locally advanced salivery gland carcinoma were included in this retrospective study. Before 125I implants, the implantation plan was made through the brachytherapy treatment planning system software based on patient’s CT. The template was designed by using Mimics and Geomagic software based on the implantation plan and made through rapid prototyping technique. The template data in STL format and CT were imported into the iPlan CMF software, merged into one object according to the 3-D appearance of the skin and became the navigation plan, which was transferred to the VectorVision navigation system before implantation. During the implantation, the template was placed to the planned position by the guidance of the navigation plan. The needles were implanted using the template and navigation plan guidance, to ensure that all needles were in the expected position and depth. After implants, treatment quality evaluation was made by TPS based on the post-implantation CT. The implantations of all patients were performed sucessfully under navigation plan guidance. The seeds and dosages distribution (D90,V100,V150) were well meet the treatment requirement. The navigation system will be a very useful clinical tool for interstitial brachytherapy applications. Clinical practice confirms that this approach can facilitate easier and more accurate implantation.