ABSTRACT
Objective:To introduce the workflow of individualized 3D-printed intracavitary/interstitial vaginal template design. Dosimetric parameters and operation safety were investigated to evaluate the performance of 3D-printed template and freehand implantation.Methods:Forty patients previously treated with intracavitary/interstitial Ir-192 HDR brachytherapy were enrolled in this study. All patients were randomly divided into the treatment ( n=20) and control groups ( n=20). In the treatment group, twenty patients were treated with individualized 3D-printed template. CT-based preplan was carried out to determine the needle implantation cannels. Template with customized shape and implantation cannels was then produced by a 3D printer. Finally, the template was inserted under CT guidance. In the control group, twenty patients received freehand implantation. Needle insertion was decided empirically without the preplan process. Results:The difference of D 90 for high risk CTV was found to be minor, while the D 2cm 3 in the rectum, bladder and sigmoid was significantly improved in the treatment group. Meanwhile, the high dose region and conformal index were also improved in the treatment group. A total of 273 needles were inserted and one (0.3%) not-used needle was found. No normal tissues were penetrated during needle insertion in the treatment group. In the control group, a total of 203 needles were inserted and 4(2.0%) not-used needles were observed, and normal tissue penetration occurred in 3(1.5%) needle insertion. Conclusions:The individualized 3D-printed template implantation approach has advantages in terms of dosimetry and safety compared with freehand implantation. The actual treatment can achieve the dosimetric design requirements of the preplan.
