Feasibility of three-dimensional-printed template-guided ¹²⁵I seed brachytherapy and dosimetric evaluation in...

The objective of the study is to test whether three-dimensional (3D)-printed template can be used reproducibly for guiding malignant tumors brachytherapy and study the dosimetric consistency and adequacy between pre- and post-plan.

Between January and December 2016 in our hospital, a total of 14 patients underwent 3D-printed template-guided brachytherapy. All the patients were fixed into position using a vacuum cushion before undertaking a computed tomography (CT) scan. After the preplan was designed, the templates were printed. The tumors were punctured through predesigned needle holes. Following this, another CT scan was used to confirm the locations of needles, and then the ¹²⁵ I radioactive seeds were implanted into the tumor according to the preplan. Postplan was performed after the operation. Data of the D90 (minimum absorbed dose of 90% target volume), V90 (90% prescription dose coverage volume percentage of target volume), V100, V150, and seed number pre- and post-operation were collected and compared.

The mean D90, V90, V100, V150, and seed number preoperation were 94.96 ± 16.43 Gy, 94.64% ± 1.43%, 91.21% ± 1.59%, 65.01% ± 5.78%, and 46.67 ± 21.87, respectively. The mean D90, V90, V100, V150, and seed number postoperation were 91.97 ± 17.54 Gy, 93.35% ± 2.45%, 89.35% ± 3.21%, 63.40% ± 6.36%, and 46.60 ± 22.85, respectively. No significant difference between pre- and post-operation was observed across the data (P >0.05).

For immobilized malignant tumors, 3D-printed template can be used reproducibly. The dose parameters in preplan can be achieved easily and satisfactorily by 3D-printed template guided brachytherapy, and it may become an easily reproducible standardized procedure in the future.