[The dosimetry comparison study between 3D print template and free-hand guided of precision (125)I seeds implantation on superficial metastatic carcinoma].

Objective: To compare the dose difference of (125)I seeds implantation on superficial metastatic carcinoma between 3D print template guided operation and traditional implantation. To investigate the accuracy of seeds implantation according preplan guided by 3D print template. Methods: A total of 21 cases of patient with 27 lesions underwent (125)I seeds implantation from January 2015 to May 2018 in Hebei General Hospital were analyzed retrospectively. In which, ten lesions underwent seeds implantation guided by 3D print template (template group) and 17 lesions underwent free-hand traditional implantation (traditional group). All patients had been fixed as the position of operation and then performed CT scan. After preplan was designed, the 3D templates were printed in template group. Postplan was performed after the operation.The dose volume histogram, D90 was calculated. The D90 pre and post operation were collected and compared in each group. The difference of D90 and the percentage difference of D90 between pre and post operation were calculated by the formula D90d=D90post-D90pre, D90d%=(D90post-D90pre)/D90pre×100%, and compared the difference between two groups. Results: The mean D90 pre and post operation in template group were (92±26) and (93±27) Gy respectively, t=-0.749, P=0.473. The mean D90 pre and post operation in traditional group were (104±29) and (104±26) Gy respectively, t=-0.139, P=0.891. The difference of D90 in two groups were (3.1±2.4) and (10.0±8.7) Gy, Z=-2.5, P=0.012. The percentage difference of D90 in two groups were 3.1%±1.9% and 9.5%±7.9%, Compared with the traditional group, the template group had smaller fluctuations, and the difference was statistically significant (Z=-2.7, P=0.006) (all P<0.05). Conclusions: The dose parameters of 3D template guided seeds implantation between postplan and preplan are nearly consistent.3D template has good repeatability, which provides a theoretical basis for the popularization of 3D printing technology.

[Dose comparison between pre and post operation of 125I seeds implantation guided by 3D print tamplate].

OBJECTIVE: To compare the dose difference between pre and post operation of (125)I seeds implantation guided by 3D print tamplate and investigate the dose accuracy. METHODS: From August 2015 to November 2015, a total of 9 patients were selected and underwent 3D print tamplate guided (125)I seeds implantation in Hebei General Hospital. All patients had been fixed as the position of operation and then performed CT scan. After preplan was designed, the 3D tamplates were printed. The tumors were punctured through needles holes predesigned. Another CT scan was used to confirm the locations of needles and then seeds were implanted into tumor according to preplan. Postplan was performed after the operation. The D90, V90, V100, V150 and seeds number pre and post operation were collected and compared. RESULTS: The mean D90, V90, V100, V150 and seeds number preoperation was (7 684±3 279)cGy, 93.2%±0.8%, 89.8%±0.9%, 62.8%±4.7% and 58±17 respectively. The mean D90, V90, V100, V150 and seeds number postoperation was (7 531±3 523) cGy, 92.4%±2.0%, 88.0%±2.5%, 61.9%±5.3% and 56±17 respectively. The difference of all data between pre and post operation was not statistically significant (all P> 0.05). CONCLUSIONS: The dose parameters in postplan show no difference compared with preplan. For the fixed tumor, 3D print tamplate guided seeds implantation may become an easy repeated and standard procedure.