Dosimetry verification of radioactive seed implantation for recurrent malignant tumor of head and neck assisted by 3D printing individual guide plate

Abstract

Objective To compare the dose distributions of postoperative plans with preoperative plans for 3D printing guide plate assist radioactive seeds implantations, explore the effects of the technology for seeds implantations in dosimetry level. Methods From January 2016 to December 2016, a total of 42 patients of local recurrent malignant tumor of head and neck received 3D printing guide plate assist radioactive seeds implantations in in Peking University Third Hospital, and included in the retrospective study. The prescribed dose was 110-160 Gy. All patients carried out preoperative planning design, individual guide plate production, and compared the dose distribution of postoperative plan with preoperative plan. Dose parameters include D90, mPD, V100, V150, V200, CI, EI and HI. Statistical method was paired t-test. Results A total of 42 3D printing individual templates were produced. The mean GTV volume of all patients was 28.6 cm3, and mean D90 of postoperative target area (GTV) was 142.6 Gy. For postoperative plans, the mean D90, mPD, V100, V150, V200 was 142.6 Gy, 77.3 Gy, 92.48%, 68.40% and 42.98%, respectively, and 144.5 Gy, 70.2 Gy, 91.45%, 63.12% and 34.74%, respectively, in preoperative plans. Except mPD, V150, V200(t=-2.166, -2.863, -4.778, P<0.05), there was no significant difference between the two groups. Conclusions 3D printing guide plate could provide good accuracy for positioning and direction. For local recurrent malignant tumor of head and neck, the actual dose distributions in postoperative validations were close to the expectations of preoperative plans which mean the improvement of accuracy in treatment. Key words: 3D printing; Radioactive seed implantation; Dosimetry; Malignant tumor; Head and neck; Cancer