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Purpose To investigate the accuracy of needle distribution and dosimetric parameter differences of 3D-printing non-coplanar template (3D-PNCT)-assisted computed tomography (CT)-guided iodine-125 seed ablative brachytherapy (125I-SAB) in gynecological cancer patients with non-central pelvic recurrence between pre-operative plan and post-operative plan. Material and methods Thirty-eight patients with forty-one non-central pelvic recurrent gynecological carcinomas after radiotherapy were enrolled in this study. All patients received 3D-PNCT-assisted CT-guided 125I-SAB from January 2016 to January 2019. The position, angle, and depth of seed needles were measured in both pre-operative plan and intra-operative real-time plan in brachytherapy treatment planning system (B-TPS). Dosimetric parameters of D90, D100, V100, V150, and V200 as well as quality parameters of conformal index (CI), external index (EI), and homogeneity index (HI) were compared between pre-operative plan and post-operative plan. Peri-operation complications and radiation-related toxicity were assessed. Results Median follow-up time was 12 months (range, 5-34 months). Prescribed dose was 100-170 Gy (median, 120 Gy). Radioactivity of 125I seed was 0.4-0.7 mCi (median, 0.55 mCi). Mean depth deviation for 499 needles was 0.8 ±1.0 cm. Mean angular deviation was 2.2 ±2.1 degrees. Mean tip distance deviation of needles was 0.4 ±0.3 cm. There were significant differences between pre-operative and post-operative plans in CI (p = 0.001) and EI (p = 0.005). No significant differences were shown in D90, D100, V100, V150, V200, and HI between pre-operative and post-operative plans. Only few patients suffered from ≤ grade 2 toxicities. Conclusions 3D-PNCT-assisted CT-guided 125I-SAB is safe and feasible for non-central pelvic recurrence of gynecological cancer. All complications are tolerable and mild.

Purpose To verify the accuracy and efficacy of three-dimensional printing individual template (3D-PIT) with computed tomography-magnetic resonance imaging (CT-MRI) fusion for radioactive iodine-125 (125I) seed implantation in high-grade brain gliomas. Material and methods Between June 2017 and June 2018, 16 patients with recurrent high-grade gliomas (rHGG) underwent radioactive seed implantation with 3D-PIT. The prescribed dose was 120-140 Gy. We compared the dose distribution of the postoperative plan with the preoperative plan. Dose parameters included D90, V100, V200, conformity index (CI), and external index of the target volume (EI). Local control and early complications were also analyzed. Results Sixteen treatment areas were reported in our study. Median gross tumor volume (preoperative) of patients was 64.2 cm3, median needle number was 8, and median number of implanted 125I seeds was 60. For postoperative plans, the median D90, V100, and V200 was 152.1 Gy, 96.8%, and 49.1%, respectively, and 151.7 Gy, 97.0%, and 48.9%, respectively, in preoperative plans. Comparing with the preplanned cases, the dose of the target volume was slightly higher; the high-dose area of the target volume was larger in postoperative cases, but the difference was not statistically significant (p > 0.05). Actual dose conformity of the target volume was greater than preplanned, and the difference was not statistically significant (p > 0.05). Local control was 81.25% and 75% at 3 and 6 months after implantation, respectively. No serious early toxicities were observed. Conclusions 3D-PIT based on the CT-MRI fusion images can result in good accuracy for positioning and dose distribution in radioactive seed implantation for treatment of rHGG.