Dosimetry Verification of ¹²⁵I Seeds Implantation With Three-Dimensional Printing Noncoplanar Templates and CT Guidance for Paravertebral/Retroperitoneal Malignant Tumors

Abstract

Objective:To compare dose distributions of postoperative plans with preoperative plans for radioactive seed implantation of paravertebral/retroperitoneal tumors assisted by 3-dimensional printing noncoplanar templates and computed tomography.Methods:Sixteen patients with paravertebral/retroperitoneal tumors (21 lesions) underwent radioactive seed implantation with 3-dimensional printing noncoplanar templates. Prescribed dose was 110 to 160 Gy. We compared the dose distribution of the postoperative plan with the preoperative plan. Dose parameters were D90, minimum peripheral dose, V100, V150, conformal index and external index of the target volume, and the dose received by 2 cm3 of normal tissue of organs at risk (spinal cord, aorta, and kidney).Results:Sixteen 3-dimensional printing noncoplanar templates were produced for 21 treatment areas. Mean gross tumor volume (preoperative) of patients was 61.1 cm3, mean needle number was 17, mean number of implanted 125I seeds was 65, and mean D90 of postoperative target area (gross tumor volume) was 131.1 Gy. Actual number of seeds postbrachytherapy increased by 1 to 12 in 8 cases. For postoperative plans, the mean D90, minimum peripheral dose, V100, V150 was 131.1 Gy, 67.1 Gy, 90.2%, and 64.1%, respectively, and 135.0 Gy, 64.7 Gy, 90.9%, and 64.1%, respectively, in preoperative plans. Comparing with the preplanned cases, the dose of the target volume was slightly lower and the high-dose area of the target volume was larger in postoperative cases, but the difference was not statistically significant (P > .05). Actual dose conformity of the target volume was lower than preplanned, and the difference was statistically significant (P = .005).Conclusion:Three-dimensional printing noncoplanar templates can provide good accuracy for positioning and direction in radioactive seed implantation.

Efficacy and dosimetry analysis of image-guided radioactive 125I seed implantation as salvage treatment for pelvic recurrent cervical cancer after external beam radiotherapy

“…In line with previous reports, the tumor volume, dose and recurrent sites might influence the effect [212324]. Encouragingly, with the improvement of technology, we were the first brachytherapy center to incorporate 3-dimensional printing template into RIS implantation, in order to increase the accuracy of treatment [252627]. Furthermore, the combination with multiple modern image technologies helped us to define the tumor margin more precisely, which might overcome the problems of target area delineation and dose coverage.…”

The accuracy and safety of CT-guided iodine-125 seeds implantation assisted by 3D non-coplanar template for retroperitoneal recurrent carcinoma.

“…In order to expand the indications of RSI-BT, CT-guidance technique was integrated into RSI-BT in 2002 in China, which was used to treat head and neck, thoracic, abdomen, and spinal vertebrate carcinoma [25][26][27][28][29][30]. The CTguided 125I RSI-BT was very safety and effective approach for anti-cancer treatment, especially for recurrent or metastasis carcinomas.…”

<p>Efficacy and Safety of Iodine-125 Brachytherapy in the Treatment of Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma</p>

“…Using 3D-printed non-coplanar templates (3D-PNCT) and CT technology, the particles can more accurately locate paravertebral/postperitoneal lesions. 35 Liu et al reported that in the treatment of recurrent high-grade gliomas, 3D-PIT based on CT/MRI fusion images can enable better positioning accuracy and dose distribution of radioactive I125 particle implantation. 36 Jiang et al studied the acute and late side effects of 3D- PNCT used in CT-guided radioactive I125 particles (RIS) implanted in recurrent cancer of the head and neck.…”