ABSTRACT
Objective: The objective of the study was to investigate the radiation damage to125 I seeds implanted in canine gastric wall tissue. Materials and Methods: Eight beagles were randomly assigned to either the treatment or control group, with four beagles per group. For each beagle in the treatment group, six125 I seeds were implanted in the gastric wall in two rows, spaced at 1.0 cm, with a seed activity of 0.5 mCi and a half-life of 60.2 d. For each beagle in the control group, six 125 I seeds were similarly implanted as a cold source. After implantation, the beagles were scanned by computed tomography (CT) (slice thickness: 2 mm), the region of interest was labeled along the seed boundaries, and postoperative doses were verified. One beagle per group was sacrificed at the 1, 2, 3, and 4 half-lives to be used as gross specimens for observing histological and ultrastructural changes using light microscopy and electron microscopy, respectively. Results: Beagles from the treatment group who had125 I radioactive seeds implanted in their stomach walls had the most radiation damage after two half-lives, damage repair began after three half-lives, and the damage was stabilized and further repaired after four half-lives. In the control group, only mild inflammatory reactions were observed around the seeds. Conclusion: Appropriate and well-planned implantation of125 I radioactive seeds in beagle stomach walls is safe and reliable
ABSTRACT
Objective: The objective of the study was to evaluate computed tomography (CT)-guided 125I implantation for the treatment of recurrent and malignant pelvic tumors. Materials and Methods: Fifteen cases of pelvic malignant tumors were studied. Tumor length/diameter was 4–10 cm (average: 6.8 ± 2.3 cm). In patients with pelvic recurrence or metastasis of malignant tumors, comprehensive treatment, including surgery, chemotherapy, or radiotherapy, was performed alongside CT-guided 125I implantation. The follow-up clinical benefit rate, rate of pain relief, quality of life score, and status of any complications were analyzed. Results: The patients were followed up for 6 months after the operation, and evaluation of lesions revealed complete response (CR) in 3/15 cases, partial response (PR) in 8/15 cases, stable disease in 3/15 cases, and progressive disease in 1/15 cases. The total effective rate (CR + PR) was 73.3% (11/15), and the pain relief rate was 86.6% (13/15). No bleeding, pelvic abscesses, intestinal fistulas, intestinal perforations, or other complications were reported. Conclusions: When using CT-guided 125I implantation, patients with malignant abdominal tumors undergo a convenient operation, sustain little trauma, and have an improved quality of life
ABSTRACT
Interstitial permanent radioactive seed implantation delivers a high local dose to tumors and sharply drops off at surrounding normal tissues. Radioactive seeds implanted via ultrasound or computed tomography (CT) guidance are minimally invasive and facilitate quick recovery. Transrectal ultrasound-guided 125I seed implantation assisted by a transperineal plane template is standard for early-stage prostate carcinoma, with a highly consistent target volume dose distribution. The postplan dose evaluation is consistent with the preplan evaluation. Until now, there was no workflow for seed implantation elsewhere in the body, and it was difficult to effectively preplan for seed implantation because of patients' position changes, organ movement, and bone structure interference. Along with three-dimensional (3D) printing techniques and seed implantation planning systems for brachytherapy, coplanar and X Y axis coordinate templates were created, referred to as 3D-printed coplanar templates (3D-PCT). 125I seed implantation under CT guidance with 3D-PCT assistance has been very successful in some carcinomas. Preplanning was very consistent with postplanning of the gross tumor volume. All needles are kept parallel for 3D-PCT, with no coplanar needle rearrangement. No standard workflow for 3D-PCT-assisted seed implantation exists at present. The consensus topics for CT-assisted guidance compared to 3D-PCT-assisted guidance for seed implantation are as follows: Indications for seed implantation, preplanning, definition of radiation doses and dosimetry evaluation, 3D-PCT workflow, radiation protection, and quality of staff. Despite current data supporting 125I seed implantation for some solid carcinomas, there is a need for prospectively-randomized multicenter clinical trials to gather strong evidence for using 125I seed implantation in other solid carcinomas