Efficacy and Safety of Radioactive 125I Seed Implantation for Patients with Oligo-Recurrence Soft Tissue Sarcomas

Experts consensus on 3D-printing template-assisted CT-guided radioactive iodine-125 seed implantation for recurrent soft tissue carcinoma in China

Permanent radioactive iodine-125 seed implantation (RISI), known as radioactive seed implantation, is a minimally invasive internal radiation technique. This method involves implanting 125I seeds (4.5 × 0.8 mm, encapsulated in a nickel-titanium alloy) into tumors under image guidance. The radionuclide continuously releases low energy γ-rays, effectively killing tumor cells. RISI delivers high local doses with minimal damage to surrounding normal tissues. It is performed through image-guided percutaneous puncture, accompanied by high precision, minimal trauma, and rapid recovery. In Western countries, RISI is primarily utilized for early-stage prostate cancer. In 2002, Professor Junjie Wang introduced computed tomography (CT)-guided technology for RISI, expanding its indications to head and neck, thoracic, abdominal, pelvic, and spinal tumors. In 2014, he proposed the concept of image-guided interventional brachytherapy, advancing minimally invasive brachytherapy. In 2015, he integrated three-dimensional 3D-printing template (3D-PT) with CT-guided technology, significantly enhancing the precision, quality, and efficiency of RISI, and introduced the concept of stereotactic brachytherapy. Over nearly 20 years, RISI has developed into a standardized procedure, involving preoperative planning, intraoperative optimization, and postoperative verification, highlighting its role in comprehensive cancer treatment. The main treatments for soft tissue sarcoma (STS) include surgery or surgery combined with radiotherapy and chemotherapy. However, STS is prone to local recurrence, and effective treatments are lacking after recurrence. Experts have conducted extensive trials on RISI for the treatment of recurrent STS (r-STS), accumulating significant clinical experience. This study aimed to establish standards and consensus on 3D-PT-assisted CT-guided RISI for the treatment of r-STS.

Iodine-125 seed inhibits proliferation and promotes apoptosis of cholangiocarcinoma cells by inducing the ROS/p53 axis

With advances in radioactive particle implantation in clinical practice, Iodine-125 (125I) seed brachytherapy has emerged as a promising treatment for cholangiocarcinoma (CCA), showing good prognosis; however, the underlying molecular mechanism of the therapeutic effect of 125I seed is unclear. To study the effects of 125I seed on the proliferation and apoptosis of CCA cells. CCA cell lines, RBE and HCCC-9810, were treated with reactive oxygen species (ROS) scavenger acetylcysteine (NAC) or the p53 functional inhibitor, pifithrin-α hydrobromide (PFTα). Cell counting kit-8 (CCK-8) assay, 5-bromo-2-deoxy-uridine (BrdU) staining, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay and flow cytometry assay were performed to test the radiation-sensitivity of 125I seed toward CCA cells at different radiation doses (0.4 mCi and 0.8 mCi). 2,7-dichlorofluorescein diacetate (DCF-DA) assay, real-time quantitative polymerase chain reaction (RT-qPCR), and western blot analysis were performed to assess the effect of 125I seed on the ROS/p53 axis. A dose-dependent inhibitory effect of 125I seeds on the proliferation of CCA cells was observed. The 125I seed promoted apoptosis of CCA cells and induced the activation of the ROS/p53 pathway in a dose-dependent manner. NAC or PFTα treatment effectively reversed the stimulatory effect of 125I seed on the proliferation of CCA cells. NAC or PFTα suppressed apoptosis and p53 protein expression induced by the 125I seed. 125I seed can inhibit cell growth mainly through the apoptotic pathway. The mechanism may involve the activation of p53 and its downstream apoptotic pathway by up-regulating the level of ROS in cells.