Ultrasound-Guided 125I Seed Implantation in Treatment of Abdominal Wall Metastases

Hydrogen-Generating Magnesium Alloy Seed Strand Sensitizes Solid Tumors to Iodine-125 Brachytherapy

Radioactive iodine-125 (125I) seed implantation, a brachytherapy technique, effectively kills tumor cells via X-rays and gamma rays, serving as an alternative therapeutic option following the failure of frontline treatments for various solid tumors. However, tumor radioresistance limits its efficacy. Hydrogen gas has anticancer properties and can enhance the efficacy of immunotherapy. However, its role in radiotherapy sensitization has rarely been reported. Many current hydrogen delivery methods involve hydrogen-generating nanomaterials, such as magnesium-based nanomaterials. This study introduces an AZ31 magnesium alloy 125I seed strand (termed AMASS) with pH-dependent slow-release hydrogen characteristics and excellent mechanical properties. AMASS can be implanted into tumors via minimally invasive surgery, releasing hydrogen around the 125I seeds. In vitro experiments showed that hydrogen from AMASS degradation significantly inhibited tumor proliferation, increased apoptosis, disrupted redox homeostasis and mitochondrial membrane potential, reduced adenosine triphosphate levels, and induced DNA damage due to 125I radiation. In mouse xenograft and rabbit liver tumor models, hydrogen from AMASS showed superior therapeutic effects compared with 125I seeds alone, with no noticeable side effects. In addition, AMASS has a uniform radiation dose distribution and simple implantation. Therefore, hydrogen from AMASS enhanced 125I seed efficacy, supporting the further promotion and application of 125I seed implantation in cancer therapy.

Clinical efficacy and prognostic factors of CT-guided radioactive iodine-125 seed implantation for the treatment of superficial soft tissue metastasis: a 12-year retrospective analysis

BACKGROUND

Superficial soft tissue metastasis (S-STM) of malignant tumors is uncommon and often brings great pain to patients. However, current treatment options are limited. The purpose of this study was to explore the clinical efficacy and prognostic factors of CT-guided radioactive iodine-125 (125I) seed implantation (RISI) for the treatment of S-STM.

METHODS

We retrospectively evaluated 132 patients with S-STM who received RISI between June 2010 and July 2022. Local tumor progression-free survival (ltPFS), tumor response, pain control and complication were analyzed. The independent factors affecting ltPFS were screened out using a layered Cox proportional hazards model.

RESULTS

The median follow-up time was 8.3 months (interquartile range [IQR], 4.5-15.3 months). The objective response rate (ORR) was 81.8%. The median ltPFS was 9.1 (95% CI: 6.6, 11.6) months. The Cox proportional hazard regression model revealed that the independent factors influencing ltPFS included KPS score, primary tumor, metastases, boundary, density and postoperative D90 (All P < 0.05). After RISI, the rate of pain relief was 92.3%. 66 (84.6%) patients reported pain marked relief, and 6 (7.7%) experienced pain moderate relief. No severe adverse events associated with RISI were observed during follow-up.

CONCLUSIONS

CT-guided RISI was associated with high local control and pain relief without severe adverse events and should be considered as a reliable palliative treatment modality for S-STM.

TRIAL REGISTRATION

Trial registration Retrospectively registered.

Iodine-125 seed implantation in the treatment of malignant tumors

Malignant tumors are major causes of morbidity and mortality in China. Despite advances in surgical, radiological, chemotherapeutic, molecular targeting, and immunotherapeutic treatments, patients with malignant tumors still have poor prognoses. Low-dose-rate brachytherapy, specifically 125I seed implantation, is beneficial because of its high local delivery dose and minimal damage to surrounding tissues. Consequently, it has gained increasing acceptance as a treatment modality for various malignant tumors. In this study, we explored the fundamental principles, clinical applications, and new technologies associated with 125I radioactive seed implantation.

CT-guided Radioactive 125I Seed Implantation for Abdominal Incision Metastases of Colorectal Cancer: Safety and Efficacy in 17 Patients

INTRODUCTION

To retrospectively evaluate the safety and efficacy of computed tomography (CT)-guided iodine-125 (¹²⁵I) seed implantation for patients with abdominal incision metastases from colorectal cancer.

MATERIALS AND METHODS

Data of patients with abdominal incision metastases of colorectal cancer from November 2010 to October 2020 were retrospectively reviewed. Each incisional metastasis was percutaneously treated with ¹²⁵I seed implantation under CT guidance. Follow-up contrast-enhanced CT was reviewed, and the outcomes were evaluated in terms of objective response rate, complications, and overall survival.

RESULTS

A total of 17 patients were enrolled in this study. The median follow-up was 18 months (range, 2.7-22.1 months). At 3, 6, 12, and 18 months after the treatment, objective response rate was 52.9%, 63.6%, 33.3%, and 0%, respectively. A small amount of local hematoma occurred in two patients and resolved spontaneously without any treatment. Two patients experienced a minor displacement of radioactive seeds with no related symptoms. Severe complications, such as massive bleeding and radiation injury, were not observed. No ≥ grade 3 adverse events were identified. By the end of follow-up, 14 patients died of multiple hematogenous metastases. The one-year overall survival rate was 41.6%, and the median overall survival was 8.6 months.

CONCLUSION

CT-guided ¹²⁵I seed implantation brachytherapy is safe and feasible for patients with abdominal incision metastases from colorectal cancer.