Imageable Brachytherapy with Chelator-Free Radiolabeling Hydrogel

Area of Science:

• Biomaterials Science
• Radiochemistry
• Oncology

Background:

• Brachytherapy is crucial for locally advanced tumors.
• Current limitations exist in monitoring radionuclide distribution and treating metastatic disease.

Purpose of the Study:

• To develop an injectable, imageable brachytherapy hydrogel for local and metastatic tumor treatment.
• To enable real-time monitoring of radionuclide retention and therapeutic efficacy.
• To enhance brachytherapy by combining it with immunotherapy for metastatic disease.

Main Methods:

• Fe-tannins nanoparticles were radiolabeled with therapeutic radionuclides (e.g., 131I, 90Y, 177Lu, 225Ac) without a chelator.
• Radiolabeled nanoparticles were cross-linked with 4-armPEG-SH to form a hydrogel.
• The hydrogel was administered intratumorally, and its retention and therapeutic effects were monitored using MRI and in vivo studies.

Main Results:

• The hydrogel demonstrated stable radiolabeling and effective in situ formation.
• MRI allowed real-time monitoring of radionuclide dosage and retention within the tumor.
• The hydrogel achieved effective eradication of local tumors and inhibited metastatic tumor growth through synergistic immunotherapy.

Conclusions:

• An imageable brachytherapy hydrogel was successfully developed for real-time monitoring.
• This novel hydrogel expands brachytherapy applications to include metastatic tumors.
• The combination of imageable hydrogel brachytherapy and immunotherapy offers a promising strategy for comprehensive cancer treatment.