Dedicated holmium microsphere administration device for MRI-guided interstitial brain microbrachytherapy.

Area of Science:

• Medical Devices
• Radiotherapy
• Oncology

Background:

• Microbrachytherapy using radioactive holmium-166 microspheres (¹⁶⁶Ho-MS) shows promise for treating brain malignancies.
• Accurate intratumoral delivery and complete tumor dose coverage are essential for effective ¹⁶⁶Ho-MS therapy.
• Current limitations include the absence of dedicated instruments for controlled intratumoral delivery.

Purpose of the Study:

• To develop and evaluate an administration device for MRI-guided intratumoral delivery of ¹⁶⁶Ho-MS for brain malignancies.
• To assess the accuracy of stylet placement and the feasibility of MRI visualization during the intervention.
• To evaluate the delivery of ¹⁶⁵Ho-MS in a brain tumor simulant.

Main Methods:

• A novel administration device featuring an alumina oxide cannula and a nitinol stylet was designed.
• Stylet tip accuracy was measured in phantoms during insertions.
• MRI compatibility and artifact generation were assessed using a 3 Tesla MRI scanner.
• Feasibility of non-radioactive holmium-165 microsphere (¹⁶⁵Ho-MS) delivery was tested in a brain tumor simulant.

Main Results:

• The administration device achieved an absolute stylet tip accuracy of 0.88 ± 0.61 mm.
• MRI distortion varied based on needle material and orientation.
• Successful dose delivery of ¹⁶⁵Ho-MS within a brain tumor phantom was demonstrated.

Conclusions:

• The developed administration device enables accurate stylet placement for ¹⁶⁶Ho-MS injection.
• MRI can effectively visualize the intervention, facilitating precise microsphere deposition.
• This device supports the advancement of MRI-guided microbrachytherapy for brain tumors.