Research on the Optimization of Treatment for Spinal Metastases With Radioactive Particle Implantation Using TPS and Mechanical Dual Simulation

Inclusion Criteria:

* Age ≥18 years.

Radiologically or histologically confirmed bone metastasis with a lesion suitable for percutaneous radioactive seed implantation (e.g., I-125), per multidisciplinary assessment.

Indication for local palliation/control: moderate-to-severe pain at lesion (e.g., BPI/VAS ≥4) and/or imaging evidence of progression or high-risk features warranting local therapy.

Measurable/evaluable target lesion on CT/MRI; target location accessible for needle placement per institutional practice.

ECOG performance status 0-2.

Estimated life expectancy ≥3 months.

Adequate hemostasis: platelets ≥80×10\^9/L, INR ≤1.5 (or per protocol), and able to hold/bridge anticoagulation as clinically indicated.

Adequate organ function to undergo the procedure and anesthesia/sedation per site standards.

Able to undergo required imaging (CT; MRI if applicable).

Willing and able to provide written informed consent and comply with follow-up.

For women of childbearing potential and men with partners of childbearing potential: agreement to use effective contraception during and for the protocol-defined period after implantation.

Exclusion Criteria:

* Need for urgent surgical decompression or stabilization (e.g., acute/impending neurologic compromise, unstable pathologic fracture) that precludes percutaneous implantation at this time.

Uncorrected coagulopathy or ongoing antithrombotic therapy that cannot be safely managed periprocedurally.

Active systemic or local infection at/near the planned access route.

Diffuse marrow replacement or extensive cortical destruction where percutaneous implantation is unsafe or unlikely to achieve local control without stabilization, per MDT judgment.

Prior radiation or surgery to the index lesion that, in the investigator's opinion, makes additional seed implantation unsafe or non-beneficial; postoperative bed without a discrete target for seed placement.

Known hypersensitivity to materials/agents required for the procedure (e.g., contrast) not amenable to premedication or alternative imaging.

Uncontrolled medical conditions posing prohibitive procedural risk (e.g., severe cardiopulmonary disease, uncontrolled hypertension/arrhythmia).

Pregnant or breastfeeding.

Inability to lie still or contraindications to required imaging/sedation not correctable.

Concurrent participation in another interventional study that could confound efficacy/safety assessment at the treated site.

Any condition that, in the investigator's judgment, would interfere with protocol adherence, safety monitoring, or outcome assessment.