CT-guided Lumbar Puncture for Intrathecal Nusinersen Injection in Patients with Spinal Muscular Atrophy: Technical Effectiveness, Safety, and Radiation Dose.

PURPOSE: Spinal muscular atrophy (SMA) is a rare neuromuscular disease treated with intrathecal nusinersen. In patients with complex spinal anatomy or spinal instrumentation, repeated lumbar punctures can be challenging. This study evaluated the feasibility, safety, and radiation exposure of CT-guided nusinersen administration in SMA.

METHODS

In this retrospective single-center study, 458 CT-guided nusinersen injections in 44 SMA patients (October 2017-August 2024) were analyzed. Technical success, complications, procedure and puncture times, and radiation exposure were compared between subgroups. Procedures were performed in prone, lateral, or combined (oblique) positions depending on anatomy.

RESULTS

Technical success was 98.3% (449/458). Rates were slightly lower in patients with dorsal spondylodesis (97.1% vs. 98.8%). Complications occurred in 1.1% (5/458), including transient pain and two hematomas. Spondylodesis was associated with longer puncture (11.9 vs. 10.3 min) and procedure durations (16.3 vs. 14.0 min) and higher radiation doses (effective dose 2.22 vs. 1.74 mSv; all p < 0.01). Failed or complicated procedures showed prolonged durations and higher exposure. Needle repositioning correlated with duration and dose.

CONCLUSION

CT-guided lumbar puncture for intrathecal nusinersen injection is a safe and effective technique, even in complex spinal anatomy. Dorsal spondylodesis increases procedural complexity. Tailored puncture level selection, optimized positioning, and dose-reduction strategies are essential for high success rates and minimal radiation. While CT guidance ensures excellent anatomical visualization, fluoroscopy may reduce radiation and procedure time; future comparative studies should define optimal modality selection.