Comparison of cone beam CT and conventional CT guided pediatric spine biopsies

The primary study aim is to compare the total patient radiation dose of cone-beam CT guided spine biopsies (CBCTs) to conventional CT-guided spine biopsies (CTs) in children and young adults. Secondary endpoints include in-room procedure times, total cost, biopsy adequacy, and complication rates.

A 19-year retrospective review was performed of all spine biopsies performed by the Interventional Radiology department. Technical success, complications, specimen adequacy, room times, and cost were compared between CBCT and CT. Technical success was defined as a completed biopsy and specimen adequacy was assessed from pathology reports. Effective dose was computed using a National Cancer Institute (NCI) software package for both modalities. Room times were determined from electronic medical record timestamps and total cost was calculated using a time driven activity-based costing method.

Thirty-seven CBCTs were compared to 14 CTs. Biopsy success (p > 0.99), total room time (p = 0.51), and total cost (p = 0.12) did not demonstrate significance between groups in the sample. The effective dose for CBCT was significantly higher than CT (median 8.4 mSv IQR [4.3, 15.8] mSv vs. median 2.0 mSv IQR [1.5, 3.2] mSv; p < 0.001).

Cone beam CT guided spine biopsies appear to have a significantly higher effective dose than conventional CT guided spine biopsies using conventional protocols, however this difference is dependent on the CBCT algorithm used. This conclusion is based on established methods using representative parameters not otherwise available in a retrospective study. Success rates, procedure times, and cost were found to be similar for both modalities.