The incremental value of SPECT/CT in characterizing solitary spine lesions

The purpose of this study was to investigate the incremental value and diagnostic impact of SPECT/CT in patients who had a solitary spinal lesion on a bone scan.

A prospective study was performed on 80 patients (50 with known cancer) who underwent (99m)Tc-methylene diphosphonate whole-body planar bone scintigraphy and had a solitary spinal lesion. These lesions were then further evaluated using SPECT/CT.

Lesions were localized to the vertebral body in 38 patients (47.5%), pedicle in 15 (18.8%), facet joint in 15 (18.8%), transverse process in 2 (2.5%), spinous process in 2 (2.5%), lamina in 3 (3.8%), and end plates in 5 (6.2%). Although the specificity of planar bone scans was excellent (100%), sensitivity was only 6.1% but increased to 78.8% after the addition of SPECT/CT. The results provide evidence of a substantial incremental increase in diagnostic accuracy using SPECT/CT over planar imaging alone for patients in whom a solitary spinal lesion is noted.

The addition of SPECT/CT significantly reduced the number of false-negative results and increased the number of true-positive results. SPECT/CT also reduced the number of equivocal reports. A definitive diagnosis was given for most patients, indicating improved diagnostic confidence with the addition of SPECT/CT, compared with planar imaging alone, in patients with solitary spinal lesions.