Purpose: The aim of this study was to investigate the added value of single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) versus SPECT alone in the differential diagnosis of solitary spinal lesions in patients with extraskeletal malignancies.
Materials and methods: A total of 90 patients who had a solitary spine ‘hot spot’ that could not be definitively diagnosed using planar scintigraphy were enrolled in the study. SPECT/spiral CT was performed on the indeterminate lesions in the spine. Images were independently interpreted by two experienced nuclear medicine physicians. Each spinal lesion was graded on a four-point diagnostic scale (1, benign; 2, likely benign; 3, likely bone metastasis; 4, bone metastasis). The final diagnosis of each lesion was based on pathological confirmation or follow-up. κ scores were used to evaluate inter-reviewer agreement and agreement of the SPECT and SPECT/spiral CT diagnoses with the final diagnosis.
Results: Final diagnoses revealed 25 bone metastases and 65 benign lesions. Forty percent (36/90) of the solitary spinal lesions were diagnosed as equivocal (likely benign or likely bone metastasis) according to SPECT, whereas only 5.6% (5/90) were diagnosed as equivocal according to SPECT/spiral CT. For SPECT/spiral CT-based and SPECT-based diagnoses, the κ scores for inter-reviewer agreement were 0.889 (P<0.001, 95% confidence interval 0.824–0.954) and 0.504 (P<0.001, 95% confidence interval 0.401–0.607). The diagnostic accuracies of SPECT/spiral CT and SPECT images were 91.1% (82/90) and 58.9% (53/90), respectively (χ2=24.919, P<0.001).
Conclusion: Compared with SPECT imaging alone, SPECT/spiral CT imaging was more accurate and valuable in the differential diagnosis of solitary spinal lesions in patients with extraskeletal malignancies.
aDepartment of Nuclear Medicine, Zhongshan Hospital
bNuclear Medicine Institute, Fudan University
cShanghai Institute of Medical Imaging, Shanghai, China
Correspondence to Hongcheng Shi, MD, PhD, Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China Tel: +86 216 404 1990 x2064; fax: +86 216 403 8472; e-mail: firstname.lastname@example.org
Received December 30, 2012
Accepted January 28, 2013