Fluorine-18 deoxyglucose Positron Emission Tomography, Magnetic Resonance Imaging and Bone Scintigraphy for the Diagnosis of Bone Metastases in Patients with Lung Cancer: Which One is the Best? – a Meta-analysis

Abstract

Aims To carry out a meta-analysis to compare fluorine-18 deoxyglucose ( 18FDG) positron emission tomography (PET), magnetic resonance imaging (MRI) and bone scintigraphy imaging for the diagnosis of bone metastases in patients with lung cancer. Materials and methods MEDLINE, EMBASE, Scopus and other databases were searched for relevant original articles published between January 1995 and January 2010. Inclusion criteria were as follows: 18FDG PET, MRI or 99mTc-MDP bone scintigraphy was carried out to detect bone metastases in patients with lung cancer; sufficient data were presented to construct a 2 × 2 contingency table; histopathological analysis and/or close clinical and imaging follow-up and/or radiographic confirmation by multiple imaging modalities were used as the reference standard. Two reviewers independently extracted data. META-DiSc was used to obtain pooled estimates of sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curves and the *Q index. Results In total, 14 articles that consisted of 34 studies fulfilled all inclusion criteria. On a per-patient basis, the pooled sensitivity estimates for PET, MRI and bone scintigraphy were 91.9, 80.0 and 91.8%, respectively. The sensitivity for PET and bone scintigraphy were significantly higher than for MRI ( P < 0.05). There was no significant difference between PET and bone scintigraphy ( P > 0.05). The pooled specificity estimates for PET, MRI and bone scintigraphy were 96.8, 90.6 and 68.8%, respectively. The specificity for PET was significantly higher than for MRI and bone scintigraphy ( P < 0.05), and the specificity for MRI was significantly higher than for bone scintigraphy ( P < 0.05). The pooled DOR estimates for PET, MRI and bone scintigraphy were 365.5, 53.8 and 34.4, respectively. The DOR for PET was significantly higher than for MRI and bone scintigraphy ( P < 0.05). There was no significant difference between MRI and bone scintigraphy ( P > 0.05). The SROC curve for PET showed better diagnostic accuracy than for MRI and bone scintigraphy. The SROC curve for MRI was better than for bone scintigraphy. The *Q index estimates for PET, MRI and bone scintigraphy were 0.933, 0.903 and 0.857, respectively. The *Q index for PET and MRI were significantly higher than for bone scintigraphy ( P < 0.05). There was no significant difference between PET and MRI ( P > 0.05). On a per-lesion basis, the pooled sensitivity estimates for PET, MRI and bone scintigraphy were 95.0, 83.8 and 71.5%, respectively. The sensitivity for PET was significantly higher than for MRI and bone scintigraphy ( P < 0.05), and the sensitivity for MRI was significantly higher than for bone scintigraphy ( P < 0.05). The pooled specificity estimates for PET, MRI and bone scintigraphy were 94.6, 96.3 and 91.0%, respectively. The specificity for MRI was significantly higher than for PET and bone scintigraphy ( P < 0.05), and the specificity for PET was significantly higher than for bone scintigraphy ( P < 0.05). The pooled DOR estimates for PET, MRI and bone scintigraphy were 431.9, 158.1 and 9.0, respectively. The DOR for PET was significantly higher than for MRI and bone scintigraphy ( P < 0.05) and the DOR for MRI was significantly higher than for bone scintigraphy ( P < 0.05). The SROC curve for PET and MRI showed better diagnostic accuracy than for bone scintigraphy. There was no significant difference between PET and MRI. The *Q index estimates for PET, MRI and bone scintigraphy were 0.953, 0.962 and 0.778, respectively. The *Q index for PET and MRI were significantly higher than for bone scintigraphy ( P < 0.05). There was no significant difference between PET and MRI ( P > 0.05). Conclusion 18FDG PET was found to be the best modality to detect bone metastasis in patients with lung cancer, both on a per-patient basis and a per-lesion basis; MRI had the highest specificity on a per-lesion basis. For the subgroup analysis of 18FDG PET, PET/computed tomography was shown to be better than PET and there were no significant differences between using 68Ge and computed tomography for attenuation correction on a per-patient basis.