J Nucl Med 2003 Apr;44(4):540-548
18F-FDG Accumulation with PET for Differentiation Between Benign and
Malignant Lesions in the Thorax.
Demura Y, Tsuchida T, Ishizaki T, Mizuno S, Totani Y, Ameshima S, Miyamori I,
Sasaki M, Yonekura Y.
Recent reports have indicated the value and limitations of (18)F-FDG PET and
(201)Tl SPECT for determination of malignancy. We prospectively assessed and
compared the usefulness of these scintigraphic examinations as well as (18)F-FDG
PET delayed imaging for the evaluation of thoracic abnormalities. METHODS:
Eighty patients with thoracic nodular lesions seen on chest CT images were
examined using early and delayed (18)F-FDG PET and (201)Tl-SPECT imaging within
1 wk of each study. The results of (18)F-FDG PET and (201)Tl SPECT were
evaluated and compared with the histopathologic diagnosis. RESULTS: Fifty of the
lesions were histologically confirmed to be malignant, whereas 30 were benign.
On (18)F-FDG PET, all malignant lesions showed higher standardized uptake value
(SUV) levels at 3 than at 1 h, and benign lesions revealed the opposite results.
Correlations were seen between (18)F-FDG PET imaging and the degree of cell
differentiation in malignant tumors. No significant difference in accuracy was
found between (18)F-FDG PET single-time-point imaging and (201)Tl SPECT for the
differentiation of malignant and benign thoracic lesions. However, the retention
index (RI) of (18)F-FDG PET (RI-SUV) significantly improved the accuracy of
thoracic lesion diagnosis. Furthermore, (18)F-FDG PET delayed imaging measuring
RI-SUV metastasis was useful for diagnosing nodal involvement and it improved
the specificity of mediastinal staging. CONCLUSION: No significant difference
was found between (18)F-FDG PET single-time-point imaging and (201)Tl SPECT for
the differentiation of malignant and benign thoracic lesions. The RI calculated
by (18)F-FDG PET delayed imaging provided more accurate diagnoses of lung
cancer.
