TY - JOUR T1 - Comparison of [<sup>18</sup>F]FDG PET and <sup>201</sup>Tl SPECT in Evaluation of Pulmonary Nodules JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1489 LP - 1496 VL - 42 IS - 10 AU - Kotaro Higashi AU - Yoshimichi Ueda AU - Tsutomu Sakuma AU - Hiroyasu Seki AU - Manabu Oguchi AU - Mitsuru Taniguchi AU - Suzuka Taki AU - Hisao Tonami AU - Shogo Katsuda AU - Itaru Yamamoto Y1 - 2001/10/01 UR - http://jnm.snmjournals.org/content/42/10/1489.abstract N2 - Recent reports have indicated the value of [18F]FDG PET and 201Tl SPECT in diagnosing lung cancer. In this study, we compared the diagnostic value of FDG PET and 201Tl SPECT in the evaluation of pulmonary nodules. Methods: Sixty-three patients with 66 pulmonary nodules suspected to be lung cancer on the basis of chest CT were examined by FDG PET and 201Tl SPECT (early and delayed scans) within a week of each study. For semiquantitative analysis, the standardized uptake value (SUV) or the tumor-to-nontumor activity ratio (T/N) (or both) was calculated. All of these lesions were completely removed thoracoscopically or by thoracotomy and were examined histologically. Results: Fifty-four nodules were histologically confirmed to be malignant tumors, and 12 were benign. Both techniques delineated focal lesions with an increase in tracer accumulation in 41 of 54 lung cancers. 201Tl SPECT on early or delayed scans (or both) identified 4 additional lung cancers that FDG PET images did not reveal: 3 bronchioloalveolar carcinomas and a well-differentiated adenocarcinoma. FDG PET identified 3 additional lung cancers that 201Tl SPECT images did not reveal; 2 of these lung cancers were &lt;2 cm in diameter. The mean FDG SUV and T/N of bronchioloalveolar carcinomas (2.06 ± 0.76 and 3.49 ± 1.03, respectively) were significantly lower than those of poorly differentiated adenocarcinomas (5.55 ± 2.01 [P = 0.026] and 8.23 ± 2.16 [P = 0.01], respectively). However, no significant difference was found in 201Tl T/N on early and delayed scans between bronchioloalveolar carcinomas (1.64 ± 0.29 and 1.87 ± 0.42, respectively) and poorly differentiated adenocarcinomas (1.58 ± 0.32 and 2.76 ± 1.36, respectively). Of the 12 benign nodules, FDG PET and 201Tl SPECT showed false-positive results for the same 7 benign nodules (58.3%) (4 granulomas, 1 sarcoidosis, 1 inflammatory pseudotumor, and 1 aspergilloma). Negative FDG PET findings and positive 201Tl SPECT findings were obtained only for bronchioloalveolar carcinomas or a well-differentiated adenocarcinoma but not for other histologic types of lung cancers or benign pulmonary nodules. Conclusion: No significant difference was found between FDG PET and 201Tl SPECT in specificity for the differentiation of malignant and benign pulmonary nodules. The degree of differentiation of lung adenocarcinoma correlated with FDG uptake but not with 201Tl uptake. Bronchioloalveolar carcinoma (a well-differentiated, slow-growing tumor) findings typically were positive with 201Tl but were negative with FDG. The combination of FDG PET and 201Tl SPECT may provide additional information regarding the tissue characterization of pulmonary nodules. ER -