Evalution of Tl-201 SPECT in Differential Diagnosis of Benign and Malignant Lesion of the Chest

胸部良性病変と悪性病変の鑑別における^<201>Tl-SPECTの有用性

Evalution of Tl-201 SPECT in Differential Diagnosis of Benign and Malignant Lesion of the Chest

Creators Orihashi Norihiro

Creators Suga Kazuyoshi

Creators Yoneshiro Shigeru

Creators Fujita Takeshi

Creators Kawata Youko

Creators Arita takeshi

Creators Ohno Yoshitaka

Creators Matsunmoto Tsuneo

Creators Utsumi Hiromoto

Creators Yamada Norimasa

Creators Nakanishi Takashi

Tl-201 SPECT was examined in 22 being and 15 malignant lesions, with a size equal to or more than 10 mm on chest CT, and we evaluated the usefulness of this modality in differential diagnosis of benign and malignant lesions. The Tl-201 SPECT image was obtained 15min. (early scan) and 2-3hr. (delayed scan) following the intravenous injection of a dose of 240MBq Tl-201 Chrolide. The ^<201>TlCl uptake in the benign lesions was not corelated to the size of the lesions, while the ^<201>TlCl uptake in the malignant lesions was obtained in only lesions with a size equal to or more than 25×20 mm. We calculated the lesion/normal contralateral lung ratio of ^<201>TlCl activity in early & delayed scans, and the retention index using the method of Tonami et al. Retention index in malignant lesions (21.5±8.9%) showed significantly higher than that in the benign lesions (-4.6±11.4%) (p<0.01). Therefore, when the border-line value of the retention index was set at 10%, and the lesions with higher values were diagnosed as malignancy, the value of the sensitivity, accuracy and specificity showed 92%, 93%, and 92% respectively. These results indicate that the Tl-201 SPECT is a potentially useful method for differential diagnosis of benign and malignant lesions in the chest.

[ISSN]0513-1731

[NCID]AN00243156