Objective:

To investigate the clinical value of

131

I single-proton emission computed tomography (SPECT)/CT in assessing distant metastases of differentiated thyroid carcinoma (DTC).

Methods:

A total of 153 DTC patients with pulmonary metastasis and (or) bone metastasis were included

in this study. All the patients were treated with oral

131

I [average dose: (147.97 45.35) mCi

]

and performed

131

I planar whole body imaging and SPECT/CT scan 80-96 h after administration of

131

I. The values of SPECT images

CT images and SPECT/CT fusion images were compared.

Results:

Based on the SPECT/CT fusion images

127 patients were confirmed with pulmonary metastasis (109 patients with bilateral lung metastasis

9 patients with right lung metastasis and 9 patients with left lung metastasis). Of 127 patients

80 patients SPECT images were positive

and 47 patients SPECT images were negative. In addition

15 patients with lung metastasis were observed on SPECT images

but the corresponding CT images were negative. Of all 153 patients

26 patients were found bone metastasis on SPECT/CT images. Bone metastatic lesions were located at spine in 14 patients

at ribs in 6 patients

at limbs in 6 patients

at sternum in 5 patients

at pelvis in 5 patients and at clavicle in 2 patients.

131

I was abnormally accumulated in all patients with bone metastasis

however

CT images were negative in 3 patients.

Conclusion:

131

I SPECT/CT fusion imaging can do help to evaluate pulmonary metastasis and bone metastasis of DTC.