SPECT/CT Fusion Imaging In Diagnosis And Treatment Of Differentiated Thyroid Cancer Clinical Study

Objective:To evaluate SPECT/CT tomography fusion imaging in differentiated thyroid carcinoma (DTC) after high-dose 131I in patients with metastatic lesions after the treatment and diagnosis of thyroid residues to guide the clinical treatment of patients with DTC.Methods:54 patients who was diagnosed DTC with aged 21 to 75 years old, with an average of 48.48±15.33years,they were carried out 121 times 131I whole body planar imaging (WBS) and/or local planar imaging,53 times SPECT/CT fusion images. All patients were total thyroid resection or subtotal resection.25 cases of differentiated thyroid cancer patients at the first radioexmination before treatment with 131I run routine 99mTcO4- thyroid imaging, WBS and/or partial planar imaging after treatment, the results of thyroid nodules with unclear in patients run SPECT/CT fusion imaging. All patients stoped eating iodine for 4 weeks before treatment to stop taking L-T4 (or thyroid tablets) 4-6 weeks, such as a recent surgery patient, can be 3 weeks after surgery until the surgical wounds healed across 131I therapy. A conventional treatment of patients with thyroid scan for residual thyroid except for a large organization, fasting 4 hours before treatment, do 131I dose:5130.46±925.44Bq (range of 2775～8140MBq), for the first time or early thyroid tissue removed (surgical resection or sub-total resection without residual organization) dose is relatively small, in order to 4245.31±815.41MBq (range of 2775～6660MBq); while for the dose of thyroid cancer metastasis is relatively large, in order to 5843.79±975.47MBq (range 3700-8140MBq).131I in patients after serving an average of 7.69 days (range 4-14 days) around line WBS, on the 131I uptake is not clear who was diagnosed (location not clear and/or malignant lesions can not be the exception) plus doing SPECT/CT examination. All the patients were not seen before by diagnostic imaging dose of 131I.Results:The study of all DTC patients after 131I therapy SPECT/CT fusion imaging accurate diagnosis:the residual thyroid tissue(RT)(18.87%),RT and partial LNM(37.74%),local LNM (15.09%), lung and/or scattered lesions transfer(28.30%).Accurate positioning:nasal cavity,oral cavity,salivary glands, digestive tract,bladder and liver; Elimination:the temporal,shoulders, chest and waist area pollution.In this study 35 cases of DTC patients after SPECT/CT fusion imaging was found 141 uptake is higher than planar imaging, increased 29.36%(32/109),the 109 hot-points initial diagnosis of SPECT/CT changed 54(49.5%) of which,and the diagnosis and give re-classification,26 were lowered to re-diagnosed as low-risk group,28 have been raised again as a high-risk group.In this study 25 cases of DTC patients at the first radioablation, by thyroid 99mTcO4- imaging, diagnosis was changed or re-classification in the 11 cases(44%) in planar imaging,each 3 patients have been reduced to re-diagnosed as low-risk group and high-risk groups;The SPECT/CT imaging has been changed or re-classified in the 17 cases(68%) in planar imaging, resulting in 2 patients has been reduced to re-diagnosed as low-risk group,12 cases of re-rise as high-risk group.Conclusion:SPECT/CT fusion imaging in patients with 131I treatment for DTC diagnosis of metastasis;DTC patients after 131I treatment of SPECT/CT fusion imaging in detection of radioactivity than the WBS lesion and/or partial planar imaging is more accurate,can change or re-classification of patients with an initial diagnosis, to guide clinical diagnosis and treatment of DTC work;The 99mTcO4- imaging before the first radioablation has a certain added value for thyroid nodules in bed and its surrounding diagnosis and staging.