68-Gallium-DOTATATE-PET/CT for Metastatic Thyroid Cancer

* INCLUSION CRITERIA: Data prospectively collected from the 28 subjects enrolled under this protocol, and data from 26 subjects collected under 77-DK-0096 and/or 00-CH-0093 will be analyzed. Among the 26 subjects prospectively evaluated under 77-DK-0096 protocol, 21 out of 26 had research 68Ga-DOTATATE PET/CT performed under the DOTATATE sub-study of 77-DK-0096, and 5 out of 26 had 68Ga-DOTATATE PET/CT done under 00-CH-0093. Again, the inclusion of the above data was per the IRB s request to transition the sub-study into a new standalone protocol. This will give us a total of 54 subjects for the final analyses, with at least 18 subjects from each group (e.g., HTC, DTC, and MTC), which is required to meet the primary objectives of this study with sufficient power of 80% and type 1 error alpha of \< 0.05. Patients with HTC, DTC, and MTC will be identified by the investigators. The potential candidates for the study will be screened for eligibility to participate in the study and invited to sign the Research 68Ga-DOTATATE PET/CT imaging informed consent form. The same inclusion/exclusion criteria were applied to the subjects who underwent imaging with the 68GADOTATATE PET/CT, either under the 77-DK-0096 sub-study or as clinically-indicated imaging under 00-CH-0093. In order to be eligible to participate in this study, an individual with DTC (including HTC) must meet all of the following criteria: * Male or female, aged \>18 years. * Patients with established thyroid cancer diagnosis presenting with either: * Locally advanced or distant metastases, which are RAI-non-avid based on the or diagnostic or post-treatment whole body scan (WBS) OR --Patients with RAI-non-responsive disease, who have the evidence of disease progression defined by RECIST 1.1 criteria after therapy with RAI. In order to be eligible to participate in this study, an individual with MTC must meet all of the following criteria: * Male or female, aged \>18 years. * Patients with locally advanced or metastatic MTC or patients suspected of locally advanced or metastatic MTC with calcitonin level \> 500 pg/mL. EXCLUSION CRITERIA: Subjects with either HTC, DTC, or MTC who meet any of the following criteria will be excluded from participation in this study: * Pregnancy or lactation by self-report. * Serious underlying medical conditions that restrict diagnostic testing or therapy such as renal failure, congestive cardiac failure or active coexisting non-thyroid carcinoma; * Patients unable to give informed consent.