Radioiodine-avid Bone Metastases From Thyroid Cancer Without Structural Abnormality

Study Overview
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Brief Summary
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Bone radioiodine (RAI) uptake without structural abnormality in thyroid cancer (TC) patients may be related to false positive or to microscopic foci of metastatic tissue. In such cases, outcome is reported to be excellent. Indeed, Robenshtok et al. reported a serie of patients with RAI-avid bone metastases of TC without structural abnormality on imaging studies who have more favorable long-term prognosis than those harbouring structurally visible bone metastases and do not undergo skeletal-related complications. The investigators report the case of Mrs D., who had been operated for a pathologic tumor stage 3: pT3(m) poorly differentiated TC at the age of 43. The first post-therapeutic whole body scan revealed 3 foci of bone uptake (right clavicle, L2, L3). The elevated level of thyroglobulin (157ng/mL) favoured the hypothesis of bone metastases despite the absence of any structural lesion on CT and MRI. She received 7 courses of radioiodine therapy. The right clavicle RAI uptake persisted, and subsequent CT disclosed an osteolytic lesion which was treated by radiofrequency and external beam radiation. Twenty-five years after the diagnosis, she has a persistent morphological disease with a 30x8mm progressive lesion on the right clavicle, for which surgery is planned. The aim of the present study is to describe the natural history and evolution of radioiodine avid bone metastases from thyroid cancer without structural abnormalities and to identify prognosis factors.

Official Title
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Radioiodine-avid Bone Metastases From Differentiated Thyroid Cancer Without Structural Abnormality, a Singular Entity With Heterogeneous Outcomes.

Conditions
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Bone Metastases, Thyroid Cancer

Intervention / Treatment
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* Other: Administrative data
* Other: Clinical data
* Other: Histological data
* Other: Imaging data
* Other: Biological data
* Other: Further treatment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Differentiated thyroid cancer Ablation therapy with post dose scintigraphy At least one radioiodine bone uptake without structural correlation on high-resolution imaging Exclusion Criteria: A single radio iodine bone uptake with structural correlation on imaging Diagnosis of bone metastasis after a skeletal related event including spinal cord compression, pathological fracture, need for external beam radiation, surgery to bone, or development of hypercalcemia of malignancy Follow up less than 6 months Missing data in medical record

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Administrative data|Evaluation of month and year of birth, sex, referent doctor and surgeon|
|Other: Clinical data|Evaluation of diagnostic circumstances, vital status at last follow up|
|Other: Histological data|Evaluation of Pathology report of thyroid surgery|
|Other: Imaging data|Evaluation of scintigraphy, MRI, scan|
|Other: Biological data|Evaluation of thyroglobulin, antithyroglobulin antibodies|
|Other: Further treatment|Evaluation of surgery, radiotherapy, targeted therapy|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of complete remission of thyroid cancer | Disappearance of pathologic radio iodine uptake, including bone uptake, on post-therapy scintigraphy No structural evidence of disease on high-resolution imaging Suppressed serum Tg < 0.6 ng/mL, no detectable TgAb (thyroglobulin antibody) | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Radioiodine Bone Metastases, Thyroid Cancer