Follicular thyroid cancer surgery
|
Follicular thyroid cancer Microchapters |
|
Differentiating Follicular thyroid cancer from other Diseases |
|---|
|
Diagnosis |
|
Treatment |
|
Case Studies |
|
Follicular thyroid cancer surgery On the Web |
|
American Roentgen Ray Society Images of Follicular thyroid cancer surgery |
|
Risk calculators and risk factors for Follicular thyroid cancer surgery |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ammu Susheela, M.D. [2]
Overview
Surgery is the mainstay of treatment for follicular thyroid cancer.
Surgery
Surgical Treatment
- Unilateral hemithyroidectomy (removal of one entire lobe of the thyroid) is uncommon due to the aggressive nature of this form of thyroid cancer.
- Total thyroidectomy is almost automatic with this diagnosis. This is invariably followed by radioiodine treatment at levels from 50 to 200 millicuries following two weeks of a low iodine diet (LID). Occasionally treatment must be repeated if annual scans indicate remaining cancerous tissue.
Stage I and II Follicular Thyroid Cancer
Total Thyroidectomy
- This procedure is advocated because of the high incidence of multicentric involvement of both lobes of the gland and the possibility of dedifferentiation of any residual tumor to the anaplastic cell type.
- The objective of surgery is to completely remove the primary tumor, while minimizing treatment-related morbidity, and to guide postoperative treatment with radioactive iodine (RAI). The goal of radioactive iodine (RAI) is to ablate the remnant thyroid tissue to improve the specificity of thyroglobulin assays, which allows the detection of persistent disease by follow-up whole-body scanning. For patients undergoing radioactive iodine (RAI), removal of all normal thyroid tissue is an important surgical objective. Additionally, for accurate long-term surveillance, radioactive iodine (RAI) whole-body scanning and measurement of serum thyroglobulin are affected by residual, normal thyroid tissue, and in these situations, near total or total thyroidectomy is required. This approach facilitates follow-up thyroid scanning.
- I-131: Studies have shown that a postoperative course of therapeutic (ablative) doses of I-131 results in a decreased recurrence rate among high-risk patients with papillary and follicular carcinomas. It may be given in addition to exogenous thyroid hormone but is not considered routine.
Lobectomy
- Lobectomy is associated with a lower incidence of complications, but approximately 5% to 10% of patients will have a recurrence in the thyroid following lobectomy. Patients younger than 45 years will have the longest follow-up period and the greatest opportunity for recurrence. Follicular thyroid cancer commonly metastasizes to lungs and bone; with a remnant lobe in place, use of I-131 as ablative therapy is compromised. Abnormal regional lymph nodes should be biopsied at the time of surgery. Recognized nodal involvement should be removed at initial surgery, but selective node removal can be performed, and radical neck dissection is usually not required. This results in a decreased recurrence rate but has not been shown to improve survival.
- Following the surgical procedure, patients should receive postoperative treatment with exogenous thyroid hormone in doses sufficient to suppress thyroid-stimulating hormone (TSH); studies have shown a decreased incidence of recurrence when thyroid-stimulating hormone is suppressed.
Stage III Follicular Thyroid Cancer
Standard Treatment Options
- Total thyroidectomy plus removal of involved lymph nodes or other sites of extrathyroid disease.
- I-131 ablation following total thyroidectomy if the tumor demonstrates uptake of this isotope.
- External-beam radiation therapy if I131 uptake is minimal
Stage IV Follicular Thyroid Cancer
- The most common sites of metastases are lymph nodes, lung, and bone. Treatment of lymph node metastases alone is often curative. Treatment of distant metastases is usually not curative but may produce significant palliation.
Lymph Node Metastasis
- For lymph node metastasis, central neck dissection is recommended.
- Central neck dissection includes evacuation of fibrofatty and nodal tissue from common carotid artery to hyoid bones superiorly and inferiorly upto the innominate artery.
- Modified neck dissection is reserved for lymphnodes with macroscopic metastasis. In this procedure, all nodal and fibrofatty tissues are removed from levels II to level V in the neck.
Bone Metastasis
- Spine stabilization is reserved for bone metastasis with neurologic symptoms.
- Percutaneous vertebroplasty is also recommended for bone metastasis.