Well-differentiated thyroid cancers (IFTC) are seen in 95 percent of all thyroid cancers. IFTKs; It is grouped under 3 subheadings: papillary thyroid cancer (PTK) with a frequency of 85 percent, follicular thyroid cancer (FTK) with a rate of 10 percent, and Hurthle cell thyroid cancer with a rate of 3 percent.
REASONS FOR APPLICATION. WHAT ARE THEY? The typical presentation of a patient with IFT is a painless thyroid nodule without any symptoms. It should be noted that an average of 5 percent of all nodules are cancer. Thyroid nodules are found incidentally on their own or during physical examination performed by a physician or during radiological imaging performed for other reasons. It is not possible to say whether it is cancer or not, based on clinical appearance alone. However, some unique findings may raise the suspicion of cancer. These develop when thyroid cancer puts pressure on or spreads to neighboring organs. These symptoms, which we call pressure symptoms, do not always indicate only thyroid cancer; However, a patient presenting with these findings should also be evaluated from this aspect. Alarming symptoms; These can be listed as hoarseness due to spread to the vocal nerve, difficulty in swallowing due to esophageal involvement, feeling of being stuck and loud breathing as a result of spread to the air pipe.
WHAT SHOULD THE PRE-OPERATIVE EVALUATION BE?
p>
Surgical treatment should be chosen in patients whose fine needle aspiration biopsy results are compatible with cancer, suspicious for cancer, or suspicious for follicular or Hurtle cell neoplasia. Considering that PTC spreads to the neck lymph nodes in an average of 50 percent of the patients, and that preventive neck dissection is definitely recommended for T3-T4 tumors (those with a tumor diameter of more than 4 cm and extrathyroidal spread); in the preoperative period, every patient should undergo neck ultrasonography to evaluate the lymph nodes. It should be examined with (USG). Determining lymph node involvement before surgery is important when determining the limits of the surgery to be performed.
WHAT SHOULD THE EXTENSION OF SURGICAL TREATMENT BE?
The purpose of surgical treatment is to remove all of the tumor tissue. The main surgical treatment of choice is total thyroidectomy. Treatment of patients with IFTK with total thyroidectomy The purpose of the video; To reduce the risk of recurrence of the disease by removing all visible thyroid tissue, to allow both the destruction treatment with RAI and scanning with whole body scintigraphy of the remaining thyroid and tumor tissue or tumor-spread tissues after surgery, since IFTs are generally sensitive to radioactive iodine (RAI-atom). To increase the diagnostic value of serum thyroglobulin (Tg) measurements, which are an indicator of cancer recurrence. The extent of surgery and the experience of the surgeon play an important role in determining surgical risks.
Tg is produced only by normal thyroid tissue and tissues with IFT. Therefore, any procedure less than total thyroidectomy leaves thyroid tissue behind and Tg measurements are less helpful in detecting recurrent or residual disease. The Tg value measured about 1 month after thyroid surgery should be less than 1ng/ml, which means that all visible It is possible by completely removing the thyroid tissue. A high Tg level is suspicious for recurrent or persistent thyroid cancer and requires further examination.
The extent of the surgery performed, especially if it is larger than 1 cm It is effective against general recurrence in PTC. It has been reported that up to 10 percent of those treated with lobectomy surgery, in which only one side where the cancer is located, experience recurrence on the opposite side. In addition, since 50 percent of PTCs have multifocal disease, there is a risk of leaving cancer on the opposite side of the thyroid gland. Even in low-risk patients, within 20 years; The risk of lymph node spread has been reported as 19 percent in unilateral surgery and 6 percent in bilateral surgery, and these rates are higher in high-risk patients.
IS LYMPH NODE DISSECTION REQUIRED?
There is no consensus regarding intervention in the lymph nodes in the anterior neck region in patients without significant lymph node involvement. There is a potentially higher rate of secondary intervention in patients who only undergo total thyroidectomy without the prophylactic 'anterior cervical lymph node removal' (SNLD) procedure. In a recent study, suspicious lymph nodes were detected on preoperative ultrasound. It has been reported that lymph node spread is common in patients with PTC that is clear and smaller than 2cm. When SNLD is performed in patients with PTC, microscopic (less than 2 mm) cancer spread in the lymph nodes; It was found to be 45 percent in the front neck region and 47 percent in the lateral neck region. In addition, in a retrospective study, postoperative Tg levels were found to be lower in patients who underwent SNLD on the affected side than in patients who underwent total thyroidectomy alone.
Those who oppose this procedure say: Since microscopic lymph node spreads, unlike detectable ones, have little effect on survival and recurrence, and when the SNLD procedure is performed by low-volume (lack of experience) surgeons, the risk of calcium deficiency and negative effects of the vocal nerve, which are the risks of the surgery, are increased; They recommended that SNLD be performed in T3-T4 tumors (tumor diameter over 4 cm and extrathyroidal spread) rather than small tumors.
Initial surgery in patients with visibly abnormal or palpable lymph nodes on examination. SNLD operation should be performed during The presence of palpable lymph nodes in the lateral neck region is a clinical sign of cancer spread and 'removal of lateral neck lymph nodes' (LNLD) should be performed. Needle biopsy should be performed on suspicious lymph nodes before surgery.
In determining the risk after surgery, the most important factor in evaluating the patient with thyroid cancer in the low-risk group is the complete surgical removal of the thyroid. In addition, the tumor diameter is Being under 1cm, reporting a histological subtype with a good prognosis in the pathological result, and having no family history of thyroid cancer are also low risk groups.
Last word: The purpose of surgical treatment in IFTKs is; Whether or not intervention in the neck lymph nodes is required, the thyroid gland is completely removed while minimizing the risks that may occur during the surgery. Experience, meticulous and careful surgery is the most important thing required to minimize this risk.
Read: 0
