Removal of postoperative residual tissue of differentiated thyroid cancer by 131I
Rationale]
After total or near-total thyroidectomy for DTC, a small amount of thyroid tissue remains in almost all thyroid beds, and the residual thyroid tissue may have microscopic lesions that cannot be detected by the naked eye. The tumor cells still retain the function of 131I uptake, and the patient can destroy the residual microscopic lesions after surgery by taking high dose of 131I orally (nail clearing treatment), which can help to review after surgery, reduce the recurrence rate and prolong the survival period.
Indications】
1.Treatment of lung and bone metastases should be treated with nail clearing therapy first.
2.The primary foci >1cm should be treated with nail clearance.
3.Regardless of the size of the primary foci, any lymph node metastasis, extra-thyroidal vascular, muscle or fatty fiber tissue should be treated with nail clearance.
4, large cells, columnar cells, eosinophilic subtypes and other aggressive pathological types, to clear nail treatment.
Contraindications]
1.Pregnancy, lactation.
2.Severe hepatic and renal insufficiency.
3, Leukopenia, WBC <3.0×109 /L.
Method and procedure
1.After total or near-total thyroidectomy, histopathological diagnosis of DTC.
2, not taking levothyroxine sodium for 3~4 weeks, those already taking it need to stop taking it for 3~4 weeks, no enhanced CT within the last month.
3, plasma TSH ≥ 30mU/L.
4.Low iodine diet for 2 weeks.
5.Patients sign the informed consent.
6, Perform technetium-99m ECT imaging before conventional treatment to determine the residual thyroid tissue in the thyroid bed, too large to recommend surgical excision followed by nail clearing treatment.
7.Record the present medical history, the relevant departments for complete medical record writing, nuclear medicine department according to the number of patients to order drugs in advance, notify patients to come to the designated time to take drugs.
8.Safety preaching by the nurse in charge, including taking 131I medication, hygiene, general knowledge of protection, etc.
9.The recommended dose is 30~100mci, which is dispensed by automatic dispenser, and patients are instructed to learn how to take 131I orally before taking the medication.
10. Check the patient’s name, drug name, dosage, medication time and usage according to the doctor’s prescription. Throw the cup of water after medication use in the red garbage bag container, video management throughout the process, and give real-time guidance and help when necessary.
11.After taking the medication, the isolation ward is observed for at least 48 hours, with video monitoring throughout the whole process, equipped with a telephone to talk when necessary.
12.Start levothyroxine sodium on the 3rd day, starting with a small dose and gradually increasing to the target dose of 2.1μg/kg according to body weight.
13.A 131I whole body scan was performed one week later.
【Complications】.
1. Headache, nausea, vomiting, etc.
2. Local neck edema, swelling and pain.
3, radioactive salivary glanditis, can be alleviated by oral VC, etc. to promote salivary gland secretion.
4. Transient decrease in white blood cells and platelets;
5.Gonadal injury is uncommon.
Efficacy test]
1. Determine thyroid function 3 months after treatment and adjust the dose of levothyroxine sodium.
2. Stop taking levothyroxine sodium for 3~4 weeks after 6 months of thyroid clearing treatment, and follow a low iodine diet for 2 weeks, with fasting blood sampling for lateral thyroid function, Tg, TGAb, and 131I whole body scan.
3. If no uptake is seen in the thyroid bed area and Tg <10 μg/L in TSH stimulated state, the first clearing of the thyroid is judged to be successful.
4. Those with incomplete treatment can be treated again in 6~12 months.
【Caution】.
1. Some patients have more residual thyroid tissue or have distant metastases and secrete more thyroid hormone in the body, but TSH cannot reach 30 mU/L. Or some patients have insufficient TSH secretion from the pituitary gland, these cases can also be treated with nail clearing therapy.
2.Some patients have recently had an enhanced CT scan and need 4 weeks before treatment.
3. Radionuclides are expensive and decaying, once ordered, they cannot be returned or exchanged.