The purpose of long-term follow-up of thyroid cancer patients is: 1. to monitor those who are clinically cured for early detection of recurrent tumors and metastases; 2. to dynamically observe the progress of disease and treatment effects for those who have recurrence or survive with tumors and adjust the treatment plan; 3. to monitor the effect of TSH suppression therapy; 4. to monitor the condition of certain concomitant diseases (e.g., heart disease, other malignant tumors, etc.) in patients with DTC. Dynamic observation of certain concomitant diseases (such as heart disease, other malignant tumors, etc.) in DTC patients.
(1) Exogenous thyroxine suppression therapy is required after DTC surgery. The degree of TSH suppression therapy is determined by the risk of recurrence after surgery. After each dose adjustment of oral exogenous thyroxine, thyroid function should be reviewed at 4-6 weeks follow-up, and the follow-up interval may be extended as appropriate when the ideal equilibrium point is reached.
(2) For patients with DTC who have had total thyroid clearance (after surgery + 131I thyroid clearance), serum Tg levels should be measured regularly (along with TgAb), and the same test reagent is recommended. Long-term follow-up of serum Tg begins 6 months after 131I thyroid clearance, when basal Tg or sTg is measured. sTg is repeated 12 months after 131I treatment, and basal Tg is repeated every 6 to 12 months thereafter. sTg may be repeated 3 years after thyroid clearance for those at intermediate or high risk of recurrence.
The sTg may be repeated within 3 years of thyroid clearance in those at intermediate or high risk of recurrence;
- Neck ultrasound should be performed periodically during DTC follow-up to assess the status of the thyroid bed and lymph nodes in the central and lateral cervical regions of the neck. The first postoperative ultrasound examination is recommended at 3 months postoperatively for high-risk patients and 6 months postoperatively for intermediate and low-risk patients. If suspicious lesions are found, the examination interval can be shortened as appropriate. Ultrasound-guided puncture biopsy and/or puncture eluate Tg testing is indicated for suspicious lymph nodes.
- Patients with DTC may be followed up with Dx-WBS optionally after surgery and 131I thyroid clearance, depending on the risk of recurrence.
1) Patients with DTC at low to moderate risk of recurrence who have Dx-WBS that does not suggest 131I uptake outside the thyroid bed and who have no abnormal neck ultrasound and basal serum Tg levels at follow-up
(in TSH suppressed state) are not high, Dx-WBS is not required.
(ii) In patients with DTC at moderate to high risk of recurrence, the application of Dx-WBS during long-term follow-up may be valuable in detecting tumor lesions, and an examination interval of 6 to 12 months is recommended. Dx-WBS is feasible in patients with progressively elevated Tg levels or suspected DTC recurrence during follow-up.
- CT and MRI are not routinely performed at DTC follow-up. CT or MRI of the cervical thorax should be performed if: (1) the lymph node recurrence is extensive and cannot be accurately described by ultrasound; (2) the metastases may have invaded the upper aerodigestive tract and require further evaluation of the extent of invasion; or (3) the serum Tg level is elevated (>10 ng/ml) or TgAb is elevated in high-risk patients. If Dx-WBS is negative, iodine-containing contrast should be avoided if follow-up 131I therapy is possible. If an enhanced CT scan with iodine contrast is performed, 131I therapy is recommended 4 to 8 weeks after the examination.
(6) Iodine-containing contrast is not currently recommended in Doppler;
(6) The routine use of 18F-FDG PET in DTC follow-up is not currently recommended, but may be considered in the following situations: (1) to assist in finding and localizing lesions when serum Tg levels are elevated (>10 ng/ml) and Dx-WBS is negative; (2) to evaluate and monitor disease in lesions that do not uptake iodine; and (3) to evaluate and monitor disease in invasive or metastatic DTC.
(7) Long-term follow-up of DTC should also include the following: (1) Long-term safety of 131I therapy: including the effect on secondary tumors and reproductive system. However, excessive screening and examination should be avoided; (ii) the effect of TSH suppression therapy: including whether TSH suppression therapy meets the standard and the side effects of therapy; (iii) the concomitant diseases of DTC patients: since the clinical importance of certain concomitant diseases (such as heart disease, other malignant tumors, etc.) may be higher than that of DTC itself, the disease of the above concomitant diseases should also be dynamically observed during long-term follow-up.