1. Highly differentiated PTC and FTC
The current recommended indications for external radiation therapy are shown in Figure 2.
Figure 2.
Figure 2. Indications for radiotherapy for DTC
The indications for external radiation include: (1) those who have obvious tumor residuals that cannot be removed surgically and cannot be controlled by radionuclide therapy alone; (2) those who do not absorb iodine for residual or recurrent lesions after surgery.
2. MTC
For patients who cannot be completely resected by surgery or who have recurrence, external radiation therapy can be considered. External radiotherapy is usually considered to help local control in these patients. See Figure 3.
Figure 3. Indications for radiotherapy for MTC
3. ATC
Combination therapy is the main treatment modality and is individualized according to the patient’s specific situation. Radiotherapy can function as part of the preoperative and postoperative combination therapy. Radiotherapy alone can also be used, and high-dose radiotherapy (recommended dose 60Gy) is feasible.
4. Palliative radiotherapy for thyroid cancer with distant metastatic lesions such as lung, liver, bone and brain with clinical symptoms, surgery or 131I treatment combined with EBRT or stereotactic body radiation therapy can be considered to relieve symptoms and slow down tumor progression.