Adjuvant Radiotherapy in High Risk Locally Advanced DTC

Inclusion Criteria:

1. The patient voluntarily joined this study and signed an informed consent form;

2. Age: ≥ 14 years old,<80 years old, male or female not limited;

3. Histopathological diagnosis of differentiated thyroid cancer;

4. Surgical total or near total thyroidectomy;

5. The surgery did not achieve R0 resection, and R1/ R2 resection was performed. Thevolume of residual tumor in R2 resected patients is less than 2cm3;

6. The main organ functions are normal;

7. Good compliance and cooperation with follow-up.

Exclusion Criteria:

1. Previously received radiation therapy for the head and neck area;

2. Differentiated thyroid cancer with poorly differentiated, or undifferentiatedcomponents;

3. There is distant metastasis;

4. Previously received 131I treatment;

5. Previously received or currently receiving targeted therapy, immunotherapy,chemotherapy;

6. Within 5 years or simultaneously suffering from other active malignant tumors. Curedlocal tumors, such as skin basal cell carcinoma, skin squamous cell carcinoma,superficial bladder cancer, prostate carcinoma in situ, cervical carcinoma in situ,breast carcinoma in situ, can be included in the group;

7. Pregnant or lactating women;

8. Other physical illnesses that affect patients' ability to receive standardtreatment;

9. According to the researchers' assessment, there may be other factors that couldforce the subjects to terminate the study, such as suffering from other seriousillnesses (including mental illnesses) that require concurrent treatment, severeabnormal laboratory test values, family or social factors that may affect the safetyof the subjects or the collection of experimental data;

10. Individuals with claustrophobia who are unable to undergo radiation therapy;

11. Patients deemed unsuitable for inclusion by other attending physicians.