There is no scientific data on post-thermal ablation cytological aspects, but treated nodules that grow back significantly after a procedure justify a new cytology in order not to ignore a neoplastic process.

The EU-TIRADS classification usually used to stratify the risk of cancer (and to justify a fine needle aspiration biopsy) of thyroid nodules is not validated for nodules treated by thermal ablation (TA) (post-RF nodules). However, these nodules often acquire ultrasound criteria of suspicion making it necessary to develop an ultrasound stratification of the risk of malignancy specific to nodules treated by TA.

The objective of this work is to describe the ultrasound and cytological aspects of these treated nodules by performing a systematic assessment at 3 years after thermal ablation including systematic neck ultrasound and fine needle aspiration biopsy. Thus, an ultrasound and cytological atlas (Bethesda classification 2017) of nodules treated by thermal ablation will be constituted.

Inclusion Criteria:

1. Patients > 18 years old
2. Carrier of a benign thyroid nodule that has undergone radiofrequency thermoablation 36 months previously ± 12 months +/- 1 month, whether the nodule is stable, progressing or decreasing in volume during the screening period and/or on the day of inclusion.
3. Obtaining written informed consent
4. Affiliation to a social security system (excluding AME)

Exclusion Criteria:

1. Pregnant or breastfeeding women
2. Previous alcohol use
3. Patients on anti-vitamin K anticoagulants
4. Patients on direct oral anticoagulants
5. Persons deprived of liberty by judicial or administrative decision
6. Persons under forced psychiatric care
7. Persons admitted to a health or social institution for purposes other than research
8. Persons of full age who are under legal protection (guardianship or curatorship)
9. Persons unable to express their consent
10. Persons under a legal protection measure (there can be no derogation for this category)