1. Ablation of thyroid nodules using techniques such as radiofrequency ablation (RFA), laser ablation, microwave ablation, and ethanol injection can effectively reduce nodule size and improve symptoms. 2. Current guidelines recommend ablation for benign non-functional or autonomously functioning thyroid nodules causing compressive symptoms or cosmetic concerns, with two benign cytology results. 3. Ablation may also be considered for recurrent or unresectable thyroid cancers in high-risk surgical patients or those refusing surgery, following a multidisciplinary discussion.

1. Ablation of
thyroid nodule
Mohamed M.A. Zaitoun, MD
Associate Professor of Interventional Radiology
Faculty of Medicine, Zagazig University, Egypt
FINR-Switzerland
zaitoun2015@gmail.com

2. Disclosure
I have no actual or potential conflict of interest in relation to
this presentation.

3. Agenda
History of thyroid ablation
Thyroid ablation, Why, How & What
Current guidelines
Key techniques
Outcome
Complications
Concerns
Recommendations

4. History of thyroid ablation 8 patients with autonomous thyroid
nodules 2.4-4.3 cm.
Ethanol 95%.
Follow-up 2 to 10 months.
symptoms subsided, hormonal
levels became normal, at US, all
nodules had shrunk.
8 patients, biopsy-proven recurrent
WTC.
RFA.
Follow-up of 10.3 months.
No complications.
No recurrent disease at the
treatment site was detected.

5. 12 patients (7 with autonomous hyperfunctioning thyroid nodule “A” &
5 with compressive nodular goiter “B”).
Laser ablation.
Follow up 12 months.
No complications.
Group A, decrease in the thyroid volume, disappearance of clinical
signs and symptoms related to hyperthyroidism, normalization of
thyroid hormones.
Group B, thyroid volume decreased, Pressure symptoms in the neck,
difficulty in swallowing and tracheal displacement improved in all
patients.

6. In 2009, the Korean Society of Thyroid Radiology (KSThR), an organization of thyroid
radiologists in Korea primarily involved in the diagnosis and treatment of thyroid
nodules, proposed the first set of recommendations for RF ablation of thyroid
nodules.

7. Thyroid ablation, why, how & what

8. Why?
A need for thyroid
preservation
Advanced
techniques &
equipment
Evidence on clinical
efficacy and safety

9. How?
Minimally invasive procedures include:
Percutaneous ethanol injection (PEI)
Laser thermal ablation (LTA)
Radiofrequency ablation (RFA)
High intensity focused ultrasound (HIFU)
Percutaneous microwave ablation (PMWA)
Tumino D, Grani G, Di Stefano M, et al. Nodular Thyroid Disease in the Era of Precision Medicine. Front Endocrinol (Lausanne). 2020;10:907.
Published 2020 Jan 23.

10. What?

11. Current guidelines
a) Patient selection:
Benign nonfunctional thyroid nodules
Autonomously functioning thyroid nodules
Malignancy
b) Pre-procedure evaluation
c) Specific recommendations based on nodule composition
d) Technical considerations:
Pain control
Modality
Follow up

12. Patient selection
Benign nonfunctional thyroid nodules
Autonomously functioning thyroid nodules
Malignancy

13. Benign nonfunctional thyroid nodules
Both the KSIR and ETA guidelines support the use of ablation in
the treatment of benign thyroid nodules that cause
compressive symptoms or are cosmetically disfiguring, both
recommend against treatment for asymptomatic thyroid
nodules.
Prior to treatment, 2 fine needle aspirations (FNA) demonstrate
benign (Bethesda II) cytology is recommended.
There is no guidance on the recommended timing between the 2
FNAs.
A single benign FNA can be sufficient when the nodule
demonstrates ultrasonographic findings that are classically
benign.

14. Autonomously functioning thyroid nodules
The KSIR guidelines recommend that RFA be considered for
both toxic and pre-toxic functional thyroid nodules.
The ETA guidelines differ slightly, they recommend that RFA
be considered for younger patients with small nodules
and incomplete thyroid gland suppression.
They also recommend against RFA for large functional
nodules, unless patients refuse surgery or radioactive
iodine.

15. Malignancy
Both guidelines recommend consideration of RFA for small
primary thyroid cancers and recurrent thyroid cancers in
patients at high surgical risk or who refuse surgery.
The ETA and CIRSE 2021 guidelines are more comprehensive.
For papillary thyroid microcarcinoma:
RFA is recommended as an alternative to surgery or active
surveillance, but a multi-disciplinary discussion of patients
prior to treatment is recommended.

16. Unresectable differentiated thyroid cancer:
A multi-disciplinary discussion of treatment options,
including RFA, is also recommended for patients who are
not surgical candidates, who have had prior neck
dissection or RAI, and who are seeking palliation.
Patients with extensive aggressive disease, central neck
involvement, painful metastases, or liver (<3 cm) or lung
(<2 cm)metastases can all be considered for ablation as a
palliative option.

17. Pre-procedure evaluation
In addition to FNA, both societies recommend ultrasound
evaluation, and thyroid function tests as part of the
routine pre-procedure evaluation.
The ETA guidelines also include consideration of a single
calcitonin measure due to the risk of medullary thyroid
cancers having ambiguous cytology and lacking high risk
sonographic features.
The ETA guidelines recommend laryngoscopy for patients
with voice changes, prior surgery, or nodules near the
recurrent laryngeal nerve.

18. In regard to cytology, both societies recommend RFA for
only Bethesda II nodules.
The KSIR guidelines recommend avoiding Bethesda III and
IV nodules.
The ETA guidelines recommend caution with follicular
variants and to avoid EU-TIRADS 5 lesions.
The area of cytologic atypia remains an area of ongoing
research, pathology re-review or genetic testing may help
in these cases.

19. Specific recommendations based on nodule
composition
Size:
For benign nonfunctional solid nodules, the KSIR guidelines
suggest that nodules less than 2 cm are typically
asymptomatic, and that 2 cm can be generally considered
as a lower limit for treatment.
The ETA guidelines suggest 3 cm.
Neither of these size limits are based on strong evidence,
and smaller nodules can be symptomatic based on
location and proximity to the trachea or surrounding
nerves.

20. Cystic nodules:
Are common in clinical practice, and aspiration and ethanol
sclerosis are a well-established method of treatment.
Both societies recommend ethanol injection as first line
treatment for purely cystic nodules based on cost and
efficacy.
Both societies recommend RFA be considered if initial
ethanol injection fails.
Additionally, the ETA guidelines recommend considering
RFA if there are solid components to the cystic nodule.

21. Ethanol
ablation
Combination Therapy
Ethanol ablation/ ablation
Ablation

22. Autonomously functioning thyroid nodules:
Both societies recommend that surgery, and RAI be
presented as the standard options, but that RFA is an
alternative that may be preferred by some patients.
Both societies point out that large (>20 cc) functional
nodules respond less well in the reported literature.
The ETA guidelines go on to suggest avoiding RFA for both
Grave’s disease and for toxic multinodular goiter based
on lack of evidence.

23. Technical considerations
Pain control
Modality
Follow up

24. Pain control
Both societies recommend that pain control be achieved
with local anesthetic (lidocaine), injected into the neck
soft tissues, and in a perithyroidal distribution.
The KSIR guidelines recommend against the use of general
anesthesia or moderate sedation noting that it is usually
unnecessary and presents additional risks and costs.
The ETA guidelines mention that conscious sedation can be
considered in select patients.

25. Modality
The 2017 KSIR guidelines are specifically focused on RFA,
while the ETA guidelines encompass thermal ablation
more broadly, including RFA, laser ablation (LA),
microwave ablation (MWA), and high frequency
ultrasound (HIFU).
The ETA guidelines consider both RFA and LA first line
therapies based on the available evidence.

26. They recommend that MWA and HIFU be reserved for use in
clinical trials or for patients who refuse RFA or LA, due to
the high cost and limited availability.
The choice of modality will depend on local expertise and
resources, as well as regulatory approval of devices in the
interventionalist’s home country.

27. When using RFA, both societies recommend that the
moving shot technique (pulling back slowly to ablate
small subunits) be used in conjunction with a trans-
isthmic approach for greatest patient safety.

28. Follow up
Both societies recommend regular post-procedure follow up
with thyroid function tests, ultrasound evaluation, and
clinic visits in the first year.
The KSIR guidelines do not specify the frequency of follow
up visits, the ETA guidelines recommend 3, 6, 12-month
visits, and then every 1-2 years.
For malignant tumors, the KSIR guidelines recommend 1, 6,
12-month visits, followed by visits every 6-12 months
thereafter, they recommend including thyroglobulin,
thyroglobulin antibodies, and either US or contrast
enhanced CT.

29. Both societies make the point that follow up ultrasound
should be performed by someone who is familiar with the
post-ablation appearance of thyroid nodules.
Benign nodules will appear hypoechoic after treatment as
they involute.
The post ablation appearance can be mistaken for a high-
risk nodule, which can lead to unnecessary patient anxiety
or overtreatment.

30. Key techniques
Patient in supineposition
Mild neckextension
No pre-incision of theskin required
Anaesthesia:perithyroidal LidocaineInjection,conscioussedation
Hydrodissection
Trans-Isthmic Approach
Movingshottechnique/ Pullback technique
Vascularablationtechnique(Artery-firstablation,Marginalvenous
ablation)

32. Outcome
75 studies , 35 studies focused on RFA use for solid nodules, 12
studies on predominantly cystic nodules, 10 for autonomously
functioning thyroid nodules, and 18 studied were published
on differentiated thyroid cancer.
RFA seems to be an effective and safe alternative to surgery in
high-risk surgical patients with thyroid cancers and for
selected BTNs.

33. 19 researches and 2137 patients.
PLA has significant clinical value in the treatment of
benign TNs for reducing nodule volume after 1, 3, 6,
12, 24 and 36 months.
PLA is an effective technique for improving thyroid
function, including increasing serum TSH levels and
reducing serum T4 and Tg levels at 1 and 12 months
post-treatment.

34. 7 studies.
The results showed significant improvements in nodule volume,
clinical symptom scores, and beauty scores between the
baseline and final follow-up visits.
MWA is effective and safe for the treatment of benign thyroid
nodules and papillary thyroid microcarcinomas.

35. Nine studies were included in the systematic review and 6 in the
meta-analysis.
HIFU may be an effective and safe alternative treatment
modality for benign thyroid nodules.

37. RFA achieved a significantly larger nodule volume
reduction at 12 months; however, the technical
success rate was similar in the RFA and LA groups.

38. RFA, MWA and HIFU showed comparable results
considering volume reduction.
All methods are safe and effective treatments of benign
thyroid nodules.

39. Complications
(I) Major:
1-Voice change
2-Nodule rupture
3-Nodule rupture with abscess formation
4-Hypothyroidism
5-Brachial plexus injury

40. (II) Minor:
1-Vomiting
2-Skin burn
(III) Side effects:
1-Pain
2-Vasovagal reaction
3-Coughing

41. Concerns
• Nodule factors
• Baseline Nodule Volume
• Vascularity
• Technical factors
• TA Modalities
• Energy Delivered
• Multiple-Session Ablation

42. Recommendations
Thyroid ablation has been shown to be a consistently safe
and effective treatment for benign thyroid nodules with
excellent long-term results.
Ablation has been shown to be safe and effective for long-
term local tumor control for malignant thyroid nodules in
patients ineligible for surgery or those who do not wish to
undergo active surveillance.