Eun Ju Ha1, Jung Hwan Baek1, Jeong Hyun Lee1, Jin Young Sung2,

Jae Kyun Kim3 , Young Kee Shong4

1Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center

2Department of Radiology, Thyroid Center, Daerim St. Mary’s Hospital

3Department of Radiology, Chung-Ang University College of Medic ine

4Department of Endocrinology and Metabolism, University of Ulsan College of Medicine, Asan Medical Center

RF Ablation of Benign Thyroid Nod-

ules Does Not Affect Thyroid Function

in Patients with Previous Lobectomy

Previous lobectomy patientsSymptomatic benign thyroid nodule in the remaining thyroid gland

What would be the best treatment option for this patient?

For patients with previous lobectomy

Surgical treatment

① Risks of recurrent laryngeal nerve injury and hypoparathyroidism

② Permanent hypothyroidism

Introduction

Monzani et al. 1997. Clin Endocrinol (Oxf) 46:9-15

Baek et al. AJR Am J Roentgenol 194:1137-1142

Papini et al. 2008. Curr Opin Endocrinol Diabetes Obes 15:434-439

Valcavi et al.2010.Thyroid 20:1253-1261

Lefevre et al. 2007. Langenbecks Arch Surg 392:685-691

Rafferty et al. 2007. J Am Coll Surg 205:602-607

Non-surgical treatments (RF-, laser- and ethanol ablation)

attractive treatment options that may preserve thyroid function

Regarding thyroid function,

Transient hyperthyroidism in a few patients

Permanent hypothyroidism in two patients: the reason was unclear

Thyroid function seems to be rarely influenced by RF ablation

but no studies in patients with previous lobectomy

RF ablation

Kim et al.2006.Thyroid 16:361-367

Jeong et al. 2008. Eur Radiol 18:1244-1250

Baek et al. 2012. Radiology 262:335-342

To evaluate whether RF ablation for the treatment of benign

thyroid nodules affects thyroid function in patients with

previous lobectomy

Purpose

Inclusion criteria

2002.6-2009.1222 patients of previous lobectomy due to benign thyroid nodules

Inclusion criteria

11 patients with 14 thyroid nodules

7 patientsHypothyroidism before RFA

4 patientsFU for less than 6-month

Exclusion

Materials & Methods(1) predominantly solid nodule (2) pressure symptoms or

cosmetic problems(3) cytologic confirmation of

benignancy at least twice (4) no malignant features de-

tected using US (5) refusal of surgery

The Procedure of RF ablation

By an experienced radiologist

Using the Cool-Tip RF system, Internally cooled electrode

Using the Moving shot technique

Materials & Methods

< Illustration for Moving Shot Technique>

Baek et al. 2011 Korean J Radiol. 12:525-540

Pre-procedural evaluation

Clinical concern: symptomatic (0-10) / cosmetic (1-4) scores

US examination: the largest diameter, volume

Laboratory test: TSH, fT4, T3, anti-TPO/Tg/TSHRc Ab

Follow-up periods

Clinical concerns, US examination: 1-, 6-month, and last F/U

Laboratory test: 6-month, and last F/U

Complications

Materials & Methods

Statistical analysis

SPSS for Windows (version14.0; SPSS, Chicago, IL)

Compare the variables at the time of enrollment and the last F/U

: Wilcoxon’s signed rank test

Materials & Methods

Follow-up duration : 43.7 ± 30.7 months

Interval (surgery- RF ablation): 122.9 ± 151.3 months

Efficacy

Characteristic Enrollment Last follow-up P value

Volume (mL) 9.7±36.3 (0.9-57.6) 2.8±12.4 (0.0-17.9) 0.001

Symptom score 4.6 ± 2.1 (2-9) 1.4 ±0.7 (0-5) 0.003

Cosmetic score 3.5 ±0.0 (3-4) 1.5±0.7 (1-3) 0.003

VRR at last follow-up : 87.2%

Results

Thyroid Function

Thyroid Antibodies

None of the patients showed newly developed thyroid antibodies during the F/U

Characteristic Enrollment Last follow-up P value

Thyrotropin (mU/mL) 1.7±1.1 (0.4-3.8) 2.0 ± 1.2 (0.8-4.0) 0.306

Free thyroxine (ng/dL) 1.4± 0.1(1.0-1.9) 1.4±0.2 (0.9-2.4) 0.789

Triiodothyronine (ng/dL) 113.3±6.4 (80.2-133.0) 113.3±21.2 (82.4-151.0) 0.878

Results

Each value is the mean ± SD, with the range in parenthesis

Results

1.77 1.09 114 (-/-/-)

92-month F/U

Complications : no major complications including voice change

None of the patients required additional surgery

Results

Case

2 RF ablations Improvement of symptomatic andcosmetic problems

Thyroid function was well preserved in all patients The efficacy is usually confined to targeted nodules

=> damage to surrounding normal thyroid gland can be minimized

Discussion ①

Comparison with LA and EA

Baek et al. Baek et al. Valcavi et al. Monzani et al. Livraghi et al.

Published journal Radiology WJS Thyroid Clin Endocrinol Radiology

Published year 2012 2009 2010 1997 1994

Ablation methods RF RF Laser EA EA

N. of patients 1459 9 122 117 101

Mean diameter 3.8 ± 1.4 cm 3.2 ± 1.4cm 1.5 - 7.0 cm

(range)

> 3cm

Hypothyroidism 1 1 2 1 1

Thyroid Abs TPO Ab Tg Ab TPO Ab/Tg Ab TPO Ab/Tg Ab TPO Ab

Note. NFTN AFTN NFTN AFTN AFTN

Discussion ②

Abbreviations: Tg: Thyroglobulin, TPO: Thyroid peroxidase, Ab: antibodyNFTN: nonfunctioning thyroid nodule, AFTN: autonomously functioning thyroid nodule

The cause of hypothyroidism…

Discussion ②

Progression of autoimmune thyroiditis

Treatment of autonomously functioning thyroid nodule (AFTN)

It may be necessary to warn the patients with thyroid antibodies

and the patients with AFTNs about the possibility of

hypothyroidism prior to the treatment

In patients with previous lobectomy,

RF ablation

has advantages in terms of maintaining thyroid function

should be considered as a first-line treatment

Conclusion

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