Radiofrequency Ablation for Autonomously Functioning Thyroid

Nodules (AFTN): Multicenter Study of Korean Society of Thyroid Ra-

diology (KSThR)

Jin Yong Sung1, Jung Hwan Baek1,3, So Lyung Jung5, Ji-hoon Kim6, Kyu Sun Kim1, Ducky Lee2, Jeong Hyun Lee3, Young Kee Shong4, Dong Kyu Na7

1Department of Radiology, Thyroid Center, Daerim St. Mary's Hospital, 2Department of Internal Medicine, Thyroid Center, Daerim St. Mary's Hospital, 3Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 4Department of Endocrinology and Metabolism, University of Ulsan College of Medicine, Asan Medical Center, 5Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 6Department of Radiology, Seoul National University College of Medicine, 7Department of Radiology, Human Medical Imaging & Intervention Center

Definition of AFTN

Scintigraphy : increased uptake in the nodule

compared with surrounding normal thyroid parenchyma

Hormone TSH: low or undetected

Problems of AFTN

Malignancy : Papillary, follicular, medullary, poorly differen-

tiated

Large nodule volume 1) symptomatic 2) cosmetic

Functional problem: Thyrotoxicosis 1) decreased bone density -- osteoporosis 2) atrial fibrillation

Baek et al. Thyroid 2008;18(6):675-676

Baek et al. World J Surg 2009; 33(9):1971-7Hegedus L. N Engl J Med 2004; 351:1764–1771Toft AD. N Engl J Med 2001; 345:512–516

Treatment options

Radioactive iodine therapy

Surgery

Gharib H. J Clin Endocrinol Metab 2005; 90:581–587Hegedus L. N Engl J Med 2004; 351:1764–1771Toft AD. N Engl J Med 2001; 345:512–516

Effect/Side effect is dose dependant 10mCi: mild symptom, less than 3cm

nodule

TSH normalize in 6 months 20mCi: 38/42 (normal), 1/42 (repeat)

3/42 (hypothyroidism)

Radioactive iodine treat-ment

Gharib H. J Clin Endocrinol Metab 2005; 90:581–587Hegedus L. N Engl J Med 2004; 351:1764–1771Toft AD. N Engl J Med 2001; 345:512–516

Scar formation

Hypothyroidism

Anesthetic risk

Long recovery time

Voice change

Hypoparathyroidism

Surgery, drawbacks

Radiofrequency Ablation for AFTN

Author (Year) Cases

Normal-ized TSH

(%)

Volume Reduc-tion at last fol-

low-up (%)

Follow up periods (Mo)

Baek et al. (2008 and 2009) 10 60 72.2 12

Deandrea et al. (2008) 23 21.7 52.6 6

Small number of enrolled nodules, short F/U periods, different RFA technique (moving vs fixed)

Baek et al. Thyroid 2008;18(6):675-676

Baek et al. World J Surg 2009; 33(9):1971-7Deandrea et al. Ultrasound Med Biol 34:784–791

Objectives

To evaluate the efficacy and safety of

RFA for the treatment of AFTN

Materials and Methods

Patients Multicenter study, Korean Society of Thyroid Radiology 5 institutions, from August 2007 to July 2011

Selection Criteria

• Hot nodule with / without suppression of normal thyroid

• Low TSH

• Benign lesion: FNAB or CNB

• Refused or not suitable for Op. or iodine therapy

44 patients [M:F=2:42, 43 ± 14.7 (range, 17-70) years] 25 (56.8%) toxic nodules, 19 (43.2%) pre-toxic nodules

Pre-Ablation Assessment

Clinical sign / symptom

: Symptom (Visual Analogue Scale, 0-10cm) and

cosmetic grading score (grade 1-4)

T3, fT4, TSH, TSH-R-Ab

US – gray scale and color doppler

: Diameter, volume and vascular grade

FNAB and/or CNB

Thyroid scan with 99mTc pertechnetate

RFA Procedure

Internally cooled electrode: 18 G 0.5-1.5 cm active tip

Trans-Isthmic Approach and Moving-Shot Technique

Termination of ablation:

Whole nodule changed to transient hyperechoic  

Patient Care and Follow up

Post-treatment care : Evaluation of complications and observation for 1-2 hours   Following at 1, 3, 6 months and every 6-12 months

: Symptom (self-check list) and cosmetic grading score

Complication

T3, fT4 and TSH

US : diameter, volume and vascularity

Thyroid scan : nodule and surrounding thyroid gland

Treatment Effects

Complete Cure (CC) : Normal hormone level & Hot nodule converted to cold or invisible nodule

Partial Cure (PC) Hormonal Remission (HR) Failure (F)

SymptomScan Hormone

Nodule Extran-odular

T3 / fT4 TSH

CC - ↓ N N N

PC - ↑/→ N N N

HR - ↑/→ ↓ N ↓

F + ↑ ↓ ↑ ↓

Statistical Analysis

Wilkoxon signed rank test : At each follow up periods• The nodule volume change and % volume reduction • Changes of T3, fT4 and TSH• Changes in thyroid scan (nodule and extranodular area)• Changes of cosmetic and symptom grading scores

Significance : P < 0.05

Results

RFA Characteristics

Treatment Sessions: 1-6 (mean, 1.8 ± 0.9)

Ablation Time: 2.5-30 minutes (range, 12 ± 5.9) Ablation Power: 20-120 W (range, 63.3 ± 26.3)

Total Energy: 4500-539460 J (mean, 76939.6 ± 87264.2) Mean Energy/mL: 1589-19014 J/mL (mean, 6417.3 ± 4318.4)  

US and Clinical Findings

Pre-RFA 1 M 3 M 6 M Last F/U

Diameter (cm)

3.8 ± 1.4 3.1 ± 1.4* 2.8 ± 1.6* 2.5 ± 1.4* 2.1 ± 1.2*

Volume (ml) 18.5 ± 30.1 11.8 ± 26.9* 12.2 ± 28.2* 7.0 ± 14.7* 4.7 ± 10.1*

Volume Re-duction (%)

0 28.6 ± 109.6 64.1 ± 18.4 61.5 ± 77.2 70.8 ± 69.9

Vascularity Grade

3.1 ± 0.7 0.9 ± 1.0*

Symptom Grade Score

3.3 ± 2.1 0.9 ± 1.0*

Cosmetic Grade Score

3.8 ± 0.5 1.8 ± 0.9*

* P < 0.001 vs pre-RFA.

Changes in T3, fT4 and TSH

Hor-mone† Pre-RFA 1 M 3 M 6 M Last F/U

T3 (ng/dL)

179.3 ± 102.5*

124.4 ± 44.5*

121.4 ± 43.6*

143.8 ± 69.1*

132.4 ± 63.3*

fT4 (ng/dL)

1.94 ± 1.29* 1.20 ± 0.37*

1.24 ± 0.27*

1.32 ± 0.68*

1.34 ± 0.44*

TSH (uIU/ml)

0.12 ± 0.12* 0.72 ± 0.81*

0.94 ± 0.80*

1.69 ± 2.84*

1.50 ± 2.15*

† Normal range (T3 : 61-173, fT4 : 0.89-1.76, TSH : 0.4-4). * P < 0.001 vs pre-RFA.

Changes in Scintigraphy

Pre-RFA 1 M 3 M 6 M Last F/U

Nodule* 1.0 ± 0.2† 1.9 ± 1.0† 2.0 ± 1.0† 2.1 ± 0.8† 2.3 ± 0.8†

Extranodu-lar area**

1.4 ± 0.5† 2.0 ± 0.8† 2.3 ± 0.8† 2.2 ± 0.6† 2.4 ± 0.5†

* 1 : Hot nodule, 2 : Similar uptake to extranodular area, 3 : Cold nodule.

** 1 : non-visualized, 2 : weak uptake, 3 : normal uptake.

† P < 0.001 vs pre-RFA.

Treatment Effects: Nodule Vol-ume

Pre-RFA Vol. (ml) Nodule number (n=44)

CC*(n=21)

PC* (n=16)

HR* (n=5)

F* (n=2)

< 10 24 13 7 4 0

10<20 9 6 3 0 0

20<30 4 1 2 1 0

≥30 7 1 4 0 2

Success Rate (CC+PC; Normalized TSH level) : 37/44 (84.1%)

* CC (Complete Cure), PC (Partial Cure), HR (Hormonal Remission), F (Failure).

Complications

During RFA

• Most complaining of mild pain and/or heat sense

in the neck, sometimes radiating to the head,

shoulders, teeth and chest. • None to stop the procedure by symptom

No major complication

(voice change, skin burn, hematoma or infection)

Cases

• Sx/Sg: Fatigue

• FNA: Bethesda Category II

• Pre-toxic nodule: T3/fT4/TSH (114/1.69/0.148)

CASE 1, F/17 Palpable Thyroid Nodule

RFA : 1cm electrode, 70 W, 6 min (12 min)

6 Mo F/U : Cold 1.8 x 1.2 x

1.5cm (vol. 1.7 ml), C2, S1, V0

Index : Hot2.2 x 2.0 x 2.7cm

(vol. 6.4 ml) C3, S4, V2

SymptomHormone

VolumeVolume Re-duction (%)

T3 fT4 TSH

Pre RFA ± 114 1.69 0.048 6.22 0

6 Mo - 71 1.48 1.55 1.91 69.0

12 Mo - 78 1.34 1.62 1.88 70.0

Single Session, Complete Cure

• Sx/Sg: Palpitation, weight loss, dyspnea

• FNA: Bethesda Category II

• Toxic nodule: T3/fT4/TSH (319/>6.0/<0.004)

CASE 2, F/66 Palpable Thyroid Nodule

Index : Hot 3.8 x 4.3 x 5.6 cm

(vol. 49.1 ml)

2 sessions of RFA : 1.5cm, 100W,

12(15) & 10(13) min

6 Mo : Cold1.4 x 2.6 x 3.3 cm

(vol. 11.2 ml)

SymptomHormone

VolumeVolume Re-duction(%)

T3 fT4 TSH

Pre RFA + 319 > 6.0<

0.004 49.1 0

3 Mo - 106 1.38 1.37 15.6 68.2

6 Mo - 110 1.15 0.78 11.2 77.2

Two Sessions, Complete Cure

Limitations

Retrospective study

Small number of patients

Short follow-up period (16.1 ± 12.5 months)

Conclusion

RFA appears an effective and safe alternative

procedure to surgery or radioiodine therapy for AFTN

Thank You!