Fate of Residual Cervical Metastatic Lymph nodes Found on I-131 Post-ablation SPECT/CT in Patients...

Fate of Residual Cervical Metastatic Lymph nodes Found on I-131 Post-ablation SPECT/CT in Patients

with Differentiated Thyroid Cancer

20121023- AOTA

Hong CM, Ahn BC, Jeong SY, Lee SW, Lee J

Department of Nuclear Medicine

Kyungpook National University

School of Medicine & Hospital

Discovery Kartika Plaza Hotel, Bali, Indonesia

Kyungpook National University/Hospital School of Medicine Department of Nuclear Medicine

Metastatic lymph nodesin thyroid cancer

• Residual metastatic lymph nodes are the most com-

mon site of disease persistence or recurrence in thy-

roid cancer.

• Completeness of surgical resection is an important de-

terminant of outcome in thyroid cancer.

Background



• Prevalence of cervical metastatic lymph nodes

(MLN) is known to be relatively high (20~50%) ,

even in small intrathyroidal tumor.

• Incidence of lymph node resection and prevalence of

MLN are not that high in certain surgery units.

Background



• Late local recurrence of thyroid cancer is reported to

be relatively high (exceeds 25%) and it might be re-

lated to the hidden residual cancers in the cervical

lymph nodes.

Background


I-131 ablation in DTC

• I-131 ablation is known to decrease risk of recurrence and disease specific mortality – by the destruction of the suspected, but unproven

metastatic disease.

• A number of studies showed a significant reduction in the rates of disease recurrence and cause-specific mortality by the I-131 ablation

Background


Post I-131 ablation WBS

• Post ablation I-131 Whole body scan (WBS) is one of

the most powerful imaging tools to detecting residual

thyroid cancers

• Planar WBS visualizes both residual normal thyroid

tissues and persistent DTC;

– There is a difficulty to differentiate the metastatic lesion of

a focal cervical radioiodine uptake in unusual cases.

Background


Post I-131 ablation SPECT/CT

• SPECT/CT provides the synergistic combination of functional

and anatomic information and has many advantages over the

planar imaging in many clinical settings.

• I-131 SPECT/CT is able to allows more precise differentiation

between malignant and benign radioiodine activities.

Background


Aims of this study

• To evaluate prevalence of clinical metastatic cervical

lymph nodes based on postablation I-131 SPECT/CT

in thyroidectomized DTC patients with suspicious

pathologic tracer uptake at neck area on the planar

imaging.

• To elucidate fate of iodine avid cervical metastatic le-

sions by the I-131 ablation in DTC patients.

Objectives


Subjects

• 194 DTC patients who underwent postablation I-131

SPECT/CT owing to suspicious pathologic uptake at

neck on planar WBS were enrolled.

– F/M=138:56

– Age; 48.6±12.2 yr

Subjects


Methods

• The patients were divided into remnant and metastasis

groups based on postablation I-131 SPECT/CT finding.

• Clinicopathological characteristics were compared be-

tween the two groups.

• Fate of the residual MLN were assessed at 8 months af-

ter the ablation with TSH stimulated Tg, ultrasonogra-

phy, chest X-ray, I-123 WBS, and etc.

Methods


Statistics

• Independent student-T test

• Chi-square test, Fisher’s exact test

• P<0.05

Methods


Prevalence of cervical lymph node metastases

• Prevalence of cervical lymph node metastases based

on postablation SPECT/CT findings in patients with

suspicious pathologic uptake at neck on postablation

planar WBS are following:

– Metastasis group : 73 patients (37.6%)

– Remnant group : 121 patients (62.4%)

Results


Patients characteristics (I)

Metastasis group(n=73)

Remnant group(n=121)

P value

Age 48.6±12.3 48.6±12.2 0.9664

Sex (F:M) 50:23 88:33 0.6405

Histologic type(papillary:follicular)

73:0 118:3 0.4501

Results

All 3 patients of follicular type were included in the remnant group.


Patients characteristics (II)

Metastasis group(n=73)

Remnant group(n=121)

P value

T stage(1:2:3:4)

12:3:47:5 31:2:74:12 0.3595

N stage(0:1a:1b)

16:30:19 17:63:26 0.2038

AJCC Stage(I:II:III:IV)

23:2:31:15 44:0:56:9 0.2223

Results


TSH stimulated Tg at I-131 ablationMetastasis group vs. Remnant group

Results

Metastasis group Remnant group0.0

5.0

10.0

15.0

20.0

25.0

30.0

P=0.033

ng/mL


Clinical outcomes at 8 months after the ablation

• Metastasis group (22)

– A patient ; persistent lymph node metastasis

– 21 patients : no evidence of persistent or recurrent

disease

• Remnant group (26)

– All 26 patients : no evidence of persistent or recur-

rent disease

Results


TSH stimulated Tg at 8 mo W/Udisease free in metastasis group vs. remnant group

Results

Disease free in metastasis group

Disease free in remnant group

0.0

0.5

1.0

1.5

2.0

2.5

P=0.1905

ng/mL

Disease freein metastasis group

Disease freein remnant group


CASE

M/56, papillary type, T3N1aMx, TSH: 41.16uIU/mL, Tg: 397.9ng/mL, anti-Tg: 118.8U/mL

Post I-131 ablation WBS and SPECT/CT

Case 1

anterior

Right lateral Left lateral

SPECT/CT

Diagnosed as lymph node metastases.


Recur work up at 8 month after the ablation

TSH: 80.9uIU/mL, Tg: 284.3ng/mL, anti-Tg: 116.23U/mL

Surgical removal is planned for the metastastic lesions

Case 1CASE

FDG PET Ultrasound


M/56, papillary type, III, T3NxMx, TSH: 77.76uIU/mL, Tg: 6.10ng/mL, anti-Tg: 106.44U/mL

Post I-131 ablation WBS and SPECT/CT

Case 2CASE

anterior SPECT/CTposterior

Diagnosed as lymph node metastases.lymph node metastasis

remnant at thyroid bed


Recur work up at 8 month after the ablation

TSH: 80.9uIU/mL, Tg: 0.92ng/mL, anti-Tg: 95.37U/mL

Neck ultrasonography ; negative

Case 2

Regular follow up was recommended.

CASE

I-123WBS


Summaries (I)

• Prevalence (37.6%) of cervical lymph node metastases based on

postablation SPECT/CT findings was quite high in patients with

suspicious pathologic uptake at neck on postablation planar

WBS.

• Patients with metastatic cervical lymph modes had higher TSH

stimulated Tg compared to patients without metastasis.


Summaries (II)

• Only 1 of 22 patients with cervical lymph nodes metastases

found on postablation SPECT/CT had persistent the metastases

at 8 months after the ablation.

• Although statistically not significant, TSH stimulated Tg was

higher in disease free patients of metastasis group than that of

remnant group at 8 month after the ablation.


Conclusions

•Postablation SPECT/CT visualized residual metastatic lymph

nodes (MLN) after surgery and prevalence of cervical MLN is high

in patients showing suspicious pathologic uptake at neck on the

postablation WBS.

•More than 95% of patients with residual cervical MLN receiving

radioiodine ablation were in remission status at the 8 month after

the ablation.

Fate of Residual Cervical Metastatic Lymph nodes Found on I-131 Post-ablation SPECT/CT in Patients...

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