Nucl Med Mol Imaging.  2018 Apr;52(2):135-143. 10.1007/s13139-017-0502-9.

The Predictive Values of Lesion Size, F-18 FDG Avidity and I-131 Avidity for the Clinical Outcome of I-131 Treatment in Patients with Metastatic Differentiated Thyroid Carcinoma Only in the Lung

• Choi JH
• Byun BH
• Lim I
• Moon H
• Park J
• Chang KJ
• Kim BI
• Choi CW
• Lim SM

• KMID: 2414801
• DOI: http://doi.org/10.1007/s13139-017-0502-9

Abstract

PURPOSE
We aimed to evaluate the prognostic values of radiography, F-18 FDG PET, and I-131 whole body scans in patients with lung-only metastasis from differentiated thyroid carcinoma (DTC).
METHODS
Between 1998 and 2013, we included 31 patients (F: 26, M: 5) with lung-only metastasis from DTC who had been treated with I-131 and underwent PET. Lung metastasis was categorized according to the size (macronodular ≥1.0 cm vs. micronodular <1.0 cm), FDG avidity (avid vs. non-avid), and I-131 avidity (avid vs. non-avid). Progression-free survival (PFS) was evaluated for each patient.
RESULTS
Among 31 patients, seven (23%) had macronodular lung metastasis, 26 (84%) had FDG avid lung metastasis, and 16 (52%) had I-131 avid lung metastasis. During the median follow-up period of 9.4 y, median PFS was 6.1 y. Based on Kaplan-Meier analysis, macronodular lung metastasis (p = 0.017) and I-131 non-avid lung metastasis (p = 0.059) were significantly associated with worse outcomes, but FDG avid lung metastasis was not (p = 0.135). Patients with FDG non-avid lung metastasis did not experience disease progression during follow-up, while 11 of 26 patients (42%) experienced disease progression. Based on univariate analysis, the hazard ratio for a poor prognosis was 3.78 (p = 0.029) for macronodular lung metastasis and 3.29 (p = 0.079) for I-131 non-avid lung metastasis.
CONCLUSIONS
Macronodular and I-131 non-avid lung metastasis were associated with a poor prognosis in lung-only metastasis from DTC. Although FDG avid lung metastasis may be associated with a poor prognosis, a larger-scale study is needed.

Keyword

Differentiated thyroid carcinoma; Lung metastasis; F-18 FDGavidity; I-131 avidity; Micronodular; Macronodular

MeSH Terms

Disease Progression
Disease-Free Survival
Follow-Up Studies
Humans
Kaplan-Meier Estimate
Lung*
Neoplasm Metastasis
Prognosis
Radiography
Thyroid Gland*
Thyroid Neoplasms*
Whole Body Imaging