Semi-quantitative assessment of diffuse hepatic uptake seen in I-131 scans – an indicator of functioning thyroid tissue and disease burden in differentiated thyroid cancer | Thyroid Research | Full Text

Semi-quantitative assessment of diffuse hepatic uptake seen in I-131 scans – an indicator of functioning thyroid tissue and disease burden in differentiated thyroid cancer | Thyroid Research | Full Text

Thyroid Research

Semi-quantitative assessment of diffuse hepatic uptake seen in I-131 scans – an indicator of functioning thyroid tissue and disease burden in differentiated thyroid cancer

• Prasanta K. PradhanEmail authorView ORCID ID profile,
• Suruchi Jain,
• Madhusudhanan Ponnuswamy,
• Amitabh Arya and
• Manish Ora

Thyroid Research201912:4

https://doi.org/10.1186/s13044-019-0065-1

©  The Author(s). 2019

• Received: 30 November 2018
• Accepted: 12 April 2019
• Published: 25 April 2019

Abstract

Background

To semi-quantitatively analyze liver uptake of I-131 in diagnostic and post-therapy scans by calculating hepatic to thigh ratios (HTR) and evaluate its clinical significance in management of differentiated thyroid cancer.

Method

Two hundred forty-nine patients were included in the study. Hepatic to thigh ratio (HTR) of counts were calculated for 249 diagnostic and 104 post-therapy scans. Patients were divided into six study groups based on their disease status:1-Serum thyroglobulin (serum Tg) negative (serum Tg ≤ 4 ng/dl) and scan negative; 2-Thyroid remnant only; 3-Thyroid remnant and lymph node metastasis; 4- Tg positive (serum Tg > 4 ng/dl) and scan negative; 5-Bone or/and lung metastasis, and 6-Only lymph node metastasis. Comparison of HTR between these groups was done using one-way ANOVA test. Correlation of HTR with serum Tg, serum thyroid stimulating hormone (TSH), anti-thyroglobulin antibody (ATg) titer and therapeutic dose of I-131 was also assessed.

Results

Comparison of HTR between different study groups (1 to 6) showed significant difference in HTR (p = .001). Study group 5 (bone or/and lung metastasis) showed significantly higher mean HTR compared to other groups (p = 0.001). There was only a weak correlation between serum Tg and HTR (r = 0.395). Dose of I-131 administered also had a weak correlation with HTR (r = 0.207).

Conclusion

HTR has good correlation with functional status of tumor cells, while it has weak correlation to therapeutic dose of I-131 administered and serum Tg. Increased HTR predicts significant disease burden in the form of distant bone and lung metastasis and may potentially be used as a second prognostic factor apart from serum Tg.

Keywords

• Differentiated thyroid cancer
• Liver uptake
• Thyroglobulin
• Hepatic to thigh ratios