Rebound thymic hyperplasia detected by18F-FDG PET/CT after radioactive iodine ablation therapy for thyroid cancer

Tae Joo Jeon, Yong Sang Lee, Jae Hoon Lee, Hang Seok Chang, Young Hoon Ryu

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Background: Rebound thymic hyperplasia (RTHP) is not an uncommon finding after radiation or chemotherapy in patients with various malignancies. However, there are limited case reports of this phenomenon after radioactive iodine ablation therapy (RIAT) in differentiated thyroid cancer (DTC). The goal of this study was to evaluate the incidence, patterns, and factors affecting RTHP after RIAT using 18F-FDG PET/CT. Methods: The study design was a retrospective review of 2550 patients (568 men, 1982 women; age 13-79 years) who underwent FDG PET/CT imaging after total thyroidectomy and RIAT from June 2009 through June 2012. Patients were divided into four age-related subgroups. Overall incidence, age-related incidences, and sex distribution were evaluated in patients with thymic FDG uptake on PET/CT (RTHP+). The correlation between incidence of RTHP and age was assessed using the Cochran-Armitage trend test. The Wilcoxon rank-sum test and multiple regression were applied to investigate the effect of applied dose of radioactive iodine (RAI) and age on the incidence of RTHP. Correlations of standardized uptake value (SUV) and thymic volume with age and morphologic type were also evaluated. Results: Overall incidence of RTHP after RIAT was 1.49%, and all of the RTHP+ patients except one were female. The Cochran-Armitage trend test revealed significantly decreased incidence from the second to fifth decade (8.84%, 1.74%, 0.98%, and 0.39% respectively; p<0.001). In each age-related subgroup, the RAI dose was significantly higher in the RTHP+ than RTHP- group (p<0.001), while there was no difference in RAI dose in RTHP+ patients among age-related subgroups (p=0.838). SUVmean and SUVmax of RTHP revealed no meaningful correlation with RAI dose or age. There were no differences among morphologic patterns of RTHP in age distribution and ablation dose. Conclusions: RTHP after RIAT showed a strong female predominance, despite the higher administration dose of RAI in male patients. Although the decreased incidence of RTHP after RIAT with age is similar to the pattern of RTHP induced by other causes, the fact that older patients, even sixth decade patients, can present with RTHP after RIAT is noteworthy in the management of DTC.

Original languageEnglish
Pages (from-to)1636-1641
Number of pages6
JournalThyroid
Volume24
Issue number11
DOIs
Publication statusPublished - 2014 Jan 1

Fingerprint

Thymus Hyperplasia
Thyroid Neoplasms
Iodine
Incidence
Therapeutics
Nonparametric Statistics
Sex Distribution

All Science Journal Classification (ASJC) codes

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology

Cite this

Jeon, Tae Joo ; Lee, Yong Sang ; Lee, Jae Hoon ; Chang, Hang Seok ; Ryu, Young Hoon. / Rebound thymic hyperplasia detected by18F-FDG PET/CT after radioactive iodine ablation therapy for thyroid cancer. In: Thyroid. 2014 ; Vol. 24, No. 11. pp. 1636-1641.
@article{fa6b0febfe934b18a600ef2221272845,
title = "Rebound thymic hyperplasia detected by18F-FDG PET/CT after radioactive iodine ablation therapy for thyroid cancer",
abstract = "Background: Rebound thymic hyperplasia (RTHP) is not an uncommon finding after radiation or chemotherapy in patients with various malignancies. However, there are limited case reports of this phenomenon after radioactive iodine ablation therapy (RIAT) in differentiated thyroid cancer (DTC). The goal of this study was to evaluate the incidence, patterns, and factors affecting RTHP after RIAT using 18F-FDG PET/CT. Methods: The study design was a retrospective review of 2550 patients (568 men, 1982 women; age 13-79 years) who underwent FDG PET/CT imaging after total thyroidectomy and RIAT from June 2009 through June 2012. Patients were divided into four age-related subgroups. Overall incidence, age-related incidences, and sex distribution were evaluated in patients with thymic FDG uptake on PET/CT (RTHP+). The correlation between incidence of RTHP and age was assessed using the Cochran-Armitage trend test. The Wilcoxon rank-sum test and multiple regression were applied to investigate the effect of applied dose of radioactive iodine (RAI) and age on the incidence of RTHP. Correlations of standardized uptake value (SUV) and thymic volume with age and morphologic type were also evaluated. Results: Overall incidence of RTHP after RIAT was 1.49{\%}, and all of the RTHP+ patients except one were female. The Cochran-Armitage trend test revealed significantly decreased incidence from the second to fifth decade (8.84{\%}, 1.74{\%}, 0.98{\%}, and 0.39{\%} respectively; p<0.001). In each age-related subgroup, the RAI dose was significantly higher in the RTHP+ than RTHP- group (p<0.001), while there was no difference in RAI dose in RTHP+ patients among age-related subgroups (p=0.838). SUVmean and SUVmax of RTHP revealed no meaningful correlation with RAI dose or age. There were no differences among morphologic patterns of RTHP in age distribution and ablation dose. Conclusions: RTHP after RIAT showed a strong female predominance, despite the higher administration dose of RAI in male patients. Although the decreased incidence of RTHP after RIAT with age is similar to the pattern of RTHP induced by other causes, the fact that older patients, even sixth decade patients, can present with RTHP after RIAT is noteworthy in the management of DTC.",
author = "Jeon, {Tae Joo} and Lee, {Yong Sang} and Lee, {Jae Hoon} and Chang, {Hang Seok} and Ryu, {Young Hoon}",
year = "2014",
month = "1",
day = "1",
doi = "10.1089/thy.2014.0164",
language = "English",
volume = "24",
pages = "1636--1641",
journal = "Thyroid",
issn = "1050-7256",
publisher = "Mary Ann Liebert Inc.",
number = "11",

}

Rebound thymic hyperplasia detected by18F-FDG PET/CT after radioactive iodine ablation therapy for thyroid cancer. / Jeon, Tae Joo; Lee, Yong Sang; Lee, Jae Hoon; Chang, Hang Seok; Ryu, Young Hoon.

In: Thyroid, Vol. 24, No. 11, 01.01.2014, p. 1636-1641.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Rebound thymic hyperplasia detected by18F-FDG PET/CT after radioactive iodine ablation therapy for thyroid cancer

AU - Jeon, Tae Joo

AU - Lee, Yong Sang

AU - Lee, Jae Hoon

AU - Chang, Hang Seok

AU - Ryu, Young Hoon

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Background: Rebound thymic hyperplasia (RTHP) is not an uncommon finding after radiation or chemotherapy in patients with various malignancies. However, there are limited case reports of this phenomenon after radioactive iodine ablation therapy (RIAT) in differentiated thyroid cancer (DTC). The goal of this study was to evaluate the incidence, patterns, and factors affecting RTHP after RIAT using 18F-FDG PET/CT. Methods: The study design was a retrospective review of 2550 patients (568 men, 1982 women; age 13-79 years) who underwent FDG PET/CT imaging after total thyroidectomy and RIAT from June 2009 through June 2012. Patients were divided into four age-related subgroups. Overall incidence, age-related incidences, and sex distribution were evaluated in patients with thymic FDG uptake on PET/CT (RTHP+). The correlation between incidence of RTHP and age was assessed using the Cochran-Armitage trend test. The Wilcoxon rank-sum test and multiple regression were applied to investigate the effect of applied dose of radioactive iodine (RAI) and age on the incidence of RTHP. Correlations of standardized uptake value (SUV) and thymic volume with age and morphologic type were also evaluated. Results: Overall incidence of RTHP after RIAT was 1.49%, and all of the RTHP+ patients except one were female. The Cochran-Armitage trend test revealed significantly decreased incidence from the second to fifth decade (8.84%, 1.74%, 0.98%, and 0.39% respectively; p<0.001). In each age-related subgroup, the RAI dose was significantly higher in the RTHP+ than RTHP- group (p<0.001), while there was no difference in RAI dose in RTHP+ patients among age-related subgroups (p=0.838). SUVmean and SUVmax of RTHP revealed no meaningful correlation with RAI dose or age. There were no differences among morphologic patterns of RTHP in age distribution and ablation dose. Conclusions: RTHP after RIAT showed a strong female predominance, despite the higher administration dose of RAI in male patients. Although the decreased incidence of RTHP after RIAT with age is similar to the pattern of RTHP induced by other causes, the fact that older patients, even sixth decade patients, can present with RTHP after RIAT is noteworthy in the management of DTC.

AB - Background: Rebound thymic hyperplasia (RTHP) is not an uncommon finding after radiation or chemotherapy in patients with various malignancies. However, there are limited case reports of this phenomenon after radioactive iodine ablation therapy (RIAT) in differentiated thyroid cancer (DTC). The goal of this study was to evaluate the incidence, patterns, and factors affecting RTHP after RIAT using 18F-FDG PET/CT. Methods: The study design was a retrospective review of 2550 patients (568 men, 1982 women; age 13-79 years) who underwent FDG PET/CT imaging after total thyroidectomy and RIAT from June 2009 through June 2012. Patients were divided into four age-related subgroups. Overall incidence, age-related incidences, and sex distribution were evaluated in patients with thymic FDG uptake on PET/CT (RTHP+). The correlation between incidence of RTHP and age was assessed using the Cochran-Armitage trend test. The Wilcoxon rank-sum test and multiple regression were applied to investigate the effect of applied dose of radioactive iodine (RAI) and age on the incidence of RTHP. Correlations of standardized uptake value (SUV) and thymic volume with age and morphologic type were also evaluated. Results: Overall incidence of RTHP after RIAT was 1.49%, and all of the RTHP+ patients except one were female. The Cochran-Armitage trend test revealed significantly decreased incidence from the second to fifth decade (8.84%, 1.74%, 0.98%, and 0.39% respectively; p<0.001). In each age-related subgroup, the RAI dose was significantly higher in the RTHP+ than RTHP- group (p<0.001), while there was no difference in RAI dose in RTHP+ patients among age-related subgroups (p=0.838). SUVmean and SUVmax of RTHP revealed no meaningful correlation with RAI dose or age. There were no differences among morphologic patterns of RTHP in age distribution and ablation dose. Conclusions: RTHP after RIAT showed a strong female predominance, despite the higher administration dose of RAI in male patients. Although the decreased incidence of RTHP after RIAT with age is similar to the pattern of RTHP induced by other causes, the fact that older patients, even sixth decade patients, can present with RTHP after RIAT is noteworthy in the management of DTC.

UR - http://www.scopus.com/inward/record.url?scp=84910647761&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84910647761&partnerID=8YFLogxK

U2 - 10.1089/thy.2014.0164

DO - 10.1089/thy.2014.0164

M3 - Article

C2 - 25065897

AN - SCOPUS:84910647761

VL - 24

SP - 1636

EP - 1641

JO - Thyroid

JF - Thyroid

SN - 1050-7256

IS - 11

ER -