Dataset Information

18F-PET/CT imaging of metastasis to the thyroid gland: Imaging findings and effect on patient management.

ABSTRACT: Purpose:While metastasis to the thyroid from a primary cancer remote to the thyroid is uncommon, current imaging techniques have improved detection of these intrathyroid metastases. The purpose of this study was to evaluate the 18F-PET/CT appearance of intrathyroid metastases and assess the impact of detection on patient management. Methods:The 18F-PET/CT appearance of intrathyroid metastasis, including standardized uptake value (SUV), disease extent, and the effect on patient management following diagnosis were retrospectively reviewed. Inclusion criteria included 18F-PET/CT imaging and diagnosis of the intrathyroid metastasis matching the remote primary tumor. Results:Intrathyroid metastasis were detected in 24 patients. The intrathyroid metastases presented on 18F-PET/CT as focal nodular uptake (n = 21), multiple nodular uptake (n = 2), or diffuse uptake/infiltration of the thyroid gland (n = 1). The SUV ranged between 3.9 and 42 (median 12.5 ± 7.5); in 2 patients, the FDG-avidity was minimal. On 18F-PET/CT, distant metastases were present outside the neck (n = 18), or limited to the neck (n = 6). In 2 of these 6 patients, the thyroid was the only site of metastatic disease. Due to the metastatic disease, the therapy was changed in 23 of 24 patients; 1 patient was lost to follow-up. Conclusion:In any patient with a previous or current history of an extrathyroid malignancy, an 18FDG-avid thyroid mass or diffuse infiltration of the thyroid on 18F-PET/CT should be considered a potential intrathyoid metastasis until proven otherwise. Knowledge of an intrathyroid metastasis may impact patient management, especially if the thyroid or neck are the only sites of metastatic disease.

SUBMITTER: Millare GG

PROVIDER: S-EPMC6217829 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

<sup>18</sup>F-PET/CT imaging of metastasis to the thyroid gland: Imaging findings and effect on patient management.

Millare Giovanni G GG Kwon Michael M Edeiken-Monroe Beth S BS Debnam J Matthew JM

Journal of solid tumors 20170101 2

<h4>Purpose</h4>While metastasis to the thyroid from a primary cancer remote to the thyroid is uncommon, current imaging techniques have improved detection of these intrathyroid metastases. The purpose of this study was to evaluate the <sup>18</sup>F-PET/CT appearance of intrathyroid metastases and assess the impact of detection on patient management.<h4>Methods</h4>The <sup>18</sup>F-PET/CT appearance of intrathyroid metastasis, including standardized uptake value (SUV), disease extent, and the ...[more]

PMID: 30405862

Similar Datasets

Project description:PurposeTo investigate the possibility of reducing the injected activity for whole-body [18F]FDG-PET/CT studies of paediatric oncology patients and to assess the usefulness of time-of-flight (TOF) acquisition on PET image quality at reduced count levels.ProceduresTwenty-nine paediatric oncology patients (12F/17M, 3-18 years old (median age 13y), weight 45±20 kg, BMI 19±4 kg/m2), who underwent routine whole-body PET/CT examinations on a Siemens Biograph mCT TrueV system with TOF capability (555ps) were included in this study. The mean injected activity was 156 ± 45 MBq (3.8 ± 0.8 kg/MBq) and scaled to patient weight. The raw data was collected in listmode (LM) format and pre-processed to simulate reduced levels of [18F]FDG activity (75, 50, 35, 20 and 10% of the original counts) by randomly removing events from the original LM data. All data were reconstructed using the vendor-specific e7-tools with standard OSEM only, with OSEM plus resolution recovery (PSF). The reconstructions were repeated with added TOF (TOF) and PSF+TOF. The benefit of TOF together with the reduced count levels was evaluated by calculating the gains in signal-to-noise ratio (SNR) in the liver and contrast-to-noise ratio (CNR) in all PET-positive lesions before and after TOF employed at every simulated reduced count level. Finally, the PSF+TOF images at 50, 75 and 100% of counts were evaluated clinically on a 5-point scale by three nuclear medicine physicians.ResultsThe visual inspection of the reconstructed images did not reveal significant differences in image quality between 75 and 100% count levels for PSF+TOF. The improvements in SNR and CNR were the greatest for TOF reconstruction and PSF combined. Both SNR and CNR gains did increase linearly with the patients BMI for both OSEM only and PSF reconstruction. These benefits were observed until reducing the counts to 50 and 35% for SNR and CNR, respectively.ConclusionsThe benefit of using TOF was noticeable when using 50% or greater of the counts when evaluating the CNR and SNR. For [18F]FDG-PET/CT, whole-body paediatric imaging the injected activity can be reduced to 75% of the original dose without compromising PET image quality.

Project description:The aim of the study was to analyze the use of block sequential regularized expectation maximization (BSREM) with different β-values for the detection of brain metastases in digital fluorine-18 labeled 2-deoxy-2-fluoro-D-glucose (18F-FDG) PET/CT in lung cancer patients. We retrospectively analyzed staging/restaging 18F-FDG PET/CT scans of 40 consecutive lung cancer patients with new brain metastases, confirmed by MRI. PET images were reconstructed using BSREM (β-values of 100, 200, 300, 400, 500, 600, 700) and OSEM. Two independent blinded readers (R1 and R2) evaluated each reconstruction using a 4-point scale for general image quality, noise, and lesion detectability. SUVmax of metastases, brain background, target-to-background ratio (TBR), and contrast recovery (CR) ratio were recorded for each reconstruction. Among all reconstruction techniques, differences in qualitative parameters were analyzed using non-parametric Friedman test, while differences in quantitative parameters were compared using analysis of variances for repeated measures. Cohen's kappa (k) was used to measure inter-reader agreement. The overall detectability of brain metastases was highest for BSREM200 (R1: 2.83 ± 1.17; R2: 2.68 ± 1.32) and BSREM300 (R1: 2.78 ± 1.23; R2: 2.68 ± 1.36), followed by BSREM100, which had lower accuracy owing to noise. The highest median TBR was found for BSREM100 (R1: 2.19 ± 1.05; R2: 2.42 ± 1.08), followed by BSREM200 and BSREM300. Image quality ratings were significantly different among reconstructions (p < 0.001). The median quality score was higher for BSREM100-300, and both noise and metastases' SUVmax decreased with increasing β-value. Inter-reader agreement was particularly high for the detectability of photopenic metastases and blurring (all k > 0.65). BSREM200 and BSREM300 yielded the best results for the detection of brain metastases, surpassing both BSREM400 and OSEM, typically used in clinical practice.

Dataset Information

18F-PET/CT imaging of metastasis to the thyroid gland: Imaging findings and effect on patient management.

Publications

<sup>18</sup>F-PET/CT imaging of metastasis to the thyroid gland: Imaging findings and effect on patient management.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets