Article

Can (18)F-FDG-PET/CT be generally recommended in patients with differentiated thyroid carcinoma and elevated thyroglobulin levels but negative I-131 whole body scan?

Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Annals of Nuclear Medicine (Impact Factor: 1.51). 01/2012; 26(1):77-85. DOI: 10.1007/s12149-011-0545-4
Source: PubMed

ABSTRACT Exact localization of recurrent iodine-negative thyroid cancer is mandatory, since surgery is the only curative therapy option in patients with iodine-negative tumor tissue. The aim of this study was to evaluate the impact of (18)F-FDG-PET/CT as a routine diagnostic tool on clinical management in patients with suspected thyroid cancer recurrence and elevated serum thyroglobulin (Tg) but negative radioiodine whole body scan.
After total thyroidectomy followed by radioiodine ablation, 30 consecutive patients with differentiated thyroid cancer, elevated serum thyroglobulin levels and negative whole body radioiodine scan underwent (18)F-FDG-PET/CT. Results were verified by histology, ultrasound, or clinical follow-up. Diagnostic accuracy was determined for the whole study population and for subgroups with serum thyroglobulin below and above 10 ng/ml, respectively. Impact of PET/CT on clinical management was assessed.
PET/CT identified FDG accumulating lesions in 19 of 30 patients. 17 were true-positive and 2 false-positive. In the true-positive group, 11 of the 17 patients had loco-regional disease, 3 had distant metastases only and 3 patients had both loco-regional and distant metastatic involvement. (18)F-FDG-PET/CT was true-negative in 3 patients and false-negative in 8 patients. Overall sensitivity, specificity and accuracy were 68.0, 60.0, and 66.7%, respectively. In the subgroup of patients with serum thyroglobulin above 10 ng/ml (n = 21) the sensitivity, specificity and accuracy were substantially higher with 70.0, 100.0, and 71.4%, respectively. Clinical management was changed for 17 (57%) of 30 patients, guiding to a curative surgical intervention in 9 patients (30%).
(18)F-FDG-PET/CT enables detection and precise localization of loco-regional recurrence and distant metastases of differentiated thyroid cancer in patients with elevated serum thyroglobulin but negative radioiodine with significant impact on patient management and can therefore be recommended as a routine diagnostic tool.

0 Followers
 · 
177 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Klinisches/methodisches Problem In den letzten Jahren hat die Hybridbildgebung mit Verbindung von funktioneller und morphologischer Information zur Diagnostik zahlreicher Erkrankungen zunehmend an Bedeutung gewonnen. Bei Patienten mit differenziertem Schilddrüsenkarzinom (DTC) wird nach erfolgter Radiojodtherapie (RJT) ein planares Ganzkörperszintigramm zum Staging durchgeführt. Die diagnostische Genauigkeit dieser szintigraphischen Methode ist jedoch aufgrund limitierter räumlicher Auflösung begrenzt. Die Radioembolisation von mit 90Yttrium beladenen Mikrosphären (selektive interne Radiotherapie, SIRT) ermöglicht eine wenig invasive Therapie primärer und sekundärer Lebertumoren. Zur Vermeidung von Nebenwirkungen der Mikrosphären durch einen Abstrom in Darm, Magen und Lunge muss vor Therapiebeginn eine Darstellung des durch die leberversorgenden Arterien versorgten Gebiets mittels 99mTc-MAA (99mTechnetium-makroaggregiertes Albumin) und einer Szintigraphie erfolgen. Auch hier limitiert die begrenzte morphologische Information der Szintigraphie das Therapiemonitoring. Radiologische/nuklearmedizinische Standardverfahren 131Jod-Ganzkörperszintigramm zum Nachweis einer erfolgreichen Ablation und Staging ca. 3–4 Tage postablativ bei Patienten mit DTC. Überwachung des Tumormarkers Thyreoglobulin, ergänzt durch Radiojodganzkörperszintigraphien im weiteren Follow-up bei besonderem Risikoprofil. Darstellung des durch die leberversorgenden Arterien versorgten Gebiets durch eine 99mTc-MAA-Szintigraphie als Vorbereitung auf eine SIRT. Methodische Innovationen „Single photon emission computed tomography“/CT (SPECT/CT) der Hals- und Thoraxregion mit einer therapeutischen Aktivitätsmenge Radiojod im Rahmen des postablativen Stagings. Darstellung der leberversorgenden Arterien mittels 99mTc-MAA-SPECT/CT vor Beginn einer SIRT. Analyse und Quantifizierung des Speicherverhaltens der Lebertumoren, insbesondere im Vergleich zum Leberparenchym durch die SPECT/CT. Leistungsfähigkeit Aufgrund der Kombination von funktioneller und morphologischer Information ist die SPECT/CT in der Lage, radiojodpositive Herde exakter morphologisch zu korrelieren, damit optimiertes Staging im Vergleich zur Ganzkörperszintigraphie. Durch die zusätzliche, von der SPECT/CT gebotene anatomische Information gelingt eine genauere Darstellung der arteriellen Versorgung der Leber sowie potenzieller Abströme der Mikrosphären in andere Organe. Darüber hinaus ermöglicht die SPECT/CT eine Analyse und Quantifizierung des Speicherverhaltens der Lebertumoren. Bewertung Verbessertes postablatives Staging bei Patienten mit differenziertem Schilddrüsenkarzinom, insbesondere in Bezug auf das Auffinden von Lymphknotenmetastasen (LKM) im Vergleich zur üblichen Radiojodganzkörperszintigraphie. Verbesserte Planung und Durchführung einer SIRT-Therapie bei Leberläsionen; Optimierung der applizierten Dosis durch Einsatz der SPECT/CT. Empfehlung für die Praxis Integration der SPECT/CT in den klinischen Standard im Rahmen des postablativen Stagings bei Patienten mit DTC. Anwendung der SPECT/CT im Planungsprozess einer SIRT-Therapie sowie bei der Dosisberechnung.
    Der Radiologe 07/2012; 52(7). DOI:10.1007/s00117-011-2267-y · 0.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: CLINICAL/METHODICAL ISSUE: Hybrid imaging of function and morphology has gained significant importance for lesion detection and treatment monitoring in oncology. In patients with differentiated thyroid carcinoma (DTC) a planar whole body scan is carried out after radioiodine therapy (RIT) for staging. However, due to limited spatial resolution the diagnostic accuracy of this scintigraphy method is impaired. Radioembolization utilizing (90)Yttrium loaded micro-spheres by selective internal radiotherapy (SIRT) allows a minor invasive therapy of primary and secondary liver tumors. In order to avoid side effects of the micro-spheres caused by an outflow into intestines, stomach or lungs, imaging the arteries supplying the liver has to be performed by means of technetium-99m macroaggregated albumin ((99m)Tc-MAA) and scintigraphy. The limited morphological information supplied by scintigraphy is again a challenge in treatment monitoring. STANDARD RADIOLOGICAL/NUCLEAR MEDICAL METHODS: (131)Iodine whole body scanning is used for staging in patients with DTC 3-4 days after ablation. Monitoring of the tumor marker thyroglobulin and selective radioiodine whole body scans are available for patients with a high risk profile in the further follow-up with imaging of the arteries supplying the liver by means of (99m)Tc-MAA scintigraphy in preparation of SIRT. METHODICAL INNOVATIONS: Single photon emission computed tomography/computed tomography (SPECT/CT) of the neck and thorax with a therapeutic activity of radioiodine for staging after ablation. Techniques include imaging of arteries supplying the liver by means of (99m)Tc-MAA SPECT/CT before SIRT and evaluation and quantification of the uptake of liver tumors, especially in comparison to the uptake of liver parenchyma by means of SPECT/CT. PERFORMANCE: Due to the integration of combined functional and morphological information SPECT/CT can be used to characterize the morphology and iodine uptake of lesions more accurately, resulting in optimized staging in patients with DTC in comparison to whole body iodine scans and SPECT/CT provides more accurate imaging of the arterial supply of the liver and of potential outflows of micro-spheres into other organs. SPECT/CT allows evaluation and quantification of the uptake of liver tumors. ACHIEVEMENTS: Improved postablative staging in patients with differentiated thyroid cancer by SPECT/CT in comparison to radioiodine whole body scans can be achieved. Improved planning and monitoring of SIRT therapies utilizing SPECT/CT leads to optimized therapeutic doses within liver lesions. PRACTICAL RECOMMENDATIONS: Integration of SPECT/CT into the clinical standard for postablative staging in patients with DTC is recommended as well as utilization of SPECT/CT during the planning process, for dose calculation and treatment monitoring of SIRT therapies.
    Der Radiologe 06/2012; 52(7):646-52. · 0.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In differentiated thyroid cancer (DTC) nuclear medicine is able to cover the spectrum from diagnosis and treatment to follow up keeping patient's management in one institution. Nowadays, DTC is often diagnosed per chance, presenting as small indolent nodule diagnosed on routinely performed ultrasound. Ultrasound and ultrasonography-guided fine-needle aspiration biopsy together with scintigraphy are probably the most adequate tools for diagnosis. After thyroidectomy, treatment with iodine-131 is routinely performed in a nuclear medicine therapy institution as a standard procedure in most of the cases with regard to histology. In case of iodine positive metastases, repeated therapies can be performed in order to reduce tumour burden. In the follow up of DTC thyroglobulin (tumour marker), ultrasound and diagnostic whole body scan are established procedures. With the development of SPECT/CT and PET/CT ((18)F-FDG, (68)Ga-somatostatin receptor) combining functional and anatomic imaging the nuclear medicine spectrum has further increased.
    Wiener Medizinische Wochenschrift 07/2012; DOI:10.1007/s10354-012-0129-5