Presentation on theme: "Recent Advances IN THYROID IMAGING"— Presentation transcript:
1 Recent Advances IN THYROID IMAGING Asia Oceania Thyroid Association CongressBali, IndonesiaOctober 22, 2012Recent Advances IN THYROID IMAGINGEmerita a. Barrenechea MD, FPCP, FPSNMDepartment of Nuclear MedicineSt. Luke’s Medical CenterVeterans Memorial Medical Center
3 Mainstream Thyroid Imaging ScintigraphySonographythere have been several recent advances that are of interest to thyroidologists, radiologists and endocrinologists
4 What is available?Planar/SPECT/SPECT-CT imaging (e.g. 99mTc- based radiotracers,123I, 131I)Positron emission tomography ( PET)Ultrasonography (USG), USG elastographyComputed tomography (CT)Magnetic resonance imaging (MRI)Optical coherence tomography
5 Ultrasonography Most common Facilitate diagnosis of clinically apparent nodulesMost affordablePrimary imaging modalityAmerican Thyroid Associationother authoritative bodies
6 Ultrasonography Patterns most frequently associated with thyroid CA MicrocalcificationsRelative hypoechogenicity of the noduleIrregular margins or absent halo signSolid pattern and taller-than-wide morphologyIntranodular vascularizationShould not be used singly
10 Thyroid Nodule Evaluation Fine needle aspiration cytology is cornerstoneSimpleUsefulCost-effectiveBUT evaluation of non-diagnostic and insufficient FNA samples continues to be a problem
11 ElastographySonographic estimation of rigidity/deformability of tissuechange in Doppler signal after external application of pressure/vibrationsby tracking shear wave propagationMay correlate with:palpable consistency of goitercytology of a noduleMay enhance cancer-prediction in non-cystic, non-calcified thyroid nodules or inflammatory conditions
12 Computed Tomography 3D image of internal organs Uses 2D X-ray images“Windowing” allows better visualization of targeted organsCannot detect small nodulesUses:Detection of goiter or larger thyroid nodulesEvaluation of cervical lymphadenopathyLocal tumor extensionMediastinal/Retrotracheal extension
14 Magnetic Resonance Imaging Anatomic imaging onlyEvaluation of thyroid size and shapePreferable than CTNo patient exposure to radiationNo need for contrast study
15 Magnetic Resonance Imaging Arterial spin labeling (ASL)Differentiation of autoimmune thyroid conditionsTreatment response evaluation in Graves diseaseDiffusion weighted imaging (DWI)Apparent diffusion coefficient (ADC) can be used to differentiate benign from malignant nodules (Schueller)Benign = low signal intensities on DWI + high ADCMalignant = high signal intensities on DWI + low ADC
33 Remnant ThyroidComplete AblationComplete ablation ofResidual thyroidTissue in neckVery low/ UndetectableLevel of Tg
34 II III I IV Initial Presentation Post-SURGERY Post remnant Ablation Functioning MetsInBoth LungsIIIIIII-131 Therapy ofFunctioningMetastasesProceed toto stage IVIV
35 SPECT/CTImproved detection and localization of disease (superior to SPECT alone)In radionuclide therapy, provides more insight into the effectiveness of targeting and may explain the observed response
38 131I SPECT/CT131I SPECT-CT is more accurate than 18FDG PET-CT in well-differentiated thyroid cancerregional and distant metastasisresidual/recurrent diseaseThe most important advantage of fusion 18FDG PET-CT and 131I SPECT-CT is detection of metastasis in normal sized lymph nodes.
47 18FDG PET/CT Well-established usefulness in WDTC if Tg (+) and WBS (–) Helpful in anaplastic/medullary thyroid cancerMay be complimented by PET studies using 68Ga-DOTATOC and 18F-DOPA when looking for recurrent disease
48 Indications of PET/CTresidual or recurrent thyroid cancer WHEN elevated Tg + RAI scan (–)When localized, may require surgery or radiotherapyExtent of poorly differentiated TCAs & invasive Hurthle cell CasTreatment response following systemic or local therapy
49 BNMS Guidelines on TCAAssessment of patients with elevated thyroglobulin levels and negative iodine scintigraphy with suspected recurrent disease.To evaluate disease in treated medullary thyroid carcinoma associated with elevated calcitonin levels with equivocal or normal cross-sectional imaging, bone and octreotide scintigraphy - for alternative PET imaging with 68Ga- DOTA- octreotate (DOTATATE), DOTA-1-NaI3- octreotide (DOTANOC) or DOTA- octreotide (DOTATOC).
55 68Ga DOTA-TATE PET/CT SCAN Somatostatin receptor expression in thyroid CAPatients with positive studies may be treated with Peptide Receptor Radionuclide Therapy (PRRT)117Lu DOTA-TATE90Y DOTA-TATE
56 18FDG Scan in Medullary TCA PET onlyCT OnlyIntense FDG uptake in a hypodense nodule, L thyroid lobeSerum Calcitonin: 800Final Diagnosis: Medullary TCAPET-CT Fusion
57 Other findings in PET↑FDG uptake in thyroid nodule as part of whole body study for cancer imaging = moderately high risk of malignancyRequire further evaluationDifferentials = Graves' disease & thyroiditisOtherwise, thyroid gland should be normal in PET
59 Philippine Data (2002 to 2012)170 18FDG PET on 105 patients from 2005 to 201272 ♀ and 33 ♂17- to 83-years oldIndications116 – disease recurrence6 – staging11 – residuals21 – response to therapy13 – monitoring
61 Results 32 PTCA + 4 FTCA 14 PTCA Most frequent sites of metastases ↑Tg, (–) RAI scan, (+) 18FDG PET14 PTCANormal Tg, (–) RAI scan, (+) 18FDG PETMost frequent sites of metastasesNeck areaCervical lymph nodesPretracheal nodesLungs
62 Results Most common resultant interventions: LN dissection Gamma knife therapyEBRTChemotherapy↑dose RAI therapy
63 Advantages of PET/CT Can detect significantly more tumor sites Only imaging modality that can screen for malignancy in multiple organs at onceCan lead to more appropriate clinical management
64 Other uses of 18FDG PET Indeterminate thyroid nodules (3 cases) Calcitonin-positive medullary TCA18F-DOPA is superior to 18FDG for thisOne case was negative on 18FDGAnaplastic thyroid cancerInsular thyroid carcinoma
65 Summary of 18FDG PET Impact on Thyroid Cancer Management Determination of definitive therapy for RAI scan (–) WDTCA with elevated TgEvaluation of aggressive and difficult-to-treat TCA and poorly differentiated TCADiscrimination of malignancy from thyroiditis in questionable thyroid nodules
66 Greatest impact of PET/CT For WDTCA whose I-131 WBS is negative with increasing thyroglobulin but positive in PET as therapy is more definitiveFor aggressive and difficult to treat TCA and undifferentiated TCAFor questionable thyroid nodules differentiating malignancy and thyroiditis
67 Interesting CaseCT (L) & fused PET/CT (R) in 56 y/o woman with lung cancer. Focal FDG uptake in R thyroid lobe with low CT attenuation (76 HU). PTCA on histopath.
68 Interesting CaseCT (L) & fused PET/CT (R) in 65 y/o man with esophageal cancer. Focal FDG uptake in L thyroid lobe with very low CT attenuation (3.6 HU). Diffusely increased FDG uptake in surrounding gland tissue. Follicular adenoma with lymphocytic thyroiditis on histopath.
69 Interesting Case63/M with PTCA, s/p thyroidectomy, RAI therapy, thoracotomy, and radiotherapyNeck MRI = L anterior neck nodule suspicious for recurrence(+) pulmonary nodules on CTBiopsy of thyroid & lung nodules = not malignant(+) RAI-avid right cervical lesion with elevated Tg
70 Interesting CaseCalcified hypermetabolic R paratracheal node, multiple bilateral hypermetabolic non-calcified pulmonary nodules, multiple cervical, hilar and substernal nodes, and hypermetabolic lesions in a left rib and sternum, suspicious for metastases.
71 Interesting Case65/F with PTCA, s/p thyroidectomy & multiple RAI therapies (cumulative dose = 1150 mCi)elevated Tg at >800(+) nodules in both lungs and left adrenal(+) R lung base RAI-avid lesion on post- therapy whole body scan
72 Interesting CaseHypermetabolic right lung base mass corresponding to RAI-avid R lung base lesion seen on post-therapy scan, consistent with persistent metastatic thyroid cancer.
73 Interesting Case67/F with PTCA, s/p thyroidectomy, L radical neck dissection, multiple RAI therapies & gamma knife treatmentelevated Tg, (–) RAI whole body scan(+) nodules in both lungs and left adrenal(+) R lung base RAI-avid lesion on post- therapy whole body scanCT showed possible recurrence in L thyroid bed
74 Interesting CaseFDG-avid right cavernous sinus mass involving the petrous part of the temporal bone is most likely metastatic in nature.
75 Interesting CaseHypermetabolic lesions/masses in the left neck extending to the thoracic inlet specifically to the left thyroid bed with hypermetabolic bilateral cervical lymphadenopathies are consistent with recurrent metastatic disease.
76 Interesting CaseHypermetabolic osseous metastases in the cervico thoracic spine.
77 Interesting Case 77/M with insular TCA, s/p thyroidectomy L thyroid nodule and lung nodules on pre-op CTPost-op PET was requested for evaluation of disease extent
78 Interesting CaseHypermetabolic lesion in the left thyroid bed may be inflammatory but residual disease cannot be ruled out.
79 Interesting CaseHypermetabolic R hilar nodes. Differentials include inflammatory reaction vs. metastases.
82 Review of 2594 cases were reviewed for 1.5 years Focal and diffuse thyroid FDG uptake were identified and were correlated with patholological diagnosis3.8% (99/2594) showed incidental thyroid FDG uptake46 diffuse (21 chronic thyroiditis)53 focal11/53 with focal FDG uptakeFNAB results4 benign7 malignant (63.3%)Use of SUV to delineate benign from malignant uptake is still undeterminedChen, et al. Evaluation of thyroid FDG uptake incidentally identified on FDG imaging. NMC 2009 March 30(3):240-4
83 ConclusionsUltrasound and thyroid scans are still the mainstay in imaging the thyroid glandCT and MRI have limited values and can be utilized in identifying lymph nodes, local tumor extension, diff. thyroiditis and as FNA guidePET/CT is best for WDTCA that have dedifferentiated hence negative on I-131- WBS but increasing thyroglobulin as well as in aggressive and difficult cases of TCA and certain suspicious nodules by FNAB