Characterisation of a high resolution small field of view portable gamma camera

A handheld, high-resolution small field of view (SFOV) pinhole gamma camera has been characterised using a new set of protocols adapted from standards previously developed for large field of view (LFOV) systems. Parameters investigated include intrinsic and extrinsic spatial resolution, spatial linearity, uniformity, sensitivity, count rate capability and energy resolution. Camera characteristics are compared to some clinical LFOV gamma cameras and also to other SFOV cameras in development.     

CZT gamma camera for scintimammography

A high performance prototype gamma camera based on the semiconductor radiation detector Cd(Zn)Te is described. The camera features high spatial resolution, high-energy resolution, a reduced dead space on the edge of the field of view, and a compact format. The camera performance was first examined by comparison of small field of view examinations with those from an Elscint SP6HR standard clinical gamma camera. The new camera was found to give equal or improved image quality. The camera was then used for a systematic phantom study of small lesions in a background as would be found in breast cancer imaging. In this study the camera was able to systematically detect smaller, deeper, and fainter lesions. The camera is presently being used in a clinical trial aimed to assess its value in scintimammography where previous limitations of image quality and detector size have restricted the use of the functional imaging techniques. Preliminary results from 40 patients show high sensitivity and specificity with respect to X-ray mammography and surgery.     

Long-Term Follow-Up of a Patient With Papillary Thyroid Carcinoma,Elevated Thyroglobulin Levels,and Negative Imaging Studies

ObjectiveTo describe a patient with papillary thyroid carcinoma who had measurable thyroglobulin (Tg) levels for 20 years without clinical or imaging evidence of a malignant lesion.MethodsWe reviewed the clinical course, pathologic findings, Tg measurements, and results of various imaging studies in our patient and reviewed the literature regarding Tg-positive, diagnostic total-body radioiodine scan-negative patients with thyroid cancer.ResultsFour months after a 3.5- by 3.5-cm follicular thyroid cancer was removed from the anterior neck area of a 5-year-old girl, a bilateral subtotal thyroidectomy was performed. At age 12 years, she presented with a 2-cm mass on the right side of the neck. After a completion thyroidectomy, recurrent mixed papillary-follicular thyroid cancer was found scattered throughout the remaining thyroid parenchyma. Although a postoperative diagnostic total-body radioiodine scan did not reveal uptake of ¹³¹I, the Tg level was 58 ng/mL. Despite Tg levels as high as 2,528 ng/mL, the patient had no clinical evidence of thyroid cancer during a 20-year period of follow-up. Moreover, numerous imaging studies, including total-body scanning after the administration of 150 mCi of ¹³¹I and [¹⁸F]fluorodeoxyglucose positron emission tomography, were negative. Review of pathologic specimens from both operations with use of updated diagnostic criteria indicated that the tumor was a papillary thyroid carcinoma.ConclusionOur observations and the observations of other investigators indicate that some thyroid cancers produce Tg so efficiently that high levels of Tg may be associated with tumors that remain too small to be detected by imaging studies. The Tg levels may remain stable, decline, or even disappear over time without treatment. (Endocr Pract. 2005;11:43-48)     

CdTe compact gamma camera for coded aperture imaging in radioguided surgery

The aim of this work was to assess the performance of a prototype compact gamma camera (MediPROBE) based on a CdTe semiconductor hybrid pixel detector, for coded aperture imaging. This probe can be adopted for various tasks in nuclear medicine such as preoperative sentinel lymph node localization, breast imaging with ^99mTc radiotracers and thyroid imaging, and in general in radioguided surgery tasks. The hybrid detector is an assembly of a 1-mm thick CdTe semiconductor detector bump-bonded to a photon-counting CMOS readout circuit of the Medipix2 series or energy-sensitive Timepix detector. MediPROBE was equipped with a set of two coded aperture masks with 0.07-mm or 0.08-mm diameter holes. We performed laboratory measurements of field of view, system spatial resolution, and signal-difference-to-noise ratio, by using gamma-emitting radioactive sources (¹⁰⁹Cd, ¹²⁵I, ²⁴¹Am, ^99mTc). The system spatial resolution in the lateral direction was 0.56 mm FWHM (coded aperture mask with holes of 0.08 mm and a 60 keV source) at a source-collimator distance of 50 mm and a field of view of 40 mm by side. Correspondingly, the longitudinal resolution in 3D source localization tasks was about 3 mm. MediPROBE showed a significant improvement in terms of spatial resolution when equipped with the high-resolution coded apertures, with respect to the performance previously reported with 1–2 mm pinhole apertures as well as with respect to adopting a 0.35 mm pinhole aperture.     

A scheme for assessing the performance characteristics of small field-of-view gamma cameras

Existing protocols for assessing the performance characteristics of large field-of-view (LFOV) gamma cameras can be inappropriate and require modification for use with small field-of-view (SFOV) gamma camera systems. This communication proposes a generic scheme suitable for evaluating the performance characteristics of SFOV gamma cameras, based on modifications to the standard procedures of NEMA NU1-2007. Key differences in methodology between tests for LFOV and SFOV gamma cameras are highlighted along with the rationale for these changes. It is envisaged that this scheme will provide more appropriate methods for equipment characterisation, ensuring quality and consistency for all SFOV cameras.     

Development of a dynamic imaging method for gravitropism in pea sprouts using clinical magnetic resonance imaging system

Although magnetic resonance imaging (MRI) is a useful technique, only a few studies have investigated the dynamic behavior of small subjects using MRI owing to constraints such as experimental space and signal amount. In this study, to acquire high-resolution continuous three-dimensional gravitropism data of pea (Pisum sativum) sprouts, we developed a small-bore MRI signal receiver coil that can be used in a clinical MRI and adjusted the imaging sequence. It was expected that such an arrangement would improve signal sensitivity and improve the signal-to-noise ratio (SNR) of the acquired image. All MRI experiments were performed using a 3.0-T clinical MRI scanner. An SNR comparison using an agarose gel phantom to confirm the improved performance of the small-bore receiver coil and an imaging experiment of pea sprouts exhibiting gravitropism were performed. The SNRs of the images acquired with a standard 32-channel head coil and the new small-bore receiver coil were 5.23±0.90 and 57.75±12.53, respectively. The SNR of the images recorded using the new coil was approximately 11-fold higher than that of the standard coil. In addition, when the accuracy of MR imaging that captures the movement of pea sprout was verified, the difference in position information from the optical image was found to be small and could be used for measurements. These results of this study enable the application of a clinical MRI system for dynamic plant MRI. We believe that this study is a significant first step in the development of plant MRI technique.     

Unusual Initial Manifestation of Metastatic Follicular Carcinoma of the Thyroid with Thyrotoxicosis Diagnosed by Technetium Tc 99m Pertechnetate Scan: Case Report and Review of Literature

ObjectiveTo report a case of metastatic thyroid cancer diagnosed on a technetium Tc 99m pertechnetate (TcO₄^–) thyroid scan.MethodsWe present the clinical findings, laboratory results, imaging studies, and surgical pathology report in a man with thyrotoxicosis in whom metastatic well-differentiated thyroid cancer was diagnosed incidentally on a routine TcO₄ ^– thyroid scan in the setting of a presumed diagnosis of benign toxic thyroid disease. In addition, we review the literature regarding coexistence of metastatic thyroid cancer and thyrotoxicosis.ResultsA 68-year-old man with thyrotoxicosis was referred for radioiodine therapy. A routine TcO₄^- thyroid scan revealed high-grade extrathyroidal uptake in the right upper hemithorax as well as in the left side of the thorax. In view of this finding, radioiodine treatment was deferred; further imaging with computed tomography revealed a 6.5-cm mass in a rib on the right side. A biopsy of the rib confirmed the presence of metastatic follicular carcinoma of the thyroid. Scintigraphy revealed sites of metastatic involvement predominantly in the bones along with a cold nodule in the left thyroid lobe, consistent with the primary tumor.ConclusionThis case emphasizes the impact of scintigraphic findings on determining the correct management of a patient who would have otherwise undergone inappropriate treatment. Through an extensive literature review, the incidence of malignant involvement in hyperfunctioning thyroid glands and the possible role of sodium iodide symporter expression by thyroid cancer metastatic lesions in preoperative detection of metastatic sites are addressed. (Endocr Pract. 2009;15:458-462)     

Comprehensive quality assurance phantom for the small animal radiation research platform (SARRP)

PurposeTo develop and test the suitability and performance of a comprehensive quality assurance (QA) phantom for the Small Animal Radiation Research Platform (SARRP).Methods and materialsA QA phantom was developed for carrying out daily, monthly and annual QA tasks including: imaging, dosimetry and treatment planning system (TPS) performance evaluation of the SARRP. The QA phantom consists of 15 (60 × 60 × 5 mm³) kV-energy tissue equivalent solid water slabs. The phantom can incorporate optically stimulated luminescence dosimeters (OSLD), Mosfet or film. One slab, with inserts and another slab with hole patterns are particularly designed for image QA.ResultsOutput constancy measurement results showed daily variations within 3%. Using the Mosfet in phantom as target, results showed that the difference between TPS calculations and measurements was within 5%. Annual QA results for the Percentage depth dose (PDD) curves, lateral beam profiles, beam flatness and beam profile symmetry were found consistent with results obtained at commissioning. PDD curves obtained using film and OSLDs showed good agreement. Image QA was performed monthly, with image-quality parameters assessed in terms of CBCT image geometric accuracy, CT number accuracy, image spatial resolution, noise and image uniformity.ConclusionsThe results show that the developed QA phantom can be employed as a tool for comprehensive performance evaluation of the SARRP. The study provides a useful reference for development of a comprehensive quality assurance program for the SARRP and other similar small animal irradiators, with proposed tolerances and frequency of required tests.     

微波热声成像技术用于人体甲状腺检测

本文首次通过人体实验验证了微波热声成像技术用于人体甲状腺检测的可行性.文章首先讨论了该技术用于人体甲状腺检测的可行性;然后对3名志愿者的健康甲状腺进行了微波热声成像实验.结果表明:微波热声成像能够对人体健康甲状腺进行清晰成像,能够真实反映皮肤、甲状腺和气管等不同组织的结构特征;并且一次完整的检测过程时间约5 s,系统操作简单成像快速.综上所述,微波热声成像技术有望为甲状腺疾病的基础研究和临床诊断提供一种新的影像学参考.     

Assessment and evaluation of MV image guidance system performance in radiotherapy

Background and aim

The clinical use of imaging system in image guided radiotherapy (IGRT) necessitates performing periodic quality assurance of the system to be confident in applying corrections for patient set-up errors. We aim to develop and implement a quality assurance (QA) programme for megavoltage (MV) based image guidance system and assess its long term performance for a period of 3 years.

Materials and methods

Periodic QA tests were performed for the MV planar and cone beam computed tomography (CBCT) imaging system to assess the system safety, mechanical and geometrical accuracy, image quality and dose. The tests were performed using the equipment supplied by the manufacturer along with the image guidance system and using simple methods developed in-house. The test results were compared with expected or baseline values established during commissioning.

Results

The safety system was found to be functional. The results of mechanical and geometrical tests were in good agreement with the expected results. The system mechanical positioning was stable and reproducible within ±2 mm accuracy. The image quality and the imaging dose of the planar and CBCT imaging were found to agree with the baseline values and the manufacturer specifications.

Discussion

Throughout the three-year period, all the QA tests were within the specification. The mechanical and geometrical tests are most crucial as they directly affect the patient positioning accuracy.

Conclusion

We conclude that the MV image guidance system is efficient to perform IGRT and insist to perform periodic QA tests and calibration for the system.     

Incidental Radiologic Finding of an Anterior Superior Mediastinal Mass Masquerading as Metastatic Thyroid Cancer in Patients with Treated Thyroid Cancer

ObjectiveTo demonstrate that an anterior superior mediastinal mass on radiologic imaging may represent an incidental finding and not metastases in patients with a history of treated well-differentiated thyroid cancer.MethodsWe report the clinical presentation and outcomes of 4 patients with a history of thyroid cancer who were incidentally found to have anterior superior mediastinal masses on imaging. We also review the relevant literature.ResultsFour young adults with a history of stage I papillary thyroid cancer treated with total thyroidectomy and radioiodine were incidentally found to have thymic enlargement on imaging studies within a 3-year posttreatment window. In each case, this enlargement was believed to be secondary to thymic hyperplasia and not metastatic disease, and each patient has exhibited a benign clinical course. Review of the literature revealed few reports of an association between thymic hyperplasia and thyroid cancer.ConclusionsThymic hyperplasia may be discovered on posttreatment imaging studies in patients with a history of well-differentiated thyroid cancer, particularly in young adults who have received radioiodine therapy. Recognition of the possible coexistence of this incidental finding in patients with thyroid cancer may help to avoid unnecessary invasive procedures and treatments. (Endocr Pract. 2011;17:65-69)     

Montage electron tomography of vitrified specimens

Cryo-electron tomography provides detailed views of macromolecules in situ. However, imaging a large field of view to provide more cellular context requires reducing magnification during data collection, which in turn restricts the resolution. To circumvent this trade-off between field of view and resolution, we have developed a montage data collection scheme that uniformly distributes the dose throughout the specimen. In this approach, sets of slightly overlapping circular tiles are collected at high magnification and stitched to form a composite projection image at each tilt angle. These montage tilt-series are then reconstructed into massive tomograms with a small pixel size but a large field of view. For proof-of-principle, we applied this method to the thin edge of HeLa cells. Thon rings to better than 10 Å were detected in the montaged tilt-series, and diverse cellular features were observed in the resulting tomograms. These results indicate that the additional dose required by this technique is not prohibitive to performing structural analysis to intermediate resolution across a large field of view. We anticipate that montage tomography will prove particularly useful for lamellae, increase the likelihood of imaging rare cellular events, and facilitate visual proteomics.     

Apport de l’imagerie hybride TEMP-TDM dans le suivi d’un cancer différencié de la thyroïde

In the management of patients with differentiated thyroid cancer (DTC), abnormalities detected on planar whole body scan and ¹³¹I-SPECT are difficult to interpret because of a lack of anatomical landmarks and limited specificity. Integrated ¹³¹I-SPECT-CT imaging has an additional value for characterization of equivocal tracer uptake seen on planar imaging as well as for precise localization. We illustrate through an observation the incremental diagnostic value of ¹³¹I-SPECT-CT images in the diagnosis of a cervical lymph node mimicking a physiological uptake on planar views. A 35-year-old Tunisian female was followed for papillary thyroid carcinoma, for which she underwent total thyroidectomy and iratherapy. Three years after a complete remission, the thyroglobulin (Tg) level on TSH stimulation increased. Diagnostic planar images with ¹³¹I did not disclose any obvious pathological foci. Furthermore, we noticed an increased ¹³¹I-uptake in the left sub-mandibulary area, which suggested a salivary physiological activity. SPECT-CT of the neck and chest were then performed with a Symbia T camera. Fused images demonstrate that this activity corresponds to a cervical lymph node closely adjacent to sub-mandibulary gland. Management of the patient was then changed. In selected patients with DTC, hybrid imaging should be used as a complementary to planar imaging in terms of diagnostic accuracy, because of superior focus localization and additional anatomic information derived from the CT component. Integrated SPECT-CT is then a useful tool, especially in cases of unclear diagnoses, precising anatomical localization of areas of increased ¹³¹I-uptake and distinguishing malignant lesions from normal physiological uptakes. This is particularly important in an oncologic center, as ours, where we don’t yet have a positron emission tomography (PET) camera is not yet available.     

Unusual spread of the follicular thyroid carcinoma,metastases to liver and pancreas

We report a multimetastatic follicular thyroid carcinoma(FTC) with match lesions between ¹⁸F-FDG PET/CT and post-treatment ¹³¹I imaging. The patient had a history of thoracic vertebra corpectomy surgery and liver tru-cut biopsy; both resulted in metastases of FTC. After total thyroidectomy surgery, the patient was referred to the ¹⁸F-FDG PET/CT to investigate other possible metastatic foci. ¹⁸F-FDG PET/CT showed increased FDG uptakes on a cervical lymph node, bones, lung, liver, and pancreas. After treatment of ¹³¹I, post-treatment iodine scintigraphy demonstrated iodine uptakes in the same areas as the ¹⁸F-FDG PET/CT scan and at the thyroid bed. All the matched lesions were concluded as a spread of the FTC. Here we describe an infrequent differentiated thyroid carcinoma case with metastases to the liver and pancreas. This case report also highlights the importance of ¹⁸F-FDG PET/CT in determining the extent of thyroid cancer.     

A Case of Gestational Thyrotoxicosis Associated With Wernicke’s Encephalopathy

ObjectiveTo present a case of gestational thyrotoxicosis and hyperemesis gravidarum associated with Wernicke’s encephalopathy.MethodsWe present a detailed case report with the clinical, imaging, and laboratory findings of the patient and review the pertinent literature.ResultsA 36-year-old woman at 14 weeks of gestation was admitted to the hospital for management of severe hyperemesis gravidarum (HG). While hospitalized, she developed low-grade fever, tachycardia, hypotension, and altered mentation. Laboratory tests were diagnostic of hyperthyroidism. Physical examination revealed a confused, lethargic woman with a normal-size thyroid and pendular nystagmus in primary and lateral gaze. She was treated empirically for thyroid storm with methimazole and other measures. A brain magnetic resonance imaging (MRI) study done later showed hyperintense abnormal signals in bilateral thalamic regions, consistent with Wernicke’s encephalopathy (WE). She was immediately started on intravenous thiamine and her mental status improved considerably within 3 to 4 days. Within 2 weeks, the patient’s thyroid-function tests normalized and methimazole was discontinued. A repeat brain MRI 6 months later showed marked reduction of signal intensity in both thalamic regions.ConclusionThis case demonstrates that gestational thyrotoxicosis in a patient with HG can precipitate acute WE, which may mimic thyroid storm and thus delay appropriate management of this neurologic disorder. We conclude that prophylactic thiamine administration may be considered before caloric replacement in patients who present with HG and acute neurologic dysfunction. (Endocr Pract. 2014;20:e237-e240)     

Le DOTATOC-(68Ga) pour l’imagerie TEP des tumeurs endocrines digestives : présentation d’un cas et revue de la littérature

⁶⁸Ga is a positron emitter, obtained from a ⁶⁸Ge/⁶⁸Ga generator, which can be used to label peptides of clinical interest. DOTATOC is a tracer of high affinity for the type 2 somatostatin receptors and is used for imaging of tumours which are expressing them, including endocrine tumours. We report on the case of a patient with a history of small bowel carcinoid tumour with hepatic metastases, treated by somatostatin analogues, in whom somatostatin receptor scintigraphy showed three liver foci and DOTATOC-(⁶⁸Ga) PET/CT highlighted much more liver lesions. Two recent studies emphasised on the superiority of DOTATOC-(⁶⁸Ga) PET over somatostatin receptor scintigraphy, and its complementarity with CT, especially for the diagnosis of bone metastases. DOTATOC-(⁶⁸Ga) PET/CT, which associates the specificity of somatostatin receptor scintigraphic detection with the spatial resolution of PET and the anatomical precision of CT, seems to be promised to a brilliant future, the more so as it offers many advantages to the patient: a shorter waiting time, one single image acquisition and a satisfying dosimetry.     

X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging

X-ray fluoroscopy is widely used for image guidance during cardiac intervention. However, radiation dose in these procedures can be high, and this is a significant concern, particularly in pediatric applications. Pediatrics procedures are in general much more complex than those performed on adults and thus are on average four to eight times longer¹. Furthermore, children can undergo up to 10 fluoroscopic procedures by the age of 10, and have been shown to have a three-fold higher risk of developing fatal cancer throughout their life than the general population^2,3.We have shown that radiation dose can be significantly reduced in adult cardiac procedures by using our scanning beam digital x-ray (SBDX) system⁴-- a fluoroscopic imaging system that employs an inverse imaging geometry^5,6 (Figure 1, Movie 1 and Figure 2). Instead of a single focal spot and an extended detector as used in conventional systems, our approach utilizes an extended X-ray source with multiple focal spots focused on a small detector. Our X-ray source consists of a scanning electron beam sequentially illuminating up to 9,000 focal spot positions. Each focal spot projects a small portion of the imaging volume onto the detector. In contrast to a conventional system where the final image is directly projected onto the detector, the SBDX uses a dedicated algorithm to reconstruct the final image from the 9,000 detector images.For pediatric applications, dose savings with the SBDX system are expected to be smaller than in adult procedures. However, the SBDX system allows for additional dose savings by implementing an electronic adaptive exposure technique. Key to this method is the multi-beam scanning technique of the SBDX system: rather than exposing every part of the image with the same radiation dose, we can dynamically vary the exposure depending on the opacity of the region exposed. Therefore, we can significantly reduce exposure in radiolucent areas and maintain exposure in more opaque regions. In our current implementation, the adaptive exposure requires user interaction (Figure 3). However, in the future, the adaptive exposure will be real time and fully automatic.We have performed experiments with an anthropomorphic phantom and compared measured radiation dose with and without adaptive exposure using a dose area product (DAP) meter. In the experiment presented here, we find a dose reduction of 30%.     

A difficult diagnosis: a case report of combined Riedel's disease and fibrosing Hashimoto's thyroiditis

Riedel's disease (RD) is a rare form of chronic thyroiditis, predominantly characterised by fibrosis which may involve neighbouring tissues and organs. Hashimoto's disease (HD), on the other hand, is fairly common. Clinical differentiation between these diseases is often difficult, and the results of diagnostic imaging, laboratory tests and cytology studies are often similar. We report the case of a female patient with Riedel's thyroiditis displaying clinical, laboratory and radiological traits of both diseases. A 44 year-old Caucasian female was diagnosed with hypothyroidism. A fine-needle aspiration biopsy was performed; the findings were suggestive of an exacerbated chronic inflammatory process. However, a small lymphocyte-derived malignancy could not be ruled out with certainty, and so the patient was referred for elective thyroidectomy. The microscopic features of both specimens did not meet the criteria of Hashimoto's thyroiditis. The immunohistochemical studies revealed few scattered B lymphocytes (CD20 positive) and numerous scattered T lymphocytes (CD3 positive). Finally, Riedel's thyroiditis with an intense inflammatory infiltrate composed of lymphocytes was diagnosed. Reaching a diagnosis was particularly difficult in this patient, since Riedel's thyroiditis, the fibrosing form of Hashimoto's disease and malignant tumours of the thyroid can show similar traits upon physical and histopathological examination. As the clinical data was indicative of Hashimoto's thyroiditis and there were partial histological criteria of two forms of thyroiditis, namely Hashimoto's and Riedel's, the very rare diagnosis of a combined disease was made. Dense B and T lymphocytes and some plasma cell infiltrates, as well as the destruction of thyroid follicles by fibrosis extending into surrounding tissues, were supportive of the eventual diagnosis. Differentiating between the histopathological and clinical presentation of both diseases in one patient is difficult, primarily due to the partial overlapping of their histopathological traits. In order to avoid a diagnostic error, close cooperation between the endocrinologist and pathologist is mandatory. It is our opinion that in our patient the two diseases existed separately, and their coexistence was most likely coincidental.     

Optimization of dose and image quality of paediatric cardiac catheterization procedure

The purpose of this study is to quantify the quality of the available imaging modes for various iodine-based contrast agent concentration in paediatric cardiology. The figure of merit (FOM) was defined as the squared signal to noise ratio divided by a patient dose related parameter. An in house constructed phantom simulated a series of vessel segments with iodine concentrations from 10% or 30 mg/cc to 16% or 48 mg/cc of iodine in a blood plasma solution, all within the dimensional constraints of a paediatric patient. The phantom also used test inserts of tin (Sn). Measurements of Entrance Surface Air Kerma (ESAK) and exit dose rate were performed along with calculations of the signal-to-noise ratio (SNR) of all the objects. A first result showed that it was favourable to employ low dose fluoroscopy mode and lower frame rate modes in cine acquisition if dynamic information is not critical. Normal fluoroscopy dose mode provided a considerably higher dose level (in comparison to low dose mode) with only a slight improvement in SNR. Higher frame rate cine modes should be used however when the clinical situation dictates so. This work also found that tin should not be intended as iodine replacement material for research purposes due to the mismatching SNR, particularly on small vessel sizes.     

Insular Variant of Poorly Differentiated Thyroid Carcinoma

ObjectiveTo present a case of an insular variant of poorly differentiated thyroid carcinoma (PDTC) and to review the literature related to diagnosis, natural history, and treatment of this unusual form of thyroid cancer.MethodsWe present the clinical, laboratory, and pathologic findings of the study patient and review Englishlanguage literature related to PDTC published between 1970 and the present.ResultsPDTC is a controversial and rare epithelial thyroid cancer, intermediate between differentiated thyroid carcinoma and anaplastic thyroid carcinoma that exhibits increased aggressiveness, propensity to local recurrence, distant metastases, and increased mortality. PDTC warrants aggressive management with total thyroidectomy followed by radioactive iodine ablation and potentially additional therapy for residual or recurrent disease. Some carcinomas do not take up radioactive iodine, and dedifferentiated clones of distant metastases may evolve. It is unclear whether chemotherapy is beneficial. Use of additional imaging modalities, including positron emission tomography, 18-fludeoxyglucose positron emission tomography/computed tomography, 18-fludeoxyglucose positron emission tomography/computed tomography/magnetic resonance imaging, ¹²⁴I positron emission tomography/computed tomography, positron emission tomography/magnetic resonance imaging fusion studies, and recombinant human thyrotropin-stimulated radioactive iodine uptake for cancer surveillance are discussed.ConclusionsPDTC is an unusual and aggressive form of thyroid cancer. Fine-needle aspiration cytology may not yield sufficient information to specifically diagnose PDTC. Aggressive management with total thyroidectomy and neck dissection followed by high-dose radioactive iodine remnant ablation is standard. Iodine I 131 whole body scanning is often the initial test for tumor surveillance, with other imaging modalities applied as needed. (Endocr Pract. 2011;17:115-121)