Search

Aim report primary results from the first multicentre randomised trial evaluating induction chemotherapy prior to trimodality therapy in patients with oesophageal or gastro-oesophageal junction adenocarcinoma. Notably, recent data from a single-institution randomised trial reported that induction chemotherapy prolonged overall survival (OS) in patients with well/moderately differentiated tumours. Methods In this phase 2 trial (28 centres in the U.S. NCI-sponsored North Central Cancer Treatment Group [Alliance]), trimodality-eligible patients (T3-4N0, TanyN+) were randomised to receive induction (docetaxel, oxaliplatin, capecitabine; Arm A) or no induction chemotherapy (Arm B) followed by oxaliplatin/5-fluorouracil/radiation and subsequent surgery. The primary endpoint was the rate of pathologic complete response (pathCR). Secondary/exploratory endpoints were OS and disease-free survival (DFS). Results Of 55 patients evaluable for the primary endpoint, the pathCR rate was 28.6% (8/28) in A versus 40.7% (11/27) in B (P = .34). Given interim results indicating futility, accrual was terminated, but patients were followed. After a median follow-up of 60.4 months, a longer median OS in Arm A versus B was unexpectedly observed (3-year rates 57.1% versus 41.7%, respectively) driven by longer DFS after margin-free surgery. In posthoc analysis, induction (versus no induction) chemotherapy was associated with significantly longer OS and DFS among patients with well/moderately differentiated tumours, but not among patients with poorly/undifferentiated tumours (Pinteraction = 0.037). Conclusions Adding induction chemotherapy prior to trimodality therapy did not improve the primary endpoint, pathCR. However, induction chemotherapy was associated with longer median OS, particularly among patients with well/moderately differentiated tumours. These findings may inform further development of curative-intent trials in this disease.

Choline positron emission tomography (PET)/computed tomography (CT), with both carbon 11 ((11)C) choline and fluorine 18 ((18)F) choline, is an increasingly used tool in the evaluation of patients with biochemically recurrent prostate cancer. It has allowed detection and localization of locally recurrent and metastatic lesions that were difficult or impossible to identify using more conventional modalities. Many of the patients followed for their prostate cancer are elderly and have a higher rate of nonprostate cancer lesions or malignancies. As our experience with choline PET/CT has grown, it has become apparent that many of these nonprostate cancer processes, both benign and malignant, can be detected. Invasive thymoma, renal cell carcinoma, papillary thyroid carcinoma, and parathyroid adenoma are a few of the processes that have been incidentally detected with (11)C-choline PET/CT at our institution and have significantly altered subsequent clinical management of the patient. Although most of the secondary lesions are detected due to their increased (11)C-choline avidity, several have been detected due to their decreased or lack of avidity in the background of a highly avid organ. For instance, large liver masses that are relatively non-choline-avid create large activity defects in the otherwise highly active liver. Familiarity with normal (11)C-choline physiologic activity, the most common prostate metastatic patterns, and imaging characteristics of secondary lesions is essential for the detection and correct diagnosis of such lesions so that proper follow-up and management can be recommended.

The advances in PET scanning for thoracic diseases that are deemed most likely to have clinical impact in the near-term future are highlighted in this article. We predict that the current practice of medicine will continue to embrace the power of molecular imaging and specifically PET scanning. 18F-fluorodeoxyglucose-PET scanning will continue to evolve and will expand into imaging of inflammatory disorders. New clinically available PET scan radiotracers, such as PET scan versions of octreotide and amyloid imaging agents, will expand PET imaging into different disease processes. Major improvements in thoracic PET/CT imaging technology will become available, including fully digital silicone photomultipliers and Bayesian penalized likelihood image reconstruction. These will result in significant improvements in image quality, improving the evaluation of smaller lung nodules and metastases and allowing better prediction of prognosis. The birth of clinical PET/MRI scan will add new imaging opportunities, such as better PET imaging of pleural diseases currently obscured by complex patient motion.

Background The mammalian target of rapamycin (mTOR) functions within the phosphatidylinositol-3 kinase (PI3K)/Akt pathway as a critical modulator of cell survival. This clinical trial evaluated the combination of the mTOR inhibitor everolimus with conventional temozolomide (TMZ)-based chemoradiotherapy.

Purpose The objective of this study was to evaluate brain metabolism with F-FDG-PET in patients with definite or possible paraneoplastic neurologic syndromes (PNS) using qualitative assessment and semiquantitative measurements with subsequent correlation with MRI. Methods The institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. A prospective PET database of patients referred for PNS between 2001 and 2010 was queried retrospectively and identified 102 patients who met the diagnostic criteria for PNS, had PET brain imaging, and lacked clinical or MRI evidence of an alternative diagnosis.Qualitative and semiquantitative evaluation of brain metabolism was obtained by 3-dimensional stereotactic surface projection and region-based analysis. Qualitative and semiquantitative assessment was performed blinded to clinical data. Results PET/CT demonstrated that 67 patients had abnormal brain glucose metabolism. Six categories of brain hypometabolism were identified: diffuse (36/67), cerebellar (10/67), basal ganglia (10/67), frontal (9/67), temporal (1/67), and occipital (1/67). The mean Z score of the cerebral cortex in diffuse hypometabolism was 1.65 (range, 0.25-3.46). For cerebellar hypometabolism, the mean Z score of the cerebellum was 2.31 (range, 0.52-4.54). In basal ganglia hypometabolism, the mean Z score was 2.53 (range, 1.78-3.89), and in frontal lobe hypometabolism, the mean Z score was 2.11 (range, 1.39-4.45). The majority (39/67, 62.9%) with abnormal glucose metabolism on PET had a normal MR. Conclusions Patients with PNS frequently have abnormal brain metabolism on semiquantitative PET/CT. With semiquantitative analysis, we defined 6 common patterns of abnormalities, which often correlated with clinical symptoms. Both qualitative and semiquantitative analyses of brain glucose metabolism may be helpful in evaluating PNS, especially in patients with a normal MRI.

OBJECTIVE. Multimodality imaging plays an important role in the structural and functional characterization of neurodegenerative conditions. This article illustrates the basic concepts of anatomic, metabolic, and amyloid imaging and describes the application of a multimodality approach in the evaluation of patients with the more common neurodegenerative dementia processes. Proper utilization of clinically available imaging techniques allows greater insight into these common disease processes. CONCLUSION. Recognizing the strength of combined anatomic, metabolic, and amyloid imaging can allow a more complete and confident assessment of patients with common degenerative dementias. This added knowledge can improve clinical care, allow initiation of appropriate therapies and counseling, and improve prognostication.

OBJECTIVE. The purpose of this article is to describe the role of multimodality imaging in the evaluation of atypical neurodegenerative conditions. An imaging approach to the more common dementia disease processes was described in part 1. This article, part 2, briefly discusses current Centers for Medicare & Medicaid Services coverage for imaging patients with dementia and illustrates the basic concepts of combining anatomic, metabolic, and amyloid imaging in the evaluation of patients with atypical neurodegenerative dementia. Although these disease processes are rare, the growing repertoire of clinically available imaging techniques necessitates an understanding of their imaging patterns. CONCLUSION. Despite the rarity of these conditions, imaging of patients with neurodegenerative disorders is on the rise, and familiarity with the imaging appearances of these atypical causes is increasingly important.

Whole-body fluorine 18 fluorodeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) is performed primarily for oncologic indications; however, FDG uptake is not specific for malignancy. Herein we focus on causes of increased FDG uptake in and around joints, as lesions in these locations are commonly benign. A combination of primary intra-articular processes and osseous processes that may occur near the joint space will be discussed. Causes of intra-articular and periarticular increased FDG activity can be broadly divided into infectious, inflammatory, degenerative, and benign neoplastic categories. A familiarity with the full range of these processes is important to avoid misinterpretation, in turn decreasing unnecessary follow-up studies, procedures, and treatments. Differentiation from malignancy is often possible on the basis of a different level of FDG activity, divergent response to therapy, or differing changes over time, in comparison with a patient's known primary cancer. Recognizing an intra-articular lesion location can also be critical, as intra-articular metastases are rare. In some cases, benign FDG-avid articular and periarticular entities have a specific appearance at FDG PET/CT and a correct diagnosis may be made without any additional workup. In most other cases, comparison with prior studies and/or additional imaging can afford an accurate diagnosis. This review is meant to introduce the reader to a spectrum of benign FDG-avid articular and periarticular processes that may be encountered at oncologic FDG PET/CT to increase confidence and diagnostic accuracy. (©)RSNA, 2016.

The clinical diagnosis of Parkinson disease (PD) is difficult, as several other neurodegenerative and basal ganglia disorders have similar clinical presentations. Dopamine transporter single-photon emission computed tomography has been proposed as possible diagnostic tool to help differentiate idiopathic PD from essential tremor and other disorders that present with parkinsonian symptoms. In addition, it is valuable in the diagnosis of dementia with Lewy bodies, differentiating it from other causes of dementia such as Alzheimer disease.

We examined the clinical impact of commercially available quantitation software using 3-dimensional stereotactic surface projection (3D-SSP) on the diagnostic accuracy of 18F fluorodeoxyglucose positron emission tomography (18F FDG PET) in mild cognitive impairment (MCI) and Alzheimer disease (AD).Enrollees underwent clinical evaluation to determine cognitive status and subsequent 18F FDG PET neuroimaging. Four blinded readers (2 novices and 2 experts) rated the images for degree of abnormality and interpretive confidence without and with 3D-SSP. Diagnostic accuracy was determined with area under the curve (area under the curve) of a receiver operating characteristic (receiver operating characteristic) curve analysis and change in confidence with model-based means (LSMeans).Twenty-three normal controls and 31 patients with cognitive impairment (18 MCI and 13 AD) were enrolled (28 female and 26 male; mean age 74 years). During follow-up (mean 3.6 years), all normal participants remained normal, 12 of 18 participants with MCI progressed to dementia, and all participants with baseline dementia progressed. The area under the curve with 3D-SSP (0.88; 95% CI: 0.76-0.95) was significantly higher than without it (0.72; 95% CI: 0.55-0.83). The specificity increased from 26% to 63% for novices and from 56% to 87% for experts with addition of 3D-SSP, whereas the sensitivity was essentially unchanged at 86% and 86% for the beginners and 81% and 79% for the experts. The interpretive confidence increased significantly from 3.3 to 4.0 (maximum value = 5, P = 0.048).The use of commercially available 3D-SSP quantitation improved diagnostic accuracy for evaluation of MCI and AD with 18F FDG PET.

The purpose of this study was to evaluate the clinical utility of 18F-FDG PET/CT in esthesioneuroblastoma staging and restaging and quantify the additional benefit of PET/CT to conventional imaging. Methods: A retrospective review was performed with institutional review board approval for patients with a diagnosis of esthesioneuroblastoma who underwent PET/CT from 2000 to 2010. PET/CT results were retrospectively reviewed by 2 radiologists who were unaware of the clinical and imaging data. Positive imaging findings were classified into 3 categories: local disease, cervical nodal spread, and distant metastasis. All conventional imaging performed in the 6 mo preceding PET/CT, and the medical records, were reviewed to determine the potential added value. Results: Twenty-eight patients (mean age, 52.3 ± 10 y; range, 23–81 y) were identified who underwent a total of 77 PET/CT examinations. Maximum standardized uptake value (SUVmax) was 8.68 ± 4.75 (range, 3.6–23.3) for the primary tumor and 8.57 ± 6.46 (range, 1.9–27.2) for the metastatic site. There was no clear association between primary tumor SUVmax and tumor grade (P = 0.30). Compared with conventional imaging, PET/CT changed disease stage or altered clinical management in 11 (39%) of 28 esthesioneuroblastoma patients. Of these, 10 (36%) of 28 were upstaged on the basis of their PET/CT studies. Cervical nodal metastases were found in 5 (18%) of 28, local recurrence in 2 (7%) of 28, cervical nodal and distant metastases in 2 (7%) of 28, and distant metastases in 1 (4%) of 28. One patient (4%) was downstaged after negative findings on PET/CT. Conclusion: PET/CT is a useful adjunct to conventional imaging in the initial staging and restaging of esthesioneuroblastoma by detecting nodal and distant metastatic disease not demonstrated by conventional imaging and identifying local recurrence hidden by treatment changes on conventional imaging.

Background The mammalian target of rapamycin (mTOR) functions within the PI3K/Akt signaling pathway as a critical modulator of cell survival. On the basis of promising preclinical data, the safety and tolerability of therapy with the mTOR inhibitor RAD001 in combination with radiation (RT) and temozolomide (TMZ) was evaluated in this Phase I study. Methods and Materials All patients received weekly oral RAD001 in combination with standard chemoradiotherapy, followed by RAD001 in combination with standard adjuvant temozolomide. RAD001 was dose escalated in cohorts of 6 patients. Dose-limiting toxicities were defined during RAD001 combination therapy with TMZ/RT. Results Eighteen patients were enrolled, with a median follow-up of 8.4 months. Combined therapy was well tolerated at all dose levels, with 1 patient on each dose level experiencing a dose-limiting toxicity: Grade 3 fatigue, Grade 4 hematologic toxicity, and Grade 4 liver dysfunction. Throughout therapy, there were no Grade 5 events, 3 patients experienced Grade 4 toxicities, and 6 patients had Grade 3 toxicities attributable to treatment. On the basis of these results, the recommended Phase II dosage currently being tested is RAD001 70 mg/week in combination with standard chemoradiotherapy. Fluorodeoxyglucose (FDG) positron emission tomography scans also were obtained at baseline and after the second RAD001 dose before the initiation of TMZ/RT; the change in FDG uptake between scans was calculated for each patient. Fourteen patients had stable metabolic disease, and 4 patients had a partial metabolic response. Conclusions RAD001 in combination with RT/TMZ and adjuvant TMZ was reasonably well tolerated. Changes in tumor metabolism can be detected by FDG positron emission tomography in a subset of patients within days of initiating RAD001 therapy.

OBJECTIVE. This article will discuss the 18F-FDG normal variant uptake and the role of FDG PET/CT in malignancies in HIV-infected patients, CNS manifestations of HIV, assessing fever of unknown origin in HIV patients, assessing response to highly active antiretroviral therapy and assessing complications. CONCLUSION. FDG PET/CT is a valuable imaging study in the management of HIV-infected patients.

OBJECTIVE. Primary hepatobiliary malignancies consist of hepatocellular carcinoma, cholangiocarcinoma, and gallbladder cancer. Benign hepatic lesions include hepatic cysts, hemagiomas, adenomas, and focal nodular hyperplasias. The utility of PET/CT in imaging primary hepatobiliary lesions varies according to the type and location of the lesion. CONCLUSION. There is a consistent benefit to the use of PET/CT for detection and staging, and it ultimately helps to establish the best course of treatment and to determine prognosis. In addition, PET/CT is very useful in local ablative and systemic therapy assessment and surveillance for hepatobiliary malignancies.

OBJECTIVE. The objective of this article is to provide an illustrative tutorial showing the utility of 11C-choline PET/CT for imaging prostate cancer. CONCLUSION. Carbon-11-labeled choline PET/CT is a powerful adjunct to the currently available imaging modalities for evaluating prostate cancer. As with any diagnostic method, false-positives and false-negatives occur. However, these diagnostic errors can be reduced if readers are familiar with the normal and abnormal patterns of 11C-choline distribution in the body.

Received February 20, 2010; accepted after revision June 10, 2010. 1Department of Radiology, Mayo Clinic, 200 First St SW, Charlton 1-219, Rochester, MN 55905. Address correspondence to P. J. Peller (peller.patrick@mayo.edu). 2Department of Pathology, Mayo Clinic, Rochester, MN. 3Department of Radiology, Boston University School of Medicine and Boston Medical Center, Boston, MA. AJR 2011; 196:WS78–WS82 0361–803X/11/1966–WS78 © American Roentgen Ray Society Clinical History A 31-year-old healthy man presented with a 1-month history of a palpable left neck mass and was referred to a tertiary care center for further evaluation. On clinical examination, there was a spongy, nontender, supraclavicular mass deep in relation to his left sternocleidomastoid muscle. CT of the neck and chest performed at an outside institution showed a 6-cm round heterogeneous mass in the inferior left carotid space with no surrounding lymphadenopathy and a normal thyroid. The radiologic differential diagnosis initially favored a neurogenic tumor over a metastatic lymph node. An initial blind fine-needle aspiration of the mass performed before referral was nondiagnostic. Neck MRI was then ordered, likely intended to help narrow the differential diagnosis. The initial pathologic evaluation of an ultrasound-guided core needle biopsy of the mass was consistent with a metastatic poorly differentiated neoplasm. PET/CT was performed for identification of the primary site of tumor and failed initially to identify a primary malignancy. A complete blood count was normal. Later, further pathologic evaluation of the biopsy suggested that a germ cell neoplasm was a possibility, and testicular ultrasound was performed. There was no initial clinical detection of a primary focus of malignancy, but physical examination later confirmed a hard mass in the inferior pole of the left testicle.

Background Multiple Systems Atrophy (MSA) and Dementia with Lewy bodies (DLB) can present with both REM behavior disorder and severe autonomic dysfunction. In rare occasions, patients with MSA progress to cognitive impairment and even dementia. Positron emission topography (PET) imaging using both the amyloid ligand Pittsburgh Compound B (11C-PiB) and 18 flurodeoxyglucose (18F-FDG) was used to ascertain the presence of amyloid and pattern of glucose metabolic derangement in both disorders. Methods Patients diagnosed with probable DLB or MSA, with clinical symptoms of either REM Behavior Disorder (RBD), Parkinsonism, or dysautonomia were prospectively identified. All underwent both 11C-PiB and 18F-FDG PET imaging. Statistical comparison between DLB, MSA, and normal controls was performed. Results Six patients, 3 with DLB, 2 with Parkinson predominant MSA (MSA-P), and 1 with cerebellar predominant MSA (MSA-C) were identified. Increased level of PiB retention was noted in all patients diagnosed with DLB, but was absent in MSA. In those with DLB, glucose hypometabolism corresponded with regions of amyloid presence, and included prefrontal, parietotemporal, occipital and primary visual cortex regions. MSA patients were distinguished by cerebellar glucose hypometabolism. Conclusions These findings emphasize the distinguishing characteristics between the alpha-synuclein related disorders of DLB and MSA. The absence of amyloid in the cases of MSA is a possible distinguishing characteristic of the disorder.

The hybrid technique of PET/CT has significantly impacted the imaging and management of HNSCC since its introduction in 2001 and has become the technique of choice for imaging of this cancer. Diagnostic FDG-PET/CT is useful for identification of an unknown primary tumor, delineation of extent of primary tumor, detection of regional lymph node involvement even in a normal-sized node, detection of distant metastases and occasional synchronous primary tumor, assessment of therapy response, and long-term surveillance for recurrence and metastases. The role of PET/CT is evolving in radiation therapy planning. Combined diagnostic PET/CT provides the best anatomic and metabolic in vivo information for the comprehensive management of HNSCC.

Malignant pleural mesothelioma (MPM) is the most common primary pleural tumor and its incidence is rising. Its diagnosis, staging and response assessment are challenging for imaging. Integrated positron emission tomography (PET)/CT increases the accuracy of overall staging in patients with mesothelioma and improves the selection of patients for curative surgical resection. It is particularly useful in identifying occult distant metastases. It may be used to predict prognosis and to assess the metabolic response to therapy.

Purpose To our knowledge, there are no published data pertinent to the use of [ 18 F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with natural killer (NK)/T—cell lymphoma. The purpose of this study was to assess the value of FDG PET/CT in this aggressive type of non-Hodgkin lymphoma. Patients and Methods All patients with NK/T-cell lymphoma referred for FDG PET/CT at our institution from July 2001 to July 2006 were retrospectively studied. PET/CT examinations were blindly reviewed by 2 experienced readers. The results were compared with the status of the disease, which was determined after evaluation of biopsy, laboratory, clinical and conventional imaging examination, and follow-up results. PET/CT results were thereby classified as true-positive, true-negative, false-positive, or false-negative. The degree of FDG uptake in the positive lesions was semiquantified using maximum standard uptake value (SUV max ). Results Twenty-one PET/CT examinations were performed in 10 patients with NK/T-cell lymphoma. For nasal disease, PET/CT was true-positive in 5 cases, true-negative in 15 cases, and positive but unconfirmed in 1 case. For extranasal disease, PET/CT was true-positive in 3 cases, true-negative in 16 cases, and false-negative in 2 cases. The mean SUV max in PET-positive lesions in nasal cavities or paranasal sinuses was 16 gm/mL (range, 5–25 gm/mL; median, 19.3 gm/mL). In extranasal disease, the mean SUV max was 10.9 gm/mL (range, 4.6–34.1 gm/mL; median, 5.6 gm/mL). Conclusion Viable NK/T-cell lymphoma is intensely FDG hypermetabolic. PET/CT appears to be sensitive for the detection of disease in the nasopharynx and, to a lesser extent, in extranasal sites.

Choline positron emission tomography (PET)/computed tomography (CT), with both carbon 11 ((11)C) choline and fluorine 18 ((18)F) choline, is an increasingly used tool in the evaluation of patients with biochemically recurrent prostate cancer. It has allowed detection and localization of locally recurrent and metastatic lesions that were difficult or impossible to identify using more conventional modalities. Many of the patients followed for their prostate cancer are elderly and have a higher rate of nonprostate cancer lesions or malignancies. As our experience with choline PET/CT has grown, it has become apparent that many of these nonprostate cancer processes, both benign and malignant, can be detected. Invasive thymoma, renal cell carcinoma, papillary thyroid carcinoma, and parathyroid adenoma are a few of the processes that have been incidentally detected with (11)C-choline PET/CT at our institution and have significantly altered subsequent clinical management of the patient. Although most of the secondary lesions are detected due to their increased (11)C-choline avidity, several have been detected due to their decreased or lack of avidity in the background of a highly avid organ. For instance, large liver masses that are relatively non-choline-avid create large activity defects in the otherwise highly active liver. Familiarity with normal (11)C-choline physiologic activity, the most common prostate metastatic patterns, and imaging characteristics of secondary lesions is essential for the detection and correct diagnosis of such lesions so that proper follow-up and management can be recommended.

Purpose Primary central nervous system lymphoma (PCNSL) accounts for approximately 3% of all primary brain tumors and 1% of all non-Hodgkin lymphomas. Detection of systemic spread of PCNSL, although rare (4%), is very important since therapy is usually modified. Contrast-enhanced computed tomography (CT) is commonly used for systemic staging of PCNSL. No previous case report is available in the published literature elaborating the potential contribution of F-18 FDG PET in systemic staging of PCNSL. The purpose of this case report was to document the potential usefulness of F-18 FDG-PET in the detection of occult systemic involvement in PCNSL. Materials and methods A 50-year-old, immunocompetent, male patient completed successful treatment of PCNSL. As part of a routine pretransplant evaluation he had an F-18 FDG PET coregistered with CT (PET-CT). The PET-CT results were then compared with those of contrast-enhanced CT of the chest, abdomen, and pelvis. Results The PET-CT examination detected multiple sites of extranodal systemic disease that were not seen in the contrast-enhanced CT of the chest, abdomen, and pelvis (both studies were performed within 24 hours of each other). Percutaneous ultrasound guided biopsy confirmed the presence of systemic spread of PCNSL. The patient's subsequent therapy was modified to include rituximab with cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP). A follow up PET-CT confirmed resolution of systemic spread. Conclusion F-18 FDG PET coregistered to CT may be a useful examination in the detection and monitoring for systemic spread of the disease in PCNSL patients.

This practice parameter is for both FDG and amyloid brain PET or PET/computed tomography (CT) for patients with cognitive decline, and has been developed collaboratively by the American College of Radiology (ACR) and the American Society for Neuroradiology (ASNR). It is estimated that the number of people with dementia, 36.5 million worldwide in 2010, will increase to 65.7 million in 2030 and to 115 million in 2050. Four primary neurodegenerative etiologies of dementia have been defined: Alzheimer disease (AD), vascular dementia, frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB). Alzheimer disease is the most common form of dementia, accounting for approximately 60%-80% of all cases. Indications for FDG and amyloid brain PET and qualifications for personnel are discussed in this practice parameter.

This article presents a review of multiple myeloma, precursor states, and related plasma cell disorders. The clinical roles of fluorodeoxyglucose PET/computed tomography (CT) and the potential to improve the management of patients with multiple myeloma are discussed. The clinical and research data supporting the utility of PET/CT use in evaluating myeloma and other plasma cell dyscrasias continues to grow.

Multiple myeloma is a common hematologic malignancy among the elderly population. Although there have been many advances in treatment over the past few decades, the overall prognosis for the disease remains poor. Conventional radiography has long been the standard of reference for the imaging of multiple myeloma. However, 10%-20% of patients with multiple myeloma do not have evidence of disease at conventional radiography. There is a growing body of evidence supporting use of magnetic resonance (MR) imaging and 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) in diagnosis and management of multiple myeloma. MR imaging is useful in detection of bone marrow infiltration, a finding often missed at conventional radiography. FDG PET/CT is especially sensitive for the detection of extramedullary disease and can help detect the metabolically active lesions that often precede evidence of osseous destruction at conventional radiography. MR imaging and FDG PET/CT are useful tools that can provide essential information for diagnosis and management of patients with multiple myeloma. Both modalities allow accurate localization of disease after chemotherapy or autologous stem cell transplantation and can provide important prognostic information that can influence further clinical decision making regarding therapy, particularly when tumor serum markers may be a less reliable indicator of disease burden after repeated treatments.

Received February 19, 2010; accepted after revision June 10, 2010. 1Department of Radiology, Mayo Clinic, 200 First St SW, Charlton 1-219, Rochester, MN 55905. Address correspondence to P. J. Peller (peller.patrick@mayo.edu). 2Department of Radiology, Boston University School of Medicine and Boston Medical Center, Boston, MA. AJR 2011; 196:WS83–WS85 0361–803X/11/1966–WS83 © American Roentgen Ray Society Clinical History A 51-year-old woman presented for staging and planned wide local reexcision of a Merkel cell carcinoma of the left upper arm. Merkel cell carcinoma is a rare, aggressive cutaneous neuroendocrine cell malignancy with some properties similar to melanoma. The diagnostic excisional biopsy showed lymphovascular invasion and positive microscopic margins. PET/ CT from the mid calvaria to the mid thighs was performed.

The clinical and imaging evaluation of peripheral neuropathies in patients with cancer is challenging. It is critically important to differentiate malignant invasion of the peripheral nervous system from nonmalignant causes, such as radiation-induced neuritis, neuropathy associated with chemotherapy, and inflammatory neuropathies. Contrast material-enhanced magnetic resonance (MR) imaging is the initial noninvasive test of choice; however, interpretation can be challenging when the anatomic features are distorted by prior surgery, radiation, or both. Fluorine 18 ((18)F)-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is an imaging adjunct to MR imaging that is particularly helpful for evaluating peripheral nerves because the metabolic activity depicted with (18)F-FDG PET/CT helps differentiate malignant from benign disease and assists in making certain management decisions. For example, sites of high (18)F-FDG activity in a peripheral nerve can be targeted to increase the diagnostic yield of a biopsy because malignant involvement of peripheral nerves can be patchy. Of note, (18)F-FDG PET/CT can show clinically unsuspected metastases elsewhere in the body. If cancer is found, (18)F-FDG PET/CT allows excellent assessment of treatment response. (18)F-FDG PET/CT is also useful in evaluating primary nerve sheath tumors in that such tumors with low metabolic activity on FDG PET/CT images are unlikely to be malignant, although the specificity is limited. It is essential to have a good understanding of the imaging characteristics of benign and malignant causes of peripheral neuropathy if (18)F-FDG PET/CT is to be used effectively for accurate diagnosis.

BACKGROUND: Mammalian target of rapamycin (mTOR) signaling plays a critical role in tumor cell function and mTOR inhibitors have demonstrated promising activity in glioblastoma multiforme (GBM). Nevertheless, robust genetic predictors for sensitivity to mTOR inhibition remain elusive. As part of the biomarker discovery process, the North Central Cancer Treatment Group (NCCTG) incorporated functional imaging with 18FLT-PET/CT and focused exon sequencing into N057K, a Phase II clinical trial evaluating the mTORC1 inhibitor everolimus in combination with radiation(RT) and temozolomide(TMZ) in newly diagnosed GBM patients. METHODS: N057K began weekly everolimus one week prior to standard RT/TMZ. Patients who had >1cm3 of residual tumor were imaged with 18FLT-PET/CT before and after the initial two doses of everolimus, before initiating RT/TMZ. Imaged patients with a ΔSUVmax of >25% were classified as metabolic responders adapted from EORTC criteria for FDG-PET. Imaged patients with sufficient tumor samples also underwent immunohistochemical and focused exon sequencing analysis using the Seqwright 201 gene panel. Tertiary analysis focused on genes implicated in the PI3K/Akt/mTOR pathway (PTEN, PIK3CA, AKT, mTOR, Raptor/Rictor, S6, TSC1/2, NF1, CCND1, FGFR1/2). RESULTS: Nine patients had 18FLT-PET/CT imaging of which 4/9 had a metabolic response to everolimus alone. Six patients had sufficient tumor samples for further analysis, of which 3/6 had response. On IHC, 18FLT-PET responders had higher levels of PTEN expression and lower levels of pAKT and Ki-67 expression in comparison to non-responders. Focused exon sequencing found 1,458 coding alterations in 454 genes when compared to the reference genome. Only one 18FLT-PET responder had any genetic alterations within a PI3K/Akt/mTOR-implicated pathway, while all 18FLT-PET non-responders had multiple alterations within PI3K/Akt/mTOR-implicated pathways. CONCLUSIONS: 18FLT-PET successfully identified cohorts of patients who had robust, early metabolic responses to mTOR inhibition alone. These responders had robust PTEN expression on IHC and were less likely to have alterations within PI3K/Akt/mTOR-implicated pathways.

Movement disorders with parkinsonian features are common, and in recent years imaging has assumed a greater role in diagnosis and management. Thus, it is important that radiologists become familiar with the most common imaging patterns of parkinsonism, especially given the significant clinical overlap and diagnostic difficulty associated with these disorders. The authors review the most common magnetic resonance (MR) and molecular imaging patterns of idiopathic Parkinson disease and atypical parkinsonian syndromes. They also discuss the interpretation of clinically available molecular imaging studies, including assessment of cerebral metabolism with 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET), cortical amyloid deposition with carbon 11 ((11)C) Pittsburgh compound B and fluorine 18 ((18)F) florbetapir PET, and dopaminergic activity with iodine 123 ((123)I) ioflupane single photon emission computed tomography (SPECT). Although no single imaging test is diagnostic, a combination of tests may help narrow the differential diagnosis. Findings at (123)I ioflupane SPECT can confirm the loss of dopaminergic neurons in patients with parkinsonism and help distinguish these syndromes from treatable conditions, including essential tremor and drug-induced parkinsonism. FDG PET uptake can demonstrate patterns of neuronal dysfunction that are specific to a particular parkinsonian syndrome. Although MR imaging findings are typically nonspecific in parkinsonian syndromes, classic patterns of T2 signal change can be seen in multiple system atrophy and progressive supranuclear palsy. Finally, positive amyloid-binding PET findings can support the diagnosis of dementia with Lewy bodies. Combined with a thorough clinical evaluation, multimodality imaging information can afford accurate diagnosis, allow selection of appropriate therapy, and provide important prognostic information.

Background The utility of diagnostic imaging in paraneoplastic autoimmune multiorgan syndrome (PAMS) is unknown. Methods We examined the role of diagnostic imaging in patients with PAMS evaluated at our tertiary referral center (at Mayo Clinic, Rochester, MN, USA) and in the English literature between January 1, 1996, and August 31, 2012. Results We included 17 patients from our institution and 208 patients from the literature review. Of these 225 patients, 113 (50.2%) were not known to have a malignancy diagnosis at the time of PAMS diagnosis. Of the 123 patients from our institution and from the literature reported to undergo imaging studies, conventional computed tomography (CT) was the predominant imaging modality (n = 110; 89.4%); 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT was also used, albeit infrequently (n = 12; 9.8%). When CT was included in imaging to identify or confirm the presence of a malignancy, imaging was successful in all patients who ultimately were diagnosed with an associated malignancy. At our institution, a relatively high percentage (n = 7; 41%) of patients had 18F-FDG PET/CT, which not only identified all tumors found on CT but also facilitated staging of lymphoma and guided biopsy procedures. Conclusion Diagnostic imaging is frequently utilized in PAMS with unknown malignancy. Both conventional CT and 18F-FDG PET/CT are likely to detect the typical underlying neoplasms. Relative to conventional CT, 18F-FDG PET/CT may provide additional useful information regarding prognosis for the likely underlying malignancies, although there is a paucity of reports describing the use of this modality for this purpose.

This article presents an overview of positron emission tomography combined with computed tomography (PET/CT) imaging of bone tumors for the practicing radiologist. The clinical roles and utility of (18)F-labeled fluorodeoxyglucose PET/CT in patients with primary bone tumors, osseous metastases, and multiple myeloma are reviewed. The clinical and research data supporting the utility of PET/CT in the evaluation of skeletal malignancies continues to grow.

Objective: We describe the operationalization of the National Institute on Aging–Alzheimer’s Association (NIA-AA) workgroup diagnostic guidelines pertaining to Alzheimer disease (AD) dementia in a large multicenter group of subjects with AD dementia. Methods: Subjects with AD dementia from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) with at least 1 amyloid biomarker (n = 211) were included in this report. Biomarker data from CSF Aβ42, amyloid PET, fluorodeoxyglucose-PET, and MRI were examined. The biomarker results were assessed on a per-patient basis and the subject categorization as defined in the NIA-AA workgroup guidelines was determined. Results: When using a requirement that subjects have a positive amyloid biomarker and single neuronal injury marker having an AD pattern, 87% (48% for both neuronal injury biomarkers) of the subjects could be categorized as “high probability” for AD. Amyloid status of the combined Pittsburgh compound B–PET and CSF results showed an amyloid-negative rate of 10% in the AD group. In the ADNI AD group, 5 of 92 subjects fit the category “dementia unlikely due to AD” when at least one neuronal injury marker was negative. Conclusions: A large proportion of subjects with AD dementia in ADNI may be categorized more definitively as high-probability AD using the proposed biomarker scheme in the NIA-AA criteria. A minority of subjects may be excluded from the diagnosis of AD by using biomarkers in clinically categorized AD subjects. In a well-defined AD dementia population, significant biomarker inconsistency can be seen on a per-patient basis.

OBJECTIVE. Pancreatic cancer continues to have a poor prognosis despite impressive improvements in the outcomes of many other types of cancer, often because most pancreatic neoplasms are found to be unresectable at diagnosis. The purpose of this review is to provide an overview of pancreatic cancer and the role of modern imaging in its diagnosis and management with an emphasis on 18F-FDG PET/CT fusion imaging. CONCLUSION. Multimodality imaging is critical in the diagnosis and management of pancreatic cancer. PET/CT is increasingly viewed as a useful, accurate, and cost-effective modality in diagnosing and managing pancreatic cancer, but further studies are warranted. Early data suggest that contrast-enhanced PET/CT performed with modern PET/CT scanners yields high-resolution anatomic information for surgical and radiotherapeutic planning and functional information for whole-body staging in the care of patients with this disease.

Although an extremely useful technique for sentinel lymph node (SLN) identification in breast cancer, injections of 99mTc-sulfur colloid can be quite painful. The purpose of this study was to determine whether there is a correlation between perceived pain of injection and age, breast density, or timing of topical anesthetic cream administration. Methods: A retrospective review was conducted of women with breast cancer who received injections for sentinel lymphoscintigraphy from 2008 to 2010. After receiving 4 unilateral, intradermal, periareolar injections, women ranked their pain using a comparative scale (0 = no pain; 10 = unbearable pain). There were 3 categories based on length of time that topical anesthetic cream (2.5% lidocaine and 2.5% prilocaine) was applied before injection (1 h prior, 20 min prior, or no cream). In addition, other demographic information and breast density on mammography were analyzed for correlation with the comparative pain scale. Results: Among the 82 women (mean age, 58 y; range, 32–87 y), a wide spectrum on the comparative pain scale was recorded (mean, 4.0; SD, 2.6), with 35% attesting to significant pain, rated 5 or greater. The demographic information and breast density per the Breast Imaging Reporting and Data System were retrospectively reviewed (density: fatty, 14.6%; scattered fibroglandular, 36.6%; heterogeneous, 39.0%; extremely dense, 9.8%). Using bivariate linear regression, no correlation between the comparative pain scale and age (R2 = 0.0029, P = 0.63) or breast density (R2 = 0.00049, P = 0.84) was identified. Most patients had topical anesthetic cream applied 20 min before injection (n = 47, or 57.3%) with 24 (29.3%) having topical anesthetic cream applied 1 h beforehand. Eleven women (13.4%) had no topical anesthetic cream applied because of patient preference or concern about allergy. Again, no correlation was found between comparative pain scale and time of application or use of topical anesthetic cream (Kruskal–Wallis: χ22 = 1.0, P = 0.61). Conclusion: A wide range of pain is experienced with sentinel lymphoscintigraphy injections. In this study, the severity of perceived pain did not correlate with age or breast density. There was no correlation between the use or timing of anesthetic cream and perceived pain from injection. The use of topical anesthetic cream may need to be reexamined, and other means of pain control should be further investigated.

PET-CT and PET-MRI in oncology , PET-CT and PET-MRI in oncology , کتابخانه دیجیتال جندی شاپور اهواز

Objective: To report the phenotypic characterization of monozygotic twins with mutations encoding progranulin (PGRN). Methods: We studied a twin pair with an exon 4 gene deletion in the PGRN gene. Both twins had clinical and neuropsychological examinations as well as structural MRI and fluorodeoxyglucose PET (FDG-PET) scans. PGRN gene sequencing was performed followed by progranulin ELISA in plasma. Results: Both twins manifested symptoms within 3 years of each other, with early behavioral, language, dysexecutive, and memory problems. MRI and FDG-PET imaging demonstrated a strikingly similar topography of findings with clear left hemisphere predominance. Serum progranulin levels in both were well below those from a normal population sample. Conclusions: Compared with the heterogeneity seen in many families with PGRN mutations, these monozygotic twins demonstrated strong clinical, neuroimaging, and serum progranulin level similarities, demonstrating the importance of shared genetic profiles beyond environmental influences in the symptomatic expression of the disease. Neurology (R) 2012;78:1245-1249

The vast majority of PET radiopharmaceuticals today are cyclotron produced. Carbon-11 ( 11 C), Nitrogen-13 ( 13 N), Oxygen-15 ( 15 O) products are created for in-house use only due to their short half-lives. The longer half-life of Fluorine-18 means that 18 F-labeled PET radiotracers can be widely distributed. Production of radiopharmaceuticals is computer-controlled and automated. Automation increases both reliability and efficiency of PET operations while decreasing the radiation dose to the staff. For today, FDG remains the workhorse of oncologic PET imaging. Additional 18 F PET radiotracers directed at a range of molecular processes are being studied and should become available in the future.

Thyroid cancer cells have been shown to take up 99mTc-sestamibi. The role for 99mTc-sestamibi scintigraphy (Tc-MIBI) in the diagnosis of thyroid cancer in patients with primary hyperparathyroidism (PHPT) is unclear. Our aim was to determine whether dual-isotope parathyroid scintigraphy is useful in identifying thyroid cancer. A prospective database of 3,187 patients who underwent neck exploration for PHPT was reviewed to identify patients who had concurrent thyroid resection. Patients with benign and malignant thyroid disease were comparatively analyzed. A total of 470 patients underwent both thyroidectomy and parathyroidectomy (reoperations in 21%). Benign disease (n = 391, 83%) was more common than malignancy [papillary thyroid cancer (n = 75) and medullary thyroid cancer (n = 5); 1 had both]. Dual-isotope scintigraphy obtained in 374 patients (80%) had a sensitivity of 67% and a positive predictive value of 66% for parathyroid adenoma localization in these patients with thyroid disease. False-positive scintigraphy occurred in 22% with benign and 45% with malignant thyroid disease (P = 0.002). On Tc-MIBI imaging, 54 (86%) of 63 patients with malignancy had hot nodules, compared to 248 (81%) of 308 patients with benign disease (P = 0.49). On I-123 imaging, 34 (54%) of 63 patients with malignancy had cold nodules, compared to 42 (14%) of 304 patients with benign disease (P

The kinetic pattern of a 11C-labeled histamine H1 receptor antagonist, [11C]pyrilamine, was investigated in the human brain by factor analysis of dynamic PET studies. Tissue time activity curves were also processed by compartment model curve fitting preceded by deconvolution analysis. Factor analysis revealed two statistically significant and physiologically meaningful kinetic patterns: one for specific and another for nonspecific binding of the radioligand. From these two factors a compartment model containing two tissue compartments (one for specific binding and another for nonspecific binding and free ligand) was constructed. The two-compartment model was also supported by the impulse response function, which was obtained by deconvolution and showed two components. The factor image constructed from factor two demonstrated a distribution pattern characteristic for brain regions rich (frontal, parietal, and temporal lobes) or poor (occipital lobe and cerebellum) in H1 receptors. Blockade of H1 receptors with unlabeled pyrilamine, diphenhydramine, or hydroxyzine caused a significant reduction of this factor. Blockade produced no significant changes in factor one representing nonspecific binding. We conclude that the kinetics of [11C]pyrilamine in the brain can be described by two tissue compartments, one related to the distribution of the H1 receptors. Factor analysis of dynamic studies can be used to locally separate these two compartments, for identification of regions rich and poor in H1 receptors and for noninvasive quantitative investigation of the effects of H1 receptor blockers such as pyrilamine, diphenhydramine, or hydroxyzine. © 1993 Wiley-Liss. Inc.

Scintigraphy with technetium-99m methylene diphosphonate (MDP) delineates a wide spectrum of nonosseous disorders. Neoplastic, hormonal, inflammatory, ischemic, traumatic, excretory, and artifactual entities demonstrate abnormal soft-tissue uptake of Tc-99m MDP. Mechanisms leading to increased extraosseous Tc-99m MDP uptake include extracellular fluid expansion, enhanced regional vascularity and permeability, and elevated tissue calcium concentration. The composition of the calcium deposition and the presence of other metallic ions (eg, iron and magnesium) are important. Soft-tissue Tc-99m MDP uptake is seen in benign (tumoral calcinosis, myositis ossificans) and malignant (sarcomas, adenocarcinomas, metastases) neoplastic entities. Hormonal disturbances in calcium metabolism, especially in hyperparathyroidism, can lead to metastatic calcification, visualized with Tc-99m MDP scintigraphy. Tissue damage from inflammation, infection, or physical trauma results in localized hyperemia, edema, or calcium (and hemosiderin) deposition based on their pathophysiologic characteristics. Urinary tract obstruction, anomalies, or dysfunction are demonstrated by Tc-99m MDP imaging. Common artifacts are related to faulty radiopharmaceutical preparation, Tc-99m MDP administration, and imaging technique. Recognition of these modes of extraskeletal Tc-99m MDP uptake can enhance the diagnostic value of bone scintigraphy.