Papers by Dimitrios Karantanis
Τα ευρήματα των μελετών της συγκεκριμένης διατριβής, είναι υπέρ της θεωρίας, η οποία έχει διερευν... more Τα ευρήματα των μελετών της συγκεκριμένης διατριβής, είναι υπέρ της θεωρίας, η οποία έχει διερευνηθεί μόνο στους πιο συχνά συναντόμενους τύπους NHL, ότι η FDG-PET είναι χρήσιμη και ευαίσθητη εξέταση για τα λεμφώματα. Επιβεβαιώνεται στις περισσότερες περιπτώσεις, για πρώτη φορά σε σειρά ασθενών, ότι η συμβολή της FDG-PET στην αντιμετώπιση ασθενών με τους μελετηθέντες σπάνιους τύπους NHL είναι σημαντική. Συνολικά μελετήθηκαν 50 ασθενείς με πρωτοπαθές λέμφωμα του ΚΝΣ, λέμφωμα Burkitt’s και NK/T-cell λέμφωμα και 120 εξετάσεις PET αυτών των ασθενών. Το 18F-FDG συγκεντρώνονταν ζωηρά στις βλάβες, δίνοντας υψηλές τιμές SUV στις θετικές περιοχές. Η ευαισθησία για τον εντοπισμό ενεργού νόσου ήταν πολύ μεγάλη, όπως το ίδιο και η ειδικότητα. Η σταδιοποίηση και η διερεύνηση για υποτροπή με FDG-PET ήταν έγκυρες. Οι αρνητικές σε ευρήματα εξετάσεις με FDG-PET έδειξαν ότι αποκλείουν με αρκετά μεγάλη σιγουριά την πιθανότητα ύπαρξης ενεργού νόσου, εκτός από την περίπτωση οφθαλμικής νόσου στο λέμφωμα τ...
Nuclear Medicine Communications, 2007
To determine the value of F-FDG PET/CT in the different manifestations of primary central nervous... more To determine the value of F-FDG PET/CT in the different manifestations of primary central nervous system lymphoma (PCNSL) in HIV-negative patients. All PCNSL and HIV-negative patients referred for PET/CT in our institution from July 2001 to June 2006 were retrospectively studied. PET/CT examinations were reviewed by two experienced readers and evaluated for each possible anatomical site of nervous system involvement: cerebral, spinal/nerve and ocular. PET/CT results were characterized as true positive or negative and false positive or negative according to the status of the disease, which was determined after the evaluation of biopsies, laboratory, clinical and imaging examinations, and follow-up. Forty-two PET/CT examinations were carried out in 25 PCNSL patients. For intracerebral disease, PET/CT was true positive in 13 cases, true negative in 27 and false negative in two. For disease involving spinal cord and/or nerves, PET/CT was true positive in four cases, true negative in 37 and false negative in one. For ocular disease, PET was true positive in only one case and false negative in four. The sensitivity of PET/CT in detecting active disease in the brain was 87% (13/15), in the spine/nerves 80% (4/5), and in the eyes only 20% (1/5). PET/CT seems to be sensitive for the detection of viable intracerebral as well as for spinal and peripheral nerve disease, but not for the detection of ocular involvement.
Nuclear Medicine Communications, 2007
To determine if quantification of [18F]fluorodeoxyglucose (18F-FDG) uptake in a thyroid nodule fo... more To determine if quantification of [18F]fluorodeoxyglucose (18F-FDG) uptake in a thyroid nodule found incidentally on whole-body 18F-FDG positron emission tomography-computed tomography (PET-CT) can be used to discriminate between malignant and benign aetiology. A retrospective review of all patients with focally high uptake in the thyroid as an incidental finding on 18F-FDG PET-CT from May 2003 through May 2006. The uptake in the nodules was quantified using the maximum standardized uptake value (SUVmax). The aetiology was determined by cytology and/or ultrasound, or on histopathology. Incidental focally high uptake was found in 79/7347 patients (1.1%). In 31/48 patients with adequate follow-up, a benign aetiology was determined. Median SUVmax for the benign group was 5.6, range 2.5-53. Malignancy was confirmed in 15/48 patients. The malignancies were papillary thyroid carcinoma in 12, metastasis from squamous cell carcinoma in one, and lymphoma in two. Median SUVmax for the malignant lesions was 6.4, range 3.5-16. Cytology suspicious for follicular carcinoma was found in 2/48 patients. No statistical difference (P=0.12) was found among the SUVmax between the benign and malignant groups. Focally high uptake of 18F-FDG in the thyroid as an incidental finding occurred in 1.1% of the patients. Malignancy was confirmed or was suspicious in 17/48 (35%) of the patients that had adequate follow-up. There was no significant difference in the SUVmax between benign and malignant nodules.
Journal of Thoracic Oncology, 2007
Journal of Nuclear Medicine, 2007
Our purpose was to determine the clinical significance of diffusely increased 18 F-FDG uptake in ... more Our purpose was to determine the clinical significance of diffusely increased 18 F-FDG uptake in the thyroid gland as an incidental finding on PET/CT. Methods: All patients who were found to have diffuse thyroid uptake on 18 F-FDG PET/CT in our institution between November 2004 and June 2006 were investigated and compared with an age-and sex-matched control group. The 18 F-FDG uptake in the thyroid was semiquantified using maximum standardized uptake value and correlated to the available serum thyroid-stimulating hormone (TSH) and thyroid peroxidase (TPO) antibody levels using regression analysis. Results: Of the 4,732 patients, 138 (2.9%) had diffuse thyroid uptake. Clinical information was available for 133 of the 138 patients. Sixty-three (47.4%) had a prior diagnosis of hypothyroidism or autoimmune thyroiditis, of whom 56 were receiving thyroxine therapy. In the control group, consisting of 133 patients with no thyroid uptake, there were 13 (9.8%) with a prior diagnosis of hypothyroidism, 11 of whom were receiving thyroxine therapy. In the study group, 38 (28.6%) of 133 patients did not undergo any further investigation for thyroid disease, whereas 32 (24.1%) of 133 patients were examined for thyroid disease after PET. Nineteen were found with autoimmune thyroiditis or hypothyroidism, and replacement therapy was initiated in 12. No significant correlation was found between maximum standardized uptake value and TSH (P 5 0.09) or TPO antibody (P 5 0.68) levels. Conclusion: The incidental finding of increased 18 F-FDG uptake in the thyroid gland is associated with chronic lymphocytic (Hashimoto's) thyroiditis and does not seem to be affected by thyroid hormone therapy. SUV correlated neither with the degree of hypothyroidism nor with the titer of TPO antibodies.
Clinical Nuclear Medicine, 2007
Primary central nervous system lymphoma (PCNSL) accounts for approximately 3% of all primary brai... more 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. 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. 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. 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.
American Journal of Roentgenology, 2012
CME SAM OBJECTIVE. Pancreatic cancer continues to have a poor prognosis despite impressive improv... more CME SAM 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 18 F-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.
European Journal of Radiology, 2010
Aims: (1) To perform a comprehensive analysis of the time elapsed between the last G-CSF injectio... more Aims: (1) To perform a comprehensive analysis of the time elapsed between the last G-CSF injection and the PET/ CT examination on the biodistribution of 18 F-FDG, with emphasis on liver, spleen, and bone marrow uptake, and (2) to investigate whether an inversion of the liver to spleen ratio affects the Deauville scoring. Materials and methods: Retrospectively included were 74 consecutive diffuse large B cell lymphoma (DLBCL) patients referred for baseline and interim examinations and receiving immunochemotherapy with various G-CSF regimens. A comprehensive evaluation considering baseline metabolic active tumour volume (MATV), factors affecting liver uptake, the type of G-CSF, and the time elapsed between chemotherapy/G-CSF and interim PET/CTs was performed. Results: Mean (± SD) percentage variations between baseline and interim PET/CTs (i-PET/CT) for bone marrow (%Variation_ BONE), liver (%Variation_ LIVER) and spleen (%Variation_ SPLEEN) were equal to 32.0 ± 46.9%, 16.1 ± 42.8%, and 10.6 ± 51.1 %, respectively. %Variation_ LIVER and %Variation_ SPLEEN were higher in patients using lenograstim, but this was linked to lower uptakes at baseline and was therefore likely not due to G-CSF itself. The mean delay between G-CSF injection and i-PET/CT acquisition was not an independent explanatory variable for %Variation_ BONE , %Variation_ LIVER , and %Variation_ SPLEEN. On the contrary, %Variation_ BONE and %Variation_ SPLEEN were negatively correlated to the time-lapse between the end of chemotherapy and i-PET/CT: ρ = − 0.342 (p = 0.010) and ρ = − 0.529 (p < 0.0001), respectively. Patients with a time-lapse since the last injection of chemotherapy < 17 days displayed higher bone and spleen SUVmax EARL. %Variation_ LIVER was positively correlated to baseline MATV: ρ = 0.243 (p = 0.039). Patients displaying a high baseline MATV ≥ 177 cc had significantly lower liver SUVmax EARL at baseline. This difference was no longer observed at i-PET/CT, after tumours had shrunk. Conclusions: Neither the type of G-CSF used nor the time elapsed between its last injection and i-PET/CT examination independently influences bone, hepatic, or splenic uptakes at i-PET/CT. The major determinant for the occurrence of a bone or spleen hypermetabolism on i-PET/CT is the time elapsed between the chemotherapy and the examination, which should be maintained above 15 days. Inversion of the liver to spleen ratio appeared to be due to increased spleen hypermetabolism on i-PET/CT, making unlikely an impact on the Deauville scoring.
Hellenic journal of nuclear medicine, 2012
Positron emission tomography (PET)/computed tomography (CT)-subsequently referred to as PET/CT is... more Positron emission tomography (PET)/computed tomography (CT)-subsequently referred to as PET/CT is emerging as a critically important diagnostic tool in oncology. There has been a substantial increase in the utilization of this modality over the last decade. The optimal imaging protocols are, however, still not established which results in considerable confusion and uncertainty among referring physicians and providers. Oncologists, hematologists and other physicians managing oncologic patients frequently face the dilemma of whether or not to order a PET/CT scan for their patients. The large body of evidence from clinical research often overwhelms the ability of physicians to stay adequately informed on the disease specific performance of PET/CT. Moreover, regulatory agencies have changed their requirements for reimbursement of PET/CT scans in an effort to curtail health care expenditures. In this article we attempt to inform users and providers about the appropriate use of this techn...
Molecular Imaging and Biology, 2010
Purpose: To explore the prognostic value of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emissi... more Purpose: To explore the prognostic value of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography (PET) in patients with suspected residual or recurrent medullary thyroid carcinoma (MTC). Procedures: This retrospective study included all patients with MTC examined with FDG-PET at Mayo Clinic, Rochester, Minnesota, from October 1999 to March 2008. The PET results were compared with other imaging studies and clinical findings, including carcinoembryonic antigen and calcitonin levels. Results: Twenty-nine patients with MTC were included. PET was positive in 14 patients, with follow-up information for 11; six died from metastatic disease, four had disease progression, and one remained in stable condition. PET was negative in 15 patients, with follow-up for 12; one had recurrent disease, and 11 had no evidence of clinical disease. Calcitonin doubling time was shorter for PET-positive than for PET-negative patients. Conclusion: FDG-PET has high prognostic value in patients with suspected residual or recurrent MTC.
Society of Nuclear Medicine Annual Meeting Abstracts, May 1, 2011
Society of Nuclear Medicine Annual Meeting Abstracts, May 1, 2006
Nuclear Medicine and Molecular Imaging, 2016
A 63-year-old male with a recently diagnosed right lung lesion was referred for staging. F-FDG PE... more A 63-year-old male with a recently diagnosed right lung lesion was referred for staging. F-FDG PET/CT scan revealed a hypodense, cystic-like mass in the right upper lung lobe, which demonstrated low, diffuseF-FDG uptake, likely due to the presence of mucus, as well as intensely hypermetabolic right hilar and right paratracheal lymph nodes. Transbronchial biopsy revealed a primary pulmonary mucinous cystadenocarcinoma with the presence of signet ring cell carcinoma, a co-existence of two rare variants of lung adenocarcinoma. This case report demonstrates the metabolic phenotype along with the radiographic characteristics of this rare tumor and its metastases.
PURPOSE/AIM The purpose of this exhibit is: 1. To review the lymphatic drainage of the breast, em... more PURPOSE/AIM The purpose of this exhibit is: 1. To review the lymphatic drainage of the breast, emphasizing both anatomy and physiology 2. To illustrate, compare and contrast the imaging techniques which can evaluate nodal disease in breast cancer patients 3. To demonstrate the complementary value of both anatomic and functional imaging CONTENT ORGANIZATION I. Lymphatic drainage of the breast A. Anatomy B. Physiology and pathophysiology C. Current staging II. Nodal imaging A. Anatomic: CT, MR and US B. Functional: sentinel node, PET/CT III. Nodal metastasis A. Axillary B. Extra-axillary SUMMARY The major teaching points of this exhibit are: 1. Understanding the physiology and anatomy of the breast's lymphatic drainage is crucial for radiologists. 2. Multiple imaging techniques play an important role in the nodal staging of breast cancer patients. 3. Detection of nodal metastasis is an important and adverse prognostic indicator for breast cancer patients.
Hellenic journal of nuclear medicine
Positron emission tomography (PET)/computed tomography (CT)-subsequently referred to as PET/CT is... more Positron emission tomography (PET)/computed tomography (CT)-subsequently referred to as PET/CT is emerging as a critically important diagnostic tool in oncology. There has been a substantial increase in the utilization of this modality over the last decade. The optimal imaging protocols are, however, still not established which results in considerable confusion and uncertainty among referring physicians and providers. Oncologists, hematologists and other physicians managing oncologic patients frequently face the dilemma of whether or not to order a PET/CT scan for their patients. The large body of evidence from clinical research often overwhelms the ability of physicians to stay adequately informed on the disease specific performance of PET/CT. Moreover, regulatory agencies have changed their requirements for reimbursement of PET/CT scans in an effort to curtail health care expenditures. In this article we attempt to inform users and providers about the appropriate use of this techn...
Journal of Nuclear Medicine, 2014
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Papers by Dimitrios Karantanis