Biomedical subjects

Einat Even-Sapir

Publications and source records attributed to Einat Even-Sapir.

At least 19 recordsLinked to original sources

PubMed2006

The presentation of malignant tumours and pre-malignant lesions incidentally found on PET-CT.

PURPOSE: The purpose of the study was to determine the general and organ-specific presentation of incidental primary tumours on PET-CT. METHODS: PET-CT reports of 2,360 consecutive patients were reviewed and revealed 156 lesions suspicious for a new unexpected malignancy, in 151 patients. One hundred and twenty of these lesions, in 115 patients, were further assessed, by biopsy (n=84 patients) or by clinical and imaging follow-up (n=31 patients) for a mean of 17+/-4 months (range 12-25 months). RESULTS: Forty-four unexpected malignancies were found in 41 of the study patients (1.7%). Twenty-seven of the 44 incidental tumours were identified on the basis of their location, which was uncommon for metastasis of the known malignancy. Eight were detected as a result of either the difference in FDG avidity of the known malignancy and the incidental lesion or the presence of an incidental non-FDG-avid mass on the CT part of the study. Four tumours were synchronous carcinomas in patients with known colorectal malignancy, three were identified by virtue of the discordant response to treatment compared with the known primary tumour and two were detected as new sites of disease after a prolonged disease-free period. There was organ variability in the positive predictive values (PPV) of PET-CT findings for incidental primary malignancy or pre-malignant lesions: 62% for colonic lesions, 54% for lung lesions and 24% for thyroid lesions. CONCLUSION: Incidental primary tumours may be identified on PET-CT based on their location, FDG avidity, response to therapy and time of appearance. The PET and CT parts of the study appear to complement each other and assist in identification of these incidental tumours.

Adult↗

PubMed2006

Lymphoscintigraphy for sentinel node mapping using a hybrid single photon emission CT (SPECT)/CT system in oral cavity squamous cell carcinoma.

BACKGROUND: We assessed the added clinical value of fused single photon emission computed tomography (SPECT) and low-dose CT images compared with planar images for sentinel node (SN) mapping in patients with oral cavity squamous cell carcinoma (SCC). METHODS: Twenty consecutive patients with newly diagnosed biopsy-proven SCC of the oral cavity were enrolled. Scintigraphy was performed using a hybrid gamma-camera/low-dose CT system. Planar images and fused SPECT/CT images were interpreted separately. All patients underwent a sentinel node biopsy (SNB) followed by a neck dissection. All SNs underwent meticulous pathologic examination and immunohistochemistry staining (cytokeratin complex) in addition to routine pathologic examinations of the neck dissection specimen. RESULTS: The sensitivity for the detection of nodal metastases was 87.5%. SPECT/CT improved SN identification and/or localization compared with planar images in 6 patients (30%). CONCLUSIONS: SPECT/CT SN mapping provides additional preoperative data of clinical relevance to SNB in patients with oral cavity SCC.

Aged↗

PubMed2006

Technetium-99m-MIBI SPECT/CT in primary hyperparathyroidism.

The novel trend toward focused parathyroidectomy requires precise preoperative localization of the parathyroid adenoma in patients with primary hyperparathyroidism (PHPT). The present study evaluated the impact of hybrid single photon emission computed tomography/computed tomography (SPECT/CT), using 99mTc-sestamibi (MIBI), on the surgical management of these patients. In a retrospective study of 36 patients with PHPT, SPECT/CT was undertaken when planar 99mTc-MIBI scintigraphy was negative or when an ill-defined focus in the neck or an ectopic site on planar views was visualized. Imaging data were compared with intraoperative findings, and the incremental value of SPECT/CT to lesion localization and surgical procedure was assessed. Three patients with both negative planar and SPECT/CT studies subsequently underwent bilateral neck exploration, with multiglandular hyperplasia diagnosed in two patients and a parathyroid adenoma in one. Of 33 patients with a positive MIBI study, parathyroid adenoma was confined to the neck in 23 patients and to the lower neck-mediastinum in 10. SPECT/CT facilitated the surgical exploration of all 10 ectopic parathyroid adenomas and 4 of 23 cervical parathyroid adenomas, the latter four either at reexploration or in patients with nonvisualization of the thyroid after thyroidectomy. SPECT/CT contributed to the localization of parathyroid adenomas in patients with PHPT and to planning the surgical exploration in 14 of 36 (39%) patients, predominantly those with ectopic parathyroid adenomas or who had distorted neck anatomy.

Adenoma↗

PubMed2006

Chiral dimethylamine flutamide derivatives--modeling, synthesis, androgen receptor affinities and carbon-11 labeling.

Most prostate cancers are androgen dependent upon initial diagnosis. On the other hand, some very aggressive forms of prostate cancer were shown to have lost the expression of the androgen receptor (AR). Although the AR is routinely targeted in endocrine treatment, the clinical outcome remains suboptimal. Therefore, it is crucial to demonstrate the presence and activity of the AR in each case of prostate cancer, before and after treatment. While noninvasive positron emission tomography (PET) has the potential to determine AR expression of tumor cells in vivo, fully optimized PET imaging agents are not yet available. Based on molecular modeling, three novel derivatives of hydroxyflutamide (Compounds 1-3) were designed and synthesized. They contain an electron-rich group (dimethylamine) located on the methyl moiety, which may confer a better stability to the molecule in vivo. Compounds 1-3 have AR binding that is similar or higher than that of the currently used commercial drugs. An automated carbon-11 radiolabeling route was developed, and the compounds were successfully labeled with a 10-15% decay-corrected radiochemical yield, 99% radiochemical purity and a specific activity of 4Ci/mumol end of bombardment (n=15). These labeled biomarkers may facilitate the future quantitative molecular imaging of AR-positive prostate cancer using PET and may also allow for image-guided treatment of prostate cancer.

Carbon Radioisotopes↗

PubMed2006

Novel imaging techniques in melanoma.

Cutaneous melanoma is one of the most deadly malignancies. Although it accounts for approximately 4% of all cancer cases, it ac-counts for approximately 79% of skin cancer-related deaths. In the past few years, the nuclear medicine platform used in the management of melanoma has extended to biochemical and structural imaging. In clinical practice, integrated positron emission tomography/CT devices allow anatomic and metabolic characterization of meta-static disease in a single study. Similarly, more accurate localization of sentinel nodes in a 3-D space now is feasible with hybrid single photon emission CT/CT system. In translational research, [18F]fluorodeoxyglucose probes have been designed to optimize the detection of melanoma tumor sites in vivo.

Diagnostic Imaging↗

PubMed2006

The role of 18F-FDG PET/CT in the evaluation of solid splenic masses.

18F-Fluorodeoxyglucose-positron emission tomography/computed tomography is a noninvasive imaging modality that appears to have a high negative-predictive value for malignancy in assessing solid splenic masses discovered on conventional imaging modalities. Histological sampling is recommended for fluorodeoxyglucose-avid splenic masses, as the main differential diagnosis includes malignancy, either primary or secondary, or granulomatous disease.

Diagnosis, Differential↗

PubMed2006

18F-FDG PET/CT in the evaluation of adrenal masses.

UNLABELLED: Our purpose was to evaluate the performance of (18)F-FDG PET/CT, using data from both the PET and the unenhanced CT portions of the study, in characterizing adrenal masses in oncology patients. METHODS: One hundred seventy-five adrenal masses in 150 patients referred for (18)F-FDG PET/CT were assessed. Final diagnosis was based on histology (n = 6), imaging follow-up (n = 118) of 6-29 mo (mean, 14 mo), or morphologic imaging criteria (n = 51). Each adrenal mass was characterized by its size; its attenuation on CT, expressed by Hounsfield units (HU); and the intensity of (18)F-FDG uptake, expressed as standardized uptake value (SUV). Receiver operating characteristic curves were drawn to determine the optimal cutoff values of HU and SUV that would best discriminate between benign and malignant masses. RESULTS: When malignant lesions were compared with adenomas, PET data alone using an SUV cutoff of 3.1 yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 98.5%, 92%, 89.3%, 98.9%, respectively. For combined PET/CT data, the sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 98%, 97%, 100%, respectively. Specificity was significantly higher for PET/CT (P < 0.01). Fifty-one of the 175 masses were 1.5 cm or less in diameter. When a cutoff SUV of 3.1 was used for this group, (18)F-FDG PET/CT correctly classified all lesions. CONCLUSION: (18)F-FDG PET/CT improves the performance of (18)F-FDG PET alone in discriminating benign from malignant adrenal lesions in oncology patients.

Adolescent↗

PubMed2006

The detection of bone metastases in patients with high-risk prostate cancer: 99mTc-MDP Planar bone scintigraphy, single- and multi-field-of-view SPECT, 18F-fluoride PET, and 18F-fluoride PET/CT.

UNLABELLED: The aim of this study was to compare the detection of bone metastases by 99mTc-methylene diphosphonate (99mTc-MDP) planar bone scintigraphy (BS), SPECT, 18F-Fluoride PET, and 18F-Fluoride PET/CT in patients with high-risk prostate cancer. METHODS: In a prospective study, BS and 18F-Fluoride PET/CT were performed on the same day in 44 patients with high-risk prostate cancer. In 20 of the latter patients planar BS was followed by single field-of-view (FOV) SPECT and in 24 patients by multi-FOV SPECT of the axial skeleton. Lesions were interpreted separately on each of the 4 modalities as normal, benign, equivocal, or malignant. RESULTS: In patient-based analysis, 23 patients had skeletal metastatic spread (52%) and 21 did not. Categorizing equivocal and malignant interpretation as suggestive for malignancy, the sensitivity, specificity, positive predictive value, and negative predictive value of planar BS were 70%, 57%, 64%, and 55%, respectively, of multi-FOV SPECT were 92%, 82%, 86%, and 90%, of (18)F-Fluoride PET were 100%, 62%, 74%, and 100%, and of 18F-Fluoride PET/CT were 100% for all parameters. Using the McNemar test, 18F-Fluoride PET/CT was statistically more sensitive and more specific than planar or SPECT BS (P < 0.05) and more specific than 18F-Fluoride PET (P < 0.001). SPECT was statistically more sensitive and more specific than planar BS (P < 0.05) but was less sensitive than 18F-Fluoride PET (P < 0.05). In lesion-based analysis, 156 lesions with increased uptake of 18F-Fluoride were assessed. Based on the corresponding appearance on CT, lesions were categorized by PET/CT as benign (n = 99), osteoblastic metastasis (n = 46), or equivocal when CT was normal (n = 11). Of the 156 18F-Fluoride lesions, 81 lesions (52%), including 34 metastases, were overlooked with normal appearance on planar BS. SPECT identified 62% of the lesions overlooked by planar BS. 18F-Fluoride PET/CT was more sensitive and more specific than BS (P < 0.001) and more specific than PET alone (P < 0.001). CONCLUSION: 18F-Fluoride PET/CT is a highly sensitive and specific modality for detection of bone metastases in patients with high-risk prostate cancer. It is more specific than 18F-Fluoride PET alone and more sensitive and specific than planar and SPECT BS. Detection of bone metastases is improved by SPECT compared with planar BS and by 18F-Fluoride PET compared with SPECT. This added value of 18F-Fluoride PET/CT may beneficially impact the clinical management of patients with high-risk prostate cancer.

Aged↗

PubMed2006

Role of nuclear medicine in the management of cutaneous malignant melanoma.

Malignant melanoma of the skin is one of the most lethal cancers. The disease may spread either locally or regionally and to distant sites through predictable or unpredictable metastatic pathways. Accurate staging and restaging of disease are required for appropriate treatment decision making. Routine protocols based on clinical examinations and traditional radiologic evaluations are not cost-effective for the detection of systemic disease. In the last decade, nuclear medicine techniques, such as lymphoscintigraphy-directed lymphatic mapping and sentinel lymphadenectomy and (18)F-FDG PET, have played key roles in nodal and distant staging of melanoma. More recently, anatomic-functional imaging has been improved with the development of integrated PET/CT devices or combined SPECT/CT systems. (18)F-FDG-sensitive intraoperative probes have been specifically designed to detect small nodal and visceral metastases from melanoma and may become important tools for the cancer surgeon. In this article, we review the role of nuclear medicine in the assessment of malignant melanoma.

Humans↗

PubMed2005

Prostate cancer PET bioprobes: synthesis of [18F]-radiolabeled hydroxyflutamide derivatives.

Approximately 80-90% of prostate cancers are androgen dependent at initial diagnosis. The androgen receptor (AR) is present in most advanced prostate cancer specimens and is believed to have a critical role in its development. Today, treatment of prostate cancer is done by inhibition of AR using antiandrogens such as flutamide (pro-drug of hydroxyflutamide), nilutamide, and bicalutamide. However, there is currently no noninvasive imaging modalities to detect, guide, and monitor specific treatment of AR-positive prostate cancer. (R)-3-Bromo-N-(4-fluoro-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methyl-propanamide [18F]-1 and N-(4-fluoro-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide [18F]-2, derivatives of hydroxyflutamide, were synthesized as a fluorine-containing imaging agent candidates. A three-step fluorine-18 radiosynthesis route was developed, and the compounds were successfully labeled with a 10+/-3% decay corrected radiochemical yield, 95% radiochemical purity, and a specific activity of 1500+/-200 Ci/mmol end of bombardment (n = 10). These labeled biprobes not only may enable for the future quantitative molecular imaging of AR-positive prostate cancer using positron emission tomography but may also allow for image-guided treatment of prostate cancer.

Androgen Antagonists↗

PubMed2005

Assessment of neurolymphomatosis by brachial plexus biopsy and PET/CT. Report of a case.

OBJECTIVE: To report a biopsy-proven neurolymphomatosis in a young woman with previous non-Hodgkin's lymphoma (NHL) of uterine cervix. PATIENT: The patient presented with a painful brachial plexopathy and developed multiple cranial and spinal nerve palsies. METHODS AND RESULTS: The diagnosis was achieved by an open brachial plexus biopsy. A PET/CT study was used to assess the full extent of the disease and showed involvement of additional cranial nerves and spinal nerve roots. A complete although short lasting clinical and radiological response was achieved by means of systemic high dose methotrexate treatment combined with rituximab and intra-CSF injections of cytarabine.

Adult↗

PubMed2005

Differentiation between malignant and benign pleural effusion in patients with extra-pleural primary malignancies: assessment with positron emission tomography-computed tomography.

OBJECTIVES: We sought to define an accurate diagnostic approach for differentiating benign from malignant pleural effusion on positron emission tomography-computed tomography (PET-CT). MATERIAL AND METHODS: PET-CT studies of 31 patients with primary extrapleural malignancy and pleural effusion were reviewed retrospectively. CT parameters assessed were size and density (Hounsfield units, or HU) of the effusion and density (HU) and morphology of any solid pleural abnormality. Interpretation of PET data included review of the attenuation-corrected and nonattenuation-corrected images. RESULTS: PET-CT parameters that were found to be significant in identifying malignant pleural effusion included focal increased uptake of 18-fluorodeoxyglucose in the pleura (P<0.0001) and the presence of solid pleural abnormalities on CT (P<0.002): the sensitivity was 86% and 71%, respectively, and the specificity was 90% for each of the 2 parameters. A PET-CT pattern composed of pleural uptake and increased effusion activity on nonattenuation-corrected images was associated with sensitivity of 95%, specificity of 80%, positive predictive value of 91%, negative predictive value of 89%, and accuracy of 90%. CONCLUSIONS: On PET-CT, the presence of concomitant pleural abnormalities is the most accurate criterion in determining the malignant nature of pleural effusion.

Adult↗

PubMed2005

PET-CT imaging of combined brachial and lumbosacral neurolymphomatosis.

Neurolymphomatosis is a rare manifestation of progressive non-Hodgkin's lymphoma. A 44-yr-old man with diffuse large B-cell lymphoma presented with unilateral progressive peripheral sensorimotor neuropathy after the 7th cycle of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) therapy. No pathology in the nervous system was evident by computerized tomography (CT), magnetic resonance imaging (MRI) of the head, spinal axis and plexuses and by repeated analysis of cerebrospinal fluid. However, the hybrid modality of positron emission tomography (PET) of fluorinated deoxyglucose (FDG) combined with CT scan (PET-CT) showed unilateral involvement of both the brachial and lumbosacral nervous plexuses. A complete recovery of neurological manifestations and normalization of PET-CT followed intensive chemotherapy with autologous stem cell transplantation. The diagnosis and localization of neurolymphomatosis may be supported by PET-CT imaging.

Adult↗

PubMed2005

Solid splenic masses: evaluation with 18F-FDG PET/CT.

UNLABELLED: Our objective was to assess the role of (18)F-FDG PET/CT in the evaluation of solid splenic masses in patients with a known malignancy and in incidentally found lesions in patients without known malignancy. METHODS: Two groups of patients were assessed: (a) 68 patients with known malignancy and a focal lesion on PET or a solid mass on CT portions of the PET/CT study; and (b) 20 patients with solid splenic masses on conventional imaging without known malignancy. The standard of reference was histology (n = 16) or imaging and clinical follow-up (n = 72). The lesion size, the presence of a single versus multiple splenic lesions, and the intensity of (18)F-FDG uptake expressed as a standardized uptake value (SUV) were recorded. The ratio of the SUV in the splenic lesion to the background normal splenic uptake was also calculated. These parameters were compared between benign and malignant lesions within each of the 2 groups of patients and between the 2 groups. RESULTS: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of (18)F-FDG PET/CT in differentiating benign from malignant solid splenic lesions in patients with and without malignant disease were 100%, 100%, 100%, and 100% versus 100%, 83%, 80%, and 100%, respectively. In patients with known malignant disease, an SUV threshold of 2.3 correctly differentiated benign from malignant lesions with the sensitivity, specificity, PPV, and NPV of 100%, 100%, 100%, and 100%, respectively. In patients without known malignant disease, false-positive results were due to granulomatous diseases (n = 2). CONCLUSION: (18)F-FDG PET can reliably discriminate between benign and malignant solid splenic masses in patients with known (18)F-FDG-avid malignancy. It also appears to have a high NPV in patients with solid splenic masses, without known malignant disease. (18)F-FDG-avid splenic masses in patients without a known malignancy should be further evaluated as, in our series, 80% of them were malignant.

Adolescent↗

PubMed2005

Imaging of malignant bone involvement by morphologic, scintigraphic, and hybrid modalities.

Detection of bone involvement is essential for optimal therapy of oncologic patients. The purpose of imaging is to identify early bone involvement, to determine the full extent of the skeletal disease, to assess the presence of accompanying complications-such as fractures and cord compression-and to monitor response to therapy. Detection of bone involvement by various imaging modalities is based on either direct visualization of tumor infiltration or detection of the reaction of bone to the malignant process. MRI can identify early involvement of bone marrow. CT, which depends mainly on bone destruction, provides detailed bone morphology. In nuclear medicine, uptake of (18)F-FDG is directly into tumor cells, thus allowing for early detection and monitoring the response to therapy of tumor sites in the marrow, bone, and soft tissue, whereas increased uptake of (18)F-fluoride and (99m)Tc-methylene diphosphonate reflects the osteoblastic reaction of bone to the presence of tumor cells. The hybrid techniques SPECT/CT and PET/CT, recently introduced into clinical practice, provide a better anatomic localization of scintigraphic findings and may improve the diagnostic accuracy of SPECT and PET in detecting malignant bone involvement. The current review discusses the basis for the detection of malignant bone involvement by various morphologic and scintigraphic imaging modalities and the advantages and the limitations of each. Special emphasize is placed on the newer integrated technique of PET/CT. The role of imaging in identifying bone involvement in different malignant diseases is also discussed.

Bone Neoplasms↗

PubMed2004

Detection of recurrence in patients with rectal cancer: PET/CT after abdominoperineal or anterior resection.

PURPOSE: To assess diagnostic accuracy of combined positron emission tomography (PET) and computed tomography (CT) in detection of pelvic recurrence in patients with rectal cancer who underwent abdominoperineal or anterior resection. MATERIALS AND METHODS: Sixty-two patients were enrolled; 37 were men, and 25 were women. Seventeen patients underwent abdominoperineal resection and 45 underwent anterior resection with an anastomosis in the pelvic region before referral for PET/CT. Pelvic sites of fluorine 18 ((18)F) fluorodeoxyglucose (FDG) uptake were rated separately on PET and PET/CT images as benign or malignant on the basis of shape, location, and intensity of (18)F FDG uptake (1-2 = benign and/or physiologic, 3 = equivocal, 4-5 = malignant). Two readers interpreted images in consensus. Altered pelvic anatomy and presence of presacral abnormalities were assessed with CT. Pelvic recurrence was confirmed with histologic analysis or clinical and imaging follow-up. Sensitivity, specificity, positive and negative predictive values, and accuracy of PET and PET/CT in the detection of pelvic recurrence were compared with lesion- and patient-based analyses by using the chi(2) test. Clinical relevance of PET/CT assessment was determined. RESULTS: Of 81 pelvic sites with increased (18)F FDG uptake, 44 were malignant. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for differentiating malignant from benign (18)F FDG uptake in the pelvis were 98%, 96%, 90%, 97%, and 93% for PET/CT and 82%, 65%, 73%, 75%, and 74% for PET, respectively. The most common cause for false-positive interpretation of PET findings was physiologic (18)F FDG uptake in displaced pelvic organs. Presacral CT abnormalities were present in 30 (48%) of 62 patients, and seven (23%) abnormalities were malignant. PET/CT was used to distinguish benign and malignant presacral abnormalities with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 96%, 88%, and 100%, respectively. PET/CT findings were clinically relevant in 29 (47%) of 62 patients. CONCLUSION: PET/CT is an accurate technique in the detection of pelvic recurrence after surgical removal of rectal cancer.

Adult↗

PubMed2004

The diagnostic accuracy of 18F-fluorodeoxyglucose PET/CT in patients with gynecological malignancies.

OBJECTIVE: To evaluate the diagnostic accuracy of integrated positron emission tomography/computerized tomography (PET/CT) in patients with gynecological cancer. METHODS: Fifty-three consecutive patients with gynecologic malignancies were included. The patients were referred to our tertiary center to undergo a PET/CT scan. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PET/CT were compared with the conventional imaging assessments [CT, magnetic resonance imaging (MRI) and ultrasonography (US)]. RESULTS: All tested values were higher for PET/CT than those for the conventional modalities: sensitivity 0.97 vs. 0.40, specificity 0.94 vs. 0.65, PPV 0.97 vs. 0.70, and NPV 0.94 vs. 0.34, respectively. CONCLUSION: PET/CT is a reliable modality for assessing the extent of disease in patients with gynecologic malignancy.

Adult↗

PubMed2004

The clinical impact of camera-based positron emission tomography imaging in patients with recurrent colorectal cancer.

RATIONALE AND OBJECTIVES: F18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) studies have clinical value in suspected recurrent or metastatic colorectal cancer cases. Because this modality is not accessible for many patients, a camera-based FDG (CB-FDG) coincidence imaging was suggested as an alternative. Although inferior in resolution to a dedicated PET system, it can make FDG studies available to more patients. We assessed the clinical value of CB-FDG in patients with recurrent colorectal cancer. METHODS: The disease stage and treatment approach in 83 patients were twice determined by an oncologist and a surgeon, first based on the patient's records and blind to CB-FDG findings and then with the inclusion of FDG results in the decision-making analysis. RESULTS: On a lesion-based analysis, the sensitivity of CB-FDG was 95% and the specificity was 81% compared with 88% and 64%, respectively, for computed tomography. Adding FDG findings led to disease-stage alteration in 47 patients (57%), upstaging in 35 (42%), and downstaging in 12 (15%). FDG localized the tumor sites in 21 of 26 patients (81%) with suspected clinical recurrence and a negative conventional imaging workup. In 8 patients, FDG ruled out viable tumor tissue suggested by other modalities. The oncologist's suggested treatment approach was altered in 54% of the patients and the surgeon altered the decision on operability in 28%. CONCLUSION: CB-FDG assessment has clinical value for both staging and selecting treatment in patients with recurrent colorectal cancer and can be considered an alternative to an nonaccessible dedicated PET system.

Adult↗