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Ora Israel

Publications and source records attributed to Ora Israel.

At least 37 records · Page 2Linked to original sources
PubMed2005

PET/CT detection of unexpected gastrointestinal foci of 18F-FDG uptake: incidence, localization patterns, and clinical significance.

UNLABELLED: Precise PET/CT localization of focal (18)F-FDG uptake in the gastrointestinal tract (GIT) may exclude malignancy in sites of physiologic activity but may also induce false-negative reports for malignant or premalignant lesions. The purpose of the present study was to retrospectively evaluate the nature and significance of unexpected focal (18)F-FDG uptake localized by PET/CT within the GIT. METHODS: The files of 4,390 patients referred for (18)F-FDG PET/CT were retrospectively reviewed. The incidence of studies showing unexpected focal uptake of (18)F-FDG localized by PET/CT to the GIT was determined. The position of these foci along the GIT and their intensity were recorded. The etiology of the findings was confirmed histologically or by long-term follow-up. RESULTS: Unexpected focal (18)F-FDG uptake in the GIT was found in 58 patients (1.3%). Follow-up data were available for 34 of these patients, including 4 with sites in the stomach, 2 in the small bowel, and 28 in the colon. GIT-related disease was confirmed in 24 patients (71%). There were 11 malignant tumors, 9 premalignant lesions, and 4 benign processes including 2 benign polyps, 1 case of active gastritis, and 1 abscess of the sigmoid. Ten patients (29%) had no further evidence of GIT abnormality, and the suggestive sites were considered to be physiologic uptake. Maximal standardized uptake value was 17.3 +/- 10.2 in malignant lesions, 14.0 +/- 10.5 in premalignant lesions, 18.0 +/- 12.1 in benign lesions, and 11.1 +/- 7.4 in foci of physiologic (18)F-FDG uptake in the GIT, with no statistically significant difference among the 4 subgroups. CONCLUSION: Incidental focal (18)F-FDG uptake localized by PET/CT within the GIT is of clinical significance in most patients. These findings should be followed up with appropriate invasive procedures guided by hybrid imaging results.

Adult↗
PubMed2004

Efficacy of I131 ablation therapy using different doses as determined by postoperative thyroid scan uptake in patients with differentiated thyroid cancer.

PURPOSE: The optimal dose of I(131) for ablation of functioning residual thyroid tissue after surgery is controversial. The current study was conducted to determine the optimal dose of I(131) for remnant postoperative ablation. A review of the literature is included. METHODS AND MATERIALS: A total of 238 patients with papillary and follicular carcinoma were treated with I(131) for ablation of a postoperative thyroid remnant. The I(131) dose was based on the 24-h percentage of neck uptake in the postoperative thyroid scans. Patients with < 5% uptake received a median of 85 mCi; 6-10% uptake, a median of 80 mCi; 11-15% uptake, a median of 60 mCi; 16-20% uptake, a median of 50 mCi; and > or =21% uptake, a median of 30 mCi. The ablation results were compared with the prognostic factors. RESULTS: Complete ablation was observed in 40 (92%) of 43 patients receiving 85 mCi, in 31 (94%) of 33 who received 80 mCi, in 39 (95%) of 41 who received 60 mCi, in 51 (93%) of 55 who received 50 mCi, in 37 (94%) of 39 who received 30 mCi, and in 18 (96%) of 19 who received 30 mCi. The overall successful ablation rate was 94% (95% confidence interval, 89-100%). CONCLUSION: Our findings suggest that patients with differentiated thyroid cancer can be treated with doses of I(131) according to the percentage of neck uptake of postoperative total body scan, with high complete ablation rates, without exposing patients to higher dose levels of I(131).

Adolescent↗
PubMed2004

Non-malignant FDG uptake in infradiaphragmatic adipose tissue: a new site of physiological tracer biodistribution characterised by PET/CT.

The purpose of this study was to characterise a benign pattern of infradiaphragmatic 18F-fluorodeoxyglucose (FDG) uptake in cancer patients using PET/CT. Infradiaphragmatic foci of FDG uptake, localised by PET/CT in regions of normal fat tissues, were demonstrated, in conjunction with fatty uptake in the neck and shoulders, in 9 of 1,241 (0.7%) patients. The imaging and clinical characteristics of this pattern and its possible clinical significance were assessed. PET/CT precisely localised infradiaphragmatic fat uptake (IDFU) within normal retroperitoneal fatty tissue of the perirenal space (nine patients) and in the paracolic or parahepatic space (four patients). Perirenal uptake was bilateral in five patients and focal in six. Paracolic and parahepatic uptake was bilateral in three patients and linear in all four patients. There was no evidence of malignancy at any of the sites during a follow-up period of 9-21 months. IDFU was significantly more prevalent in young patients assessed for monitoring response to therapy, and was always associated with the benign supradiaphragmatic uptake pattern, although its prevalence was significantly lower. There were no significant differences between the clinical characteristics of these two patterns of benign fatty FDG uptake. It is concluded that PET/CT allows for precise identification of increased FDG uptake in abdominal fatty tissue and further exclusion of disease at such sites. This benign uptake may represent increased glucose consumption in activated brown adipose tissue, similar to the mechanism suggested for supradiaphragmatic uptake. Recognition of this benign IDFU pattern is important for correct interpretation of abdominal PET findings in cancer patients.

Abdominal Neoplasms↗
PubMed2004

Positron emission tomography in the evaluation of lymphoma.

Positron emission tomography (PET) using (18)F-fluoro-deoxyglucose (FDG) has emerged in recent years as an important tool for the evaluation of lymphoma patients during their course of disease. At diagnosis, FDG imaging is capable of detecting nodal and extra nodal sites of disease and provides accurate staging. FDG-PET is superior to computed tomography, during and at the end of first-line treatment or salvage therapeutic regimens, as a tool for monitoring therapeutic response. PET enables the differential diagnosis of residual viable tumor versus a remnant fibrotic or necrotic mass. PET also provides prognostic data of high clinical significance for both Hodgkin's disease and non-Hodgkin's lymphoma. Results of this metabolic imaging modality, interpreted in view of the pretherapy risk profile of the individual patient, are predictive of the immediate success of a certain therapeutic strategy, as well as of overall and disease-free survival. PET appears to play also an important role in the detection of lymphoma relapse. Data comparing (67)Gallium scintigraphy and FDG-PET indicate the latter as the functional imaging modality of choice for assessment of lymphoma patients. Preliminary studies show an additional value of fused PET/computed tomography imaging for further improved diagnosis, staging and definition of status of lymphoma.

Citrates↗
PubMed2004

Effects of tamoxifen on bone mineral density and metabolism in postmenopausal women with early-stage breast cancer.

At the present time, tamoxifen is the most widely used anti-estrogen for adjuvant therapy and metastatic disease in postmenopausal women with breast cancer, a population at high risk for osteoporosis. This prospective study was designed to evaluate the effect of adjuvant tamoxifen on bone mineral density and all biochemical markers concomitantly in women with early-stage breast cancer in one study. Using dual-energy X-ray absorptiometry, prior to and 12 mo after tamoxifen treatment, bone mineral density in lumbar spine and femoral neck was measured in 44 women with T1-T2N0M0 estrogen-receptor-positive breast cancer receiving adjuvant treatment with tamoxifen 20 mg/d. Biomarkers that can affect bone mineral metabolism were measured before and after 3 and 12 mo of tamoxifen treatment. Bone mineral density was minimally increased in lumbar spine and femoral neck after 12 mo treatment with tamoxifen (p = 0.79 and 0.55, respectively). No differences were found in serum levels of calcium, phosphate, creatinine, ALAT, albumin, LDH, calcitonin, or estradiol. A significant decrease in osteocalcin levels was found after 3 and 12 mo (p < or = 0.01). TSH and PTH levels were increased (p < or = 0.05) after 3 mo, returning to baseline after 12 mo. In conclusion, tamoxifen has an estrogen-like effect on bone metabolism in postmenopausal women and is associated with preservation of bone mineral density in lumbar spine and femoral neck. Changes in serum concentration of biochemical markers may reflect decreased bone turnover or bone remodeling and add to the understanding of tamoxifen's effect on bone mineral density.

Aged↗
PubMed2004

PET/CT using 18F-FDG in suspected lung cancer recurrence: diagnostic value and impact on patient management.

UNLABELLED: The goal of this study was to assess the value of hybrid imaging using a combined PET/CT device with 18F-FDG in the diagnosis and clinical management of suspected recurrent lung cancer. METHODS: Forty-two patients with non-small cell lung cancer (NSCLC) with suspected recurrence due to new clinical, biochemical, and radiologic findings were prospectively evaluated. PET/CT results were compared with PET interpreted with side-by-side CT data. A final diagnosis of recurrence was confirmed by histologic tissue sampling during surgery or biopsy or by further clinical and radiologic work-up. The impact of PET/CT on patient management was assessed. RESULTS: Twenty-four of 27 positive PET/CT studies (89%) were proven to have recurrent disease. Fourteen of 15 negative PET/CT studies (93%) had no evidence of disease. The sensitivity, specificity, and positive and negative predictive values of PET/CT for diagnosis of recurrence were 96%, 82%, 89%, and 93% compared with 96%, 53%, 75%, and 90%, respectively, for PET. PET/CT changed the PET lesion classification in 22 patients (52%), by determining the precise localization of sites of increased 18F-FDG uptake. PET/CT changed the management of 12 patients (29%) by eliminating previously planned diagnostic procedures (5 patients), by initiating a previously unplanned treatment option (4 patients), or by inducing a change in the planned therapeutic approach (3 patients). CONCLUSION: In patients with a suspected recurrence of NSCLC, PET/CT provides a better anatomic localization of suspicious lesions compared with PET interpreted with side-by-side CT data. This improved diagnostic performance of PET/CT has a further impact on the clinical management and treatment planning of the patients.

Adult↗
PubMed2004

Evaluation of 18F-FDG uptake and arterial wall calcifications using 18F-FDG PET/CT.

UNLABELLED: Glucose metabolic activity expressed as (18)F-FDG uptake may be increased in active atherosclerotic plaque. Calcium depositions are often increased in mature atherosclerotic plaque. The purpose of the present study was to assess the patterns of vascular-wall (18)F-FDG uptake and CT calcifications using combined PET/CT. METHODS: One hundred twenty-two consecutive patients over the age of 50 (47 women and 75 men; mean age, 66 +/- 9 y) undergoing whole-body (18)F-FDG PET/CT for tumor assessment were retrospectively evaluated. PET, CT, and PET/CT slices were generated for review. Abnormal vascular findings in major arteries in the chest and abdomen were categorized as PET positive (PET+), PET negative (PET-), CT positive (CT+), or CT negative (CT-). The topographic relationship between increased vascular-wall (18)F-FDG uptake on PET and the presence of calcifications on CT was assessed on PET/CT fused images, with abnormal sites further classified as PET+/CT+, PET+/CT-, or PET-/CT+. The presence of CT calcifications and increased vascular-wall (18)F-FDG uptake was correlated with age, sex, presence of cardiovascular risk factors, and cardiovascular disease. RESULTS: Abnormal findings were identified at 349 sites. CT calcifications (CT+) were observed at 320 sites (92%) of 100 patients (82%), more commonly in men (P < 0.03), in older patients (P < 0.0001), in patients with hypertension (P < 0.003) or hyperlipidemia (P < 0.04), and in smokers (P < 0.008). Increased vascular-wall (18)F-FDG uptake (PET+) was observed at 52 sites (15%) of 38 patients (31%), more commonly in men (P < 0.02), in older patients (P < 0.0001), and in patients with hypertension (P < 0.02), and was borderline in patients with cardiovascular disease (P = 0.057). PET+ and CT+ findings correlated in 12 patients, a PET+/CT- pattern was found in 18 patients, and 8 patients had increased vascular-wall (18)F-FDG uptake in sites with and without calcifications (PET+/CT+, CT-). Twenty-two patients (18%) had a PET-/CT- pattern. CONCLUSION: Hybrid PET/CT can be used to identify and to correctly localize vascular-wall (18)F-FDG activity. Increased vascular-wall (18)F-FDG activity was found in 15% of sites and CT calcifications were noted in 92% of sites, with congruent findings in 7%. The clinical significance of the relationship between vascular-wall (18)F-FDG uptake and CT calcifications needs to be assessed by further prospective studies with long-term follow up.

Adult↗
PubMed2004

Is 18F-FDG PET/CT useful for imaging and management of patients with suspected occult recurrence of cancer?

UNLABELLED: Rising serum tumor markers may be associated with negative imaging in the presence of cancer. CT and (18)F-FDG PET may yield incongruent results in the assessment of tumor recurrence. The present study evaluates the incremental role of (18)F-FDG PET/CT for the diagnosis and management of cancer patients with increasing levels of tumor markers as the sole indicator of potential recurrence after initial successful treatment. METHODS: Thirty-six cancer patients with increasing levels of tumor markers during follow-up and negative CT underwent (18)F-FDG PET/CT, which showed 111 sites of increased tracer uptake. PET/CT was compared with PET results on a site-based analysis for characterization of (18)F-FDG foci and on a patient-based analysis for diagnosis of recurrence. The clinical impact of PET/CT on further patient management was evaluated. RESULTS: Thirty patients (83%) had recurrence in 85 malignant sites (77%). For the site-based analysis, PET had a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 96%, 50%, 85%, 85%, and 82%, respectively, as compared with the performance indices of PET/CT of 100%, 89%, 97%, 97%, and 100%, respectively. There was a statistically significant difference between the specificity (P < 0.05) and accuracy (P < 0.001) of PET and PET/CT for precise characterization of suspected lesions. For the patient-based analysis, PET had a sensitivity, specificity, and accuracy of 93%, 50%, and 86%, respectively, as compared with PET/CT with values of 93%, 67%, and 89%, respectively (P = not significant). PET/CT was the single modality that directed further management and treatment planning in 12 patients (33%). CONCLUSION: The results of this study indicate that PET/CT may improve the accuracy of occult cancer detection and further lead to management changes in patients with increasing levels of tumor markers as the sole suspicion of recurrent malignancy.

Adult↗
PubMed2003

Gallium-67 scintigraphy: a cornerstone in functional imaging of lymphoma.

Until recently, gallium-67 scintigraphy (GS) has been the best available functional imaging modality for evaluating patients with non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). The diagnostic accuracy of GS in detecting lymphoma is based on optimisation of the imaging protocol, knowledge of potential physiological and benign sites of (67)Ga uptake, and the Ga avidity characteristics of the individual lymphoma. As (67)Ga is a tumour viability agent, the role of GS is primarily at follow-up. A residual mass persisting on CT after treatment poses a common clinical dilemma: it may indicate the presence of viable lymphoma, which requires further treatment, or it can be benign, consisting of only fibrotic and necrotic tissues. GS can successfully differentiate between these conditions. Routine follow-up with GS may allow early diagnosis of recurrence and early institution of treatment. Reversion of a positive GS to a negative test, and the rapidity with which this occurs has a high predictive value for the outcome of the individual patient. Lymphoma showing a normal GS early during treatment has a better prognosis than lymphoma with persistence of pathological findings. Other tumour-seeking single-photon emitting agents, such as thallium-201, technetium-99m methoxyisobutylisonitrile and indium-111 octreotide, have been investigated in lymphoma, primarily as an alternative to GS in specific clinical settings, but are of limited value. The role of radioimmunoscintigraphy is gaining importance in conjunction with radioimmunotherapy. Fluorine-18 fluorodeoxyglucose (FDG) imaging of lymphoma using either dedicated or camera-based PET systems is gradually replacing GS for assessment of lymphoma. FDG overcomes some of the limitations of GS while sharing its tumour viability characteristics. The extensive clinical knowledge and experience accumulated over three decades with GS in lymphoma provides a solid background as well as a model for the assessment of new functional imaging techniques.

Female↗
PubMed2003

Camera-based FDG PET and 67Ga SPECT in evaluation of lymphoma: comparative study.

PURPOSE: To compare gallium 67 (67Ga) scintigraphy and camera-based fluorodeoxyglucose (FDG) positron emission tomography (PET) in the evaluation of patients with lymphoma. MATERIALS AND METHODS: The performance of 67Ga scintigraphy and camera-based FDG PET in the detection of lymphoma was retrospectively evaluated and compared in 84 patients with lymphoma, with 219 suspected sites of disease. Eighty-nine percent of patients were examined during or after treatment. Camera-based FDG PET was initiated by equivocal characterization of the status of disease based on clinical, radiologic, and 67Ga scintigraphic assessment. Findings of 67Ga scintigraphy and camera-based FDG PET were compared on a per-patient and per-site basis for the whole group, for histologic subtypes, and for anatomic locations. Comparison of sensitivity, specificity, and accuracy between the two modalities for detection of lymphoma was performed with the McNemar test. RESULTS: There was a statistically significant difference in sensitivity, specificity, and accuracy of 67Ga scintigraphy and camera-based FDG PET at both patient- and site-based analysis. 67Ga scintigraphy helped to accurately define disease state in 63% of patients and in 33% of sites, compared with 83% and 87%, respectively, for camera-based FDG PET. For discordant findings between the two modalities, camera-based FDG PET findings were confirmed as true-positive in 71% and as true-negative in 92% of patients. Camera-based FDG PET had a significantly higher detection rate for both nodal and extranodal lymphoma sites. It provided accurate assessment of lymphoma involvement of the skeleton in 93% of sites compared with 29% for 67Ga scintigraphy and excluded active lymphoma in 10 67Ga-positive benign parahilar sites. CONCLUSION: In this selected group of patients with lymphoma, camera-based FDG PET allowed a significantly more accurate definition of active disease compared with that allowed with 67Ga scintigraphy.

Adolescent↗
PubMed2003

SPECT/CT hybrid imaging with 111In-pentetreotide in assessment of neuroendocrine tumours.

OBJECTIVE: Somatostatin receptor scintigraphy (SRS) of neuroendocrine (NE) tumours is often challenging because of minute lesion size and poor anatomic delineation. This study evaluates the impact of sequentially performed single-photon emission computed tomography (SPECT)/CT fusion on SRS study interpretation and clinical management of these tumours. PATIENTS AND DESIGN: Seventy-two patients were studied with routine SRS and SPECT/CT at 4, 24 and optionally 48 h after injection of 222 MBq 111In-pentetreotide. Forty-five patients were evaluated for carcinoid, 15 for islet cell tumour, seven for metastatic NE tumour, four for medullary thyroid carcinoma, and one patient had ophthalmopathy. SPECT/CT induced improvement in the interpretation of SPECT and conventional CT and resultant clinical management changes were recorded. RESULTS: SRS was negative in 28 patients and positive in 44 patients. SPECT/CT provided no additional information in 48 patients, including all 28 negative studies. SPECT/CT improved localization of the SPECT-detected lesions in 23 of the 44 positive studies. It defined the extent of disease in 17, showed unsuspected bone involvement in three, and differentiated physiological from tumour uptake in three studies. SPECT/CT affected the clinical management in 10 patients, altered the surgical approach in six, spared unnecessary surgery in two, and modified the therapeutic modality in two patients. CONCLUSIONS: SPECT/CT affected the diagnostic interpretation of SRS in 32% of the patients and induced changes in management in 14% of the patients.

Adenoma, Islet Cell↗
PubMed2003

SPECT/CT in tumor imaging: technical aspects and clinical applications.

Diagnostic imaging has gained a major role in the management of patients with cancer and has made a further step forward with the introduction of fusion techniques into the field. This technology provides hybrid images of two independent modalities, a functional scintigraphic technique and an anatomical procedure, yielding a superior imaging study. Scintigraphy is based on the use of single photon or positron emitting tracers providing a description of function or processes, whereas computed tomography (CT), ultrasound, or magnetic resonance imaging (MRI) depict the precise localization and type of morphological changes that have occurred in the lesions. Initial attempts to coregister the functional and anatomical information following acquisition of the two imaging modalities on separate machines, in different sessions, failed to disclose the proper alignment with precise coregistration, in particular for non-head studies, and were associated with patient preparation and mathematical modeling that were too cumbersome to be used on a routine basis. The recent introduction of a hybrid imaging device containing a low dose CT system and a gamma camera on a single gantry enabled the sequential acquisition of the two imaging modalities, with subsequent merging of data into a composite image display. These hybrid studies have led to a revolution in the field of imaging, with highly accurate localization of tumor sites, assessment of invasion into surrounding tissues, and characterization of their functional status.

Equipment Design↗
PubMed2003

Clinical performance of PET/CT in evaluation of cancer: additional value for diagnostic imaging and patient management.

UNLABELLED: This study assessed the clinical performance of a combined PET/CT system using (18)F-FDG in oncologic patients. METHODS: (18)F-FDG PET/CT was used to evaluate 204 patients with 586 suspicious lesions. All patients had available follow-up data, enabling assessment of the clinical significance of hybrid PET/CT findings. Differences in interpretation between PET, CT, and fused PET/CT data were prospectively documented for detection, localization, and characterization of each evaluated site. The additional value of PET/CT for data interpretation over that of separate PET and CT was classified into several criteria, including change in lesion characterization to either definitely benign or definitely malignant, precise anatomic localization of malignant (18)F-FDG uptake, and retrospective lesion detection on PET and CT. The clinical impact of information provided by PET/CT on patient management was assessed on the basis of follow-up data concerning further diagnostic or therapeutic approach. Analysis of data was performed for the whole study population, for different types of cancer, and for different anatomic sites. RESULTS: PET/CT provided additional information over the separate interpretation of PET and CT in 99 patients (49%) with 178 sites (30%). PET/CT improved characterization of equivocal lesions as definitely benign in 10% of sites and as definitely malignant in 5% of sites. It precisely defined the anatomic location of malignant (18)F-FDG uptake in 6%, and it led to retrospective lesion detection on PET or CT in 8%. The results of PET/CT had an impact on the management of 28 patients (14%). Hybrid PET/CT data obviated the need for further evaluation in 5 patients, guided further diagnostic procedures in 7 patients, and assisted in planning therapy for 16 patients. CONCLUSION: Hybrid PET/CT improves the diagnostic interpretation of (18)F-FDG PET and CT in cancer patients and has an impact on both diagnostic and therapeutic aspects of patient management.

Adolescent↗
PubMed2002

Clinical pretreatment risk factors and Ga-67 scintigraphy early during treatment for prediction of outcome of patients with aggressive non-Hodgkin lymphoma.

BACKGROUND: Clinical pretreatment risk factors indicate the severity of disease in patients with aggressive non-Hodgkin lymphoma (NHL). Ga-67 scintigraphy during treatment is an early indicator of treatment-related features of lymphoma cells. The ability of risk factors and Ga-67 to predict disease outcome was compared in 139 patients with aggressive NHL. METHODS: Pretreatment clinical risk factors and Ga-67 scintigraphy performed after one cycle and at mid-treatment were evaluated for their correlation with response rate and as predictors of 5-year failure-free survival (FFS). Univariate analysis was performed to determine the ability of pretreatment risk factors and Ga-67 early during treatment to predict FFS. Subsequently, multivariate analysis was performed on the variables with significant univariate results using the Cox proportional hazards method. The predictive value of risk factors and Ga-67 scintigraphy was calculated to determine their suitability in selecting patients with poor outcome. RESULTS: Response rate correlated with stage of disease (P < 0.01) and the international prognostic index (IPI) score (P < 0.05). Five-year FFS was predicted by stage of disease (P < 0.004), performance status (P < 0.02), and the IPI score (P < 0.01). Response rate correlated with results of Ga-67 scintigraphy after one cycle of chemotherapy (P < 0.001) and at mid-treatment (P < 0.001). Five-year FFS was predicted by Ga-67 after one cycle of chemotherapy (P < 0.0004) and at mid-treatment (P < 0.0001). Positive Ga-67 after the first cycle of treatment predicted 64% of patients who had failure of treatment. A positive study at mid-treatment predicted 77% of patients who had treatment failure. Cox analysis showed Ga-67 after one course (P < 0.0012) and at mid-treatment (P < 0.0002) as being the most significant variables in predicting FFS. CONCLUSIONS: Ga-67 scintigraphy demonstrates early the effect of treatment in patients with aggressive NHL. It is a better predictor than pretreatment risk factors of both response rate and FFS. Positive Ga-67 early during treatment may be used as an independent test in selecting patients who will not respond favorably to current protocol treatment for early therapeutic modifications.

Adolescent↗
PubMed2002

Combined functional and structural evaluation of cancer patients with a hybrid camera-based PET/CT system using (18)F-FDG.

UNLABELLED: Correct diagnosis and definition of the functional and anatomic status of lesions in cancer patients are of clinical importance. The value of hybrid imaging using a gamma camera-based PET/CT and (18)F-FDG in determining the relationship between mass and cancer was assessed. METHODS: Hybrid imaging was performed using a device combining low-dose CT and gamma camera-based PET. Ninety-one patients with histologically proven malignancy and 190 suspected sites of disease were evaluated. Camera-based PET was performed after the injection of 296-370 MBq (18)F-FDG. The presence of organomegaly or an abnormal mass on CT and of abnormal uptake of (18)F-FDG was assessed for each suspected lesion. The presence of malignancy at each site was determined by biopsy, imaging follow-up, or clinical outcome. RESULTS: Five imaging patterns were found. Pattern 1 showed congruent abnormal (18)F-FDG uptake and a mass on CT in 110 of the lesions. One hundred two sites (93%) had active cancer. Pattern 2 showed a mass on CT, larger than the area of abnormal (18)F-FDG uptake, and was found in 5 lesions. Active malignancy was proven in 3 sites (60%). Pattern 3 showed an abnormal mass on CT with no (18)F-FDG uptake and was found in 52 lesions. Thirteen of these lesions (25%) had active tumor. Pattern 4 showing abnormal (18)F-FDG uptake with no mass on CT was found in 23 lesions. Sixteen of these sites (70%) were malignant. Pattern 5 showed normal CT findings and no abnormal (18)F-FDG uptake in 11 patients. Two of these patients (18%) had active disease. Hybrid imaging was of value in establishing the correct relationship between CT and (18)F-FDG findings in 98 of the 190 lesions (52%). CONCLUSION: A range of patterns presenting with or without abnormal (18)F-FDG uptake on camera-based PET and a mass on CT may occur in suspected cancer sites. Both structural changes on CT and increased cell metabolism expressed by abnormal (18)F-FDG uptake should be considered in oncologic imaging. Hybrid imaging, a combined physiologic and anatomic modality, appears to provide new diagnostic opportunities in characterizing function and morphology in malignancies.

Female↗
PubMed2002

Bone lymphoma: 67Ga scintigraphy and CT for prediction of outcome after treatment.

UNLABELLED: The purpose of the present study was to evaluate the role of 67Ga scintigraphy and CT in treatment monitoring of bone lymphoma. METHODS: Forty-four lymphoma patients with 91 sites of bone involvement were evaluated. Eight patients had Hodgkin's disease, and 36 patients had non-Hodgkin's lymphoma. Thirteen patients had primary lymphoma of the bone, and 31 patients had secondary lymphoma of the skeleton. 67Ga and CT studies were performed at baseline, during and at the end of treatment, and during follow-up. Positive 67Ga studies showed abnormal uptake in sites of lymphomatous involvement. Positive CT studies showed lesions with patterns of osteolysis, patterns of osteosclerosis, or a mixed pattern. A negative 67Ga or CT study showed disappearance of all lymphoma-related abnormalities. The sensitivity and specificity of 67Ga scintigraphy at presentation were calculated. Patterns of bone lymphoma on CT and their treatment-related changes were analyzed and recorded. Freedom-from-progression (FFP) curves were used to determine the prognostic value of positive and negative 67Ga and CT findings for predicting outcome after treatment. RESULTS: The sensitivity of 67Ga for diagnosis of bone lymphoma was 93%, and the specificity was 91%. A CT pattern of osteolysis was seen in 70% of skeletal disease sites at diagnosis and in 21% during follow-up. Osteosclerosis was present in 23% of sites at diagnosis and in 38% during follow-up. 67Ga findings became negative in 25% of patients during treatment, whereas only 1 patient showed negative CT findings. Forty-two percent of patients had negative 67Ga findings at the end of treatment, compared with 18% who had negative CT findings. Sixty-one percent of patients had negative 67Ga findings during follow-up, compared with 21% who had negative CT findings. A statistically significant difference in FFP was found between patients with positive and negative 67Ga findings at all evaluated time points. No statistically significant difference in FFP was found at any time point between patients with positive and negative CT findings. CONCLUSION: 67Ga scintigraphy has a high sensitivity and specificity for diagnosis of bone lymphoma. Bone lymphoma may show osteosclerotic and osteolytic CT patterns at diagnosis, during treatment, and after treatment. In most patients, CT studies do not become negative even 1 y after treatment. 67Ga scintigraphy, however, may be used as a predictor of long-term outcome in patients with lymphoma of the skeleton.

Adult↗
PubMedDate not supplied

PET/CT using 2-deoxy-2-[18F]fluoro-D-glucose for the evaluation of suspected infected vascular graft.

An infected vascular graft was identified using a combined positron emission tomography (PET) and computerized tomography (CT) system. The fusion of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) PET and CT images, acquired in a single session, allowed for the precise localization of the abnormal FDG uptake to the vascular graft and led to the correct diagnosis of prosthetic infection. This hybrid modality, which provides precise registration of metabolic and structural imaging data, may enhance the potential use of FDG in the diagnosis and management of infected vascular grafts.

Aged↗