Diagnostic and prognostic value of 99mTc-Tektrotyd scintigraphy and 18F-FDG PET/CT in a single-center cohort of neuroendocrine tumors.

Introduction: The aim was to assess the diagnostic value of 99mTc-Tektrotyd scintigraphy (TCT) and positron emission tomography/computed tomography using F-18 fluorodeoxyglucose (18F-FDG PET/CT) in the detection and follow-up of neuroendocrine tumors (NETs), and their predictive value for disease progression. Material and methods: In this retrospective cohort, TCT and 18F-FDG PET/CT were performed in 90 patients (37 men, 53 women, mean age 52.7 ±15.1), with NET. Correlation of Ki67 and tumor grade versus Krenning score and SUVmax was assessed, Kaplan-Meier analysis was used for progression-free survival (PFS), and Cox regression analysis was performed to identify the association between progression-related factors and PFS. Results: Out of 90, true positive TCT was detected in 56 (62.2%) patients, true negative in 19 (21.1%), false positive in 4 (4.4%), false negative in 11 (12.2%), while 18F-FDG PET/CT was true positive in 69 (76.7%) patients, true negative in 10 (11.1%), false positive in 5 (5.5%), false negative in 6 (6.7%). Mean 18F-FDG PET/CT SUVmax was 6.8 ±6.2. Diagnostic sensitivity of TCT was 83.6%, specificity 82.6%, accuracy 83.3% vs. 18F-FDG PET/CT sensitivity was 92.0%, specificity 66.7%, accuracy 87.8%. A significant correlation between Ki67 and SUVmax was found in positive 18F-FDG PET/CT findings, unlike the correlation between Ki67 and Krenning score. Median PFS was 25 months (95% CI: 18.2-31.8), in 18F-FDG PET/CT positive patients 23 months (95% CI: 16.3-29.7) and 18F-FDG PET/CT negative 26 months (p = 0.279). Progression-free survival predictors were SUVmax and Krenning score. Conclusions: In our study, TCT and 18F-FDG PET/CT have high diagnostic accuracy in detection of NET. Higher Krenning score on TCT and SUVmax in positive 18F-FDG PET/CT findings are predictors of disease progression. 99mTc-Tektrotyd scintigraphy and 18F-FDG PET/CT can be useful complementary tools in management of patients with NETs and in predicting patients' outcome.

The distinct associations of ingroup attachment and glorification with responses to the coronavirus pandemic: Evidence from a multilevel investigation in 21 countries.

While public health crises such as the coronavirus pandemic transcend national borders, practical efforts to combat them are often instantiated at the national level. Thus, national group identities may play key roles in shaping compliance with and support for preventative measures (e.g., hygiene and lockdowns). Using data from 25,159 participants across representative samples from 21 nations, we investigated how different modalities of ingroup identification (attachment and glorification) are linked with reactions to the coronavirus pandemic (compliance and support for lockdown restrictions). We also examined the extent to which the associations of attachment and glorification with responses to the coronavirus pandemic are mediated through trust in information about the coronavirus pandemic from scientific and government sources. Multilevel models suggested that attachment, but not glorification, was associated with increased trust in science and compliance with federal COVID-19 guidelines. However, while both attachment and glorification were associated with trust in government and support for lockdown restrictions, glorification was more strongly associated with trust in government information than attachment. These results suggest that both attachment and glorification can be useful for promoting public health, although glorification's role, while potentially stronger, is restricted to pathways through trust in government information.

Trust in scientific information mediates associations between conservatism and coronavirus responses in the U.S., but few other nations.

U.S.-based research suggests conservatism is linked with less concern about contracting coronavirus and less preventative behaviors to avoid infection. Here, we investigate whether these tendencies are partly attributable to distrust in scientific information, and evaluate whether they generalize outside the U.S., using public data and recruited representative samples across three studies (Ntotal = 34,710). In Studies 1 and 2, we examine these relationships in the U.S., yielding converging evidence for a sequential indirect effect of conservatism on compliance through scientific (dis)trust and infection concern. In Study 3, we compare these relationships across 19 distinct countries. Although the relationships between trust in scientific information about the coronavirus, concern about coronavirus infection, and compliance are consistent cross-nationally, the relationships between conservatism and trust in scientific information are not. These relationships are strongest in North America. Consequently, the indirect effects observed in Studies 1-2 only replicate in North America (the U.S. and Canada) and in Indonesia. Study 3 also found parallel direct and indirect effects on support for lockdown restrictions. These associations suggest not only that relationships between conservatism and compliance are not universal, but localized to particular countries where conservatism is more strongly related to trust in scientific information about the coronavirus pandemic.

A Cross-Cultural Study of Distress during COVID-19 Pandemic: Some Protective and Risk Factors.

Previous studies on the impact of the COVID-19 pandemic on mental health in different countries found an increase in anxiety, stress, and an exacerbation of previous mental health problems. This research investigated some of the protective and risk factors of distress during the COVID-19 pandemic, among which were the perception of receiving social support from family members and friends, and a chronic tendency to worry. The study was conducted in three European countries: Italy, Serbia, and Romania. A total of 1100 participants (Italy n = 491; Serbia n = 297; Romania n = 312) responded to a questionnaire. Results from this study show that distress during the COVID-19 pandemic is higher for people who are chronic worriers and those who have higher levels of fear of COVID-19. More specifically, it is confirmed that a chronic tendency to worry exacerbates the relationship between fear and distress: it is stronger for people who have a greater tendency to worry.

Close or Distant Past? The Role of Temporal Distance in Responses to Intergroup Violence From Victim and Perpetrator Perspectives.

In two different intergroup contexts, three studies investigated the role of temporal distance in responses to intergroup violence from both victim and perpetrator perspectives. In the context of the conflict between Serbs and Bosniaks, Study 1 showed that whereas increased subjective temporal distance predicted less support for justice-restoring efforts and less outgroup empathy among the perpetrator group (Serbs), it predicted more conciliatory, pro-outgroup attitudes among the victim group (Bosniaks). Furthermore, Bosniaks perceived the war as temporally closer than did Serbs. In the context of the U.S.-Iran conflict, Study 2 provided a partial conceptual replication of Study 1 and demonstrated that ingroup glorification motivated more temporal distancing among perpetrators and less temporal distancing among victims. Study 3 further established the causal effects of temporal distance on intergroup outcomes, and that these effects were moderated by glorification. Implications for post-conflict peacebuilding are discussed.

The Relationship Between 99mTc-Pertechnetate Hand Perfusion Scintigraphy and Nailfold Capillaroscopy in Systemic Sclerosis Patients: A Pilot Study.

OBJECTIVES: This study aims to assess the possible relationship between 99mTc-pertechnetate hand perfusion scintigraphy (HPS) and nailfold capillaroscopy (NC) in systemic sclerosis (SSc) patients. PATIENTS AND METHODS: The study group consisted of 25 SSc patients (6 males; 19 females; mean age 54.2±9.7 years; range, 32 to 67 years), 18 female patients with primary Raynaud's phenomenon (PRP) (mean age 47.1±9.5 years; range, 34 to 65 years) and 10 healthy individuals (3 males, 7 females; mean age 52.7±12.6 years; range, 37 to 73 years). NC and 99mTc-pertechnetate HPS were performed in all examinees. The capillaroscopic findings were classified as normal or scleroderma pattern ("early", "active", or "late"). The fingers-to-palm ratios were calculated for both blood flow (BF) and blood pool (BP) phases of the 99mTc-pertechnetate HPS. RESULTS: Systemic sclerosis patients showed a significantly lower BP ratio than PRP patients and healthy subjects (p=0.004). No statistically significant difference was observed between the SSc and PRP patients in respect to BF ratio. A gradual decrease of BF and BP with the severity of NC microangiopathy pattern ("early", "active" or "late") was found in SSc patients, while the differences were not statistically significant. Patients with diffuse SSc showed lower BF and higher BP than those with limited SSc, while these differences were without statistical significance. There was no significant correlation between BF or BP values and type of SSc (limited or diffuse) (p=0.77 versus p=0.54, respectively) as well as three microangiopathy patterns (p=0.22 versus p=0.54, respectively). CONCLUSION: 99mTc-pertechnetate HPS improves the evaluation of vascular damage in SSc patients. There is no direct relationship between NC and 99mTc-pertechnetate HPS; however, the two methods complement each other in the assessment of microcirculation in SSc.

Hybrid Imaging in Evaluation of Abdominal Sarcoidosis.

OBJECTIVE: To determine the prevalence of abdominal involvement, distribution pattern and evaluate role of hybrid molecular imaging in patients with abdominal sarcoidosis. METHODS: Between January 2010 and December 2011, 98 patients with chronic sarcoidosis and presence of prolonged symptoms or other findings suggestive of active disease were referred to FDG PET/CT examination. Active disease was found in 82 patients, and they all were screened for the presence of abdominal sarcoidosis on FDG PET/CT. All patients also underwent MDCT and assessment of serum ACE level. Follow up FDG PET/CT examination was done 12.3±5.4 months after the baseline. RESULTS: Abdominal sarcoidosis was present in 31/82 patients with active sarcoidosis. FDG uptake was present in: retroperitoneal lymph nodes (77%), liver (26%), spleen (23%), adrenal gland (3%). Majority of patients had more than two locations of disease. Usually thoracic disease was spread into the extrathoracic localizations, while isolated abdominal sarcoidosis was present in 10% of patients. After first FDG PET/CT examination therapy was changed in all patients. Eleven patients came to the follow up examination where SUVmax significantly decreased in the majority of them. Three patients had total remission, three had absence of abdominal disease but discrete findings in thorax and others had less spread disease. ACE levels did not correlate with SUVmax level. CONCLUSION: FDG PET/CT can be a useful tool for detection of abdominal sarcoidosis and in the evaluation of therapy response in these patients. Awareness of the presence of intra-abdominal sarcoidosis is important in order to prevent long-standing unrecognized disease.

All that glitters on PET is not cancer! 18F-deoxy-glucose avidity versus tumor biology: pituitary incidentaloma in a survivor of two previous unrelated malignancies.

INTRODUCTION: 18F-deoxy-glucose positron emission tomography combined with computed tomography (18F-FDG PET/CT) is routinely used in the detection of malignant disease based on the property of malignant cells to fuel their growth and replication by increased glucose uptake. Malignant lesions are rare in the sellar region, while pituitary adenomas are the most common pathology. These are benign neoplasms with insidious onset and low proliferation activity, and therefore are only exceptionally detected by 18F-FDG PET/CT. Studies that compare the biology of pituitary adenomas and their radiological properties using PET/CT are still lacking. CASE REPORT: We investigate and discuss tumour biology in light of increased 18F-FDG avidity in a symptom-free, 70-year-old male patient, previously treated for two different malignancies (lung and rectal). Increased tracer accumulation in the sellar region was incidentally detected on a follow-up 18F-FDG PET/CT scan. Additional MRI disclosed pituitary adenoma. Normal hormonal status was found, consistent with the diagnosis of non-functioning pituitary adenoma. Analysis of tumour tissue after pituitary surgery confirmed a silent gonadotroph adenoma with low proliferation index. Low expression of oncogene-induced senescence markers did not support senescence as the explanation for the tumour's low proliferative activity although it was in consonance with the hormonal activity. CONCLUSIONS: Pituitary adenomas can manifest as hypermetabolic foci on 18F-FDG PET/CT imaging with increased tracer uptake even in indolent, clinically silent pituitary adenomas with low mitotic activity. Special attention should be paid to evaluation of 18F-FDG avid pituitary adenomas in patients with multiple malignancies, bearing in mind that avidity does not always mirror its biological behaviour.

The detection of endocarditis, post implantation grafts, arteritis and other related disorders by 18F-FDG PET/CT.

INTRODUCTION: Positron emission tomography with computed tomography (18F-FDG PET/CT) is a nuclear medicine diagnostic method which, unlike other technological modalities that asses anatomical features, detects increased glucose metabolism inside the cells, thus is very helpful in diagnosing cardiovascular infection and inflammation and also in therapy planning. AIM: Aim of this study was to assess the significance of 18F-FDG PET/CT in detection of an active disease in patients with infection and inflammation of cardiovascular system. MATERIAL AND METHODS: In this cohort retrospective study 73 cardiovascular patients (56.9±15.3 years; 33 male and 40 female) with persistent symptoms of inflammatory syndrome were referred to 18F-FDG PET/CT in order to evaluate active disease. Biochemical blood analyses (erytrocite sedimentation, CRP, leukocytic formula), CT, MRI, ultrasound were performed in all the patients. Out of 73 patients, 7 had a second 18F-FDG PET/CT examination (62.1±12.3 years; 6 men and 1 woman) with a previous pathological PET/CT finding after which the therapy was changed. The degree of metabolic activity was analyzed visually and quantitatively using the maximal standardized uptake value (SUVmax). 18F-FDG PET/CT findings were considered positive in case of higher focal glucose accumulation in projection of heart and diffuse uptake in blood vessels' wall than accumulation in surrounding tissue and liver. RESULTS: Vasculitis was diagnosed in 36 patients (49,3%), endocarditis in 23 (31,5%) and graft inflammation in 14 (19,2%). The results were compared to the gold standard, biopsy of the blood vessel and histopathological verification during surgical treatment, or clinical follow up. Forty nine patients with the sights of an increased FDG uptake were considered true positive (TP) (SUVmax5.7±2.9). In 21 patients 18F-FDG uptake was physiological and they were considered true negative (ТN). Two who used corticosteroid therapy which decreases inflammation, were false negative (FN), and only 1 false positive (FP) finding in the region of recent iatrogenic vein injury. Sensitivity of this method was 96.08±, specificity 95.45±, positive predictive value 98.0±, negative predictive value 91.3± and accuracy 95.89±. CONCLUSION: Our results indicate that 18F-FDG PET/CT could be useful diagnostic method for the detection of sights of metabolically active disease in patients with persistent symptoms of infection and inflammation of cardiovascular system, as well as in monitoring therapy response.

Diagnosis of Raynaud's phenomenon by 99mTc-pertechnetate hand perfusion scintigraphy: a pilot study.

We assess the usefulness of 99mTc-pertechnetate hand perfusion scintigraphy in patients with Raynaud's phenomenon (RP). The study population consisted of 18 patients with primary RP, 25 patients with secondary RP within systemic sclerosis (SSc), and ten healthy individuals. Gamma camera dynamic first-pass study during the first 60 s and a static scintigraphy after 5 min were recorded following a bolus injection of 99mTc-pertechnetate via a cubital vein. Regions of interest were drawn on the summed images around the fingers and the palmar region. The fingers-to-palm ratios were then calculated. The mean fingers-to-palm ratio for dynamic study (blood flow) was 0.58 ± 0.19 for the healthy group, 0.45 ± 0.18 for the primary RP, and 0.43 ± 0.21 for the SSc patients. The mean fingers-to-palm ratio for static study (blood pool) was 0.44 ± 0.06 for the healthy group, 0.42 ± 0.06 for the primary RP, and 0.36 ± 0.07 for the SSc patients. Analysis of variance showed these differences to be significant (p = 0.039 from blood flow and p = 0.004 from blood pool). The receiver operating characteristic curve showed sensitivity of 80% and a specificity of 60% when using cutoff values of 0.40 for blood flow and sensitivity of 79% and a specificity of 70% when using cutoff values of 0.37 for blood pool. Our method is able to differentiate between patients with normal and those with abnormal microcirculation of the hands. Dynamic study separates the healthy subjects from patients with RP, while static study separates primary from secondary RP.

Evaluation of neuroendocrine tumors with 99mTc-EDDA/HYNIC TOC.

BACKGROUND: This paper is the short review of our preliminary results obtained with 99mTc-EDDA/HYNIC-TOC. MATERIAL AND METHODS: The total of 495 patients with different neuroendocrine tumors were investigated during last few years. RESULTS: There have been 334 true positive (TP), 73 true negative (TN), 6 false positive (FP) and 82 false negative findings (FN). Diagnosis was made according to SPECT findings in 122 patients (25%). The mean T/NT ratio for TP cases was significantly higher (p < 0.01) on SPECT (3.12 ± 1.13) than on whole body scan (2.2 ± 0.75). According to our results, overall sensitivity of the method is 80%, specificity 92%, positive predictive value 98%, negative predictive value 47% and accuracy 82%. Fifteen TP patients underwent therapy with 90Y-DOTATATE. CONCLUSION: Scintigraphy of neuroendocrine tumors with 99mTc-Tektrotyd is a useful method for diagnosis, staging and follow up of the patients suspected to have neuroendocrine tumors. SPECT had important role in diagnosis. It is also helpful in the appropriate choice of the therapy, including the peptide receptor radionuclide therapy. In the absence of 68Ga-labeled peptides and PET/CT, the special emphasize should be given to application of SPECT/CT as well as to the radioguided surgery.

The diagnostic performance and added value of (18)F-FDG PET/CT in the detection of liver metastases in recurrent colorectal carcinoma patients.

OBJECTIVE: The aim of this study was to assess the value of (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT in detection of liver metastases in patients with suspected recurrent colorectal carcinoma, as well as to compare diagnostic performance of (18)F-FDG PET/CT with conventional imaging methods (MDCT). SUBJECTS AND METHODS: This study included 73 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013, with suspicion of recurrence. The patients underwent (18)F-FDG PET/CT examination on a 64-slice hybrid PET/CT scanner (Biograph, TruePoint64, Siemens Medical Solutions, Inc. USA). Prior to (18)F-FDG PET/CT all patients underwent contrast-enhanced MDCT. Findings of (18)F-FDG PET/CT and MDCT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up over at least six months. Final diagnosis of liver metastases of colorectal cancer was made either by histopathological examination of specimen after biopsy or surgery, or based on clinical, laboratory and imaging evaluation during first six months after PET/CT scan. RESULTS: In detection of liver metastases (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 83.3%, 95.3%, 92.6%, 89.1% and 90.4%, respectively. In addition, MDCT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy in detection of liver metastases of 60%, 88.4%, 78.3%, 76% and 76.7%, respectively. There was significant difference in sensitivity (83.3% vs 60%; P=0.045) between these two methods. In addition, significant difference was observed in accuracy between PET/CT and MDCT (90.4% vs 76.7%; P=0.016). The higher specificity in visualization of liver metastases was also achieved by (18)F-FDG PET/CT compared to MDCT (95.3% vs 88.4%), but this difference was not significant (P=0.37). CONCLUSION: (18)F-FDG PET/CT was highly sensitive, specific and accurate method in detection of liver metastases in patients with suspected recurrent colorectal carcinoma in our study. This hybrid imaging showed superior diagnostic performance in evaluation of suspected colorectal cancer liver metastases compared to conventional imaging.

Can (18)F-FDG PET/CT scan change treatment planning and be prognostic in recurrent colorectal carcinoma? A prospective and follow-up study.

OBJECTIVE: To prospectively study whether in patients with resected primary colorectal cancer fluorine- 18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) examination could diagnose the stage, specify treatment procedure and be prognostic. SUBJECTS AND METHODS: This prospective study included 75 patients with resected primary colorectal adenocarcinoma referred for (18)F-FDG PET/CT to the National PET Center, at the Clinical Center of Serbia, Belgrade, from January 2010 to May 2013. Findings of (18)F-FDG PET/CT were compared to findings of subsequent histopathological examinations or with results of clinical and imaging follow-up. Patients were followed after PET/CT examination for a mean follow-up time of 16.7±5.9 months. RESULTS: In the detection of recurrent disease (18)F-FDG PET/CT showed overall sensitivity, specificity, PPV, NPV and accuracy of 96.6%, 82.4%, 94.9%, 87.5% and 93.3%, respectively. In the detection of stages I and II sensitivity, specificity and accuracy of (18)F-FDG PET/CT were: 88%, 96.6% and 94.7%, respectively, and in the detection of stages III and IV sensitivity, specificity and accuracy were 94.9%, 87.5% and 93.3%, respectively. These findings prevented or changed intended surgical treatment in 12/32 cases. Univariate and multivariate Cox proportional regression analyses revealed that metastatic recurrence (stages III and IV) was the only and independent prognostic factor of disease progression during follow-up (P=0.012 and P=0.023, respectively). Although, survival seemed better in patients with local recurrence compared to metastatic recurrent disease, this difference did not reach significance (Log-rank test; P=0.324). In addition, progression-free survival time was significantly longer in patients in whom (18)F-FDG PET/CT scan led to treatment changes (Log-rank test; P=0.037). CONCLUSION: (18)F-FDG PET/CT was sensitive and accurate for the detection and staging of local and metastatic recurrent colorectal carcinoma, with higher specificity in the detection of local recurrences. The (18)F-FDG PET/CT scan induced treatment changes in 30/75 patients, including 12/32 patients in which surgical treatment was previously planned, and progression free survival time was significantly longer in these patients.

Attitudes toward Arab ascendance: Israeli and global perspectives.

Arab nations are decades behind many other previously colonized nations in developing stronger economies, more democratic institutions, and more autonomy and self-government, in part as a result of external interference. The year 2011 brought the potential for greater Arab autonomy through popular uprisings against autocratic governments in Tunisia, Egypt, and Yemen, and through the Palestinian request for state recognition by the United Nations. We examined the psychology of support for Arab ascendancy among adults in 14 nations in the Balkans, the Middle East, Asia, Oceania, Europe, and North America. We predicted and found that people low on social dominance orientation endorsed forming an independent Palestinian state and desired that the Arab uprisings succeed. Rejection of ideologies that legitimize outside interference with Arabs mediated this support. Measures and model results were robust across world regions. We discuss theoretical implications regarding the advent of new ideologies and extending social dominance theory to address international relations.

The utility of two somatostatin analog radiopharmaceuticals in assessment of radiologically indeterminate pulmonary lesions.

PURPOSE: The aim of our study was to assess diagnostic accuracy of Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC scintigraphy for evaluation of pulmonary lesions that appeared ambiguous on computed tomography (CT). MATERIAL AND METHODS: Forty-nine consecutive patients (37 men and 12 women; mean age, 60 ± 11 years) with 60 pulmonary lesions on chest radiography and CT were referred for nuclear imaging. They were prospectively allocated to undergo whole-body scintigraphy (WBS) and single photon emission computed tomography (SPECT) using either Tc-99m depreotide (26 patients, group 1) or Tc-99m-EDDA/HYNIC-TOC imaging (23 patients, group 2). Histologic findings after tissue biopsy served as a gold standard for determining diagnostic accuracy of the 2 somatostatin analogs. Visual assessment was complemented by semiquantitative analysis based on target to background ratio. RESULTS: Among the 32 pulmonary lesions scanned with Tc-99m depreotide, focal uptake was increased in 22 of 25 malignancies, whereas no uptake was found in 6 of 7 benign lesions (88% sensitivity, 85% specificity, and 88% accuracy) on both WBS and SPECT. Imaging of 28 pulmonary lesions with Tc-99m-EDDA/HYNIC-TOC had a similar diagnostic yield (sensitivity 87%, specificity 84%, and accuracy 86%). Overall, target to background ratios were higher on SPECT than WBS but not significantly different between groups 1 and 2 (SPECT 2.72 ± 0.70 vs. 2.71 ± 0.50, WBS 1.61 ± 0.32 vs. 1.62 ± 0.28, respectively). CONCLUSION: This study demonstrates that Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC have similar diagnostic value for characterizing pulmonary lesions that appear ambiguous on CT.

Helicobacter pylori infection in various groups of patients studied, estimated by 14C-urea breath test.

The aim of this study was the detection of helicobacter pylori (HP) infection and estimation of the clinical validity and the accuracy of the 14C-urea breath test in the groups of patients studied. A total of 248 patients with gastric diseases were examined. There were 38 patients with gastric ulcer, 41 with duodenal ulcer, 43 with gastroduodenitis erosiva, 26 with hiatus hernia, 36 with gastric carcinoma and 64 patients with gastritis. There were 103 true positive (TP), 139 true negative (TN), 4 false negative (FN) and 2 false positive (FP) patients. There was no significant difference in the incidence of the HP infection between the groups of patients studied (p > 0.05). Sensitivity of the method was 96.3%, specificity 98.6%, positive predictive value 98.1%, negative predictive value 97.2% and accuracy 97.6%. Our results point out that the method is very accurate for the detection of HP infection.

Radioimmunoscintigraphy of colorectal carcinomas with 99mTc-labelled antibodies.

BACKGROUND/AIMS: The aim of the study was the evaluation of the clinical validity of immunoscintigraphy with 99mTc labeled antibodies for the detection of metastases and recurrences of colorectal carcinomas. METHODOLOGY: We examined 17 patients with colorectal carcinomas. Scintigraphy was performed with anti-CEA MoAb 99mTc-BW 431/26. RESULTS: Recurrences of carcinomas were detected and confirmed by surgery in 6 patients, recurrences with liver metastasis in 5 patients, and only liver metastases in 3 patients. Planar immunoscintigraphy was positive in 5/8 patients with liver metastases and 8/11 patients with recurrences, whereas in 1/8 liver metastases and 3/11 recurrences were detected only by tomography. In two patients with metastases in the abdominal lymph nodes immunoscintigraphic findings both on planar scintigraphy and tomoscintigraphy were false negative. CONCLUSIONS: Immunoscintigraphy with 99mTc labeled antibodies can be useful in the diagnosis of recurrences and metastases of colorectal carcinoma, viability assessment after radiotherapy and in the choice of the adequate surgical treatment.

Diagnostic role of initial renal cortical scintigraphy in children with the first episode of acute pyelonephritis.

OBJECTIVE: Assessment of the first febrile urinary tract infection (UTI) in children has been the subject of debate for many years. Diagnosis of acute pyelonephritis (APN) is usually based on clinical and biological data. The clinical usefulness of early Tc-99m DMSA scintigraphy remains controversial, although it may influence the type and duration of treatment. The aim of this study was to assess the role of initial cortical scintigraphy in the detection of early renal parenchymal damage in children highly suspected of having APN and to compare the scintigraphic findings with selected clinical/laboratory parameters and ultrasonography. METHODS: A prospective study was conducted in 34 infants and young children (18 boys, 16 girls), aged 1.5-36 months (mean 9.8 ± 8.7 months), hospitalized with a first episode of clinically suspected APN. Within the first 5 days after admission, Tc-99m DMSA renal scintigraphy, ultrasonography (US), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell count (WBC) and urine analyses were performed. RESULTS: DMSA scintigraphy showed changes consistent with APN in 27/34 (79%) patients, with a mean age of 10.9 months, including 12 males (44%) and 15 (56%) females. Out of 9 febrile children with negative urine culture and supportive evidence of UTI, scintigraphy showed parenchymal involvement in 8 children (24% in the whole group, 30% in scintigraphically documented APN). There were no statistically significant correlations between the frequency or size of the initial scintigraphic abnormalities and age, sex, body temperature, CRP levels or ESR. A CRP level of >54 mg/L and a WBC of >13,300/mm³ had sensitivities of 56 and 59% and specificities of 86 and 71%, respectively. US showed changes consistent with APN in 7/34 (21%) in the whole group and in 7/27 (26%) patients with positive cortical scan (p < 0.05). CONCLUSION: Initial DMSA renal scintigraphy is a sensitive method for the early diagnosis of APN in young children and is useful in the assessment of the severity of kidney injury even in patients with negative urine culture. Clinical, biological and ultrasound parameters do not identify children with renal damage. Normal DMSA study, excluding parenchymal involvement and late sequelae, could minimize the use of scintigraphy in the follow-up and reduce the redundancy of cystography.

Investigation of blood perfusion and metabolic activity of brain tumours in adults by using 99mTc-methoxyisobutylisonitrile.

OBJECTIVES: (i) To examine blood perfusion and metabolic activity of various brain tumours using radionuclide cerebral angiography (RCA) and single-photon emission tomography (SPET) after a single dose of Tc-methoxyisobutylisonitrile (MIBI). (ii) To examine if the inclusion of RCA can improve insight into the relative contribution of tumour perfusion to the uptake of MIBI shown by SPET, and to improve evaluation of tumour biology. (iii) To determine the value and the roles of MIBI in the management of brain tumour patients. METHODS: Fifty adult patients (38 male, 12 female) with a total of 56 intracranial space-occupying lesions have been included prospectively, 37 of which were newly diagnosed and the remaining with signs of recurrence/rest of earlier resected and irradiated brain tumours. The control group consisted of nine volunteers with no evidence of organic cerebral disease. Scintigraphic examination consisted of a dynamic first-pass study lasting 60 s (3 s/frame) and two SPET studies (60 projections each, 25 s/projection), starting 15 min and 2 h after intravenous injection of MIBI. Regions of interest of the tumour and normal brain tissue were drawn on RCA and both early and delayed SPET slices. The following tumour/brain activity ratios have been calculated: (i) tumour perfusion index (P); (ii) early uptake index (E); (iii) delayed uptake index (D); and(iv) retention index (R). Analogous indices have been calculated from the same examinations performed in controls, reflecting maximal physiologic regional variations of perfusion and uptake in brain tissue. RESULTS: Mean P of various brain tumours (low-grade gliomas 0.98, anaplastic gliomas 1.14, glioblastoma multiforme 1.20, metastases 1.09, lymphomas 1.08) differ little from each other and do not exceed maximal physiologic regional variations of cerebral perfusion (1.33), with the exception of meningioma (1.87, F=2.83, P=0.015). The receiver operating characteristics curve analysis of P showed that for the cut-off value of 1.45 the sensitivity for distinguishing meningioma from other tumours is 75%, specificity 87%, positive predictive value 33% and negative predictive value 97%. Mean E of malignant brain tumours (8.3, n=31, 23 primary, eight secondary), except anaplastic gliomas (3.5, n=5), differed significantly (P=0.02) from those of benign gliomas (3, n=9) but not from that of meningioma (11.9, n=4). The cut-off value for distinguishing malignant from benign lesions on the basis of E set at 4.8 resulted in sensitivity 67%, specificity 75%, accuracy 70%, positive predictive value 80% and negative predictive value 60%. D and R showed tendency of wash-out of MIBI from meningiomas, but otherwise did not improve the results substantially. CONCLUSION: Integrated results of RCA and SPET with Tc-MIBI indicate that blood perfusion, blood-tumour barrier permeability and metabolic activity of the tumour are all very important for the resultant uptake shown by SPET. If the perfusion index is less than 1.45, then meningioma can be ruled out. Early SPET is recommendable for distinguishing glioblastoma from low-grade gliomas, as a complement to standard magnetic resonance imaging and/or computed tomography.