[18F-FDG positron emission tomography in the diagnosis and staging of marginal zone non-Hodgkin lymphomas].

OBJECTIVE: To investigate the diagnostic value of 18F-FDG positron emission tomography (PET) in the diagnosis and staging of marginal zone non-Hodgkin lymphomas (NHLs). MATERIAL AND METHODS: Twenty-four patients with new-onset NHLs were examined. Extranodal MALT lymphoma, splenic marginal zone lymphoma (MZL), and nodal MZL lymphoma were diagnosed in 18, 3, and 3 patients, respectively. 18F-FDG PET was carried out by the standard protocol via whole-body examination, by estimating the standardized tracer uptake value (SUV(max)) in the abnormal foci. RESULTS: Most (83.3%) of the examinees were found to have abnormal tracer hyperfixation foci. The mean SUV(max) was 5.05 ± 0.9. There was no correlation between SUV(max) in the tumor foci and their metabolic sizes (r = 0.1; p = 0.7). No significant differences between the mean SUV(max) were found in patients with different histological types of MZL (p > 0.05). Disease staging by PET and other diagnostic methods yielded contradictory results in three patients. The final analysis suggested that the stage had been correctly determined in all the 3 patients from PET findings. CONCLUSION: The results of 18F-FDG PET suggest that it is of high iagnostic value in imag-ng marginal zone NHLs. The major advantage of PET is that it can accu-ately stage the disease, which can provide a ra-ionale for optimal treat-ent policy.

[Differential diagnosis of brain gliomas by positron emission tomography using various radiopharmaceuticals].

OBJECTIVE: To comparatively study the diagnostic capabilities of positron emission tomography (PET) with various tumorotropic radiopharmaceuticals (TRPs) in detecting malignant brain gliomas (BG) and estimating their degree. MATERIAL AND METHODS: One hundred and fourteen patients, including 47 with histologically verified glioblastoma multiforme (GBM), 27 with anaplastic astrocytoma (AA), 23 with benign astrocytoma (BA), and 17 with postoperative cysts, were examined. PET was performed using TRPs: 18F-fluorodesoxyglucose (18F-FDG), 11C-sodium butyrate (11C-SB), 11C-L-methionine (11C-MET), and 11C-choline (11C-COL). RESULTS: Malignant gliomas (GBM and AA) were clearly visualized by PET using 11C-MET, 11C-CHOL, and 11C-SB. 18F-FDG PET visualization of tumors was difficult because of increased RP accumulation in the cerebral cortex. WHO grades II-III gliomas were completely visualized by 11C-MET PET. Only some tumors were clearly displayed by PET with 11C-CHOL and 11C-SB. The accumulation indices (AI) obtained by 11C-CHOL PET in patients with malignant gliomas were, on average, 4.0- and 5.5-fold higher than those by 11C-MET and 11C-SB PET, respectively. Significant differences (p < 0.001) in AI obtained by "C-CHOL ("C-CHOL-AI) PET were first established between the patients with GBM (WHO grade IV) and those with AA (WHO grade III). CONCLUSION: 11C-CHOL PET is the most sensitive method to identify gliomas and estimate their grade. The advantage of 11C-MET PET is the possible imaging of the entire volume of viable tumor tissue.

[Prognostic value of 18F-FDG positron emission tomography in the early evaluation of the efficiency of treatment in patients with non-Hodgkin lymphomas].

OBJECTIVE: To define the role of 18F-FDG positron emission tomography (PET) performed after 2-3 chemotherapy cycles in the prediction of disease prognosis and to identify a group of patients requiring more intensive treatment. MATERIAL AND METHODS: Seventy-one patients with non-Hodgkin lymphoma of different histological types were examined. PET was carried out at different stages of diagnosis and primary treatment in the patients. RESULTS: The examinations made after 2-3 polychemotherapy (PCT) cycles indicated that 36 (50.7%) patients continued to have signs of metabolic activity of lymphoproliferative disease (a PET-positive group) and 35 (49.3%) patients were found to have no abnormal tracer accumulation foci (a PET-negative group). Twenty-nine (82.9%) patients from the PET-negative group continued to remain in complete remission throughout the follow-up (the median follow-up was 405 days). At late stages, 6 (17.1%) patients were identified to have abnormal tracer hyperfixation foci that were indicative of disease recurrence. Only 8 patients from the PET-positive group were observed to show a complete metabolic response to treatment at the end of first-line PCT. The metabolic activity of the disease was maintained in the remaining patients. The results of PET conducted at the late stages of the follow-up indicated that metabolically active tumor foci continued to be visualized in 20 (55.6%) patients and further treatment resulted in complete remission in 16 (44.4%) patients. CONCLUSION: PET findings could predict the further course of the disease and differentiate more intensive treatment-requiring patients at the early stages of chemotherapy.

[First experience of using positron emission tomography with 11C-choline in prostate cancer (PC)].

Introduction into clinical practice of combined positron emission technology and computer tomography (PET/CT) allows in one study to identify structural and functional abnormalities. The study involves 32 patients who underwent PET/CT with "C-choline, including 5 patients with prostate cancer (PC), 3--with chronic prostatitis and 24--with biochemical PC recurrence. PET/CT with 11C-choline has a high diagnostic efficacy in detection of local recurrence and PC metastases in patients with biochemical PC recurrence. The results of visual analysis do not permit to distinguish PC from benign prostate diseases.

[Potential of PET in the diagnosis and the assessment of treatment effectiveness in progressive malignant glioma].

Examination including MRI (CT), PET with sodium 11C-butyrate (11C-SB) and 18fluorodeoxyglucose (18F-FDG) was carried out in 59 patients with continuing growth of malignant glioma. It was established that 11C-SB-PET is characterized by high sensitivity (94.1%) in detecting continuing growth as well as to differentiating it from necrosis. Our data were instrumental in prognosis and assaying metabolic levels in tumor (T/NT ratios) which are regarded as indices of accumulation (IA) of 18F-FDG-PET (FDG-IA) prior to conservative treatment. There were a direct correlation between metabolic activity of neoplasms and an inverse one with FDG-IA (r=-0.24).

[Positron emission tomography with 18F-FDG compared with proliferative activity of tumor cells in different subtypes of non-Hodgkin lymphoma].

In the course of this study we determined the ability of positron emission tomography (PET) with the 18F-FDG to detect non-hodgkin lymphoma lesions, assess their proliferative activity and differentiate aggressive tumors from indolent. Tracer uptake in lymphoma was evaluated semiquantitatively by calculation of standardized uptake values (SUV). It was compared with tumor grade and proliferation fraction determined by Ki-67 staining. In patients with indolent lymphoma, mean SUV was 2.5 +/- 0.6. In patients with aggressive lymphoma a significantly higher 18F-FDG uptake was observed (mean SUV was 8.1 +/- 1.3). Linear regression analysis indicated significant correlation of 18F-FDG uptake to biopsy samples proliferation fraction in patients with diffuse large B-cell lymphoma (r = 0.55, p = 0.05) and indolent non-Hodgkin's lymphoma (r = 0.7, p < 0.05). In this clinical study 18F-FDG uptake correlates with the aggressiveness of malignant lymphomas and with biopsy samples proliferative activity.

[Use of 18F-FDG PET scan in the diagnosis of large liver neoplasms and in the evaluation of therapeutic effectiveness].

The study involved 207 patients with large-size tumors. Results of 18FDG PET pointed to the basic factor of malignant transformation--foci of enhanced accumulation of radiological medicinal substances. Absence of ultrasound and CT-based evidence of such pathological accumulations contributed to interpretation of changes as benign ones. The effectiveness of chemotherapy was assessed by tumor metabolic response to treatment given at the time of 18FDG PET examination.

[Twelve years' clinical experience in using positron emission tomography: advances and prospects].

The paper describes 12 years' experience in using positron emission tomography (PET) at the Russian Research Center of Radiology and Surgical Technologies to detect cancer, cardiac, and psychoneurological diseases, to make their differential diagnosis, and to evaluate the efficiency of their treatment. It shows the capacities of PET using various radiopharmaceutical agents in a broad spectrum of the above abnormalities and defines prospects for further development of the technique.

[Use of 18F-FDG positron emission tomography in the diagnosis and evaluation of the efficiency of treatment for resistant anxiety-obsessive disorders].

The purpose of the investigation was to study the capacities of 18F-FDG positron emission tomography (PET) in the diagnosis and evaluation of the efficiency of treatment for resistant anxiety-obsessive disorders (AOD). 18F-FDG PET was performed in 21 patients with AOD. In 17 cases, the studies were made before and after therapy. Fourteen patients underwent stereotactic surgical intervention. Pretreatment 18F-FDG PET showed that the patients with AOD had hypermetabolism in the cingulated gyri, caudate nuclei, and thalamus in 7, 8, and 6 cases, respectively. A varying clinical improvement (by the Y-OCS and Spilberger scales) was observed in all the examinees after complex or drug treatment throughout the follow-up. According to the data of PET, these patients were observed to have significantly reduced metabolism of glucose in the anterior cingulated guri and its increased metabolism in the heads of the caudate nuclei and thalamus. The metabolic changes detected by PET are strongly and moderately correlated with the pattern of a clinical picture (p < 0.05). It is concluded that the use of 18F-FDG PET makes it possible to provide more accurate insight into the pathogenetic mechanisms responsible for the development of AOD, to objectify the choice of targeted intracerebral structures in order to perform stereotactic neurosurgical interventions, and to optimize drug therapy and to evaluate the efficiency of the treatment performed in early periods.

[Positron emission tomography in oncourology].

The authors present the results of the examination of 61 patients with genitourinary space-occupying lesions, using 18F- fluorodeoxyglucose positron emission tomography (PET) in whole body mode. In all cases the diagnosis was verified morphologically. The results demonstrated high diagnostic accuracy of PET, including possibility to determine the extent of oncourological cancer. However, the method displays poor efficacy in cases of hypernephroid cancer due to low level of glycolysis in this type of tumor.

[The role of positron emission tomography with C18-Fluorodeoxyglucose in clinical oncology]. / Primenenie pozitronnoi émissionnoi tomografii C18-F-ftordezokcilgliukozoi v klinicheskoi onkologii.

The study was concerned with evaluation of the diagnostic potential of positron emission tomography (PET) with 18-FDG in clinical oncology and elucidation of its role in assessing therapy effectiveness. The Ecat Exact 47 and Ecat Exat HR+ (Siemens) insatllations were used to examine 674 patients, with Whole Body protocol used in 585. PET with 18-FDG proved highly effective in diagnosing malignancies of the breast, lung, liver, pancreas, testis, brain and lymphoma as well as evaluating the efficacy of therapy.

[Assessment of 18FDG PET for diagnosis of pancreatic tumors]. / Vozmozhnosti PET s 18F-FDG dlia diagnostiki opukholei podzheludochnoi zhelezy.

The paper examines the informational value of positron emission tomography (PET) using 18FDG in the diagnosis of malignant of neoplasms of the pancreas and in the estimation of the extent of a metastatic involvement. Forty-four patients (26 males and 18 females whose age ranged from 28 to 60 years) with histologically verified cancer of the pancreas were examined. The study was conducted in the whole body mode on an Ecat Exact 47 positron emission tomograph following 70-90 minutes of administration of 18FDG, 370-420 MBk. To assess the findings, the differential accumulation ratio (DAR) of formation/liver was calculated. The mean DAR in patients with benign and malignant pancreatic tumors was 1.17 +/- 0.064 and 4.90 +/- 0.3 (p < 0.05). There was a false positive case in a patient with an exacerbation of chronic pancreatitis in the study. A relationship was observed between the level of tumor tissue 18FDG capture and the degree of malignancy. PET scanning in the whole body mode estimates the extent of a tumorous process. The authors' data show that the liver was most commonly involved in a metastatic process (96.6%). Hence, 18FDG PET is a highly informative technique in the diagnosis of malignant pancreatic tumors and in the estimation of the extent of a metastatic process and permits a differential diagnosis between benign and malignant tumors.

[Comparative assessment of the diagnostic capacities of PET with 18FDG and 1-[11C] sodium butyrate in the examination of patients with tumors of the brain and cerebral circulatory disorders: results of semiquantitative assessment]. / Sravnitel'naya otsenka diagnosticheskikh vozmozhnostei PET s 18F-FDG i 1-[11C]-butiratom natriia pri obsledovanii bol'nykh s ob"emnymi obrazovaniiami golovnogo mozga i narusheniiami mozgovogo krovoobrashcheniia (rezul'taty polukolichestvennoi otsenki dannykh).

The purpose of the present study was to determine the capacities of differential diagnosis of the bulky masses of the brain by positron emission tomography (PET) with 11C-butyrate by the direct indication--the tumor RFP level measured by means of the semiquantitative indicator--the differential accumulation coefficient (DAC). For comparison, 18FDG PET widely used to detect malignant tumors was preliminarily made. Brain PET was performed in 86 patients (45 males and 41 females whose age ranged from 18 to 69 years to identify bulky masses or to rule out continuous tumor growth. In all cases, the data were histologically and morphologically verified. Of the 86 patients, 21 were found to have malignant tumors, 41 had benign tumors, arteriovenous malformations, cerebral circulatory disorders, and cysts were detected in 3, 7, and 14 cases, respectively. The level of 18FDG accumulation was ascertained to be directly related to the grade of malignancy. In 20 of the 21 patients with malignant tumors, DAC for 18FDG was greater than 1. However, it was impossible to differentiate benign tumors and non-tumoral masses by using only 18FDG. Comparing the data obtained by means of 18FDG and 11C-butyrate revealed their comparability in detecting neoplasms. Patients with vascular tumors (benign meningioma and adenoma of the pituitary were an exception. Their DAC for 11C-butyrate was greater than 1. In follow-up CT scanning, just a single injection of 11C-butyrate may allow one to estimate the vascular and tissue components of masses, which facilitates the identification of vascular non-tumoral processes and tumors. The additional criterion that allows a neoplasm to be differentiated from nontumoral processes permits a rapid tumor release of a radioactive label.

[Experience on clinical application of positron emission tomography with a new radiopharmaceutical preparation sodium 11C-butyrate in differential diagnosis of pathological volume in brain formation]. / Opyt klinicheskogo primeneniia pozitronnoi émissionnoi tomografii s novym radiofarmatsevticheskim preparatov 11C-butiratom natriia v differentsial'noi diagnostike ob"emnykh obrazovanii golovnogo mozga.

The study was aimed to investigate the possibilities of the application of a new radiopharmaceutical--"Sodium butyrate, [1-(11)C]" (11C-Butyrate) for differential diagnosis of pathological volume brain formations. Positron emission tomography (PET) ("Ecat Exact 47", Siemens) of the brain was performed in 24 patients (14 male & 10 female, aged 19-56). The scanning was carried out as static scan 4-5 min after intravenous administration of 250-350 Mbq 11C-Butyrate and proceeded within 15-20 min. In addition PET with 18F-FDG was performed in all patients. The data had been verified histologically and morphologically. In 15 out of 24 patients the brain malignant tumor has been discovered, in 4 patients--benign tumors, in 5--postoperative cysts. Results of the studies showed that the ratio tumor/normal tissue in case of 11C-Butyrate and 18F-FDG application proved to be comparable for all studied hystological types of tumors. Malignant tumors in these cases had been visualized as a hot sports-fokci of increased uptake 11C-Butyrate (ratio > 1). The obtained data testify to the possibility of 11C-Butyrate application for differential diagnosis of the pathological volumic brain formation.

[Application of new radiopharmaceutical "Sodium 11c-butyrate" and positron emission tomography in patients with coronary artery disease]. / Primenenie pozitronnoi émissionnoi tomografii s novym diofarmatsevticheskim preparatom 11C-butirat natriia dlia otsenki sostoianiia miokarda u patsientom s IBS.

UNLABELLED: The aim of this study was to examine the diagnostic value of Sodium 11C-Butyrate (11C-Butyrate) in assessing perfusion and oxydative metabolism in patients with coronary artery disease (CAD). 41 patients (39 male and 9 female, mean age 48 +/- 11) with CAD were investigated. PET-scans were performed twice: at 2-7 min and 25-31 min after i.v. injection of 250-400 MBq 11C-Butyrate. Regional perfusion was evaluated by the uptake of radioactivity in the myocardium at the first scan, intensity of beta-oxidation--by decreasing the uptake level at the second scan. RESULTS: Myocardium of the left ventricle was good visualized at the first scan. It was demonstrated fast elimination of radioactivity in segments with normal oxidative metabolism of 11C-Butyrate at the second scan. Fixed defects were seen in the scar segments both at first and second scans. Decreased uptake of 11C-Butyrate at the first scan and diminished rate of agent elimination caused by depressed beta-oxidation at the second scan were revealed in ischemic segments. CONCLUSION: Application of PET with 11C-Butyrate in patients with CAD allows estimate hypoperfused segments, evaluate heart oxidative metabolism and provides differential diagnosis of scar and ischemia.

[Joint PET and electrophysiological research on human thinking activity]. / Sovmestnye PET i élektrofiziologicheskie issledovaniia myslitel'noi deiatel'nosti cheloveka.

Recent studies of a group of researchers from the Institute of Human Brain (St.-Petersburg), concerning the role of the distributed brain systems in different kinds of perceptual and cognitive acts, are reviewed in this paper. Principally different approaches were used, i. e., electrophysiological (multi-unit record with implanted electrodes) and positron emission tomography (PET). Possibility and benefit of application of the combined analysis of these different sets of data in order to obtain more detailed information on the work of the brain systems are discussed. On the basis of some examples of such a combined analysis the authors conclude that such a combined approach is the optimal way to reach a deeper insight into the anatomical-functional organization of the human brain.