Metabolic activity of breast cancer metastatic lesions on positron emission tomography/computed tomography: comparison with histological and biological characteristics of primary tumor.

Higher intensity of FDG uptake on PET/CT in primary tumor is seen in patients with IDC compared to ILC, also in high grade tumours, tumours with negative ER and higher Ki67 values, while data are inconsistent in case of relation between primary tumor's PgR and HER2 expression with its metabolic activity levels. On account of the lack of studies that include research of breast cancer metastatic lesion metabolism level and its relation to tumor histology and biology, our goal was to investigate the association of metastatic lesions' glucose metabolism level on PET/CT with different histological and biological characteristics of primary tumor. In a total number of N=100 patients, highest SUVmax values for each patient were used in testing difference between metastatic metabolic activity in patients with different tumor histology, grade, ER, PgR and HER2 status, subtype, as well in testing relation of Ki67 index to metastasis' metabolism level. In testing difference between histological types of breast cancer, SUVmax values were also compared separately for each specific anatomical site (regional and distant lymph nodes, bones and liver). No difference was found regarding metastatic SUVmax values in patients with primary IDC (n=55, median SUVmax 9.70) and ILC (n=34, median SUVmax 7.20) independently of anatomic site, and for each of analysed sites separately. No difference was found as well between SUVmax detected in metastasis in patients with different grade (grade II: n=58, median SUVmax 7.70; grade III: n=12, median SUVmax 10.20), ER (59 positive, median SUVmax 8.50; 22 negative, median SUVmax 8.05), PgR (55 positive, median SUVmax 8.50; 23 negative, median SUVmax 7.80), and HER2 (14 positive, median SUVmax 6.84; 51 negative, median SUVmax 8.63) expression in primary tumor, and between patients with different tumor subtype. Ki67 was also not associated with tumor metastatic SUVmax values (n=11, rs = -0.21, p=0.53). We conclude that there is no association of primary breast cancer histological type, grade, ER, PgR, HER2 and Ki67 expression with metabolic activity in metastasis detected on PET/CT.

Evaluation of the SIOPEN semi-quantitative scoring system in planar simpatico-adrenal MIBG scintigraphy in children with neuroblastoma.

Neuroblastoma is the most common malignancy in children comprising 7.6% of all infantile cancers. MIBG scintigraphy is a mandatory neuroblastoma diagnostic test, which is among others methods, semi-quantified by the SIOPEN method. The aim of this study was to test both the skeletal and the soft tissue segments of the SIOPEN scoring method in the diagnostic milieu and to correlate them with the Curie score. Since there is little knowledge of their diagnostic power, the following variables were tested: VMA, HVA, LDH, and MYCN, ferritin, bone marrow infiltration, the INSS and the INPC classification. The cross-sectional study with repeated measurements of 143 scintigrams was performed on 76 pediatric patients with suspected or proven neuroblastoma, who had been referred to the Center for Nuclear Medicine of the Clinical Center of Serbia in the period 2007-2012. The range of the SIOPEN soft tissue scores was 0-5. The range of the SIOPEN skeletal scores was 0-57. The range of the Curie scores was 0-26. The skeletal SIOPEN scores were significantly higher in bone marrow positive children, in children with pathologically elevated urinary VMA levels and in children having a more advanced clinical stage. There was no difference in the SIOPEN soft tissue score due to higher VMA levels, or depending on the clinical stage and positive bone marrow assessment. There was no difference between the SIOPEN skeletal and soft tissue scores on one hand and the histological grade of the tumor; elevated or normal levels of HVA, LDH, NSE and ferritin, or the presence or absence of MYNC amplification in the neuroblastoma cell line, on the other hand. The results of both SIOPEN scores showed a high linear correlation with the Curie score. The conclusion is that the soft tissue segment of the SIOPEN score needs further elucidation in a more controlled milieu. Excellent correlation between all segments of the two semi-quantitative scoring methods speaks in favor of the application of the complete SIOPEN scoring system in every day mIBG scanning.

Comparison of 18F-FDG PET/CT and MDCT for staging/restaging of non-small cell lung cancer.

UNLABELLED: Multi-detector computed tomography (MDCT) is most commonly used for staging of non-small cell lung cancer (NSCLC). In recent years, 18F- fluorodeoxyglucose positron emission tomography combined with computed tomography (18F-FDG PET/CT) has also been used for the same purpose. Since studies comparing these two methods are scarce, our aim was to determine how the TNM classification and thereby staging of NSCLC compare between 18F-FDG PET/CT and MDCT. 18F-FDG PET/CT and MDCT were collected in 83 patients with NSCLC 3 to 30 days apart (median 17 days). The investigators interpreting 18F-FDG PET/CT were unaware of MDCT results. The Cohen's kappa (κ) was calculated to determine the rate of agreement. The hypothesis was that the strength of agreement between the two methods will be at least moderate (κ>0.40) based on the adopted criteria (κ<0.20 poor; 0.21-0.40 fair; 0.41-0.60 moderate; 0.61-0.80 good; 0.81-1.00 very good agreement). The agreement was moderate for determining the T class (κ=0.45, overall agreement 58%), poor for the N class (κ=0.13, 42%) and fair for the M class (κ=0.22, 58%). The agreement for overall staging of NSCLC was poor (κ=0.20, 45%). The major source of disagreement was that metastases were present more frequently and/or in larger number on 18F-FDG PET/CT than MDCT in the contralateral mediastinal, supraclavicular, and distant lymph nodes, as well as in the bones and suprarenal glands. Since 18F-FDG PET/CT detected more regional and distant metastases than MDCT, we conclude that FDG PET/CT is useful for staging/restaging and planning treatment of patients with NSCLC. KEYWORDS: Non-small cell lung cancer, positron emission tomography, multidetector computed tomography, metastases detection.

The clinical value of scintigraphy of neuroendocrine tumors using (99m)Tc-HYNIC-TOC.

PURPOSE: To assess the value of whole body scintigraphy using (99m)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT) in the detection of primary and metastatic neuroendocrine tumors (NETs). METHODS: Thirty patients with different neuroendocrine tumors, mainly gastroenteropancreatic (GEP), were investigated. Whole body scintigraphy was performed 2 h (if necessary 10 min and 24h) after i.v. administration of 740 Mbq (99m)Tc-Tektrotyd, Polatom. In cases of unclear findings obtained by whole body scintigraphy, investigation was followed by SPECT. RESULTS: From 12 patients with NETs of unknown origin, there were 10 true positive (TP), and 2 false negative (FN) findings. Diagnosis was made with SPECT in 6 patients. From 8 patients with gut carcinoids, there were 4 TP, 2 true negative (TN), one FN, and one false positive (FP) finding. Diagnosis was made with SPECT in 2 patients. From 7 patients with neuroendocrine pancreatic carcinomas there were 4 TP and 3 TN findings. Diagnosis was made with SPECT in 2 patients. From 3 patients with gastrinomas there were 2 TP findings and one TN findings. Diagnosis was made with SPECT findings in 2 patients. Sensitivity of (99m)Tc-HYNIC-TOC was 87%, specificity 86%, positive predictive value 95%, negative predictive value 67% and accuracy 87%. CONCLUSION: We concluded that scintigraphy with (99m)Tc-Tektrotyd is an useful method for diagnosis, staging and follow up of the patients with NETs.

The effect of certain biochemical factors on well clogging under suboxic and mildly anoxic conditions.

Research conducted at the Belgrade Groundwater Source in Serbia has shown that significant well screen clogging processes take place under reduced oxic and initial anoxic conditions. Criteria for the prevention, or deceleration, of clogging are becoming more relevant to well ageing, compared with classical, mechanical clogging criteria and the permissible entrance velocities derived from them. The research project was later expanded to encompass other alluvial sources, which feature distinct oxic conditions. This paper presents some of the outcomes of this project, which shed light on the correlation between certain important indicators of well screen clogging (such as the redox potential and iron concentration) and the rate of increase in local hydraulic resistance at the wells.

Scintigraphic detection of colon carcinomas with iodinated monoclonal antibodies.

PURPOSE: The aim of this study was to evaluate the clinical reliability of the immunoscintigraphy with iodinated monoclonal antibodies for the detection of metastases and recurrences of colon carcinomas. METHODS: A total of 45 patients with colon carcinoma was investigated with gamma camera, after intravenous application of iodinated monoclonal antibodies. RESULTS: The sensitivity of the method was 90%, specificity 86%, positive predictive value 93%, negative predictive value 80% and accuracy 87%. There was statistically significant relationship between immunoscintigraphic and ultrasonographic (US) findings (p=0.005). Also, there was significant relationship between immunoscintigraphy and Dukes stage (p=0.019). Tumor marker levels were not significantly correlated with immunoscintigraphic findings (p<0.05). Significant difference was noted in patients with positive findings for malignancy on US and immunoscintigraphic findings (p=0.006), i.e. patients with positive findings for malignancy had more frequently immunoscintigraphic findings of malignancy. Correlation with other diagnostic procedures (rectoscopy, colonoscopy, CT) did not show significant correlations. CONCLUSION: We conclude that immunoscintigraphy can be helpful in the detection of metastases and recurrences of colon carcinomas.

Several natural indicators of radial well ageing at the Belgrade groundwater source, part 2.

From 2005 to 2009, research was conducted at the Belgrade Groundwater Source (BGWS) to investigate the process of clogging of wells with horizontal lateral screens (radial wells). The clogging process was monitored via the kinetics of the increase in hydraulic losses at the laterals. A correlation of this process with the redox potential, the iron concentration in water, and the microbial population growth at the laterals and in their immediate vicinity was established. Research outcomes are presented here from a study of five wells where laterals were replaced between 2006 and 2008. Derived dependencies were later used to define the preferred approach to the installation and maintenance of well laterals at the BGWS. Results contribute to the study of well ageing caused by biochemical clogging.

The utility of 99mTc-EDDA/HYNIC-TOC scintigraphy for assessment of lung lesions in patients with neuroendocrine tumors.

UNLABELLED: Our aim was to assess clinical utility of 99mTc-EDDA/HYNIC-TOC scintigraphy for evaluation of lung lesions in patients with neuroendocrine tumors (NETs). Single photon emission computed tomography (SPECT) of the thorax and whole body scintigraphy were performed in 34 patients using 99mTc-EDDA/HYNIC-TOC. Visual assessment was complemented by semiquantitative evaluation based on tumor to non-tumor (T/NT) ratio. Clinical, laboratory, and histological findings served as the standard for comparison. Enhanced tracer uptake was observed on both SPECT and whole body scintigraphy in 29 of 34 patients (88% sensitivity). T/NT ratios were significantly higher on SPECT than whole body images (2.96+/-1.07 vs.1.70+/-0.43, p KEYWORDS: 99mTc-EDDA/Hynic-TOC, lung involvement of NETs, T/NT ratio.

Is there a future role for immunoscintigraphy in the diagnosis of colorectal carcinoma?

Immunoscintigraphy combines the advances in immunology and nuclear medicine to target tumor sites. Visualization of colorectal carcinomas is based on different monoclonal antibodies and their fragments against tumor-associated antigens labeled with gamma emitting radionuclides which accumulate in the tumor tissue due to their interaction with corresponding antigens. Available data on the role of immunoscintigraphy in detection of recurrence and metastases of colorectal carcinomas are reviewed. Despite a variety of investigations related to the application of immunoscintigraphy in diagnostics of colorectal cancer, using different radiolabeled immunoreactive agents and imaging methods there has not been a consensus among the investigators regarding the best modality of the method, including the specific radiopharmaceutical for this purpose. Some general conclusions concerning potentials of immunoscintigraphy in such diagnostics, including expectancy of the newly developed SPECT/CT systems, are suggested. The possibilities of PET imaging of colorectal carcinomas using monoclonal antibodies labeled with positron emitting radionuclides, as well as of the radioimmunoguided surgery and radioimmunotherapy are also discussed. Key words: Immunoscintigraphy, colorectal cancer, recurrences, metastases, radioimmunoguided surgery, SPECT/CT.

Estimation of the relative liver perfusion using two methods of radionuclide angiography in the patients with hemodynamic disorders in the portal system.

The aim of this study is the assessment of the relative arterial and venous contribution to the total liver blood flow (hepatic perfusion index-HPI), with two methods (S1 and S2), and estimation of their value. With this correction, HPI nonsignificantly increases (p>0.05) in all the groups of patients, with a very high correlation between the HPI (S1) and HPI (S2) values (p<0.01). In comparison to the portal perfusion in controls, values were significantly (p<0.01) lower in chronic active hepatitis and liver cirrhosis and differed between themselves (p<0.01). In the groups of cirrhotic patients with esophageal varices, sclerosated esophageal varices, recanalized umbilical vein, portal thrombosis and cavernous portal vein, portal perfusion was lower (p<0.01) than in controls, chronic active hepatitis and liver cirrhosis without collaterals. Both angioscintigraphic methods are useful for the estimation of the disturbances in the portal system. Because of the more exact estimation of the liver perfusion, S2 is recommended.

Radioimmunoscintigraphy of colorectal carcinomas with three different radiopharmaceuticals.

The aim of the study was evaluation of the clinical reliability of the immunoscintigraphy for the detection of metastases and recurrences of colorectal carcinomas using three different radiopharmaceutical substances. With IMACIS 1, the number of true negative findings (TN) was 4/7 and true positive (TP) 3/7, while in one patient, the results of immunoscintigraphy significantly influenced the therapeutical management. With INDIMACIS 19-9, there were 2/8 TN and 6/8 TP. In three patients, immunoscintigraphy results influenced patient further management. With ONCOSCINT in 2 patients findings were TN, in one FN and in one FP. In 3 patients, immunoscintigraphy influenced the management of the patient. Other imaging methods (CT, US, MRI) have advantage in detection of liver metastases, while immunoscintigraphy is more specific for the assessment of reccurences of the abdominal tumors. Thus immunoscintigraphy should be applied in patients with suggested recurrences and inconclusive outcome of routine diagnostic workup.

[Hepatobiliary scintigraphy in evaluation of liver transplant function].

The aim of the study is evaluation of hepatocellular function, as well as morphology and patency of the biliary three of the liver transplants by dynamic hepatobiliary scintigraphy. The study was performed in 10 controls and 10 patients after orthotopic transplantation (up to two years). Sixty minutes dynamic acquisition (1 frame/min) was performed with scintillation camera after injection of 360 MBq 99mTc-diethyl- IDA. Hepatobiliary scintigrams were analysed for morphology, and parenchymal and hepatobiliary TA curves were generated and analysed as regard to the time to maximal acitivity (Tmax) and the time to half of maximum acitivity (T1/2). Uptake of the radiopharmaceutical was slightly but not significantly delayed (Tmax=18.5 +/- 2.9 min) in comparison to the controls (Tmax=14.2 +/- 3.4min), while excretion was significantly prolonged (T1/2=59.5 +/- 12.1 min) than physiological (Tmax=34.2 +/- 4.1min). Intrahepatic bile flow was nonsignificantly prolonged (Tmax=31.3 +/- 3.7 min) in comparison to the controls (Tmax=25.7 +/- 3.5 min) while extrahepatic one is high significantly prolonged (T1/2=89.0 +/- 14.3 min) than physiological (T1/2 =45.0 +/- 7.2 min). Biliary phase of hepatobiliary scintigraphy showed increased accumulation of radiopharmaceutical in the left (n=1) or right (n=2) hepatic duct. Radionuclide methods are noninvasive, and apear to be sensitive and valuable for the monitoring of liver transplants.

Detection of gastrointestinal and abdominal infections by 99mTc-ciprofloxacin.

BACKGROUND/AIMS: The aim of the study is detection and evaluation of the abdominal and gastrointestinal infective foci using 99mTc-ciprofloxacin (Laboratory for radioactive isotopes, Vinca). METHODOLOGY: In total 21 patients with clinical suspicion on abdominal or gastrointestinal infection were investigated. In all the patients, planar liver/spleen scintigraphy was performed. Ciprofloxacin chloride (3.5 mg) was mixed with 555 MBq of 99mTc in 3 mL of physiological solution and incubated for 20 min. After slow i.v. injection in a cubital vein, dynamic acquisition (1 f/min) was performed during the first 60 min in the position of interest, followed by static acquisition (500,000 imp) anterior and posterior view, abdomen and pelvis after 1 h and 4 h in all patients. When necessary, additional scintigrams were acquired after 24 h. In all the patients with negative or equivocal findings of planar scintigraphy, emission computerized tomography (SPECT) was performed (60 positions, 6 degrees). Interpretation was made by three independent observers. Additional data were provided using clinical findings, ultrasonography, computed tomography and magnetic resonance imaging, laboratory analyses, and surgical or microbiological confirmation of infection. RESULTS: There were eleven true-positive findings, seven true negative, two were false negative while one was false positive due to intestinal obstruction. Sensitivity was 79%, specificity 91%, positive predictive value 92%, negative predictive value 77%, accuracy 84%. CONCLUSIONS: According to our results, scintigraphy with radiolabeled ciprofloxacin is a useful method for detection and assessment of exact localization of abdominal and gastrointestinal infections.

[Methods for the quantification of left ventricular volumes assessed by radionuclide ventriculography (first part)].

The purpose of this study was to point out the existing methods and to describe and evaluate the accuracy of new, original, "Geometric-count-based" (GCB) method, based on radionuclide ventriculography, for the measurement of left ventricular volumes compaired to the contrast ventriculography. By having done this, the aim was to compare the accuracy of GCB method and other two radionuclide methods available for left ventricular volume measurements: Count-bases Massardo method and gated blood pool SPECT method. In GCB method count based data from radionuclide ventriculography were combined with geometric ones assuming a prolate ellipsoid left ventricular's shape with identical short axes. The following equation for computing left ventricular end-diastolic volume was developed: EDV = 2 x c x M x C(tot)/C(max), (1) where: 2c--manually drown short axis of prolate ellipsoid (left ventricle) at end-diastolic frame, M-calibrated pixel size, C(tot)--total counts in left ventricular's region of interest at end-diastolic frame, C(max)--maximum pixel counts in left ventricular's region of interest. Physical experiments with two different heart shaped phantoms were used to compare volumes assessed by all three radionuclide methods with the true volumes. The true volumes of cylindrical and ellipsoid phantoms of 112.5 ml and 190.5 ml, were computed to be 114 ml and 196 ml by our GCB method, 168 ml and 180 ml by Massardo method and 142 ml and 222 ml by gated blood pool SPECT methods, respectively. In clinical study, in 65 patients volumes assessed by radionuclide methods were compared to volumes measured using single plane contrast ventriculography as a gold standard. A good correlation of our original method was obtained with a contrast ventriculography for both EDV/m2 and ESV/m2 (r = 0.94, r = 0.92), slightly lower for Massardo method (EDV/m2: r = 0.90, ESV/m2 : r = 0.89) and significantly lower for gated blood pool SPECT (EDV/m2: r = 0.85, ESV/m2: r = 0.81, p < 0.01). In conclusion, both, phantom and clinical studies indicate that GCB radionuclide method is accurate, noninvasive for left ventricular volumes' measurement and should be widely used in everyday clinical practice.

[Scintigraphic diagnosis of inflammation and infection].

Nuclear medicine, diagnostic and therapeutic application of open sources of ionizing radiation in medicine, has wide range of possibilities for non-invasive infection and inflammation detection. The broad spectrum of methods, some of which are already in routine use while the others are still in the phase of investigation, improvement, or clinical trials, is presented. Most of the methods in routine use are capable of detection and localisation of both inflammation and infection. Antibiotic and antimicrobe peptides labelings have the possibility to diagnose infection and to differentiate it from inflammation, which is not the case with other scintigraphic methods. Availability of the radiopharmaceuticals and nuclear-medicine equipment, radiation exposure of the patient, clinical situation, the baseline pathophysiology of a process, and costs are the factors which contribute to the choice of the diagnostic approach. In order to ease the choice of the appropriate diagnostic method for inflammation/infection detection in different clinical situations, the recommendations from the ISORBE (International Society of Radiolabelled Blood Elements) are quoted.

[Radionuclide detection of Helicobacter pylori infection].

The aim is the assessment of the HP infection in stomach using breath test and comparison to other diagnostic methods, as well as following up the effect of therapy. In 83 patients with digestive discomfort rapid urease test, histology and breath test were performed, while in 25 patients with proven HP infection the effect of therapy was followed up using breath test and clinical findings. For rapid urease test and histology, samples were taken from antral mucosa. Breath test was performed after per oral administration of the capsule of 14C- urea (37 kBq) (Izotop, Hungary and Laboratory for radioactive isotopes, Vinca) which, in the presence of Helicobacter pylori breaks up to 14CO2 and NH3. Radioactivity was measured by beta counter in the exhaled air fasting and 30 minutes after ingestion of the capsule. According to our results, the rise of activity over 100% was considered positive. From 83 patients, 58 were breath test was positive, 24 negative and one equivocal. Fast urease test was in 54 positive, in 29 negative while histology was in 57 postitive and 26 negative. Findings of the breath and urease tests were in accordance in 93% patients while breath test and histology in 98% patients. During follow up of the therapeutic effects, breath test and clinical findings were in accordance in 98% patients. Breath test can be useful in diagnosis but is a method of choice in following up the patients after therapy for H. pylori infection, because it is non-invasive, fast and precise.

[Implementation of the radiolabelled antibiotic in the detection of orthopedic infections].

The aim of the study is detection and evaluation of the orthopedic infections using 99mTc-ciprofloxacin, radiopharmaceutical supposed to distinguish inflammation from infection. There were 15 true positive findings, 9 true negative, and two were false positive, while 1 was false negative. Sensitivity was 94%, specificity 82%, positive predictive value 88%, negative predictive value 90% and accuracy 89%. According to our results, scintigraphy with 99mTc-ciprofloxacin is a useful method for detection and assessment of exact localization of orthopedic infections, which might be useful for (differential) diagnosis, surgical treatment in due time as well as monitoring of the treatment of conservative therapy.

[Initial 111In-platelet kinetics: indicator of platelet sequestration/destruction site or quality control of platelet labelling?].

Taking into consideration the existing disagreement in the literature, the aim of this paper was to estimate the value of the initial kinetics of autologous platelets labelled with 111In-oxinate, performed during the first 20 minutes after their intravenous injection. Two hypothesis were tested: 1. Initial 111In-platelet kinetics indicates the platelet sequestration site (in patients with normal mean platelet life span)/destruction site (in patients with shortened mean platelet life span), 2. Initial 111In-platelet kinetics indicates the quality of platelet separation and labelling procedure. We performed initial labelled platelet kinetics in thrombocytopenic patients (in order to test the first hypothesis) as well as in control (healthy) subjects (in order to test the second hypothesis). Thirty-nine persons were investigated: 33 with thrombocytopenia: 25 with shortened mean platelet life span, caused by chronic im mune thrombocytopenic purpura (ITP), eight with normal platelet life span and thrombocytopenia caused by myelodysplastic syndrome (MDS), six healthy, control subjects (C). In all 39 persons platelet blood count on the day of platelet labelling was determined, autologous platelet labelling with 111In-oxinate was performed, general and differential yields of platelet labelling (GYL and DYL), as well as mean labelled platelets life span were determined. Besides that, initial labelled platelets kinetics was performed with initial 111In-platelets accumulation in the liver (IPAL) calculation, as well as the late platelet kinetics for platelet sequestration index and platelet sequestration/destruction site determination. We obtained two types of initial labelled platelets kinetics (not only in the patients with shortened platelet life span, but also in the subjects with normal labelled platelets life span), which differed in the IPAL value and in the ratio of the liver and the heart radioactivity: IPAL < 20% and IPAL>20%. We found statistically significant difference in GYL and DYL between the two groups: IPAL<20% and IPAL > 20%. Both yields were higher in IPAL<20% group. There was no significant difference between the two IPAL groups in the platelet blood count, labelled platelet life span, sequestration index and sequestration site. No correlation could be found between IPAL on one side and platelet blood count, sequestration index, and sequestration site on another. We concluded that initial labelled platelet kinetics could not indicate the platelet sequestration/destructon site (which is accomplished by the late labelled platelets kinetics), but nevertheless, it is very sensitive and useful method of platelet separation and labelling quality control. While in vitro quality control parameters (GYL and DYL) indicate the quality of only one part of this procedure, initial labelled platelet kinetics reflects discrete platelet function disturbance that might happen from the moment of blood sample collection till the labelled platelets intravenous injection.

[Prediction of the splenectomy efficacy in chronic immune thrombocytopenic purpura].

The aim of this investigation was to estimate the possibility of predicting the splenectomy response in patients with chronic immune thrombocytopenic purpura (ITP). The patients' age, sex, megakaryocytes abundance, platelet blood count, production, life span, sequestration/destruction site were considered as possible predictive factors. Thirty-four ITP patients (23 female and 11 male) aged from five to 83 years were investigated. Platelet blood count ranged from 4 to 106 x 10(9)l (mean value was 43 x 10(9)/l). Megakaryocyte abundance was determined in 19/34 ITP patients. Megakaryocytes were numerous in 11/19, present in 7/19 ITP patients and in one patient low megakaryocyte number was registered. In all 34 ITP patients autologous platelet labelling with 111In-oxinate was performed and labelled platelets were reinjected to the ITP patients. This enabled platelet life span, production, sequestration index and sequestration/destruction site determination. Platelet life span ranged from 0,4-5 days (mean value was 1 day). Mean value for platelet production index was 1,1. Platelet sequestration/destruction site in 16 ITP patients was the spleen, and in two it was the liver. Mixed platelet sequestration/destruction site (the liver and the spleen) was registered in 7 ITP patients, while predominantly splenic sequestration/destruction was present in 9 ITP patients. All 34 ITP patients were later submitted to splenectomy, which is a therapeutic option in ITP. Splenectomy result was favorable in 28/34 ITP patients while it was unfavorable in 6/34 (17,6%). Highly significant correlation was noticed between the splenectomy result and platelet sequestration site (p < 0.01). On the other hand, there was no correlation between the splenectomy result on one side, and patient's age, sex, megakaryocyte abundance, platelet production, life span and blood count on the other. Splenectomy result was favorable in all ITP patients with splenic sequestration/detruction of labelled platelets. It was unfavorable in ITP patients with hepatic sequestration of labelled platelets. In ITP patients with mixed platelet sequestration (hepatic and splenic) there were more unfavorable than favorable splenectomy results. Non-invasive method of platelet labelling and platelet sequestration/ /destruction site determination makes easier the clinicians' and ITP patients' decision for the splenectomy in the case when the spleen is the only sequestration site of the labelled platelets, and against the splenectomy, when exclusively hepatic platelet sequestration/destruction is registered.

[Liver hemangioma blood pool as a function of time].

UNLABELLED: Aim of the study was to determine the time needed for establishing maximal labelled red blood cell concentration in hemangioma by scintigraphic semiquantitative blood pool estimation as a function of time. PATIENTS AND METHODS: Eleven patients (eight females and three males) with total number of fourteen liver hemangiomas have been examined. Nine of them had solitary lesions and remaininig two patients had two and three liver hemangiomas, respectively. All patients underwent blood pool scintigraphy 40, 60, 120 and 180 minutes after in vivo labelling of autologous red blood cells using 740 MBq of 99mTc. After correction for radioactive decay of 99mTc and back-ground correction blood pool indexes, as hemangioma/heart and liver/heart counting rate ratios, have been calculated. RESULTS: Mean blood pool indexes obtained 40-180 minutes after in vivo red blood cell labelling did not differ significantly (p > 0.05) neither in hemangioma (0.84-0.86) nor in liver tissue (0.55-0.58). In every acquisition time hemangioma blood pool index was substantialy higher than that of liver tissue (p < 0.01). CONCLUSION: The results of the study indicates that labelled red blood cells concentration reaches its plateau before 40th minute following in vivo labelling. The concentration difference between hemangioma and liver tissue also does not differ significantly after 40th minute of blood pool examination. In most patients blood pool scintigrams taken 60, 120 and 180 minutes following in vivo RBC labelling do not contribute to diagnostic value of the method.