A Biopsy-Controlled Prospective Study of Contrast-Enhancing Diffuse Glioma Infiltration Based on FET-PET and FLAIR

Accurately defining glioma infiltration is crucial for optimizing radiotherapy and surgery, but glioma infiltration is heterogeneous and MRI imperfectly defines the tumor extent. Currently, it is impossible to determine the tumor infiltration gradient within a FLAIR signal. O-(2-[18F]fluoroethyl)-L-tyrosine (FET)-PET often reveals high-grade glioma infiltration beyond contrast-enhancing areas on MRI. Here, we studied FET uptake dynamics in tumor and normal brain structures by dual-timepoint (10 min and 40-60 min post-injection) acquisition to optimize analysis protocols for defining glioma infiltration. Over 300 serial stereotactic biopsies from 23 patients (mean age 47, 12 female/11 male) of diffuse contrast-enhancing gliomas were taken from areas inside and outside contrast enhancement or outside the FET hotspot but inside FLAIR. The final diagnosis was G4 in 11, grade 3 in 10, and grade 2 in 2 patients. The target-to-background (TBRs) ratios and standardized uptake values (SUVs) were calculated in areas used for biopsy planning and in background structures. The optimal method and threshold values were determined to find a preferred strategy for defining glioma infiltration. Standard thresholding (1.6× uptake in the contralateral brain) in standard acquisition PET images differentiated a tumor of any grade from astrogliosis, although the uptake in astrogliosis and grade 2 glioma was similar. Analyzing an optimal strategy for infiltration volume definition astrogliosis could be accurately differentiated from tumor samples using a choroid plexus as a background. Early acquisition improved the AUC in many cases, especially within FLAIR, from 56% to 90% sensitivity and 41% to 61% specificity (standard TBR 1.6 vs. early TBR plexus). The current FET-PET evaluation protocols for contrast-enhancing gliomas are limited, especially at the tumor border where grade 2 tumor and astrogliosis have similar uptake, but using choroid plexus uptake in early acquisitions as a background, we can precisely define a tumor within FLAIR that was outside of the scope of current FET-PET protocols.

Combining amino acid PET and MRI imaging increases accuracy to define malignant areas in adult glioma

Accurate determination of the extent and grade of adult-type diffuse gliomas is critical to patient management. In clinical practice, contrast-enhancing areas of diffuse gliomas in magnetic resonance imaging (MRI) sequences are usually used to target biopsy, surgery, and radiation therapy, but there can be discrepancies between these areas and the actual tumor extent. Here we show that adding ¹⁸F-fluoro-ethyl-tyrosine positron emission tomography (FET-PET) to MRI sequences accurately locates the most malignant areas of contrast-enhancing gliomas, potentially impacting subsequent management and outcomes. We present a prospective analysis of over 300 serial biopsy specimens from 23 patients with contrast-enhancing adult-type diffuse gliomas using a hybrid PET-MRI scanner to compare T2-weighted and contrast-enhancing MRI images with FET-PET. In all cases, we observe and confirm high FET uptake in early PET acquisitions (5-15 min after ¹⁸F-FET administration) outside areas of contrast enhancement on MRI, indicative of high-grade glioma. In 30% cases, inclusion of FET-positive sites changes the biopsy result to a higher tumor grade.

Automatic Production of [18F]F-DOPA Using the Raytest SynChrom R&D Module

[¹⁸F]F-DOPA is widely used in PET diagnostics. Diseases diagnosed with this tracer are schizophrenia, Parkinson's disease, gliomas, neuroendocrine tumors, pheochromocytomas, and pancreatic adenocarcinoma. It should be noted that the [¹⁸F]F-DOPA tracer has been known for over 30 years. However, the methods of radiosynthesis applied in the past did not allow its clinical use due to low efficiency and purity. Currently, in the market, one encounters different types of radiosynthesis using the fluorine ¹⁸F isotope and variants of the same method. The synthesis and its modifications were carried out using a Raytest Synchrom R&D module. The synthesis consists of the following steps: (a) binding of the fluoride anion ¹⁸F^- on an anion exchange column; (b) elution with TBAHCO₃^-; (c) nucleophilic fluorination to the ABX 1336 precursor; (d) purification of the intermediate product on the C18ec column; (e) Baeyer-Villiger oxidation; (f) hydrolysis; and (gfinal purification of the crude product on a semipreparative column. The nucleophilic synthesis of [¹⁸F]F-DOPA was successfully performed in 120 min, using the ABX 1336 precursor on the Raytest SynChrom R&D module, with a radiochemical yield (RCY) of 15%, radiochemical purity (RCP) ≥ 97%, and enantiomeric purity (ee) ≥ 96%.

NIMG-39. AMINO ACID PET-MRI OF HIGH-GRADE GLIOMA

OBJECTIVE

MRI is gold standard for the diagnosis, surgery and radiation therapy of patients with high-grade glioma. Amino acid PET is useful in gliomas without contrast enhancement in MRI but it is unknown whether PET better identifies high-grade foci than T1-sequence with contrast enhancement or improve definition of high grade glioma infiltration related to T2/Flair images.

METHODS

More than 400 biopsy specimens from twenty-three patients with suspected high-grade glioma were examined in this prospective study. Patients meeting the inclusion criteria were referred for hybrid 18F-FET-PET-MRI before stereotactic biopsy. Biopsies were planned based on early FET-PET acquisition 5-15 minutes post injection and MRI. The following biopsy sites were determined in each case: (i) site of contrast enhancement and increased FET uptake; (ii) contrast enhancement but no increase in FET uptake; (iii) increased FET uptake but without contrast enhancement; and (iv) peripheral areas hyperintense in T2 FLAIR without increased FET uptake and contrast enhancement.

RESULTS

In 35% cases, the biopsy result was changed to a higher tumor grade after the inclusion of FET-positive sites. In all cases, high FET uptake was visualized and confirmed outside areas of contrast enhancement on MRI, indicative of high-grade glioma. Results from biopsies based on the FLAIR sequences corresponded to neoplastic lesions in 13 cases (57%), most often with a lower grade than in areas of high FET uptake.

CONCLUSIONS

FET-PET can be used to locate the most malignant areas of contrast-enhancing gliomas and impact the biopsy results. Surgery or radiotherapy planned solely on MRI images may miss parts of tumor presenting highest malignancy. Brain areas hyperintense in T2 FLAIR without increased amino acid uptake are not specific for malignancy in high grade gliomas.

Case report: Cellular therapy for hydroa vacciniforme-like lymphoproliferative disorder in pediatric common variable immunodeficiency with chronic active Epstein-Barr virus infection

Hydroa vacciniforme-like lymphoproliferative disorder (HV-LPD) is a cutaneous form of chronic active Epstein-Barrvirus (EBV) infection, which can develop into the extremely rare systemic lymphoma. Patients with Inborn errors of immunity (IEI), such as common variable immunodeficiency (CVID), are at higher risk of developing a severe course of infections especially viral and malignancies than the general population. The aim of the study was to present complex diagnostic and therapeutic management of HV-LPD. The clinical diagnosis was confirmed at the histological and molecular level with next generation sequencing. HV-LPD was diagnosed in a patient with CVID and chronic active Epstein–Barr virus (CAEBV) infection. The patient was refractory to CHOP chemotherapy and immunosuppressive treatment in combination with antiviral drugs (prednisone, bortezomib, gancyclovir). The third-party donor EBV-specific cytotoxic T cells (EBV-CTL, tabelecleucel) were used, which stabilised the disease course. Finally, matched unrelated donor hematopoietic cell transplantation (MUD-HCT) was performed followed by another cycle of EBV-CTL.

Safety and efficacy of irradiation boost based on 18F-FET-PET in patients with newly diagnosed glioblastoma

PURPOSE

Dual timepoint FET-PET acquisition (10 and 60 minutes after FET injection) improves the definition of glioblastoma location and shape. Here we evaluated the safety and efficacy of simultaneous integrated boost (SIB) planned using dual FET-PET for postoperative glioblastoma treatment.

EXPERIMENTAL DESIGN

In this prospective pilot study (March 2017-December 2020), 17 patients qualified for FET-PET-based SIB intensity-modulated radiotherapy after resection. The prescribed dose was 78 and 60 Gy (2.6 and 2.0 Gy per fraction, respectively) for the FET-PET- and MR-based target volumes. Eleven patients had FET-PET within nine months to precisely define biological responses. Progression-free survival (PFS), overall survival (OS), toxicities, and radiation necrosis were evaluated. Six patients (35%) had tumors with MGMT promoter methylation.

RESULTS

The one- and two-year OS and PFS rates were 73% and 43% and 53% and 13%, respectively. The median OS and PFS were 24 (95%CI 9-26) and 12 (95%CI 6-18) months, respectively. Two patients developed uncontrolled seizures during radiotherapy and could not receive treatment per protocol. In patients treated per protocol, 7/15 presented with new or increased neurological deficits in the first month after irradiation. Radiation necrosis was diagnosed by MRI three months after SIB in five patients and later in another two patients. In two patients, the tumor was larger in FET-PET images after six months.

CONCLUSIONS

Survival outcomes using our novel dose escalation concept (total 78 Gy) were promising, even within the MGMTunmethylated subgroup. Excessive neurotoxicity was not observed, but radionecrosis was common and must be considered in future trials.

RADT-21. DUAL FET PET-GUIDED SIB IN RADIOTHERAPY OF NEWLY DIAGNOSED GLIOBLASTOMA - A PILOT STUDY

BACKGROUND

PET using FET is a valuable tool to determine the actual glioblastoma infiltration.The FET-PET examination can be performed using the dual-time point acquisition of FET . Infiltration defined in dual FET PET corresponds to the location and shape of the recurrence. The aim of this study was to evaluate safety and efficacy of simultaneous integrated boost based on dual FET PET combined with temozolomide TMZ for the postoperative treatment of GBM.

METHODS AND MATERIALS

In a prospective pilot study, 17 patients were enrolled. All patient presented an active tumor in postoperative PET imaging. The radiotherapy was performed as an FET-PET-based integrated-boost IMRT. The prescribed dose was 78 and 60 Gy (single dose 2.6 and 2.0 Gy, respectively). The progression-free survival (PFS) and overall survival (OS), toxicities and radiation necrosis rate were evaluated.

RESULTS

The median follow up was 37 months.Two patients were found to have uncontrolled seizures during radiation treatment and were not able to received treatment per protocol. Patients treated per protocol presented new or increased neurological deficits in 7/15 cases in a month after irradiation. In 4 patients radiation necrosis was confirmed in pathological report after re-surgery. Three patients were still alive after 26,28 and 38 months of follow up without progression and any signs of treatment related late toxicity. The 2-year survival rate was 43% in all patients treated per protocol. Median overall survival (OS) and disease-free survival (DFS) were 20 and 12 months, respectively. In a subgroup of MGMT methylated and unmethylated the median survival was 25 and 12 months.

CONCLUSIONS

Our dose escalation concept with a total dose of 78 Gy, based on FET-PET, have lead to promising survival results even within MGMT unmethylated subgroup. However rate of early toxicity and radiation necrosis is high.

Redox State and Lysosomal Activity in Women with Ovarian Cancer with Tumor Recurrence and Multiorgan Metastasis

The aim of the study is to evaluate oxidant-antioxidant balance as well as lysosomal and anti-protease activities in ovarian cancer since it has been emphasized that the crucial inducing factor of carcinogenesis may be reactive oxygen/nitrogen species or, more precisely, oxidative stress-induced inflammation. The study involved 15 women with ovarian cancer, aged 59.9 ± 7.8 years, and 9 healthy women aged 56.3 ± 4.3 years (controls). The study material was venous blood collected from fasting subjects. In erythrocytes, the activities of superoxide dismutase, glutathione peroxidase, and catalase, as well as concentrations of conjugated dienes (CDs) and thiobarbituric acid reactive substances (TBARS), were investigated. CD, TBARS, and vitamins A and E plasma concentrations were also determined. Moreover, total antioxidant capacity and concentrations of 4-hydroxynonenal adducts and 8-iso-prostaglandin F2α, as well as activities of acid phosphatase, arylsulfatase, cathepsin D, and α₁-antitrypsin, were studied in serum. The vitamin E and 8-iso-prostaglandin F2α concentrations as well as arylsulfatase activity were lower in the women with cancer compared to the controls (p = 0.006, p = 0.03, p = 0.001, respectively). In contrast, cathepsin D activity was lower in the controls (p = 0.04). In the peripheral blood of the women with cancer, oxidant-antioxidant and lysosomal disturbances were observed.

Glioma Biopsy Based on Hybrid Dual Time-Point FET-PET/MRI-A Proof of Concept Study

Neuroimaging based on O-[2-(18F)fluoroethyl]-l-tyrosine (FET)-PET provides additional information on tumor grade and extent compared with MRI. Dynamic PET for biopsy target selection further improves results but is often clinically impractical. Static FET-PET performed at two time-points may be a good compromise, but data on this approach are limited. The aim of this study was to compare the histology of lesions obtained from two challenging glioma patients with targets selected based on hybrid dual time-point FET-PET/MRI. Five neuronavigated tumor biopsies were performed in two difficult cases of suspected glioma. Lesions with (T1-CE) and without contrast enhancement (T1 and T2-FLAIR) on MRI were selected. Dual time-point FET-PET imaging was performed 5–15 min (PET10) and 45–60 min (PET60) after radionuclide injection. The most informative FET-PET/MRI images were coregistered with MRI in time of biopsy planning. Five biopsy targets (three from high uptake and two from moderate uptake FET areas) thought to represent the most malignant sites and tumor extent were selected. Histopathological findings were compared with FET-PET and MRI images. Increased FET uptake in the area of non-CE locations on MRI correlated well with high-grade gliomas localized as far as 3 cm from T1-CE foci. Selecting a target in the motor cortex based on FET kinetics defined by dual time-point PET resulted in a grade IV diagnosis after previous negative biopsies based on MRI. An additional grade III diagnosis was obtained from an area of glioma infiltration with moderate FET uptake (between 1 and 1.25 SUV). These findings seem to show that dual time-point FET-PET-based biopsies can provide additional and clinically useful information for glioma diagnosis. Selection of targets based on dual time-point images may be useful for determining the most malignant tumor areas and may therefore be useful for resection and radiotherapy planning.

Cushing's Syndrome in a Patient With Rathke's Cleft Cyst and ACTH Cell Hyperplasia Detected by 11C-Methionine PET Imaging-A Case Presentation

Background: Adrenocorticotropic Hormone (ACTH)-dependent Cushing's Syndrome (CS) is most often caused by a pituitary adenoma. Although rarely, it can also result from pituitary corticotroph cell hyperplasia (CH). Reports on concomitant pituitary lesions including ACTH-producing adenomas and Rathke's cleft cysts (RCCs) have been published. Positron emission tomography (PET), using ¹¹C-labelled-methionine (MET) as a tracer and co-registered with magnetic resonance imaging (MRI) has been shown to be useful in the diagnosis of pituitary collision lesions, however, its role is still under investigation. In this work we present the case of a patient in whom CS was caused by non-adenomatous CH within the wall of an RCC. Case Summary: In 2015 a patient with signs and symptoms of CS was referred to our Department. Biochemical studies repeatedly showed elevated midnight serum cortisol and ACTH levels. Magnetic resonance imaging of the sellar region revealed an RCC and MET-PET/MR showed heterogeneous labelled-methionine metabolism in the vicinity of the cyst's wall. Transsphenoidal surgery resulted in rapid, complete and lasting relief of symptoms. Histopathological examination demonstrated an RCC and CH. Conclusions: Concomitance of pituitary focal lesions is a rare phenomenon. Methionine-labelled PET/MR may be useful in the diagnosis of collision sellar lesions, including CH. Corticotroph cell hyperplasia can present as mild and fluctuating hypercortisolaemia.

Comparing radioactive tracers 18F-FDG and 18F-FLT in the staging of diffuse large B-cell lymphoma by PET/CT examination: A single-center prospective study

BACKGROUND

Positron emission tomography in combination with computer tomography (PET/CT) is a very important method of imaging patients with non-Hodgkin lymphomas (NHLs). It is used to define the initial grade of the disease and to assess early response to treatment and after chemotherapy. The most commonly used radioactive tracer is 18F-FDG, but 18F-FLT seems to be more specific.

OBJECTIVES

The aim of our study was to compare the staging of diffuse large B-cell lymphoma (DLBCL) with PET/CT examination using 18F-FLT and 18F-FDG.

MATERIAL AND METHODS

The study included 33 patients with newly diagnosed DLBCL (17 women and 16 men). The median age of the patients was 57 years. In each patient, 2 PET/CT examinations were performed before treatment, one using 18F-FLT and the second using 18F-FDG.

RESULTS

The average maximum 18F-FDG uptake in the whole group of patients was higher than the average maximum of 18F-FLT. This was also true of individual patients; however, 3 patients with an aggressive disease course had greater FLT uptake than the other patients.

CONCLUSIONS

Our analysis suggests that PET/CT exams using 18F-FLT may be a useful diagnostic tool in patients with DLBCL.

Prognostic value of subventricular zone involvement in relation to tumor volumes defined by fused MRI and O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET imaging in glioblastoma multiforme

BACKGROUND

Subventricular zone (SVZ) involvement is associated with a dismal prognosis in patients with glioblastoma multiforme (GBM). Dual-time point (dtp) O-(2-[¹⁸F]fluoroethyl)-L-tyrosine (FET) PET/CT (PET) may be a time- and cost-effective alternative to dynamic FET PET, but its prognostic value, particularly with respect to SVZ involvement, is unknown.

METHODS

Thirty-five patients had two scans 5-15 and 50-60 min after i.v. FET injection to define tumor volumes and SVZ involvement before starting radiotherapy. Associations between clinical progression markers, MRI- and dtp FET PET-based tumor volumes, or SVZ involvement and progression-free (PFS) and overall survival (OS) were assessed in univariable and multivariable analyses.

RESULTS

The extent of resection was not related to outcomes. Albeit non-significant, dtp FET PET detected more SVZ infiltration than MRI (60% vs. 51%, p = 0.25) and was significantly associated with poor survival (p < 0.03), but PET-T1-Gad volumes were larger in this group (p < 0.002). Survival was shorter in patients with larger MRI tumor volumes, larger PET tumor volumes, and worse Karnofsky performance status (KPS), with fused PET-T1-Gad and KPS significant in multivariable analysis (p < 0.03). Uptake kinetics was not associated with treatment outcomes.

CONCLUSIONS

FET PET-based tumor volumes may be useful for predicting worse prognosis glioblastoma. Although the presence of SVZ infiltration is linked to higher PET/MRI-based tumor volumes, the independent value of dtp FET PET parameters and SVZ infiltration as prognostic markers pre-irradiation has not been confirmed.

The Role of 18F-FDG PET/CT in the Management of the Autoimmune Thyroid Diseases

Objective: It is a well-known fact that positron emission tomography (PET) is an effective tool in the assessment of thyroid focal lesions, however only few studies so far have investigated its role in monitoring of autoimmune thyroid diseases (AITDs). The aim of this study is to assess if PET scan may be useful for the assessment of the thyroid gland in patients with an AITD-Hashimoto's thyroiditis. Methods: We evaluated twenty subjects with diagnosed Hashimoto's thyroiditis (proven by presence of elevated thyroid antibodies level and by thyroid imaging). The maximum standardized uptake value (SUV-max) of the thyroid parenchyma was measured using ¹⁸F-FDG-PET/CT. Control group consisted of patients who have been in carcinoma remission for other reasons than thyroid cancer and who had been investigated by PET scan to exclude carcinoma recurrence. All control group subjects had their thyroid glands intact, none of them had a medical history of thyroid disease including thyroid nodules. AITDs had been excluded in all control group subjects. STATISTICA 13.1 software was used for statistical analysis. Results: Results: The SUV-max was significantly higher in patients with an AITD than in healthy subjects (median SUV-max 3.94 vs. 1.95; p = 0.005). Conclusions: ¹⁸F-FDG-PET/CT scan may differentiate normal thyroid parenchyma from the diffused inflammatory changes of the thyroid gland in patients with AITDs. However, the researchers must be continued.

15O-H2O PET/CT as a tool for the quantitative assessment of early post-radiotherapy changes of heart perfusion in breast carcinoma patients

OBJECTIVE

Studies examining radiation-induced heart toxicity in breast cancer patients are inconclusive. The aim of this study was to prospectively and quantitatively asses myocardial blood flow (MBF) with, for the first time, ¹⁵O-H₂O PET/CT as a marker of heart damage in irradiated breast cancer patients.

METHODS

15 breast cancer patients receiving intact breast or chest wall irradiation were included in the analysis (six with right-sided and nine with left-sided breast cancer). They underwent ¹⁵O-H₂O PET/CT before radiotherapy (RT) and 2 and 8 months after RT. MBF was quantitatively assessed at rest and under stress conditions in 17 heart segments distinguished according to the American Ultrasound Association classification. Regional MBF values were derived in each of the coronary artery territories.

RESULTS

MBF decreased in 53% and increased in 33% of cases 2 months after RT in both left-sided and right-sided breast cancer patients. Stress testing was more sensitive than at-rest testing, demonstrating decreased perfusion in the segments supplied by the left anterior descending coronary artery (LAD) [5.41 ± 1.74 vs 4.52 ± 1.82 ml (g*min)^-1; p = 0.018], which persisted at 6 months [5.41 ± 1.74 vs 4.40 ± 1.38 ml (g*min)^-1; p = 0.032] and a decrease in global heart perfusion [5.14 ± 1.49 vs 4.46 ± 1.73 ml (g*min)^-1; p = 0.036]. A minimal radiation dose applied to the LAD correlated with MBF changes observed 2 months after RT (r = -0.57; p = 0.032). Radiological findings were not correlated with clinical symptoms of heart toxicity.

CONCLUSION

¹⁵O-H₂O PET/CT is safe and effective for the early detection and quantitative analysis of subclinical post-RT changes in heart perfusion in breast cancer patients. The LV segments supplied by the LAD are the main site of MBF changes. A minimum radiation dose deposited in the LAD may be a predictor of radiation-induced heart toxicity. Advances in knowledge: This is the first time that ¹⁵O-H₂O PET/CT has been used to assess MBF after RT and the first granular description of the distribution of blood flow changes after breast cancer RT.

Relationship between Glioblastoma Dose Volume Parameters Measured by Dual Time Point Fluoroethylthyrosine-PET and Clinical Outcomes

Glioblastoma multiforme (GBM) is highly invasive. Despite irradiation with wide margins, GBM usually recurs in-field. Recent in vitro data have suggested that progression might be promoted by sublethal irradiation. Fluoroethylthyrosine-PET (FET-PET) can be used to detect glioblastoma invasion not apparent on MRI. We therefore performed a retrospective analysis of a prospective clinical study to examine whether glioblastoma outcomes depend on dose volume parameters measured by MRI and FET-PET. Twenty-three patients were prospectively recruited to a study examining the role of dual time point FET-PET in the treatment planning of GBM radiotherapy. The dose delivered to the site of recurrence was subdivided into suboptimal-dose (SOD) and high-dose (HD) areas. Types of progression were defined for correlation with dosimetric parameters including V100% of gross tumor volume (GTV)_PET, GTV_PETMRI, and GTV_MRI. The HD area did not cover the entire GTV_PETMRI in any case. Recurrences were significantly more frequent in the SubD area (chi-squared test, p = 0.004). There was no relationship between increasing dose volume and progression. The V100% for GTV_PET and progression-free survival (PFS) was positively correlated (Spearman’s rho 0.417; p = 0.038). Progression is more common in areas with suboptimal dosing. Dose heterogeneity within GTV_PET may be responsible for shorter PFS.

Application of artificial neural networks for predicting presence of non-sentinel lymph node metastases in breast cancer patients with positive sentinel lymph node biopsies

INTRODUCTION

The aim of this study was to present a new predictive tool for non-sentinel lymph node (nSLN) metastases.

MATERIAL AND METHODS

One thousand five hundred eighty-three patients with early-stage breast cancer were subjected to sentinel lymph node biopsy (SLNB) between 2004 and 2012. Metastatic SLNs were found in 348 patients - the retrospective group. Selective axillary lymph node dissection (ALND) was performed in 94% of cases. Involvement of the nSLNs was identified in 32.1% of patients following ALND. The correlation between nSLN involvement and selected epidemiological data, primary tumor features and details of the diagnostic and therapeutic management was examined in metastatic SLN group. Multivariate analysis was performed using an artificial neural network to create a new nomogram. The new test was validated using the overall study population consisting of the prospective group (365 patients - SLNB between 01-07.2013).

RESULTS

Accuracy of the new test was calculated using area under the receiver operating characteristics curve (AUC). We obtained AUC coefficient equal to 0.87 (95% confidence interval: 0.81-0.92). Sensitivity amounted to 69%, specificity to 86%, accuracy - 80% (retrospective group) and 77%, 46%, 66% (validation group), respectively. The Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram the calculated AUC value was 0.71, for Stanford - 0.68, for Tenon - 0.67.

CONCLUSIONS

In the analyzed group only the MSKCC nomogram and the new model showed AUC values exceeding the expected level of 0.70. Our nomogram performs well in prospective validation on patient series. The overall assessment of clinical usefulness of this test will be possible after testing it on different patient populations.

Verbal fluency in research conducted with PET technique under conditions of extended cognitive activation with the use of 18F-fluorodeoxyglucose (FDG) tracer

OBJECTIVES

Functional neuroimaging of the brain is a widely used method to study cognitive functions. The aim of this study was to compare the activity of the brain during performance of the tasks of phonemic and semantic fluency with the paced-overt technique in terms of prolonged activation of the brain.

METHODS

The study included 17 patients aged 20-40 years who were treated in the past for Hodgkin'slymphoma, now in remission. Due to the type of task, the subjectswere divided into two groups. Nine people performed the phonemic fluency task, and eight semantic. Due to the disease, all subjects were subject to neuropsychological diagnosis. The diagnosis of any cognitive impairment was an exclusion criterion. Neuroimaging was performed using PET technique with 18F-fluorodeoxyglucose (FDG) tracer.

RESULTS

Performance of a verbal fluency test, regardless of the version of the task, was associated with greater activity of the left hemisphere of the brain. The most involved areas compared with other areas of key importance for the performance of verbal fluency tasks were frontal lobes. An increased activity of parietal structures was also shown.

CONCLUSIONS

The study did not reveal differences in brain activity depending on the type of task. Performing the test in both phonemic and semantic form for a long time, in terms of increased cognitive control resulting from the test procedure, could result in significant advantage of prefrontal lobe activityin both types of tasks and made it impossible to observe the processes specific to each of them.

Quantitative anatomy of the primary ossification center of the femoral shaft in human fetuses

Purpose

Early clinical distinction of congenital defects in the femur is extremely important, as it determines the prognosis of the development of the lower limb. This study was performed to quantitatively examine the primary center of ossification in the femoral shaft with respect to its linear, planar, and volumetric parameters.

Materials and methods

Using methods of CT, digital-image analysis, and statistics, the size of the primary ossification center of the femoral shaft in 47 spontaneously aborted human fetuses aged 17–30 weeks was studied.

Results

With no sex and laterality differences, the best fit growth dynamics for femoral shaft ossification center was modelled by the following functions: y = 5.717 + 0.040 × (age)² ± 2.905 (R² = 0.86) for its length, y = −3.579 + 0.368 × age ± 0.529 (R² = 0.88) for its proximal transverse diameter, y = −1.105 + 0.187 × age ± 0.309 (R² = 0.84) for its middle transverse diameter, y = −2.321 + 0.323 × age ± 0.558 (R² = 0.83) for its distal transverse diameter, y = −50.306 + 0.308 × (age)² ± 18.289 (R² = 0.90) for its projection surface area, and y = −91.458 + 0.390 × (age)³ ± 92.146 (R² = 0.88) for its volume.

Conclusions

The size of the femoral shaft ossification center displays neither sex nor laterality differences. The ossification center in the femoral shaft follows quadratic functions with respect to its length and projection surface area, linear functions with respect to its proximal, middle, and distal transverse diameters, and a cubic function with respect to its volume. The obtained morphometric data of the femoral shaft ossification center are considered normative for respective prenatal weeks and may be of relevance in both the estimation of fetal ages and the ultrasound diagnostics of congenital defects.

Quantitative anatomy of the growing clavicle in the human fetus: CT, digital image analysis, and statistical study

Purposes

Knowledge of dimensions of fetal long bones is useful in both the assessment of fetal growth and early detection of inherited defects. Measurements of the fetal clavicle may facilitate detection of numerous defects, e.g., cleidocranial dysplasia, Holt–Oram syndrome, Goltz syndrome, and Melnick–Needles syndrome.

Methods

Using the methods of CT, digital image analysis, and statistics, the size of the growing clavicle in 42 spontaneously aborted human fetuses (21 males and 21 females) at ages of 18–30 weeks was studied.

Results

Without any male–female and right–left significant differences, the best fit growth models for the growing clavicle with relation to age in weeks were as follows: y = −54.439 + 24.673 × ln(age) ± 0.237 (R² = 0.86) for length, y = −12.042 + 4.906 × ln(age) ± 0.362 (R² = 0.82) for width of acromial end, y = −4.210 + 2.028 × ln(age) ± 0.177 (R² = 0.77) for width of central part, y = −4.687 + 2.364 × ln(age) ± 0.242 (R² = 0.70) for width of sternal end, y = −51.078 + 4.174 × ln(age) ± 6.943 (R² = 0.82) for cross-sectional area, and y = −766.948 + 281.774 × ln(age) ± 19.610 (R² = 0.84) for volume.

Conclusions

With no sex and laterality differences, the clavicle grows logarithmically with respect to its length, width, and volume, and linearly with respect to its projection surface area. The obtained morphometric data of the growing clavicle are considered normative for their respective weeks of gestation and may be of relevance in the diagnosis of congenital defects.

The combined role of biomarkers and interim PET scan in prediction of treatment outcome in classical Hodgkin's lymphoma: a retrospective, European, multicentre cohort study

BACKGROUND

Early-interim fluorodeoxyglucose (FDG)-PET scan after two ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy courses (PET-2) represents the most effective predictor of treatment outcome in classical Hodgkin's lymphoma. We aimed to assess the predictive value of PET-2 combined with tissue biomarkers in neoplastic and microenvironmental cells for this disease.

METHODS

We enrolled 208 patients with classical Hodgkin's lymphoma and treated with ABVD (training set), from Jan 1, 2002, to Dec 31, 2009, and validated the results in a fully matched independent cohort of 102 patients with classical Hodgkin's lymphoma (validation set), enrolled from Jan 1, 2008, to Dec 31, 2012. The inclusion criteria for both the training and validation sets were: the availability of a representative formalin-fixed, paraffin-embedded tissue sample collected at diagnosis; treatment with ABVD with or without radiotherapy; baseline staging and interim restaging after two ABVD courses with FDG-PET; no treatment change based solely on interim PET result; and HIV-negative status. We used Cox multivariate analysis classification and regression tree (CART) to compare the predictive values of these markers with that of PET-2 and to assess the biomarkers' ability to correctly classify patients whose outcome was incorrectly predicted by PET-2.

FINDINGS

In multivariate analysis, PET-2 was the only factor able to predict both progression-free survival (hazard ratio [HR] 33·3 [95% CI 13·6-83·3]; p<0·0001) and overall survival (HR 31·3 [95% CI 3·7-58·9]; p=0·002). In the training set, no factor had a stronger adverse predictive value than a positive PET-2 scan and none was able to correctly reclassify PET-2 positive patients. In PET-2 negative patients, expression of CD68 (≥25%) and PD1 (diffuse or rosetting pattern) in microenvironmental cells, and STAT1 negativity in Hodgkin Reed Sternberg cells identified a subset of PET-2 negative patients with a 3 year progression-free survival significantly lower than that of the remaining PET-2 negative population (21 [64%] of 33 [95% CI 45·2-79·0] vs 130 [95%] of 137 [95% CI 89·4-97·7]; p<0·0001). These findings were reproduced in the validation set.

INTERPRETATION

The CART algorithm correctly predicted the response to treatment in more than a half of patients who had a relapse or disease progression despite a negative PET-2 scan, thus increasing the negative predictive value of PET-2. In keeping with preliminary results from interim PET response adapted clinical trials of patients with advanced Hodgkin's lymphoma, there might be a non-negligible proportion of treatment failures in the interim PET negative group treated with standard ABVD.

FUNDING

Italian Association for Cancer Research, Bologna Association against leukaemia, lymphoma and myeloma, and Bologna University.

Pre-irradiation tumour volumes defined by MRI and dual time-point FET-PET for the prediction of glioblastoma multiforme recurrence: A prospective study

BACKGROUND AND PURPOSE

The diagnostic accuracy of magnetic resonance imaging (MRI) for glioblastoma multiforme (GBM) is suboptimal. We analysed pre-treatment MRI- and dual time-point 18F-fluoroethylthyrosine-PET (FET-PET)-based target volumes and GBM recurrence patterns following radiotherapy with temozolomide.

MATERIALS AND METHODS

Thirty-four patients with primary GBM were treated according to MRI-based treatment volumes (GTVRM). Patients underwent dual time-point FET-PET scans prior to treatment, and biological tumour volumes (GTVPET) were contoured but not used for target definition. Progressions were classified based on location of primary GTVs. Volume and uniformity of MRI- vs. FET-PET/CT-derived GTVs and progression patterns assessed by MRI were analysed.

RESULTS

FET-based GTVs measured 10min after radionuclide injection (a.r.i.; median 37.3cm(3)) were larger than GTVs measured 60min a.r.i. (median 27.7cm(3)). GTVPET volumes were significantly larger than corresponding MRI-based GTVs. MRI and PET concordance for the identification of glioblastoma GTVs was poor (mean uniformity index 0.4). 74% of failures were inside primary GTVPET volumes, with no solitary progressions inside the MRI-defined margin +20mm but outside the GTVPET detected.

CONCLUSIONS

The size and geometry of GTVs differed in the majority of patients. The GTVPET volume depends on time after radionuclide injection. FET-PET better defined failure site than MRI alone.

Comparison of FLT-PET/CT and CECT in gastric cancer diagnosis

AIM

To date, no data are available on the use of 18-fluorothymidine positron emission tomography/computed tomography (FLT-PET/CT) for preoperative gastric cancer staging. Herein, we attempt to assess the value of FLT-PET/CT for preoperative gastric cancer staging in comparison with contrast-enhanced computed tomography (CECT).

MATERIALS AND METHODS

In a group of 96 gastric cancer patients, 96 FLT-PET/CT, 56 abdominal cavity CECT, and 51 resective operations were done. All three (FLT-PET/CT, CECT, and resective operation) were done in 29 patients. The results of FLT-PET/CT, CECT, and histopathological examinations were used to assess the ability of FLT-PET/CT and CECT to identify primary tumors, regional nodal metastases, and distant abdominal metastases. Assessment of regional lymph nodes was based on SUVmax in FLT-PET/CT and SAD (short-axis diameter) in CECT.

RESULTS

In the group of 56 patients examined with FLT-PET/CT and CECT, identification of the primary tumor was possible in 56 cases (100%) and in 53 cases (94.6%), respectively, (p = 0.013). Using ROC curve, the sensitivity and specificity of FLT-PET/CT in metastatic regional lymph node assessment were higher than those of CECT (p = 0.0033). FLT-PE/CT enabled identification of a greater number of extraregional abdominal metastases than CECT (n = 56; 19 vs. 15, respectively), but the difference was not statistically significant (p > 0.41).

CONCLUSIONS

The ability of FLT-PET/CT to identify primary tumors is greater than that of CECT, and thus FLT-PET/CT was better in evaluating regional nodal metastases. FLT-PET/CT enabled identification of a greater number of abdominal metastases than CECT, but the difference was not statistically significant.

Morphometric study of the neural ossification centers of the atlas and axis in the human fetus

Purposes

The knowledge of the developing cervical spine and its individual vertebrae, including their neural processes may be useful in the diagnostics of congenital vertebral malformations. This study was performed to quantitatively examine the neural ossification centers of the atlas and axis with respect to their linear, planar and volumetric parameters.

Methods

Using the methods of CT, digital-image analysis and statistics, the size of neural ossification centers in the atlas and axis in 55 spontaneously aborted human fetuses aged 17–30 weeks was studied.

Results

Without any male–female and right–left significant differences, the best fit growth dynamics for the neural ossification centers of the atlas and axis were, respectively, modelled by the following functions: for length: y = −13.461 + 6.140 × ln(age) ± 0.570 and y = −15.683 + 6.882 × ln(age) ± 0.503, for width: y = −4.006 + 1.930 × ln(age) ± 0.178 and y = −3.054 + 1.648 × ln(age) ± 0.178, for cross-sectional area: y = −7.362 + 0.780 × age ± 1.700 and y = −9.930 + 0.869 × age ± 1.911, and for volume: y = −6.417 + 0.836 × age ± 1.924 and y = −11.592 + 1.087 × age ± 2.509.

Conclusions

The size of neural ossification centers of the atlas and axis shows neither sexual nor bilateral differences. The neural ossification centers of the atlas and axis grow logarithmically in both length and width and linearly in both cross-sectional area and volume. The numerical data relating to the size of neural ossification centers of the atlas and axis derived from the CT and digital-image analysis are considered specific-age reference values of potential relevance in both the ultrasound monitoring and the early detection of spinal abnormalities relating to the neural processes of the first two cervical vertebrae in the fetus.

Morphometric study of the two fused primary ossification centers of the clavicle in the human fetus

Purposes

A satisfactory understanding of the clavicle development may be contributing to both the diagnosis of its congenital defects and prevention of perinatal damage to the shoulder girdle. This study was carried out to examine the transverse and sagittal diameters, cross-sectional area and volume of the two fused primary ossification centers of the clavicle.

Methods

Using the methods of CT, digital-image analysis and statistics, the size for two fused primary ossification centers of the clavicle in 42 spontaneously aborted human fetuses at ages of 18–30 weeks was studied.

Results

Without any male–female and right-left significant differences, the best fit growth models for two fused primary ossification centers of the clavicle were as follows: y = −31.373 + 15.243 × ln(age) ± 1.424 (R² = 0.74) for transverse diameter, y = −7.945 + 3.225 × ln(age) ± 0.262 (R² = 0.78), y = −4.503 + 2.007 × ln(age) ± 0.218 (R² = 0.68), and y = −4.860 + 2.117 × ln(age) ± 0.200 (R² = 0.73) for sagittal diameters of the lateral, middle and medial ends respectively, y = −31.390 + 2.432 × age ± 4.599 (R² = 0.78) for cross-sectional area, and y = 28.161 + 0.00017 × (age)⁴ ± 15.357 (R² = 0.83) for volume.

Conclusions

With no sex and laterality differences, the fused primary ossification centers of the clavicle grow logarithmically in both transverse and sagittal diameters, linearly in cross-sectional area, and fourth-degree polynomially in volume. Our normative quantitative findings may be conducive in monitoring normal fetal growth and screening for inherited faults and anomalies of the clavicle in European human fetuses.

PET-CT derived Artificial Neural Network can predict mediastinal lymph nodes metastases in Non-Small Cell Lung Cancer patients. Preliminary report and scoring model

AIM

Mediastinal lymph nodes staging in NSCLC (non small cell lung cancer) is of undisputable importance. Although relatively precise, diagnostic modalities, mediastinoscopy and EBUS/EUS - TBNA (endobronchial/endoscopic ultrasound guided--transbronchial needle aspiration) still employ certain level of invasiveness. Artificial Neural Network (ANN) is an established predictor tool which, due to underlying distribution and relationship among the given variables, allow for construction of multidimensional models trained in prognosis of given outcome. Their performance in mediastinal staging based on radiological data only, remains limited to single studies.

METHODS

We obtained 467 groups of lymph nodes from 160 patients with primary NSCLC by means of EBUS--TBNA, mediastinoscopy or lymphadenectomy during thoracotomy and analyzed them microscopically. ANN models were created and prospectively validated on unmatched cohort of 50 consecutive patients (158 groups of lymph nodes). To identify factors correlated with nodal involvement single factor tests and logistic regression analyzes were performed. Additionally, logistic regression analysis allowed for construction of scoring model with certain parameters corresponding to risk thresholds of metastatic disease.

RESULTS

Size and standard uptake value (SUV) of the node along with primary tumour T characteristics were identified as the most sensitive variables regardless of the analysis conducted. Two ANN models predicted metastatic involvement with 89% and 92% accuracy. Single factor tests maintained high accuracy only for 2 out of 4 most sensitive variables (SUV >2.8 and length >15mm) in prospective validation.

CONCLUSIONS

ANN is a repeatable and accurate diagnostic tool in mediastinal staging in NSCLC patients. Before its role in clinical practice will be established in large multi--centre study, findings of this preliminary report should be considered as exploratory only.

Comparison of positron emission tomography/computed tomography with classical contrast-enhanced computed tomography in the initial staging of Hodgkin lymphoma

We compared initial computed tomography (CT) and positron emission tomography (PET)/CT in 96 patients with Hodgkin lymphoma (HL), assessing the role of baseline PET/CT in stage migration and treatment selection. The number of patients with stage I, II, III and IV disease based on CT versus PET/CT was: 5 vs. 7, 49 vs. 37, 28 vs. 22 and 14 vs. 30, respectively. In 33 (34%) patients, PET/CT changed HL stage: 27 (28%) were upstaged and six (6.3%) downstaged. Upstaging was caused by detection of new extranodal involvements (47 sites in 26 patients): bone marrow (10 patients), spleen (five patients) and lung (two patients). In nine patients≥2 further coexisting locations were detected. Downstaging resulted from the absence of fluorodeoxyglucose (18F-FDG) uptake in enlarged nodes (>15 mm) in the abdomen and pelvis. PET/CT modified HL stage in 34% of patients leading to treatment modification in the majority. Our results indicate that PET/CT should be mandatory in the initial staging of HL.

[The importance of imaging techniques in the modern treatment of multiple myeloma]

The main symptom of multiple myeloma (MM) are pathological changes in bone. Imaging techniques are useful in determining the proper stage of the disease, follow-up after treatment and, as highlighted in recent times, in predicting prognosis and prediction. In the near future, radiographic examination of the whole body can be replaced by more sensitive techniques, such as low-dose computed tomography (CT) of the whole body. Magnetic resonance imaging (MRI) is a standard in the evaluation of bone marrow infiltration of the spine, allowing the prediction of the risk of vertebral fractures. Positron emission tomography (PET) coupled with CT (PET/CT) provides relevant information on the extent of lesions throughout the body, including soft tissues and is the best tool to distinguish active from inactive disease after treatment. Diagnostic imaging technique of PETIMR has the potential for precisely diagnosing in this condition. Prospective use of new imaging techniques in clinical practice in the near future will help to optimize the therapeutic management in individual cases of MM.

Measurement of primary tumor volume by PET-CT to evaluate risk of mediastinal nodal involvement in NSCLC patients with clinically negative N2 lymph nodes

AIM

The study aimed to determine a prognostic value of primary tumor volume measured on the basis of integrated positron emission tomography-computerized tomography (PET-CT) in terms of mediastinal nodal metastases (N2) prediction in non-small-cell lung cancer (NSCLC) patients with PET-CT N2 negative lymph nodes.

METHODS

The records of 70 potentially operable NSCLC patients treated with surgical resection were analyzed. All patients underwent diagnostic, preoperative PET-CT, which was the basis for tumor volume calculations as well as the evaluation of N2 nodes status. The logistic regression analysis was employed to determine correlation between mediastinal nodal involvement and volume of primary tumor (izoSUV2.5 volume), that is the volume of primary tumor inside SUV 2.5 line, tumor histology, location (peripheral vs. central), hilar node status.

RESULTS

A statistically significant correlation between mediastinal node involvement and izoSUV2.5 volume, tumor histology, locations peripheral vs. central and hilar node status was found. The risk of mediastinal lymph node metastasis is 24% for tumor volume of 100 cm(3) and increases up to 40% for tumor volume of 360 cm(3). An increase of tumor volume by 1 cm(3) increases the risk of lymph node disease by 0.3%. Tumor histology adenocarcinoma vs. squamous cell carcinoma increases the risk of mediastinal lymph node involvement by 195%, location central vs. peripheral by 68% and hilar node involvement by 166%.

CONCLUSIONS

The study demonstrates that izoSUV2.5 volume of primary tumor may be considered as a prognostic factor in NSCLC patients, since it strongly correlates with mediastinal lymph node pathological status. This correlation is modified by primary tumor location, histology and hilar node involvement.

Cross-sectional study of the ossification center of the C1-S5 vertebral bodies

Purpose

Knowledge on the normative growth of the spine is relevant in the prenatal detection of its abnormalities. This study describes the size of the ossification center of C1–S5 vertebral bodies.

Materials and methods

Using CT, digital-image analysis, and statistics, the size of the ossification center of C1–S5 vertebral bodies in 55 spontaneously aborted human fetuses aged 17–30 weeks was examined.

Results

No sex significant differences were found. The body ossification centers were found within the entire presacral spine and in 85.5 % of S1, in 76.4 % of S2, in 67.3 % of S3, in 40.0 % of S4, and in 14.5 % of S5. All the values for the atlas were sharply smaller than for the axis. The mean transverse diameter of the body ossification center gradually increased from the axis to T12 vertebra, so as to stabilize through L1–L3 vertebrae, and finally was intensively decreasing to S5 vertebra. There was a gradual increase in sagittal diameter of the body ossification center from the axis to T5 vertebra and its stabilization for T6–T9 vertebrae. Afterward, an alternate progression was observed: a decrease in values for T10–T12 vertebrae, an increase in values for L1–L2 vertebrae, and finally a decrease in values for L3–S5 vertebrae. The values of cross-sectional area of ossification centers were gradually increasing from the axis to L2 vertebra and then started decreasing to S5 vertebra. The following cross-sectional areas were approximately equivalent to each other: for L5 and T3–T5, and for S4 and C1. The volumetric growth of the body ossification center gradually increased from the axis to L3 vertebra and then sharply decreased from L4 to S5.

Conclusions

No male–female differences are found in the size of the body ossification centers of the spine. The growth dynamics for morphometric parameters of the body ossification centers of the spine follow similarly with gestational age.

Alendronate 70 therapy in elderly women with post-menopausal osteoporosis: the problem of compliance

INTRODUCTION

More than half of those with chronic diseases, including osteoporosis, discontinue treatment during the first year of its administration. This problem increases over the course of continued follow-up. Additionally, it has been observed that 13% of women, prescribed oral daily alendronate, do not even start the treatment, while 20% of patients discontinue the therapy during the first four months. On the other hand, those patients who are compliant achieve increased bone mass density with a simultaneous decrease of fracture risk. The aim of our study was to assess the adherence to the recommended alendronate 70 administration protocol over the course of 12 months by women with post-menopausal osteoporosis.

MATERIAL AND METHODS

Adherence (compliance plus persistence) to alendronate 70 therapy was assessed in a prospective study of 153 post-menopausal women, followed up for one year with monitoring every two months.

RESULTS

Adherence to therapy of all the study participants was high during the entire study period, the patients remaining compliant after a year in 95.08 ± 1.39% (mean ± SEM) of cases, and the mean persistence with medication was 347.05 ± 5.07 days. In the group of patients who interrupted treatment, the mean persistence was 212.44 days. One of the study participants did not start the treatment, and another two discontinued the therapy within 30-60 days of the study onset (between the first two visits). Facilitated contacts with the doctor, continuous access to prescribed treatment and frequent visits significantly improved patient compliance. The common reason for discontinuation was side effects, while age (but not education) affected the rate of compliance with therapy. The worst results were obtained in the group of patients with osteoporosis diagnosed more than five years before the study, particularly in the subgroup where alendronate was being used for the first time or where treatment resumed after a substantial break.

CONCLUSIONS

The obtained results indicate that better adherence to alendronate 70 therapy, administered once a week, depends on more frequent monitoring of treated patients.

The role of positron emission tomography (PET) in diagnostics of gastroenteropancreatic neuroendocrine tumours (GEP NET)

PET is a successful modality to detect cancer and in recent years has demonstrated a great diagnostic value in large series of tumour types. PET combines high sensitivity and reasonable resolution, and offers the ability to perform whole body scans. 18F-deoxyglucose (FDG)-PET has also been used to diagnose tumours of neuroendocrine origin. Even if 18F-FDG has been successfully and widely employed in oncology, it has not demonstrated a significant uptake in well differentiated neuroendocrine tissues. Thus 18F-FDG is not a good tracer for neuroendocrine tumours, as FDG-PET imaging of number of GEP tumours revealed increased glucose metabolism only in less differentiated GEP tumours with high proliferative activity and in metastatising MTC associated with rapidly increasing CEA levels. In such a situation, additional 18F-FDG PET should be performed only if somatostatin receptor scintigraphy (alone or with 99mTc-DMSA) is negative. On the contrary, other positron emitter tracers seem to be more promising. 68Ga-DOTA-NOC (tetraazycyclododecanetetraacetic acid-[1-Nal3]-octreotide) has been used as a positron emitter tracer for the detection of NETs in preliminary studies. A serotonin precursor 5-hydroxytryptophan (5-HTP) labelled with 11C has shown an increased uptake in carcinoids. This uptake seems to be selective and some clinical evidence has demonstrated that it allows the detection of more lesions with PET than with CT or octreotide scintigraphy. Another radiopharmaceutical in the development for PET is 11C-L-DOPA, which seems to be useful in imaging endocrine pancreatic tumours.

[Correlation between results of transcranial doppler ultrasonography and SPECT in the brain of patients with ischemic cerebral stroke]

Single photon emission computerized tomography /SPECT/ and positron emission tomography /PET/ are used presently for the study of the cerebral blood flow /CBF/. The cost of these procedures limits the possibility of their use and makes them available mainly in large and rich clinical centres. Transcranial Doppler USG has no such drawbacks. The purpose of the present study was analysis of a possible correlation between marker cumulation /in SPECT/ in the vascularization area of the middle cerebral artery /MCA/ and the parameters Vs, Vm, Vd, PI, RI, R of the PUSG-G examination of these arteries in 50 patients aged 48-79 years treated for ischaemic cerebral episodes. Brain SPECT examination was done with Apex-SP-6-HR gamma camera assessing the distribution of 99mTc HMPAO marker in the vascularization area of both MCA. PUSG-D examination was done with Tc-2-64 unit. In both MCA the systolic Vs, the mean velocity Vm, the diastolic velocity Vd, the Gosling pulsation index PI, the Purcelot resistance index RI and the velocity amplitude R were measured. The following conclusions have been reached: 1/ in patients with ischaemic cerebral episodes a significant correlation was found between cerebral SPECT findings and the PUSG-D parameters; 2/ reduced perfusion of the cerebral tissue was correlated with lower values of Vs, Vm, Vd, and R and with higher values of PI and RI; 3/ slight disturbances of perfusion found in SPECT were not reflected in changed PUSG-D parameters; 4/ the results justify the use of PUSG-D for indirect assessment of blood flow in the MCA.

[The significance of radioisotopic methods in internal diseases diagnosis]

The present article is an attempt to show the best diagnostic radioisotopic methods which are practically applied in the internal diseases diagnostics. It was shown both the most important indications for performing these examinations and expected advantages. In particular, it was paid attention to achieved progress in the diagnostics of some diseases owing to radioisotopic methods application. In addition, a general availability and non-invasity of these methods advocates in support of using them.

[The significance of scintigraphic, echocardiographic and electrocardiographic left atrial transesophageal pacing in diagnosis of ischemic heart disease]

The aim of the study was to compare the perfusion scintigraphy (using SPECT method with Tc-99-MIBI) during left atrial transoesophageal pacing test (LAPT) with pacing electrocardiography (ECG), echocardiography (ECHO) and electrocardiography exercise test (ExT) in ischaemic heart disease (IHD) diagnostics. The effect of LATP on heart haemodynamic parameters and the correlation between scintigraphic, echocardiographic and electrocardiographic parameters during LAPT test have been also assessed. Investigations were carried out in 55 subjects (Group I: 36 patients with effort angina pectoris; group II: controls: 19 clinically healthy subjects). Coronarography was performed in 24 patients 6 weeks before or after examinations. LATP test was analyzed with ECG, ECHO and SPECT. Echocardiography did not increase significantly the LATP test diagnostic value. Perfusion scintigraphy enhanced sensitivity and predictive excluding value LATP test. These values were 93.3% v 62.9% and 90% v 59.3% respectively. LATP test assessed with ECG, ECHO and perfusion scintigraphy expressed significantly higher sensitivity and predicting excluding value in comparison to ExT. LATP test analyzed in such way was characterized by 100% sensitivity and 100% predicting excluding value.

CONCLUSION

Combination of LATP with electrocardiography, echocardiography and SPECT is a non-invasive high quality method for ischaemic heart disease diagnostics.