Added diagnostic value of respiratory-gated 4D 18F-FDG PET/CT in the detection of liver lesions: a multicenter study.

PURPOSE: The aim of the present study was to evaluate the added diagnostic value of respiratory-gated 4D18F-FDG PET/CT in liver lesion detection and characterization in a European multicenter retrospective study. METHODS: Fifty-six oncological patients (29 males and 27 females, mean age, 61.2 ± 11.2 years) from five European centers, submitted to standard 3D-PET/CT and liver 4D-PET/CT were retrospectively evaluated. Based on visual analysis, liver PET/CT findings were scored as positive, negative, or equivocal both in 3D and 4D PET/CT. The impact of 4D-PET/CT on the confidence in classifying liver lesions was assessed. PET/CT findings were compared to histology and clinical follow-up as standard reference and diagnostic accuracy was calculated for both techniques. At semi-quantitative analysis, SUVmax was calculated for each detected lesion in 3D and 4D-PET/CT. RESULTS: Overall, 72 liver lesions were considered for the analysis. Based on visual analysis in 3D-PET/CT, 32/72 (44.4%) lesions were considered positive, 21/72 (29.2%) negative, and 19/72 (26.4%) equivocal, while in 4D-PET/CT 48/72 (66.7%) lesions were defined positive, 23/72 (31.9%) negative, and 1/72 (1.4%) equivocal. 4D-PET/CT findings increased the confidence in lesion definition in 37/72 lesions (51.4%). Considering 3D equivocal lesions as positive, sensitivity, specificity, and accuracy were 88.9, 70.0, and 83.1%, respectively, while the same figures were 67.7, 90.0, and 73.8% if 3D equivocal findings were included as negative. 4D-PET/CT sensitivity, specificity, and accuracy were 97.8, 90.0, and 95.4%, respectively, considering equivocal lesions as positive and 95.6, 90.0, and 93.8% considering equivocal lesions as negative. The SUVmax of the liver lesions in 4D-PET (mean ± SD, 6.9 ± 3.2) was significantly higher (p < 0.001) than SUVmax in 3D-PET (mean ± SD, 5.2 ± 2.3). CONCLUSIONS: Respiratory-gated PET/CT technique is a valuable clinical tool in diagnosing liver lesions, reducing 3D undetermined findings, improving diagnostic accuracy, and confidence in reporting. 4D-PET/CT also improved the quantification of SUVmax of liver lesions.

The role of FDG-PET in Hodgkin lymphoma.

18-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) is currently the most valuable imaging technique in Hodgkin lymphoma. Since its first use in lymphomas in the 1990s, it has become the gold standard in the staging and end-of-treatment remission assessment in patients with Hodgkin lymphoma. The possibility of using early (interim) PET during first-line therapy to evaluate chemosensitivity and thus personalize treatment at this stage holds great promise, and much attention is now being directed toward this goal. With high probability, it is believed that in the near future, the result of interim PET-CT would serve as a compass to optimize treatment. Also the role of PET in pre-transplant assessment is currently evolving. Much controversy surrounds the possibility of detecting relapse after completed treatment with the use of PET in surveillance in the absence of symptoms suggestive of recurrence and the results of published studies are rather discouraging because of low positive predictive value. This review presents current knowledge about the role of 18-FDG-PET/CT imaging at each point of management of patients with Hodgkin lymphoma.

The Utility of Hybrid SPECT/CT Lung Perfusion Scintigraphy in Pulmonary Embolism Diagnosis.

BACKGROUND: Pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/Q) scintigraphy or pulmonary CT angiography. One of the imaging methods used in nuclear medicine is hybrid SPECT/CT scintigraphy. OBJECTIVES: The aim of this study was to evaluate the utility of SPECT/CT(Q) scintigraphy in the diagnosis of PE and to compare SPECT/CT(Q) with planar(Q) and SPECT(Q) methods. METHODS: The study group consisted of 109 consecutive patients suspected of having PE referred for performing lung scintigraphy. The inclusion criteria were: performance of perfusion planar, SPECT and SPECT/CT scans; availability of clinical data covering a 6-month follow-up period, and D-dimer level testing. The number of eligible patients was 84. PE was reported in patients with at least 1 segmental or 2 subsegmental perfusion defects without parenchymal abnormalities on CT scans. PE was excluded when there was a normal perfusion pattern or perfusion defects were caused by lung parenchymal abnormalities or were not arranged in accordance with the pulmonary vasculature. RESULTS: Twenty-six patients (31%) had a final diagnosis of PE. The sensitivity and specificity values of each method were as follows: planar(Q) 73 and 43%, SPECT(Q) 88 and 47% and SPECT/CT(Q) 100 and 83%. SPECT/CT(Q) yielded a significantly higher diagnostic accuracy than planar(Q) (p < 0.001) and SPECT(Q) (p < 0.001) scans. CONCLUSIONS: We conclude that hybrid SPECT/CT(Q) imaging has a high diagnostic efficacy in the diagnosis of PE. Lung perfusion scintigraphy performed with a hybrid SPECT/CT device has a significantly higher sensitivity and specificity than scanning performed with the planar or SPECT technique.

Nuclear medicine training and practice in Poland.

In Poland, nuclear medicine (NM) has been an independent specialty since 1988. At the end of 2013, the syllabus for postgraduate specialization in NM has been modified to be in close accordance with the syllabus approved by the European Union of Medical Specialists and is expected to be enforced before the end of 2014. The National Consultant in Nuclear Medicine is responsible for the specialization program in NM. The Medical Center of Postgraduate Training is the administrative body which accepts the specialization programs, supervises the training, organizes the examinations, and awards the specialist title. Specialization in NM for physicians lasts for five years. It consists of 36 months of training in a native nuclear medicine department, 12 months of internship in radiology, 3 months in cardiology, 3 months in endocrinology, 3 months in oncology, and 3 months in two other departments of NM. If a NM trainee is a specialist of a clinical discipline and/or is after a long residency in NM departments, the specialization in NM can be shortened to three years. During the training, there are obligatory courses to be attended which include the elements of anatomy imaging in USG, CT, and MR. Currently, there are about 170 active NM specialists working for 38.5 million inhabitants in Poland. For other professionals working in NM departments, it is possible to get the title of a medical physics specialist after completing 3.5 years of training (for those with a master's in physics, technical physics or biomedical engineering) or the title of a radiopharmacy specialist after completing 3 years of training (for those with a master's in chemistry or biology). At present, the specialization program in NM for nurses is being developed by the Medical Centre of Postgraduate Education. Continuing education and professional development are obligatory for all physicians and governed by the Polish Medical Chamber. The Polish Society of Nuclear Medicine (PTMN) organizes regular postgraduate training for physicians working in NM. Educational programs are comprehensive, covering both diagnostics and current forms of radioisotope therapy. They are aimed not only at physicians specialized/specializing in NM, but also at other medical professionals employed in radionuclide departments as well as physicians of other specialties.

[Refractory hypercalcemia in patient with lung cancer]. / Oporna na leczenie hiperkalcemia u pacjenta z rakiem pluca.

Hypercalcemia is a common complication of malignancy which recognition is usually delayed. Severe hypercalcemia can lead to death. Mechanisms of hypercalcemia of malignancy include excessive production of parathyroid hormone related protein (PTHrP), local osteolysis, absorptive hypercalcemia due to overproduction of calcitriol and ectopic parathormone (PTH) production. Volume expansion with normal saline solution, loop diuretics and intravenous bisphosphonates are mainstays of therapy for hypercalcemia. As an adjunctive therapy calcitonin and corticosteroids are used. In refractory cases gallium nitrate and denosumab can be an option. In patients with severe acute kidney disease hemodialysis with a low-calcium bath is an alternative treatment. In this paper we present a case of severe, refractory hypercalcemia in 53-years old patient with squamous cell carcinoma of the lung and multiple metastases to bones. Despite intensive treatment, that included also intravenous bisphosphonates, patient relapsed on therapy and didn't respond to subsequent doses. Patient received subcutaneous denosumab with good hypocalcemic effect. In this paper we present pathogenesis and treatment of hypercalcemia, including advantages and limitations of denosumab.

PET/CT and SPECT/CT imaging of 90Y hepatic radioembolization at therapeutic and diagnostic activity levels: Anthropomorphic phantom study.

PURPOSE: Prior to 90Y radioembolization procedure, a pretherapy simulation using 99mTc-MAA is performed. Alternatively, a small dosage of 90Y microspheres could be used. We aimed to assess the accuracy of lung shunt fraction (LSF) estimation in both high activity 90Y posttreatment and pretreatment scans with isotope activity of ~100 MBq, using different imaging techniques. Additionally, we assessed the feasibility of visualising hot and cold hepatic tumours in PET/CT and Bremsstrahlung SPECT/CT images. MATERIALS AND METHODS: Anthropomorphic phantom including liver (with two spherical tumours) and lung inserts was filled with 90Y chloride to simulate an LSF of 9.8%. The total initial activity in the liver was 1451 MBq, including 19.4 MBq in the hot sphere. Nine measurement sessions including PET/CT, SPECT/CT, and planar images were acquired at activities in the whole phantom ranging from 1618 MBq down to 43 MBq. The visibility of the tumours was appraised based on independent observers' scores. Quantitatively, contrast-to-noise ratio (CNR) was calculated for both spheres in all images. RESULTS: LSF estimation. For high activity in the phantom, PET reconstructions slightly underestimated the LSF; absolute difference was <1.5pp (percent point). For activity <100 MBq, the LSF was overestimated. Both SPECT and planar scintigraphy overestimated the LSF for all activities. Lesion visibility. For SPECT/CT, the cold tumour proved too small to be discernible (CNR <0.5) regardless of the 90Y activity in the liver, while hot sphere was visible for activity >200 MBq (CNR>4). For PET/CT, the cold tumour was only visible with the highest 90Y activity (CNR>4), whereas the hot one was seen for activity >100 MBq (CNR>5). CONCLUSIONS: PET/CT may accurately estimate the LSF in a 90Y posttreatment procedure. However, at low activities of about 100 MBq it seems to provide unreliable estimations. PET imaging provided better visualisation of both hot and cold tumours.

Preclinical evaluation of [18F]SYN1 and [18F]SYN2, novel radiotracers for PET myocardial perfusion imaging.

BACKGROUND: Positron emission tomography (PET) is now an established diagnostic method for myocardial perfusion imaging (MPI) in coronary artery disease, which is the main cause of death globally. The available tracers show several limitations, therefore, the 18F-labelled tracer is in high demand nowadays. The preclinical studies on normal Wistar rats aimed to characterise two potential, novel radiotracers, [18F]SYN1 and [18F]SYN2, to evaluate which is a better candidate for PET MPI cardiotracer. RESULTS: The dynamic microPET images showed rapid myocardial uptake for both tracers. However, the uptake was higher and also stable for [18F]SYN2, with an average standardized uptake value of 3.8. The biodistribution studies confirmed that [18F]SYN2 uptake in the cardiac muscle was high and stable (3.02%ID/g at 15 min and 2.79%ID/g at 6 h) compared to [18F]SYN1 (1.84%ID/g at 15 min and 0.32%ID/g at 6 h). The critical organs determined in dosimetry studies were the small intestine and the kidneys. The estimated effective dose for humans was 0.00714 mSv/MBq for [18F]SYN1 and 0.0109 mSv/MBq for [18F]SYN2. The tested dose level of 2 mg/kg was considered to be the No Observed Adverse Effect Level (NOAEL) for both candidates. The better results were achieved for [18F]SYN2, therefore, further preclinical studies were conducted only for this tracer. Radioligand binding assays showed significant responses in 3 from 68 assays: muscarinic acetylcholine M1 and M2 receptors and potassium channel hERG. The compound was mostly metabolised via an oxidative N-dealkylation, while the fluor substituent was not separated from the molecule. CONCLUSION: [18F]SYN2 showed a favourable pharmacodynamic and pharmacokinetic profile, which enabled a clear visualization of the heart in microPET. The compound was well-tolerated in studies in normal rats with moderate radiation exposure. The results encourage further exploration of [18F]SYN2 in clinical studies.

[A novel way to induce coronary hyperaemia]. / Nowy sposób indukcji hiperemii wiencowej.

Coronary angiography and measurement of fractional flow reserve (FFR) are used for anatomical and functional assessment of coronary stenoses. The achievement of maximal coronary hyperaemia is crucial for an accurate calculation of FFR. Although adenosine and papaverine have been well validated, their mechanisms of action as well as methods of administration have some limitations. New and better agents to induce hyperaemia are therefore still being sought. Currently regadenoson, a selective adenosine A2A receptor agonist, seems to possess the characteristics of the almost hyperaemic stimulus.

[131I]I-MIBG-negative metastases of a recurrent sporadic paraganglioma in a female with achondroplasia.

Not required for Clinical Vignette.

Respiratory gated PET/CT in a European multicentre retrospective study: added diagnostic value in detection and characterization of lung lesions.

PURPOSE: The aim of our work is to evaluate the added diagnostic value of respiratory gated (4-D) positron emission tomography/computed tomography (PET/CT) in lung lesion detection/characterization in a large patient population of a multicentre retrospective study. METHODS: The data of 155 patients (89 men, 66 women, mean age 63.9 ± 11.1 years) from 5 European centres and submitted to standard (3-D) and 4-D PET/CT were retrospectively analysed. Overall, 206 lung lesions were considered for the analysis (mean ± SD lesions dimension 14.7 ± 11.8 mm). Maximum standardized uptake values (SUV(max)) and lesion detectability were assessed for both 3-D and 4-D PET/CT studies; 3-D and 4-D PET/CT findings were compared to clinical follow-up as standard reference. RESULTS: Mean ± SD 3-D and 4-D SUV(max) values were 5.2 ± 5.1 and 6.8 ± 6.1 (p < 0.0001), respectively, with an average percentage increase of 30.8 %. In 3-D PET/CT, 86 of 206 (41.7 %) lesions were considered positive, 70 of 206 (34 %) negative and 50 of 206 (24.3 %) equivocal, while in 4-D PET/CT 117 of 206 (56.8 %) lesions were defined as positive, 80 of 206 (38.8 %) negative and 9 of 206 (4.4 %) equivocal. In 34 of 50 (68 %) 3-D equivocal lesions follow-up data were available and the presence of malignancy was confirmed in 21 of 34 (61.8 %) lesions, while in 13 of 34 (38.2 %) was excluded. In 31 of these 34 controlled lesions, 20 of 34 (58.8 %) and 11 of 34 (32.4 %) were correctly classified by 4-D PET/CT as positive and negative, respectively; 3 of 34 (8.8 %) remained equivocal. With equivocal lesions classified as positive, the overall accuracy of 3-D and 4-D was 85.7 and 92.8 %, respectively, while the same figures were 80.5 and 94.2 % when equivocal lesions were classified as negative. CONCLUSION: The respiratory gated PET/CT technique is a valuable clinical tool in diagnosing lung lesions, improving quantification and confidence in reporting, reducing 3-D undetermined findings and increasing the overall accuracy in lung lesion detection and characterization.

Comparative Analysis of the Diagnostic Effectiveness of SATRO ECG in the Diagnosis of Ischemia Diagnosed in Myocardial Perfusion Scintigraphy Performed Using the SPECT Method.

There is a great need for early diagnosis of ischemic heart disease (IHD), the most common cause of which is haemodynamic disorders caused mainly by obstructive atherosclerosis of the coronary arteries. The diagnosis of IHD is usually made with the use of functional tests, which include resting ECG (R) or examination of significant perfusion disorders during exercise using the SPECT method. Despite the fact that the ECG (R) test is commonly used in cardiological diagnostics, it has a limited diagnostic value, especially in people with a low probability of coronary artery disease (CAD). In order to increase the effectiveness of the ECG (R) examination, SATRO ECG software, based on the single fibres heart activity model (SFHAM), was used to evaluate the electrocardiograms. The introduction of new classifiers from the available medical data to the analysis made it possible to evaluate the diagnostic efficacy of SATRO ECG (TOT) in predicting significant perfusion disorders in the exercise SPECT (TOT 2). These disorders are most often caused by obstructive atherosclerosis of the coronary arteries, which is the main cause of CAD. The database of 316 patients (219 men and 97 women, aged 57 ± 10 years) was analyzed using resting and stress ECG, perfusion scintigraphy performed using the SPECT method, and SATRO ECG analysis. The diagnostic efficacy parameters of SATRO ECG (TOT) in predicting significant perfusion abnormalities in the exercise-induced SPECT (TOT 2) study were: sensitivity, 99%; specificity, 91%; concordance, 96%; and positive, 96%, and negative, 97%, predictive values. The Kappa-Cohen coefficient was 0.92, and the statistical significance coefficient was p < 0.001. These results indicate a statistically significant agreement in the diagnosis of IHD in both diagnostic methods used.

The utility of 18F-fluorocholine PET/CT in the imaging of parathyroid adenomas.

INTRODUCTION: The aim of the study was to estimate the sensitivity of ¹8F-FCH PET/CT in preoperative localisation of hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism (PHPT). MATERIAL AND METHODS: Sixty-five consecutive patients with PHPT, who underwent neck ultrasound (US) and 99mTc/99mTc-MIBI dual-phase parathyroid scintigraphy, were prospectively enrolled. Twenty-two patients had unsuccessful parathyroid surgery prior to the study. PET/CT scans were performed 65.0 ± 13.3 min after injection of 218.5 ± 31.9 MBq of 18F-fluorocholine (FCH). Three experienced nuclear medicine physicians assessed the detection rate of hyperfunctioning parathyroid tissue. Response to parathyroidectomy and clinical follow-up served as a reference test. Per-patient sensitivity and positive predictive value (PPV) were calculated for patients who underwent surgery. RESULTS: ¹8F-FCH PET/CT was positive in 61 patients, and negative in 4. US and parathyroid scintigraphy showed positive and negative results in 20, 45 and 17, 48, respectively. US showed nodular goitre in 31 patients and chronic thyroiditis in 9 patients. Parathyroid surgery was performed in 43 (66%) patients. ¹8F-FCH PET/CT yielded a sensitivity of 100% (95% CI: 87.99-100) and PPV of 85.7% (95% CI: 70.77-94.06). Similar values were observed in patients with chronic thyroiditis, nodular goitre, and patients after an unsuccessful parathyroid surgery. PET/CT identified hyperparathyroidism complications (kidney stones, osteoporotic bone fractures, and brown tumours) in 11 patients. CONCLUSIONS: ¹8F-FCH PET/CT effectively detected hyperfunctioning parathyroid tissue and its complications. The method showed excellent sensitivity and positive predictive value, including patients with nodular goitre, chronic thyroiditis, and prior unsuccessful parathyroidectomy. PET/CT performance was superior to neck ultrasound and parathyroid scintigraphy.

The scintigraphic diagnosis of cardiac amyloidosis. An expert opinion endorsed by the Section of Nuclear Medicine of the Polish Cardiac Society and the Polish Nuclear Medicine Society.

Amyloid transthyretin cardiomyopathy is a progressive disease that confers significant mortality. While it is relatively rare, the frequency of diagnoses has risen with the increased contribution of novel diagnostic approach over the last decade. Traditionally tissue biopsy was considered to be a gold standard for amyloidosis diagnosis. However, there are significant limitations in the wide application of this approach. A noninvasive imaging-based diagnostic algorithm has been substantially developed in recent years. Establishing radionuclide imaging standards may translate into a further enhancement of disease detection and improving prognosis in the group of patients. Therefore we present in the following document current evidence on the scintigraphic diagnosis of cardiac transthyretin amyloidosis. Moreover, we present standardized protocol for the acquisition and interpretation criteria in the scintigraphic evaluation of cardiac amyloidosis.

Usefulness of PET/CT with Carbon-11-Labeled Methionine in the Diagnosis of Tertiary Hyperparathyroidism.

Introduction: Tertiary hyperparathyroidism (tHP) may develop in patients treated with hemodialysis or peritoneal dialysis. Parathyroidectomy may result in a significant reduction in the severity of symptoms. For the effective surgical treatment of hyperparathyroidism, proper localization of the parathyroid glands prior to surgery is essential. The sensitivity of scintigraphy in the diagnosis of tHP is lower than in the diagnosis of primary hyperparathyroidism. In recent years, positron emission tomography (PET/CT) has been gaining importance, usually as a complementary technique. Aim: The aim of this study was to determine the usefulness of PET/CT with [11C]MET in the preoperative localization diagnosis of patients with tertiary hyperparathyroidism caused by chronic kidney disease, in whom first-line diagnostic methods did not allow the localization of pathologically parathyroid glands. Material and methods: The study was conducted in a group of 19 adult patients with severe tHP who were resistant or intolerant to non-invasive treatment, with negative results of scintigraphy and ultrasonography of the neck. The study protocol included measurement of the concentration of calcium, phosphorus, and PTH in the blood serum and performing PET/CT with [11C]MET. Results: A positive result of PET/CT was obtained in 89.5% of the patients (17/19). Parathyroidectomy was performed in 52.9% of the patients (9/17) with positive results of PET/CT with [11C]MET, which were fully consistent with the results of the histopathological examinations of the removed parathyroid glands. On this basis, the sensitivity of PET/CT with [11C]MET in the preoperative localization diagnosis of patients with tHP was found to be 100%. Multiple lesions were visualized in 57.9% of the patients (11/19). Ectopic lesions were visualized in 21.1% of the patients (4/19). Conclusions: PET/CT with [11C]MET is a sensitive technique for the second-line preoperative imaging of parathyroid glands in patients with tertiary hyperparathyroidism in whom first-line examinations, such as ultrasound and scintigraphy, has failed.

Optimal activity of [18F]FDG for Hodgkin lymphoma imaging performed on PET/CT camera with BGO crystals.

BACKGROUND: We aimed to find the minimum feasible activity of fluorodeoxyglucose ([18F]FDG) in positron emission tomography/computed tomography (PET/CT) of Hodgkin lymphoma patients performed on a camera with bismuth germanate (BGO) crystals. MATERIAL AND METHODS: Ninety-one [18F]FDG PET/CT scans (each in seven Bayesian Penalized Likelihood [BPL] reconstructions with varying acquisition time per bed position - 2 min, 1.5 min, 1 min, 50 s, 40 s, 30 s, and 20 s) were independently assessed by three physicians to evaluate image quality. Mean administered activity was 3.0 ± 0.1 MBq/kg and mean uptake time was 54.0 ± 8.7 min. The series quality was subjectively marked on a 1-10 scale and then ranked 1-7 based on the mean mark. Interobserver rank correlation and intraclass correlation within each series for the three observers were calculated. Phantom studies were also performed to determine if reduced acquisition time can be directly translated into a reduced activity. RESULTS: Time series were marked and ranked unanimously - the longer the time of acquisition the higher the mark and rank. The interobserver agreement in the ranking was excellent (100%) with a kappa coefficient of 1.00 (95% CI [0.83-1.0]). The general intraclass correlation coefficient (agreement between the marks observers gave each time series) was very high (0.945, 95% CI [0.936-0.952]) and was higher the shorter the time per bed. According to all three observers only the series with 2 min and 1.5 min acquisition time were appropriate for assessment (mean mark ≥ 7). In phantom studies there was a linear correlation between time per bed, administered activity, and number of total prompts detected by a scanner. Hence, a reduction of acquisition time of 25% (from 2 min to 1.5 min) could be directly translated into a 25% activity reduction (from 3.0 to 2.25 MBq/kg). CONCLUSIONS: In patients with HL, [18F]FDG activity can be reduced by up to 25% when using a BGO crystal camera, without substantial impact on image quality.

Extracorporeal versus peritoneal ultrafiltration in diuretic-resistant congestive heart failure--a review.

Diuretic-resistant congestive heart failure in the form of type 2 cardiorenal syndrome is a problem of growing significance in everyday clinical practice because of high morbidity and mortality. There has been scant progress in the treatment of overhydration, the main cause of symptoms in this group of patients. The aim of our review is to present recent advances in the ultrafiltration therapy of congestive heart failure, with special attention to the new dedicated device for extracorporeal isolated ultrafiltration, as well as modifications of peritoneal dialysis in the form of peritoneal ultrafiltration with icodextrin solution and incremental peritoneal dialysis. Technical and clinical features, costs and potential risks of available devices for isolated ultrafiltration are presented. This method should be reserved for patients with true diuretic resistance as part of a more complex strategy aiming at the adequate control of fluid retention. Peritoneal ultrafiltration is presented as a viable alternative to extracorporeal ultrafiltration because of medical and psychosocial benefits of home-based therapy, lower costs and more effective daily ultrafiltration. In conclusion, large, properly randomized and controlled clinical trials with long-term follow-up will be essential in assessing the logistics and cost-effectiveness of both methods. Most importantly, however, they should be able to evaluate the impact of both methods on preservation of renal function and delaying the progression of heart failure by interrupting the vicious circle of cardiorenal syndrome. Our review is supplemented with the case report of the use of peritoneal ultrafiltration with a single 12-hour nighttime icodextrin exchange as a life-saving procedure in a patient with congestive heart failure resistant to pharmacological treatment.

Comparison of positron emission tomography/computed tomography imaging and ultrasound in surveillance of head and neck cancer - The 3-year experience of the ENT Department in Poznan.

BACKGROUND: Posttreatment surveillance for the local and regional recurrence of the head and neck squamous cell carcinoma often requires a multimodality techniques that include PET combined with CT, MRI, US. AIM: The purpose of this study is to compare the diagnostic performance of two imaging techniques (PET/CT and US), and their combined use for the detection of a subclinical regional recurrence in patients after HNSCC treatment. MATERIALS AND METHODS: 83 patients after completion of the HNSCC treatment underwent both US and PET/CT on the mean follow-up of 14 months after initial treatment. RESULTS: The sensitivity and specificity of PET/CT were 86% and 82%, respectively; US values reached 81% and 87%, respectively. PPV was 79% for PET/CT, and 83% for US. NPV was 89% for PET/CT, and 85% for US. The overall accuracy for PET/CT and US was 84% for both methods. CONCLUSION: US could be regarded as complementary to PET/CT as the procedures with highest sensitivity, specificity and NPV for detecting subclinical regional recurrences after HNSCC treatment.

Feasibility of 18FDG PET in the cardiac inflammation.

The aim of the study was to assess the feasibility of 18FDG PET in cardiac inflammation with a particular focus on the delayed scan. Thirty-five consecutive 18FDG PET scans of patients with suspected or confirmed cardiac inflammation were retrospectively reviewed. The patients were referred for PET because of endocarditis (n = 16) or sarcoidosis (n = 19). Among them four patients had two consecutive for follow up and treatment control (two patients with sarcoidosis, two with endocarditis). In all of the cases a standard head to mid-thigh scan was performed 45-60 min after 18FDG injection as well as a delayed heart scan 1 h after the standard imaging was performed. 18FDG PET confirmed active inflammation in 10 out of 35 scans. Delayed scans in positive cases showed SUVmax value increase, but did not have an impact on the result, neither they did in negative cases-no significant differences between standard and delayed scan were found. Interestingly in 5 out of 14 cases with suspected endocarditis PET revealed the extracardiac inflammation focus, thus changing initial diagnosis. 18FDG PET also indicated which prosthesis caused inflammation if there were many. In the sarcoidosis group the aim was to confirm or exclude heart involvement (13 scans) or to assess the response to the steroid therapy (6 scans) in patients with previously confirmed sarcoidosis. PET revealed active heart disease in 3 initial scans, and 1 follow up scan. 18FDG PET is a valuable imaging method for the cardiac inflammation assessment. It adequately localises the active inflammation site. Also, since it is a whole-body scan it may detect the extracardiac inflammation foci, which in some cases may change the initial diagnosis. In our study the delayed scans showed no added value.

18F-FDG Positron Emission Tomography/Computed Tomography (PET/CT) for Distinguishing Tuberous Sclerosis Complex Lesions from Colon Cancer Metastases.

BACKGROUND Tuberous sclerosis complex (TSC; Bourneville-Pringle disease) is a multisystem genetic disorder manifesting as benign tumors that can affect any system. Malignant neoplasm may coexist in patients with TSC. In such cases, there are diagnostic difficulties in distinguishing between metastatic lesions and benign changes. We show the usefulness of positron emission tomography (PET) in resolving these difficulties. CASE REPORT The purpose of this article is to present the usefulness of metabolic imaging using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in distinguishing benign from neoplastic lesions in a patient with TSC. A 17-year-old female patient with TSC was referred for 18F-FDG PET/CT with suspected lung and bone metastases. The patient underwent a bilateral nephrectomy because of multiple cysts and angiomyolipomas. A colonoscopy - performed in preparation for kidney transplantation - revealed sevearal colon polyps, one of which was found to be cancerous upon histopathologic examination. A diagnosis of adenocarcinoma G3 was made and a CT scan of the chest and abdomen performed afterwards showed multiple pulmonary nodules and sclerotic bone lesions suggestive of metastases. Two 18F-FDG PET/CT scans (performed within 6 months) showed multiple nodules of 7-15 mm in diameter and changes typical of multifocal micronodular pneumocyte hyperplasia in both lungs. In the bones, we found multiple sclerotic lesions. All of the above findings showed FDG uptake at the level of the background activity which contradicted the lesions' metastatic origin. CONCLUSIONS Using the example of a 17-year-old patient with TSC, we present the usefulness of metabolic imaging using 18F-FDG PET/CT in distinguishing benign from neoplastic lesions.

Evaluation of the usefulness of positron emission tomography with [18F]fluorodeoxylglucose performed to detect non-radioiodine avid recurrence and/or metastasis of differentiated thyroid cancer - a preliminary study.

BACKGROUND: About 30% of patients with disseminated differentiated thyroid cancer (DTC) may experience a loss of iodine uptake. It is associated with higher aggressiveness of the tumour and a reduced 10-year survival rate. The diagnosis of non-radioiodine avid DTC metastases remains a diagnostic challenge. A helpful technique for this diagnosis is positron emission tomography with 2-[¹8F]fluoro-2-deoxy-D-glucose (PET/CT with [¹8F]FDG). On the other hand, there are still discussions about the clinical value of using exogenous thyroid-stimulating hormone (TSH) stimulation before PET/CT with [¹8F]FDG. The aim of the study was the assessment of the usefulness of PET/CT with [¹8F]FDG under TSH suppression and stimulation of TSH performed in the detection of non-radioiodine avid DTC metastases, as well as determination of the thyroglobulin concentration under suppression and stimulation of TSH, which influences the result of PET/CT with [¹8F]FDG in patients with non-radioiodine avid DTC. MATERIAL AND METHODS: Retrospective analysis of 37 PET/CT with [¹8F]FDG performed in patients with DTC diagnosed and treated at the Department of Endocrinology and Isotope Therapy of the Military Institute of Medicine from January 2018 to July 2020. Of these, PET/CT with [¹8F]FDG under exogenous rhTSH stimulation was performed in 22 patients and PET/CT with [¹8F]FDG under TSH suppression in 15 was performed. In all analyzed patients, the result of diagnostic whole-body scintigraphy (WBS) using 80 MBq ¹³¹I under rhTSH stimulation was negative, and the concentration of thyroglobulin after stimulation (sTg) was greater than 1.0 ng/mL. RESULTS: In the group of patients examined under TSH suppression, non-radioiodine avid in PET/CT with [¹8F]FDG were found in 6 out of 15 patients (40%) and in the group of patients examined under rhTSH stimulation in 10 out of 22 patients (45%). The differences between the groups were not statistically significant. The analysis of the receiver operating characteristic (ROC) curves allowed to determine the cut-off point for the positive result of PET/CT performed under TSH suppression with sTg concentration of 11.03 ng/mL. In the group of studies performed under rhTSH stimulation, the cut-off point for sTg was 6.3 ng/mL. There was no statistically significant difference between the baseline thyroglobulin (natTg) and sTg levels and the positive PET/CT result. The administration of rhTSH before the PET/CT examination also had no statistically significant effect on the maximum standard uptake value (SUVmax) of the dominant lesion identified in the PET/CT. CONCLUSIONS: 1) PET/CT with [¹8F]FDG is a useful tool for detection of non-radioiodine avid recurrence and/or metastases of DTC. 2) The concentration of natTg and sTg is highly correlated with a positive result of PET/CT with [¹8F]FDG. 3) The concentration of natTg is comparable with sTg in predicting a positive result of PET/CT with [¹8F]FDG. 4) The cut-off point for a positive result of PET/CT for natTg was 1.36 ng/mL and for sTg was 7.05 ng/mL.