Quantitative SPECT/CT imaging of actinium-225 for targeted alpha therapy of glioblastomas

BACKGROUND

A new, alternative option for patients with recurrent glioblastoma is targeted alpha therapy (TAT), in the form of a local administration of substance P (neurokinin type 1 receptor ligand, NK-1) labelled with 225Ac. The purpose of the study was to confirm the feasibility of quantitative SPECT imaging of 225Ac, in a model reproducing specific conditions of TAT. In particular, to present the SPECT calibration methodology used, as well as the results of validation measurements and their accuracy. Additionally, to discuss the specific problems related to high noise in the presented case.

MATERIALS AND METHODS

All SPECT/CT scans were conducted using the Symbia T6 equipped with HE collimators, and acquired with multiple energy windows (three main windows: 440 keV, 218 keV, and 78 keV, with three lower scatter energy windows). A Jaszczak phantom with fillable cylindrical sources of various sizes was used to investigate quantitative SPECT/CT imaging characteristics. The planar sensitivity of the camera, an imaging calibration factor, and recovery coefficients were determined. Additionally, the 3D printed model of the glioblastoma tumour was developed and imaged to evaluate the accuracy of the proposed protocol.

RESULTS

Using the imaging calibration factor and recovery coefficients obtained with the Jaszczak phantom, we were able to quantify the activity in a 3D-printed model of a glioblastoma tumour with uncertainty of no more than 10% and satisfying accuracy.

CONCLUSIONS

It is feasible to perform quantitative 225Ac SPECT/CT imaging. However, there are still many more challenges that should be considered for further research on this topic (among others: accurate determination of ICF in the case of high background noise, better method of background estimation for recovery coefficient calculations, other methods for scatter correction than the dual-energy window scatter-compensation method used in this study).

Slowing of EEG waves correlates with striatal [18 F]fluorodopa PET/CT uptake and executive dysfunction in Parkinson's disease

Parkinson's disease (PD) research on specific neuroimaging and neurophysiological biomarkers revealing executive dysfunction mechanisms is limited, necessitating validation. Thus, our study aimed to assess associations between electroencephalographic power spectral density (PSD-EEG), striatal [18 F]Fluorodopa uptake and neuropsychological executive function (EF) testing parameters in PD, while also estimating their diagnostic accuracy. We compared resting PSD-EEG, striatal [18 F]Fluorodopa uptake ratios based on positron emission computed tomography ([18 F]FDOPA PET/CT) and neuropsychological EF tests outcomes [Trail Making Test (TMT) and Stroop Test (ST)] between PD patients and healthy controls (HCO) and then calculated correlations among these measures separately for each group. Additionally, we estimated PD diagnostic accuracy of the PSD-EEG and [18 F]FDOPA PET/CT parameters. In PD patients, we observed the following: (i) slower EEG waves, reflected in increased power of the EEG theta and lower-alpha bands in frontal lobe areas; (ii) reduced [18 F]FDOPA PET/CT uptake in the putaminal and caudate nuclei, along with a decreased putamen-to-caudate ratio ([18 F]FDOPA PET/CT PCR); and (iii) longer performance times evident in nearly all EF tests' parameters. Slower EEG waves correlated negatively with [18 F]FDOPA PET/CT PCR and positively with most of the EF test parameters. Furthermore, we found negative correlations between [18 F]FDOPA PET/CT PCR and certain EF measures related to ST. [18 F]FDOPA PET/CT ratios and several PSD-EEG parameters, particularly those from the prefrontal cortex, demonstrated clinically reasonable diagnostic accuracy for PD. In conclusion, EEG waves slowing in the frontal lobe were correlated with striatal dopaminergic deficiency and impaired executive function in mild PD patients and showed promise as a biomarker of PD-related executive dysfunction.

The Role of the Evans Index and the Maximal Width of the Frontal Horns of the Lateral Ventricles in the Diagnostic Imaging of Progressive Supranuclear Palsy and Multiple-System Atrophy

Progressive Supranuclear Palsy and Multiple-System Atrophy are entities within the spectrum of atypical parkinsonism. The role of imaging methods in the diagnosis and differentiation between PSP and MSA is limited and Magnetic Resonance Imaging (MRI) is currently used as a reference modality. In this study, the authors examined a group of patients with atypical parkinsonism using a 1.5 T MRI system and aimed to find simple and repeatable measurements that may be useful to distinguish between these diseases. The results of the study indicate that the maximal width of the frontal horns of the lateral ventricles and Evans' Index may, to some extent, be useful as basic and simple measurements in the diagnostic imaging of patients with atypical parkinsonism.

Radiosynovectomy of the hip joint - preliminary experience

Introduction

Radiosynovectomy (RSV) is a minimally invasive method of treating and controlling joint inflammation refractory to conventional pharmacotherapy. It consist in intraarticular injection of radioactive colloids which irradiate the inflamed synovial membrane to cause its subsequent involution. Despite the fact that hip joint involvement is quite common in systemic inflammatory arthropathies, hip joint RSVs are rarely performed. The aim of this paper is to assess to safety and efficacy of hip joint radioisotope treatment.

Material and methods

We retrospectively analyzed the effects of 21 hip joint RSVs performed in 14 patients (10 female, 4 male; aged 8 to 79; mean age 48 years). Before the RSV, all the patients underwent clinical and ultrasound examination. The radiosynovectomies were performed using rhenium-186 sulfide under ultrasound guidance. Each patient underwent post-therapeutic scintigraphy to assess intraarticular distribution of the radiopharmaceutical. The effects of the treatment were assessed clinically and ultrasonographically during at least 2 follow-up visits 3 and 6 months after the RSV.

Results

In 9 cases, we observed complete resolution of symptoms 3 and 6 months after the RSV. Four patients had only a partial response and required repeated treatment, and all responded well to the second RSV. In 4 patients the treatment had no significant effect, and no repeated treatment attempt was made. All the responders suffered from inflammatory arthropathies; the non-responders had osteoarthritis, with no history of systemic diseases. In all the patients, no significant adverse effects were observed; in particular there were no radiation burns or infections. All post-therapeutic scintigrams showed proper, intraarticular distribution of the radiopharmaceutical.

Conclusions

Radiosynovectomy of the hip joint in systemic joint diseases, especially performed using ultrasound-guidance, is a safe and effective treatment modality.

Inflammation in multiple system atrophy

Misfolding protein aggregation inside or outside cells is the major pathological hallmark of several neurodegenerative diseases. Among proteinopathies are neurodegenerative diseases with atypical Parkinsonism and an accumulation of insoluble fibrillary alpha-synuclein (synucleinopathies) or hyperphosphorylated tau protein fragments (tauopathies). As there are no therapies available to slow or halt the progression of these disea ses, targeting the inflammatory process is a promising approach. The inflammatory biomarkers could also help in the differential diagnosis of Parkinsonian syndromes. Here, we review inflammation's role in multiple systems atrophy pathogenesis, diagnosis, and treatment.

Locoregional Treatment of Glioblastoma With Targeted α Therapy: [ 213 Bi]Bi-DOTA-Substance P Versus [ 225 Ac]Ac-DOTA-Substance P-Analysis of Influence Parameters

BACKGROUND

Glioblastoma (GB) is the most malignant primary brain tumor. Therefore, introduction of new treatment options is critically important. The aim of this study was to assess local treatment with α emitters [ 213 Bi]Bi-DOTA-substance P (SP) and [ 225 Ac]Ac-DOTA-SP.

METHODS

Treatment was performed as salvage therapy in patients with recurrent primary and secondary GB. [ 213 Bi]Bi-DOTA-SP with injected activity 1.85 GBq per cycle was used in 20 primary (48.2 ± 11.8 years old) and in 9 secondary (38.8 ± 10.8 years old) GB patients and [ 225 Ac]Ac-DOTA-SP in 15 primary (45.1 ± 9.9 years old) and in 6 secondary (37.8 ± 6.4 years old) GB patients with a dose escalation scheme (10, 20, and 30 MBq).

RESULTS

Local treatment with [ 213 Bi]Bi-DOTA-SP and [ 225 Ac]Ac-DOTA-SP was well tolerated with only few adverse effects. There was no statistically significant difference between [ 213 Bi]Bi-DOTA-SP and [ 225 Ac]Ac-DOTA-SP groups in survival parameters. For primary GB, survival parameters of patients treated with [ 213 Bi]Bi-DOTA-SP and [ 225 Ac]Ac-DOTA-SP were as follows(in months): progression-free survival time, 2.7 versus 2.4; OS-d (overall survival from time of diagnosis to death from any cause), 23.6 versus 21.0; OS-t (overall survival from the start of treatment to death from any cause), 7.5 versus 5.0; and OS-r (overall survival from recurrence in primary tumors to death from any cause), 10.9 versus 12.0. Survival parameters of secondary GB patients treated with [ 213 Bi]Bi-DOTA-SP and [ 225 Ac]Ac-DOTA-SP were as follows (in months): progression-free survival time, 5.8 versus 2.4; OS-d, 52.3 versus 65.0; OS-t, 16.4 versus 16.0; and OS-c (overall survival from conversion into secondary GB multiforme to death from any cause), 18.4 versus 36.0.

CONCLUSIONS

The similarity results of 213 Bi or 225 Ac may suggest that the local treatment of brain tumors can be greatly simplified. The experience to date shows that local radioisotope treatment of brain tumors requires further dosimetry studies, taking into account the complexity of biological processes.

Sleep disturbances in progressive supranuclear palsy syndrome (PSPS) and corticobasal syndrome (CBS)

INTRODUCTION

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are clinical manifestations of tauopathies. They are commonly associated with rapid motor and cognitive deterioration. Sleep disturbances are less frequently described as a feature of these diseases, though they are reported among 50-75% of PSP patients.

STATE OF THE ART

Apart from various clinical manifestations, sleep abnormalities in PSP and CBS seem to be a factor enhancing pathogenesis as well its consequences. Multiple researchers have looked into the issue of whether the complexity of sleep disturbances in PSP and CBS could be linked to atrophic changes within structures crucial for daytime regulation, coexisting pathologies, or other less explored mechanisms.

CLINICAL SIGNIFICANCE

Among sleep abnormalities in PSP and CBS have been reported excessive daytime sleepiness, night-time insomnia, reduction of total sleep time, more pronounced sleep fragmentation, restless leg syndrome (RLS), agrypnia excitata, periodic limb movements, sleep respiratory disturbances, rapid-eye movement behaviour disorder, and others.

FUTURE DIRECTIONS

The aim of this review was to elaborate upon the significance of sleep abnormalities in tauopathic parkinsonian syndromes, and to determine their usefulness in differential diagnosis with synucleinopathic parkinsonian syndromes. Extended analyses of sleep disturbances may provide a different perspective on atypical parkinsonisms.

Registry of nuclear medicine procedures in cardiology in Poland in 2019-2021

BACKGROUND

The purpose of the study was to present the cardiological procedures performed and scintigraphic devices used in Poland in 2019-2021 - based on the results of a nationwide survey.

MATERIAL AND METHODS

Forty-three (100%) institutions performing scintigraphic cardiology tests responded to the survey: 29 classic nuclear medicine centers (NM), 4 PET centers, and 10 institutions performing NM and PET examinations.

RESULTS

In 2021, 51 SPECT devices (including 5 dedicated cardiocentric semiconductor cameras, 12 SPECT gamma cameras, and 39 hybrid SPECT/CT devices) and 15 PET devices (14 PET/CT and 1 PET/MR) were used for cardiological examinations. The total number of cardiological SPECT and PET examinations has reached 33,107; PET shares 0.8%. The most frequently performed NM cardiological examination in 2019-2021 was myocardial perfusion scintigraphy (98-99% of all tests). NM cardiac amyloidosis studies accounted for less than 1% of all studies, and diagnostics of inflammation in the chest using labeled leukocytes - for less than 0.5%. The most frequently performed cardiological heart examination using the PET technique was the diagnostics of inflammation in the chest (166 of 269 examinations, i.e. 61.7%, in 2021), followed by the assessment of cardiac viability (46 examinations, i.e. 17.1%).

CONCLUSIONS

In Poland, in 2021, cardiac scintigraphy was performed in 39 classic nuclear medicine centers and 14 PET centers, using modern equipment, in approximately 1/1000 inhabitants per year. Polish nuclear cardiology is based on classical nuclear medicine. Almost 99% of the tests are stress and rest myocardial perfusion studies. PET has limited practical use (< 1% of cardiac studies).

Targeted alpha therapy for glioblastoma

According to the 2021 World Health Organization Classification of Tumors of the Central Nervous System, glioblastoma (GB) is a primary brain tumor and presents with the worst prognosis. Due to its infiltrating characteristic, molecular heterogeneity, and only partly preserved function of the blood-brain barrier, the median overall survival time is short (9-15 months), regardless of comprehensive treatment including surgery, radiotherapy, and chemotherapy. Several novel treatment strategies are under investigation. Unfortunately, none of them produced successful results; 90% of patients have a recurrence of the disease within 6 months. Local administration of the drug could be a promising approach to delivering treatment with minimized side effects, due to the recurrence of 95% glioblastomas in a margin of 2 cm at the primary site. Several ligand-receptor systems have been evaluated, such as targeting tenascin, the extracellular matrix protein, or radiolabeled somatostatin analogs, as it is overexpressed with the SSTR-2 receptor system in around 80% of gliomas. Moreover, this study revealed that the NK-1 receptor is overexpressed in GB, suggesting that substance P (SP) may serve as a ligand. A variety of radioisotopes, beta- (¹³¹I, ⁹⁰Y, or ¹⁷⁷ Lu) and alpha emitters (²¹³Bi, ²²⁵Ac, or ²¹¹At), with different physical properties were tested for treatment. Alpha particles have many advantages over beta radiation such as short range with higher linear energy transfer. According to that characteristic, it is extremely dose delivered to the targeted cells, while reducing harm to nearby healthy tissue. Additionally, the biological effect of alpha radiation is independent of the cell cycle phase, cell oxygenation and O-6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status. In this article, we summarize the experience with local treatment of primary and secondary GBs with locally used radioisotopes such as [²¹³Bi]Bi-DOTA-SP or [²²⁵Ac]Ac-DOTA-SP.

The Use of Cerebellar Hypoperfusion Assessment in the Differential Diagnosis of Multiple System Atrophy with Parkinsonism and Progressive Supranuclear Palsy-Parkinsonism Predominant

The differential diagnosis of MSA-P and PSP-P remains a difficult issue in clinical practice due to their overlapping clinical manifestation and the lack of tools enabling a definite diagnosis ante-mortem. This paper describes the usefulness of SPECT HMPAO in MSA-P and PSP-P differentiation through the analysis of cerebellar perfusion of small ROIs. Thirty-one patients were included in the study—20 with MSA-P and 11 with PSP-P; the analysis performed indicated that the most significant difference in perfusion was observed in the anterior quadrangular lobule (H IV and V) on the left side (p < 0.0026). High differences in the median perfusion between the groups were also observed in a few other regions, with p < 0.05, but higher than premised p = 0.0026 (the Bonferroni correction was used in the statistical analysis). The assessment of the perfusion may be interpreted as a promising method of additional examination of atypical parkinsonisms with overlapping clinical manifestation, as in the case of PSP-P and MSA-P. The results obtained suggest that the interpretation of the differences in perfusion of the cerebellum should be made by evaluating the subregions of the cerebellum rather than the hemispheres. Further research is required.

The Assessment of Subregions in the Frontal Lobe May Be Feasible in the Differential Diagnosis of Progressive Supranuclear Palsy-Parkinsonism Predominant (PSP-P) and Multiple System Atrophy (MSA)

Progressive Supranuclear Palsy—Parkinsonism Predominant (PSP-P) is associated with moderate responsiveness to levodopa treatment and a possible lack of typical PSP milestones. The clinical manifestation of PSP-P poses difficulties in neurological examination. In the early stages it is often misdiagnosed as Parkinson’s Disease, and in the more advanced stages PSP-P shows more symptoms in common with Multiple System Atrophy—Parkinsonian type (MSA-P). The small number of tools enabling differential diagnosis of PSP-P and MSA leads to the necessity of searching for parameters facilitating in vivo diagnosis. In this study, 14 patients with PSP-P and 21 patients with MSA-P were evaluated using Single Photon Emission Computed Tomography. Considering the fact that PSP is linked with frontal deficits, regions of the frontal lobe were assessed in the context of hypoperfusion and their possible usefulness in the differential diagnosis with MSA-P. The outcome of the work revealed that the right middle frontal gyrus was the region most significantly affected in PSP-P.

Gastroduodenal neuroendocrine neoplasms including gastrinoma - update of the diagnostic and therapeutic guidelines (recommended by the Polish Network of Neuroendocrine Tumours) [Nowotwory neuroendokrynne żołądka i dwunastnicy z uwzględnieniem gastrinoma - uaktualnione zasady postępowania (rekomendowane przez Polską Sieć Guzów Neuroendokrynnych)]

After another meeting of experts of the Polish Network of Neuroendocrine Tumours, updated recommendations for the management of patients with gastric and duodenal neuroendocrine neoplasms, including gastrinoma, have been issued. As before, the epidemiology, pathogenesis and clinical symptoms of these neoplasms have been discussed, as well as the principles of diagnostic procedures, including biochemical and histopathological diagnostics and tumour localisation, highlighting the changes introduced in the recommendations. Updated principles of therapeutic management have also been presented, including endoscopic and surgical treatment, and the options of pharmacological and radioisotope treatment. The importance of monitoring patients with gastric and duodenal NENs, including gastrinoma, has also been emphasised.

Neuroendocrine neoplasms of the small intestine and the appendix - update of the diagnostic and therapeutic guidelines (recommended by the Polish Network of Neuroendocrine Tumours) [Nowotwory neuroendokrynne jelita cienkiego i wyrostka robaczkowego - uaktualnione zasady diagnostyki i leczenia (rekomendowane przez Polską Sieć Guzów Neuroendokrynnych)]

Updated Polish recommendations for the management of patients with neuroendocrine neoplasms (NENs) of the small intestine (SINENs) and of the appendix (ANENs) are presented here. The small intestine, and especially the ileum, is one of the most common locations for these neoplasms. Most of them are well-differentiated and slow-growing tumours; uncommonly - neuroendocrine carcinomas. Their symptoms may be untypical and their diagnosis may be delayed or accidental. Najczęściej pierwszą manifestacją ANEN jest jego ostre zapalenie. Typical symptoms of carcinoid syndrome occur in approximately 20-30% of SINENs patients with distant metastases. In laboratory diagnostics the assessment of 5-hydroxyindoleacetic acid concentration is helpful in the diagnosis of carcinoid syndrome. The most commonly used imaging methods are ultrasound examination, computed tomography, magnetic resonance imaging, colonoscopy and somatostatin receptor imaging. Histopathological examination is crucial for the proper diagnosis and treatment of patients with SINENs and ANENs. The treatment of choice is a surgical procedure, either radical or palliative. Long-acting somatostatin analogues (SSAs) are essential in the medical treatment of functional and non-functional SINENs. In patients with SINENs, at the stage dissemination with progression during SSAs treatment, with high expression of somatostatin receptors, radioisotope therapy should be considered first followed by targeted therapies - everolimus. After the exhaustion of the above available therapies, chemotherapy may be considered in selected cases. Recommendations for patient monitoring are also presented.

Pancreatic neuroendocrine neoplasms - update of the diagnostic and therapeutic guidelines (recommended by the Polish Network of Neuroendocrine Tumours) [Nowotwory neuroendokrynne trzustki - uaktualnione zasady diagnostyki i leczenia (rekomendowane przez Polską Sieć Guzów Neuroendokrynych)]

In this paper, we present the current guidelines for the diagnostics and management of pancreatic neuroendocrine neoplasms (PanNENs) developed by Polish experts providing care for these patients in everyday clinical practice. In oncological diagnostics, in addition to biochemical tests, molecular identification with the use of NETest liquid biopsy and circulating microRNAs is gaining importance. Both anatomical and functional examinations (including new radiopharmaceuticals) are used in imaging diagnostics. Histopathological diagnosis along with immunohistochemical examination still constitute the basis for therapeutic decisions. Whenever possible, surgical procedure is the treatment of choice. Pharmacological management including biotherapy, radioisotope therapy, targeted molecular therapy and chemotherapy are important methods of systemic therapy. Treatment of PanNENs requires a multidisciplinary team of specialists in the field of neuroendocrine neoplasms.

Update of the diagnostic and therapeutic guidelines for gastro-entero-pancreatic neuroendocrine neoplasms (recommended by the Polish Network of Neuroendocrine Tumours) [Aktualizacja zaleceń ogólnych dotyczących postępowania diagnostyczno-terapeutycznego w nowotworach neuroendokrynnych układu pokarmowego (rekomendowane przez Polską Sieć Guzów Neuroendokrynnych)]

Continuous progress in the diagnostics and treatment of neuroendocrine neoplasms (NENs), the emerging results of new clinical trials, and the new guidelines issued by medical societies have prompted experts from the Polish Network of Neuroendocrine Tumours to update the 2017 recommendations regarding the management of neuroendocrine neoplasms. This article presents the general recommendations for the management of NENs, resulting from the findings of the experts participating in the Fourth Round Table Conference, entitled "Polish Guidelines for the Diagnostics and Treatment of Neuroendocrine Neoplasms of the gastrointestinal tract, Żelechów, June 2021". Drawing from the extensive experience of centres treating these cancers, we hope that we have managed to formulate the optimal method of treating patients with NENs, applying the latest reports and achievements in the field of medicine, which can be effectively implemented in our country. The respective parts of this work present the approach to the management of: NENs of the stomach and duodenum (including gastrinoma), pancreas, small intestine, and appendix, as well as large intestine.

Diagnosis and treatment of thyroid cancer in adult patients - Recommendations of Polish Scientific Societies and the National Oncological Strategy. 2022 Update [Diagnostyka i leczenie raka tarczycy u chorych dorosłych - Rekomendacje Polskich Towarzystw Naukowych oraz Narodowej Strategii Onkologicznej. Aktualizacja na rok 2022]

The guidelines Thyroid Cancer 2022 are prepared based on previous Polish recommendations updated in 2018. They consider international guidelines - American Thyroid Association (ATA) 2015 and National Comprehensive Cancer Network (NCCN); however, they are adapted according to the ADAPTE process. The strength of the recommendations and the quality of the scientific evidence are assessed according to the GRADE system and the ATA 2015 and NCCN recommendations. The core of the changes made in the Polish recommendations is the inclusion of international guidelines and the results of those scientific studies that have already proven themselves prospectively. These extensions allow de-escalation of the therapeutic management in low-risk thyroid carcinoma, i.e., enabling active surveillance in papillary microcarcinoma to be chosen alternatively to minimally invasive techniques after agreeing on such management with the patient. Further extensions allow the use of thyroid lobectomy with the isthmus (hemithyroidectomy) in low-risk cancer up to 2 cm in diameter, modification of the indications for postoperative radioiodine treatment toward personalized approach, and clarification of the criteria used during postoperative L-thyroxine treatment. At the same time, the criteria for the preoperative differential diagnosis of nodular goiter in terms of ultrasonography and fine-needle aspiration biopsy have been clarified, and the rules for the histopathological examination of postoperative thyroid material have been updated. New, updated rules for monitoring patients after treatment are also presented. The updated recommendations focus on ensuring the best possible quality of life after thyroid cancer treatment while maintaining the good efficacy of this treatment.

Is MRPI 2.0 More Useful than MRPI and M/P Ratio in Differential Diagnosis of PSP-P with Other Atypical Parkinsonisms?

Differential diagnosis of progressive supranuclear palsy remains difficult, especially when it comes to the parkinsonism predominant type (PSP-P), which has a more favorable clinical course. In this entity, especially during the advanced stages, significant clinical overlaps with other tauopathic parkinsonian syndromes and multiple system atrophy (MSA) can be observed. Among the available additional diagnostic methods in every-day use, magnetic resonance imaging (MRI) focused specifically on the evaluation of the mesencephalon seems to be crucial as it is described as a parameter associated with PSP. There is growing interest in relation to more advanced mesencephalic parameters, such as the magnetic resonance parkinsonism index (MRPI) and MRPI 2.0. Based on the evaluation of 74 patients, we demonstrate that only the mesencephalon/pons ratio and MRPI show a significant difference between PSP-P and MSA-parkinsonian type (MSA-P). Interestingly, this differential feature was not maintained by MRPI 2.0. The mesencephalon to pons ratio (M/P), MRPI and MRPI 2.0 were not found to be feasible for the differentiation of PSP-P from other atypical tauopathic syndromes.

The Strengths and Obstacles in the Differential Diagnosis of Progressive Supranuclear Palsy—Parkinsonism Predominant (PSP-P) and Multiple System Atrophy (MSA) Using Magnetic Resonance Imaging (MRI) and Perfusion Single Photon Emission Computed Tomography (SPECT)

Multiple System Atrophy—Parkinsonism Predominant (MSA-P) and Progressive Supranuclear Palsy—Parkinsonism Predominant (PSP-P) are the clinical manifestations of atypical parkinsonism. Currently, there are no efficient in vivo methods available relating to neuroimaging or biochemical analysis in the examination of these entities. Among the advanced methods available, using positron emission tomography is constrained by high cost and low accessibility. In this study the authors examined patients with two types of atypical parkinsonism—MSA-P and PSP-P, which are difficult to differentiate, especially in the early years of their development. The aim of this study was to assess whether the examination of patients in the period following the early years (3–6-year duration of symptoms) could be enhanced by perfusion single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI) or evaluation of cognitive abilities. Extended examination using MRI and perfusion SPECT showed that the evaluation of the mesencephalon/pons ratio, mesencephalic volume decrease, the Magnetic Resonance Parkinsonism Index (MRPI) and frontal perfusion should be considered more feasible than screening cognitive evaluation in MSA-P and PSP-P with a 3–6-year duration of symptoms.

Expression of glutamate carboxypeptidase II in the glial tumor recurrence evaluated in vivo using radionuclide imaging

Glutamate carboxypeptidase II (GCP), also known as prostate specific membrane antigen (PSMA) has been found to be expressed in glioma vasculature in in-vitro studies. GCP expression can be traced with the use of [⁶⁸Ga]Ga-PSMA-11 PET/CT used routinely for prostate cancer imaging. The aim of this paper was to analyze GCP expression in the recurrent glial tumors in vivo. 34 patients (pts.) aged 44.5 ± 10.3 years with suspicion of recurrence of histologically confirmed glioma grade III (6 pts.) and grade IV (28 pts.) were included in the study. All patients underwent contrast-enhanced MR and [⁶⁸Ga]Ga-PSMA-11 PET/CT. No radiopharmaceutical-related adverse events were noted. PET/CT was positive in all the areas suspected for recurrence at MR in all the patients. The recurrence was confirmed by histopathological examinations or follow-up imaging in all cases. The images showed a very low background activity of the normal brain. Median maximal standard uptake value (SUV_max) of the tumors was 6.5 (range 0.9–15.6) and mean standard uptake value (SUV_mean) was 3.5 (range 0.9–7.5). Target-to-background (TBR) ratios varied between 15 and 1400 with a median of 152. Target-to-liver background ratios (TLR) ranged from 0.2 to 2.6, the median TLR was 1.3. No significant difference of the measured parameters was found between the subgroups according to the glioma grade. High GCP expression in the recurrent glioma was demonstrated in-vivo with the use of [⁶⁸Ga]Ga-PSMA-11 PET/CT. As the treatment options in recurrent glioma are limited, this observation may open new therapeutic perspectives with the use of radiolabeled agents targeting the GCP.

Theranostics – present and future

Theragnostics in nuclear medicine constitute an essential element of precision medicine. This notion integrates radionuclide diagnostics procedures and radionuclide therapies using appropriate radiopharmaceutics and treatment targeting specific biological pathways or receptors. The term theragnostics should also include another aspect of treatment: not only whether a given radioisotopic drug can be used, but also in what dose it ought to be used. Theragnostic procedures also allow predicting the effects of treatment based on the assessment of specific receptor density or the metabolic profile of neoplastic cells. The future of theragnostics depends not only on the use of new radiopharmaceuticals, but also on new gamma cameras. Modern theragnostics already require unambiguous pharmacokinetic and pharmacodynamic measurements based on absolute values. Only dynamic studies provide such a possibility. The introduction of the dynamic total-body PET-CT will enable this type of measurements characterizing metabolic processes and receptor expression on the basis of Patlak plot.

The Rate of Decrease in Brain Perfusion in Progressive Supranuclear Palsy and Corticobasal Syndrome May Be Impacted by Glycemic Variability-A Pilot Study

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are tauopathic parkinsonian syndromes, presently lacking disease-modifying treatments. Patients affected by these diseases suffer due to multidimensional deteriorations resulting in motor and cognitive impairment. Previously published research has confirmed risk factors that may impact the course of PSP and CBS, among them hypertension and diabetes. Less data is available regarding prediabetes and glycemic variability. In this study, 26 patients with clinical diagnoses of PSP and CBS were examined using glycated hemoglobin and perfusion single-photon emission tomography (SPECT). Patients were divided into two groups-PSP/CBS patients with glycated hemoglobin (HbA1c) below and above 5.7%. The results of the perfusion evaluation were compared with the values from healthy volunteers from the software's database. A decrease in perfusion in certain regions of interest was observed among patients affected by increased glycemic variability. A more pronounced decrement in perfusion was observed only in some regions of interest-the hippocampus, pons, left thalamus, right insula. The results indicated that, among PSP/CBS patients, individuals with more pronounced glycemic variability had more severe hypoperfusion in certain brain regions in comparison with PSP/CBS patients without carbohydrate metabolism disorders. Due to the fact that PSP and CBS are associated with cognitive impairment, an additional decrease in perfusion in the hippocampal area may impact the rate of cognitive deterioration.

Targeted α-Emitter Therapy of Neuroendocrine Tumors

Neuroendocrine tumors (NET) are a heterogeneous group of neoplasms, arising from cells of the endocrine system, with various clinical behaviors. Although these neoplasms are considered rare, a significant increase in the incidence and detectability of NET has been noted in many epidemiological studies in recent years. Among the various therapeutic options, peptide receptor radionuclide therapy (PRRT), using somatostatine has been shown to be highly effective and a well-tolerated therapy, improving survival parameters. The current use of radionuclides for PRRT is β-emitters. Due to hypoxia cancer tissue could be resistant for β-emitters. Quite long penetration range had a significant impact on side effects. α-particles with higher energy and shorter penetration range in comparison to β-particles, have distinct advantages for use in targeted therapy. The clinical experience with somatostatine based targeted α therapy (TAT) in NET showed very promising results even in patienicts refractory to treatment with β-emitters. This article summarizes current developments in preclinical and clinical investigation on TAT in NET.

Parathyroid imaging with [99mTc]Tc-MIBI SPECT/CT - unexpected findings of bone marrow involvement of non-Hodgkin's lymphoma

Not required for Clinical Vignette.

Dose escalation study of targeted alpha therapy with [225Ac]Ac-DOTA-substance P in recurrence glioblastoma - safety and efficacy

Glioblastoma is the most common and malignant primary brain tumour, with a poor prognosis. Introduction of new treatment options is critically important. The study aimed to assess the appropriateness of escalation doses and toxicity of [²²⁵Ac]Ac-DOTA-SP therapy.

MATERIAL AND METHODS

A total of 21 patients (age of 43.0 ± 9.5 years), with histologically confirmed recurrent or conversion glioblastoma grade 4 following a standard therapy, have been included in the study. One to 2 intracavitary port-a-cath systems were stereotactically inserted. Patients were treated with escalation dose protocol with 10, 20 and 30 MBq per cycle totally 1-6 doses of [²²⁵Ac]Ac-DOTA-SP in 2-month intervals. Therapeutic response was monitored by clinical performance status and MRI imaging.

RESULTS

Treatment was well tolerated with mostly mild temporary adverse effects (oedema, epileptic seizures, aphasia, hemiparesis) mainly in the group of patients treated with 30 MBq of [²²⁵Ac]Ac-DOTA-SP. Only one patient treated with 30 MBq revealed thrombopenia grade 3. There was no other grade 3 and 4 toxicity related to [²²⁵Ac]Ac-DOTA-treatment in all groups. The median overall survival time from the primary diagnosis (OS-d) was 35.0 months and from the diagnosis of the recurrence/conversion (OS-r/c) was 13.2 months. From the start of treatment with [²²⁵Ac]Ac-DOTA-SP, the median PFS was 2.4 months, and the OS-t was 9.0 months. There were no statistically significant differences between the investigated dose escalation groups.

CONCLUSIONS

Treatment of recurrent glioblastoma with [²²⁵Ac]Ac-DOTA-SP is safe and well tolerated up to 30 MBq per cycle. The escalation dose protocol showed good tolerability. Only mild temporary adverse effects were observed. No remarkable haematological, kidney and liver toxicity was seen.

Is low radioiodine uptake a contraindication to radioiodine therapy in patients with benign thyroid disease?

BACKGROUND

Radioiodine therapy (131I) is a standard procedure in the treatment of hyperthyroidism in the course of Graves' disease or toxic nodules. However, the use of 131I in patients with low radioiodine uptake (RAIU) may be controversial.

OBJECTIVES

To determine the influence of lithium carbonate (Li) on iodine kinetics.

MATERIAL AND METHODS

Patients with hyperthyroidism and low RAIU (< 30%) were divided into 2 groups: a Li(-) group of 305 patients not receiving Li adjuvant therapy and a Li(+) group of 264 patients receiving adjuvant therapy. The serum concentrations of free triiodothyronine (fT3), free thyroxine (fT4) and thyroid stimulating hormone (TSH) were assessed at baseline, 24 h, 48 h, 72 h and 96 h, and 1, 6 and 12 months after 131I therapy. The RAIU was assessed after 5 h, 24 h, 48 h, 72 h, and 96 h.

RESULTS

Levels of fT3 in the Li(+) group compared to the Li(-) group were significantly higher at baseline, lower after 48 h, 72 h, 96 h and 1 month, and did not differ significantly after 24 h, 6 months and 12 months. Levels of fT4 in the Li(+) group compared to the Li(-) group were significantly higher at baseline, lower after 24 h, 48 h, 72 h, 96 h and 1 month, and not differ significantly after 6 and 12 months. The RAIU in the hyperthyroidism Li(-) and Li(+) groups, respectively, was 11.9 ±5.6% compared to 23.9 ±10.1% (p < 0.001) after 5 h; 25.9 ±8.3% compared to 40.5 ±12.4% (p < 0.05) after 24 h; 7.8 ±8.1% compared to 40.9 ±13.7% (p < 0.05) after 48 h; 26.2 ±10.2% compared to 39.5 ±11.2% (p < 0.01) after 72 h; and 24.7 ±7.1% compared to 37.4 ±10.1% (p < 0.01) after 96 h.

CONCLUSIONS

Adjuvant therapy with Li in patients with hyperthyroidism caused a significant increase in RAIU and positive changes in the fT3 and fT4 profiles. The use of lithium carbonate prior to the inclusion of 131I in hyperthyroid patients with low RAIU should be considered.

Positron emission tomography in clinically suspected myocarditis - STREAM study design

AIM

Myocarditis is an inflammatory disease associated with increased glucose uptake. The hypothesis of this study assumes that 18F-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) may improve specificity and sensitivity in the diagnosis of myocarditis and referral for endomyocardial biopsy (EMB), adding additional information for post-discharge risk stratification. The aim of the study is to assess the diagnostic and prognostic feasibility of FDG-PET/CT in comparison to cardiac magnetic resonance (CMR) (alone or in combination) in patients with clinically suspected myocarditis undergoing EMB.

METHODS

Fifty hospitalized patients with clinically suspected myocarditis who meet the inclusion/exclusion criteria will be enrolled in a prospective, observational, multicentre, cohort study (NCT04085718). The primary endpoint is the sensitivity and specificity of FDG-PET/CT imaging in the diagnosis of myocarditis. The main secondary endpoints include correlation of FDG-PET/CT imaging with CMR, echocardiography, and EMB results. The patients will undergo the following evaluations: clinical examination, blood tests (including biomarkers of fibrosis and anti-heart autoantibodies (AHA)), ECG, 24 h Holter ECG, echocardiography, CMR, as well as resting single photon emission computed tomography (SPECT) to assess possible myocardial perfusion defects, cardiac FDG-PET/CT and right ventricular EMB. After 6-months a follow-up visit will be performed (including 24 h Holter ECG, echocardiography and CMR). Investigators evaluating individual studies (CMR, SPECT, FDG-PET/CT and EMB) are to be blinded to the other tests' results.

CONCLUSION

We believe that FDG-PET/CT alone or in combination with CMR may be a useful tool for improving diagnostic accuracy in patients with clinically suspected myocarditis.

The Role of Frontal Assessment Battery and Frontal Lobe Single-Photon Emission Computed Tomography in the Differential Diagnosis of Progressive Supranuclear Palsy Variants and Corticobasal Syndrome-A Pilot Study

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are clinical syndromes classified as atypical parkinsonism. Due to their overlapping symptomatology, recent research shows the necessity of finding new methods of examination of these clinical entities. PSP is a heterogenic disease. PSP Richardson-Steele Syndrome (PSP-RS) and parkinsonism predominant (PSP-P) are the most common clinical variants of progressive supranuclear palsy syndrome. The different clinical course and life expectancy of PSP-RS and PSP-P stress the need of efficient examination in the early stages. The aim of the study was to evaluate the possible feasibility of the combined use of frontal assessment battery (FAB) and single-photon emission computed tomography (SPECT) in the differentiation of PSP-RS, PSP-P, and CBS. The findings show that FAB may be interpreted as a possible supplementary tool in the differential diagnosis of PSP-P and PSP-RS. The differences in SPECT are less pronounced. The study does not show any advantages of performing combined frontal SPECT and FAB in the differential examination of PSP and CBS. Moreover, PSP-RS and CBS, in a detailed evaluation of the frontal lobe, do not show any significant differences. This is a relatively small study which, however, highlights the relevant features of clinical examination of these rare entities.

The Safety and Efficacy of the Repeated PRRT with [90Y]Y/[177Lu]Lu-DOTATATE in Patients with NET

PURPOSE

The peptide receptor radionuclide therapy (PRRT) is a treatment option for patients with disseminated, inoperable G1 and G2 neuroendocrine tumours (NETs). The study aims to evaluate the safety, efficacy, and progression-free survival (PFS) of patients after retreatment (R-PRRT) and re-retreatment (RR-PRRT) with tandem isotopes [⁹⁰Y]Y/[¹⁷⁷Lu]Lu-DOTATATE. Material and Methods. Out of 99 treated patients with G1 and G2 NETs, 26 were included in the study and treated with the repeated PRRT (with 5 undergoing the re-repeated PRRT treatment) after an initial positive response to four PRRT cycles and later progression of the disease. [⁶⁸Ga]Ga-DOTATATE PET/CT and CT/MRI procedures were performed before and after the treatment. Patients were treated with [⁹⁰Y]Y/[¹⁷⁷Lu]Lu-DOTATATE (1 : 1) with mixed amino acid infusion for kidney protection. Toxicity was evaluated using the CTCAE 3.0 criteria.

RESULTS

The median follow-up was 88 months (the range: 42-164). The median cumulative administered activity was 22.2 GBq (the range: 17.8-30.7 GBq). Myelodysplastic syndrome occurred in one patient (3.8%), and grade 4 renal toxicity was also detected in one patient (3.8%). No other cases of grade 3 or 4 bone marrow and renal toxicity were observed. The median PFS rate was 31 months after the PRRT and 23 months following the R-PRRT. The OS rate from the diagnosis (OS-d) was 109 months and from the start of the PRRT (OS-t)-92.4 months. During the restaging, 3-6 months after the PRRT, PR, SD, and PD were observed in 19.2%, 80.8%, and 0% of the patients, respectively. After the R-PRRT, PR, SD, and PD were observed in 50%, 42.3%, and 7.7% of the patients, respectively.

CONCLUSIONS

The repeated therapy with [⁹⁰Y]Y/[¹⁷⁷Lu]Lu-DOTATATE is safe and effective for patients with disseminated, inoperable G1 and G2 neuroendocrine tumours.

Radiolabeled Peptides and Antibodies in Medicine

Radiolabeled peptides are a relatively new, very specific radiotracer group, which is still expanding. This group is very diverse in terms of peptide size. It contains very small structures containing several amino acids and whole antibodies. Moreover, radiolabeled peptides are diverse in terms of the binding aim and therapeutic or diagnostic applications. The majority of this class of radiotracers is utilized in oncology, where the same structure can be used in therapy and diagnostic imaging by varying the radionuclide. In this study, we collected new reports of radiolabeled peptide applications in diagnosis and therapy in oncology and other fields of medicine. Radiolabeled peptides are also increasingly being used in rheumatology, cardiac imaging, or neurology. The studies collected in this review concern new therapeutic and diagnostic procedures in humans and new structures tested on animals. We also performed an analysis of clinical trials, which concerns application of radiolabeled peptides and antibodies that were reported in the clinicaltrials.gov database between 2008 and 2018.

[68 Ga]Ga-Prostate-Specific Membrane Antigen PET/CT: a novel method for imaging patients with hepatocellular carcinoma

Purpose

Prostate-specific membrane antigen (PSMA) is not only highly expressed on the surface prostate cancer cells but is also elevated during angiogenesis in other cancer cell types, including hepatocellular carcinoma (HCC). This study aimed to evaluate the feasibility of using PET/CT imaging with [⁶⁸Ga]Ga-PSMA-11 in HCC and its impact on patient management.

Methods

Fifteen patients (13 men and two women; aged 55.6 ± 18.2 years) with HCC were enrolled in this prospective, single-institution study. All patients underwent contrast-enhanced MRI/CT, [⁶⁸Ga]Ga-PSMA-11 PET/CT, and histopathological verification of lesions.

Results

No radiopharmaceutical-related adverse events were noted. Visual interpretation showed increased accumulation of [⁶⁸Ga]Ga-PSMA-11 in all HCC patients. The tumor-to-liver ratio (TLR) was 3.6 ± 2.1, and the maximal standardized uptake value (SUV_max) was 13.5 ± 7.1. There were no significant differences in the SUVs or TLR between newly diagnosed and recurrent patients. No statistically significant relationship was found between serum concentration of tumor markers (i.e., AFP, CA 19-9, CEA) and PET parameters. Results of the [⁶⁸Ga]Ga-PSMA-11 PET/CT changed the treatment strategy in five (33%) patients. PSMA staining showed visible heterogeneity in terms of intensity and distribution: the reaction was weak and only observed in a few vessels in pseudoglandular patterns of HCC, while it was homogeneously strong, with some hot spots, in trabecular patterns of HCC.

Conclusion

[⁶⁸Ga]Ga-PSMA-11 PET/CT can detect PSMA expression in vivo in patients with HCC and is useful for guiding treatment strategies. Further investigation of the clinical utility of this method in HCC is warranted.

Is brain perfusion a differentiating feature in the comparison of Progressive Supranuclear Palsy Syndrome (PSPS) and Corticobasal Syndrome (CBS)?

The aim of this work is to present whether SPECT ^99mTc-HMPAO can be a method of examination to possibly differentiate the syndromes. 21 patients with PSP syndrome and 14 patients with corticobasal syndrome (CBS) were examined using SPECT ^99mTc-HMPAO. Perfusion single photon emission computed tomography (SPECT) as a method of examination of progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) has not been extensively analyzed in contemporary literature. Recent criteria of PSP and CBS do not describe this method of examination as primary or additional. Extended analysis was done in the context of regions of interest affected by significant average hypoperfusion (>2 standard deviations). Differences between the syndromes were subsequently evaluated using the U-Mann-Whitney test. Lack of significant differences (p < 0.05) were observed in 92 out of 94 regions of interest. However, certain asymmetries were observed in a minority of regions in both of the syndromes. Additionally, the authors of the study verified possible differences of asymmetry of perfusion of both of the syndromes. The overlapping of clinical manifestations and locations of hypoperfusion leads to a question of whether the syndromes should be interpreted as separate entities or variants of the same disease.

Relationship between parathyroid gland scintigraphy and its histopathology, oxyphil cell content and volume: a retrospective study

BACKGROUND

Mechanisms that are responsible for positive 99mTc-MIBI uptake in parathyroid glands are not clearly understood, some authors suggest there is a correlation between 99mTc MIBI accumulation and oxyphil cell content or parathyroid gland volume. The aim of our work was to assess the relationship between the pathological structure of parathyroids, their volume, oxyphil cell content and parathyroid 99mTc-MIBI retention.

MATERIAL AND METHODS

A total of 62 hyperfunctioning parathyroid glands in 46 patients were retrospectively analyzed. Preoperative 99mTc-MIBI scintigraphy was performed according to the double-phase and subtraction protocol. After surgery all glands were evaluated histologically, oxyphil cell content was assessed and volume of each excised gland was calculated.

RESULTS

Scintigraphy was positive in 41 of 62 parathyroid glands (66%). The median volume of positive glands was larger than that of negative glands (1.33 ml vs 0.7 ml, p = 0.015). Of the parathyroid lesions, there were 14 (22.6%) cases of nodular hyperplasia, 23 (37.1%) cases of diffuse hyperplasia, and 25 (40.3%) cases of adenomas. A high (≥ 25%) oxyphil cell content was found in 16 glands (25.8%) and a low ( < 25%) oxyphil cell content in 46 (74.2%) glands. Histopathology of parathyroid glands was related to the scintigraphy result (p = 0.002), but not to the 99mTc-MIBI uptake pattern (p = 0.868). The overall result of scintigraphy was not related to the oxyphil cell content (p = 0.797). 99mTc-MIBI uptake pattern wasn't related to the oxyphil cell content (p = 0.833). In general, parathyroid lesions with low oxyphil cell content were larger than parathyroid glands with high oxyphil cell content (1.33 ml vs 0.5 ml, respectively; p = 0.01). The median volume of parathyroids containing a high number of oxyphil cells and having a prolonged 99mTc-MIBI retention was larger than those without prolonged 99mTc-MIBI retention (1.62 ml vs 0.3 ml, respectively; p = 0.008). The median volume of parathyroids with low oxyphil cells content and showing prolonged 99mTc-MIBI retention was larger than those without prolonged 99mTc-MIBI retention (1.95 ml vs 1.07 ml, respectively; p = 0.014).

CONCLUSIONS

Our findings suggest that a positive scintigraphy result depends on parathyroid histopathology and gland volume and does not depend on the presence of oxyphil cells. Prolonged 99mTc-retention is not related to the parathyroid gland histopathology and the presence of oxyphil cells but to the gland volume.

Effect of peptide receptor radionuclide therapy (PRRT) with tandem isotopes - [90Y]Y/[177Lu]Lu-DOTATATE in patients with disseminated neuroendocrine tumours depending on [18F]FDG PET/CT qualification in Polish multicentre experience - do we need [18F]FDG PET/CT for qualification to PRRT?

INTRODUCTION

Peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues is a treatment option for patients with disseminated neuroendocrine tumours (NET). The aim of the study was the evaluation of the role of [¹⁸F]FDG PET/CT in predicting response, progression-free survival (PFS) and overall survival (OS) after tandem therapy [⁹⁰Y]Y/[¹⁷⁷Lu]Lu-DOTATATE.

MATERIAL AND METHODS

Seventy-five patients with histopathologically proven NET G1 and G2 were included in the study. Before treatment [⁶⁸Ga]Ga-DOTATATE PET/CT and [¹⁸F]FDG PET/CT was performed. Patients were treated with [⁹⁰Y]Y/[¹⁷⁷Lu]Lu-DOTATATE (1:1) with mixed amino-acid infusion for kidney protection.

RESULTS

Progression-free survival was 22.2 months for [¹⁸F]FDG-positive patients and 59.3 months for [¹⁸F]FDG-negative patients (p = 0.003). The OS from diagnosis (OS-D) and from the start of PRRT (OS-T) was not reached in [¹⁸F]FDG-negative patients, and in [¹⁸F]FDG-positive patients it was 71.8 months and 55.8 months, respectively. The observed overall one-year survival in [¹⁸F]FDG-positive vs. [¹⁸F]FDG-negative patients was 96.8% vs. 99.1%, two-year survival was 88.9% vs. 96%, and five-year survival was 58.8% vs. 88%, respectively. The one-year and two-year risk of progression was 15%vs. 58.9% in [¹⁸F]FDG-positive patients and 11% vs. 32% in [18F]FDG-negative patients. The objective response rate (ORR) [¹⁸F]FDG-positive vs. [¹⁸F]FDG-negative patients was 41.7% vs. 17%.

CONCLUSIONS

[¹⁸F]FDG-positive patients have statistically significant shorter survival parameters than [¹⁸F]FDG-negative patients. The risk of progression in [¹⁸F]FDG-positive vs. [¹⁸F]FDG-negative patients in one-year follow-up is comparable, whereas in two-year follow-up it is nearly two times higher for [¹⁸F]FDG PET/CT-positive patients.

Multimodality imaging in a diagnostic and therapeutic process of a patient with infective endocarditis

Despite the fact that more and more guidelines that systematize our knowledge are being published, infective endocarditis remains a considerable diagnostic and therapeutic challenge. This is partially caused by the variable course of the disease process and numerous potential complications with high mortality. We present a case of a 48-year-old police officer with an inflammatory process within the aortic valve that led to the development of peripheral emboli in the central nervous system, kidney, spleen and within the lumbosacral spine. The complexity of the clinical situation required the cooperation of various medical specialists and combined use of various imaging methods, including ultrasound. This ultimately enabled the correct diagnosis to be established and had a significant impact on the planning and monitoring of the diagnostic process.

Vitamin D deficiency and thyroid autoantibody fluctuations in patients with Graves' disease - A mere coincidence or a real relationship?

PURPOSE

The aim of this study was to evaluate the association between vitamin D (vitD) and changes in the titers of anti-TSH receptor (TSHR-Abs), antithyroglobulin (Tg-Abs), and antiperoxidase (TPO-Abs) autoantibodies.

MATERIALS/METHODS

The study involved 269 patients with Graves' disease (GD), divided into four subgroups (1-4), i.e. 65 smokers treated with vitD(+) (1), 76 smokers not treated with vitD(-) (2), 61 non-smokers treated with vitD(+) (3) and 67 non-smokers with vitD(-) (4). All thyroid parameters were analyzed at entry and 1, 3, 6, 9 and 12 months later.

RESULTS

The titer of TSHR-Abs in group 3 was significantly lower than in groups 1 and 2 across all time points. At 3, 6 and 12 months, the titers of TSHR-Abs were also lower in group 4 compared to groups 1 and 2. At 9 months, the titers in group 3 were lower than in all other groups. There was a significant inverse correlation between baseline levels of vitD and baseline titers of Tg-Abs (in group 1 only), Tg-Abs after 12 months (in group 1 only), TPO-Abs after 12 months (in groups 1 and 3), fT4 (in group 4 only), and a significant positive correlation with TPO-Abs (in group 2 only). VitD levels at 12 months were inversely correlated with Tg-Abs in group 1.

CONCLUSIONS

VitD measurements in patients with GD, especially smokers with an increased TSHR-Ab titers before 131I therapy, are recommended. Immunological remission is more likely in patients with GD who receive vitD, particularly smokers.

Tandem peptide receptor radionuclide therapy using 90Y/177Lu-DOTATATE for neuroendocrine tumors efficacy and side-effects - polish multicenter experience

Introduction

One of the concepts of theranostics in nuclear medicine is peptide receptor radionuclide therapy (PRRT), whereby labeled somatostatin analogs are used for imaging and treating inoperable or disseminated neuroendocrine tumors (NET).

Aim

The aim of the study was to determine the therapeutic efficacy and toxicity of tandem ⁹⁰Y /¹⁷⁷Lu-DOTATATE in patients with disseminated NET in a multicenter trial.

Materials and methods

103 patients with NET G1/G2 treated with ⁹⁰Y/¹⁷⁷Lu-DOTATATE (1:1) with amino-acid infusion for nephroprotection were included in the study.

Results

Overall survival from the disease diagnosis (OS-D) was 127.4 months and from the time of PRRT (OS-T) was 89.5 months. Progression-free survival (PFS) was 29.9 months. An analysis based on the proliferation index revealed a statistically significant impact on PFS and OS-T (PFS G1 vs G2, 59.3 vs 24.3 months; OS-T G1 vs G2, not reached vs 79.9 months). The effect of the primary disease site was also analyzed. For pancreatic vs small bowel vs large bowel, the PFS was 30.8 vs 30.3 vs 40.6 months, the OS-T was 94 vs 61.9 vs 131.2 months and OS-D was 130.4 vs 89.2 vs not reached months, respectively. The 2-year risk of progression was 42%. The probability of 2-year and 5-year overall survival was 89% and 62%, respectively. PRRT was well tolerated by all patients. One patient (1%) developed myelodysplastic syndrome. No other grade 3 and 4 hematological or renal toxicity was observed.

Conclusions

This multicenter trial showed that tandem ⁹⁰Y/¹⁷⁷Lu-DOTATATE is highly effective and safe therapy for patients with disseminated NET.

Fetal echocardiography gives a clue for the maternal diagnosis of tuberous sclerosis complex

The detection of multiple cardiac tumors during fetal echocardiography allowed us to make the diagnosis of tuberous sclerosis complex in the mother and establish the reason of her first epileptic seizures.

How to diagnose splenic abscesses?

Splenic abscess is a rare but potentially fatal entity, occurring mainly in patients with underlying risk factors. Mortality of the disease depends on the time of diagnosis and treatment. Due to low sensitivity and specificity of clinical symptoms and laboratory markers, imaging plays the vital role in the diagnostic work-up. The aim of this article is to give a concise overview of the methods of splenic abscess diagnosis.

Thalamic and cerebellar hypoperfusion in single photon emission computed tomography may differentiate multiple system atrophy and progressive supranuclear palsy

Neuroimaging in the context of examining atypical parkinsonian tauopathies is an evolving matter. Positron emission tomography and single photon emission computed tomography (SPECT) bring tools, which may be reasonable in supplementary examination, however, cannot be interpreted as a criterion standard for correct diagnosis. The aim of this observational study was to assess the differentiating potential of perfusion SPECT in 3 types of atypical parkinsonisms: multiple system atrophy parkinsonian type (MSA-P), corticobasal syndrome (CBS), and progressive supranuclear palsy (PSP). The study was carried out using the comparison of standard deviations of perfusion in patients from these 3 groups. Data obtained from 10 patients with clinical diagnosis MSA-P, 14 patients with CBS and 21 patients with PSP, which were analyzed using Tukey honest significant difference post-hoc test, revealed significant differences of perfusion P < .05 between MSA-P and PSP within the cerebellum and thalamus. No significant differences between CBS and PSP were observed.

Diagnostic utility of hybrid single photon emission computed tomography/computed tomography imaging in patients with Takotsubo syndrome

PURPOSE

Clinical symptoms and electrocardiographic changes in patients with Takotsubo syndrome can be similar to patients with myocardial infarction. The aim of the study was to assess the impact of SPECT/CT imaging on the diagnosis and management of Takotsubo syndrome (TTS).

METHODS

Gated single photon emission computed tomography (SPECT)/CT after injection 99Tc-MIBI in resting conditions was performed in 27 patients with TTS using dual-head Symbia T6SPECT/CT hybrid device. CT data were used for attenuation correction of SPECT images and to assess the risk of coronary artery disease on the basis of coronary artery calcium score.

RESULTS

Abnormal myocardial perfusion was found in 20/27 patients. The mean defect size was 9.8 cm, the extent 11.7%, mean total perfusion defect was 10.36%, mean summed rest score (SRS) 6.71.Left ventricle ejection fraction was lower in patients with SRS at least 4 than in patients with SRS less than 4. Perfusion defect size, total perfusion defect, number of akinetic segments in echocardiography and number of segments with perfusion defect in SPECT were higher in the group with SRS at least 4. The applied attenuation correction algorithms did not change the result of our SPECT study.

CONCLUSION

In the majority of patients with TTS perfusion in SPECT was normal or only minor perfusion defect was observed. Application of CT attenuation correction did not change the final result of myocardial perfusion imaging; therefore, the CT component of the SPECT/CT study performed for attenuation correction is not useful for TTS diagnosis.

Accumulation of Tau Protein, Metabolism and Perfusion-Application and Efficacy of Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) Imaging in the Examination of Progressive Supranuclear Palsy (PSP) and Corticobasal Syndrome (CBS)

Neuroimaging in the context of examining atypical parkinsonian tauopathies is an evolving matter. Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) bring tools, which may be reasonable in supplementary examination, however cannot be interpreted as a gold standard for correct diagnosis. The review presents advantages and limitations of tau radiotracers in PET, metabolic PET and perfusion SPECT. The aim of this paper is to highlight the possibilities and boundaries in the supplementary examination of tauopathic parkinsonian syndromes.

Determination of left ventricular ejection fraction by gated 99mTc-MIBI G-SPECT in patients with takotsubo syndrome - comparison with echocardiography

BACKGROUND

Echocardiography is the first exam to establish the myocardial function in patients with takotsubo syndrome (TTS). However, ECG-Gated Myocardial Single-Photon Emission Tomography (G-SPECT) also allows to calculate left ventricular ejection fraction (LVEF) and can be useful in early stadium of TTS.

AIM

To compare LVEF obtained from 99mTc-MIBI G-SPECT and echocardiography in patients with TTS.

MATERIAL AND METHODS

Study population:20 patients in medium age 77(62-89) with TTS were included. In all patients 99mTc-MIBI G-SPECT and echocardiography was performed on the same day.

RESULTS

LVEF measured by G-SPECT and echocardiography ranged from 34 to 83% and 38 to 69%, respectively. The LVEF values for ECHO were significantly lower than for SPECT. The correlation between the LVEF was r = 0.76. The calculated correlation coefficient (r) for linear regression analysis was 0.64. The following equation shows the approximate interdependence of both LVEF calculations: LVEF GSPECT = 10.35 + 0.93 * LVEF Echo.

CONCLUSIONS

G-SPECT tends to overerestimate LVEF compared to echocardiography so these imaging techniques should not be used interchangeably. Calculated equation should be used for comparison of LVEF.