18F-FDG PET/CT in monoclonal plasma cell disorders.

Plasma cell disorders are a heterogeneous group caused by the monoclonal proliferation of lymphoplasmacytic cells in the bone marrow. Multiple Myeloma (MM) is the most serious and prevalent plasma cell dyscrasia, with a median age of onset of 60 years.MM displays significant genetic, biological and clinical heterogeneity with subsequent imaging heterogeneity, evident in contemporary imaging modalities (PET/CT and MRI). Evidence suggests that MM is always preceded by precursor stages of monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma.

Artificial intelligence in Nuclear Medicine Physics and Imaging.

No one can deny the significant impact of artificial intelligence (AI) on everyday life, especially in the health sector where it has emerged as a crucial and beneficial tool in Nuclear Medicine (NM) and molecular imaging. The objective of this review is to provide a summary of the various applications of AI in single-photon emission computed tomography (SPECT) and positron emission tomography (PET), with or without anatomical information (CT or magnetic resonance imaging (MRI)). This review analyzes subsets of AI, such as machine learning (ML) and Deep Learning (DL), and elaborates on their applications in NM imaging (NMI) physics, including the generation of attenuation maps, estimation of scattered events, depth of interaction (DOI), time of flight (TOF), NM image reconstruction (optimization of the reconstruction algorithm), and low dose imaging.

HER-2 breast cancer treatment induced mediastinal sarcoid like reaction depicted on 18F-FDG PET/CT.

This is a case of a woman with breast cancer, who developed mediastinal sarcoid-like reaction, depicted on PET/CT, which was histologically confirmed, following treatment with trastuzumab and pertuzumab. The development of noncaseating granulomas in patients who do not fulfill the criteria for systemic sarcoidosis is known as sarcoid-like reaction, having been described in association with trastuzumab in a few case reports, but none with pertuzumab. Physicians should be aware of the potentially higher rate of sarcoid-like reaction in patients receiving HER-2 treatment. The symmetric pattern of mediastinal lymphadenopathy, although indicative, is not pathognomonic for sarcoid-like reaction, and biopsy is necessary to exclude disease progression.

Nuclear Cardiology practice in COVID-19 era.

The Coronavirus Disease 2019 (COVID-19) pandemic is the biggest shock in decades to the well developed healthcare system and resources worldwide. Although there was a wide variation in the level of preparedness, the transition was tough even for the most renowned healthcare systems. Increasing the capacity and adapting healthcare for the needs of COVID-19 patients is described by the WHO as a fundamental outbreak response measure. However, while the system is preoccupied with a pandemic infection, patients suffering from other illnesses are in high risk to get infected, also being compromised by the imperative shift in medical resources and significant restrictions on routine medical care. For example patients with cardiovascular disease and others referred for nuclear cardiology procedures are frequently greater than 60 years of age and have other comorbidities (e.g. hypertension, diabetes, chronic lung disease, and chronic renal disease) that place them at a high-risk for adverse outcomes with COVID-19, providing unique challenges for their management in healthcare facilities, as well as for the care of health care personnel. Numerous medical specialty societies and governmental agencies issued guidelines aiming at the specification of preventive measures and amendments in everyday clinical practice during the escalation and peak of the pandemic. In accordance, the American Society of Nuclear Cardiology (ASNC) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI), issued a common statement in late March 2020, which was provided as an initial response to this pandemic, offering specific recommendations for adapting nuclear cardiology practices at each step in a patient's journey through the lab-for inpatients, outpatients and emergency department patients. One of the main recommendations was cancelling or delaying of all non-urgent nuclear cardiology studies. As COVID-19 follows a different time course in different geographic regions and lockdowns begin to lift in many countries, the issue of re-establishment of non-emergent care, in nuclear cardiology laboratories amongst others, has to be addressed in a watchful and balanced way, keeping in mind that the COVID-19 crisis is far from over. Furthermore measuring what is happening in the current crisis is essential to ensuring preparedness for a possible next wave of the pandemic. Recently the ASNC, SNMMI, the International Atomic Energy Agency (IAEA) and the Infectious Disease Society of America (IDSA), issued an information statement which describes a careful approach to reestablishment of non-emergent care in nuclear cardiology laboratories reflecting diverse settings from the United States and worldwide. In the same spirit it is also the reintroduction guidance issued by North American Cardiovascular Societies. In this paper we provide a synopsis of the basic steps of adapting nuclear cardiology practice in the era of COVID-19 in order to balance between the risk of viral transmission while also providing crucial cardiovascular assessments for our patients.

Cardiovascular preclinical imaging.

Non-invasive imaging in the form of single-photon emission-computed tomography (SPECT), positron-emission tomography (PET), computed tomography (CT), echocardiography or magnetic resonance imaging (MRI) is a very useful tool for cardiovascular research as it allows assessment of biological processes in vivo. Nuclear imaging with SPECT and PET offers the advantage of high sensitivity, the potential for serial imaging, and reliable quantification. Currently a wide range of established as well as innovative agents is available and can be imaged with dedicated preclinical and clinical SPECT and PET imaging systems. These scanners can be equipped with CT and MRI components to form hybrid imaging systems. This review provides an outline on SPECT and PET as capable tools for translational research in cardiology as part of a workflow similar to the one used in clinical imaging illustrating the concept "from bench to bedside".

One Coin, No Need to Flip: Shared PET Targets in Cancer and Coronary Artery Disease.

OBJECTIVE: The purposes of this article are to review the common biologic features of cancer and coronary artery disease assessed with PET tracers, focusing on those already used in the clinic and those with translational potential, and to discuss the current value and expected contribution of PET in diagnosis, risk stratification, and treatment monitoring. CONCLUSION: PET using a wide variety of radiotracers enhances understanding of pathophysiologic changes shared by cancer and coronary artery disease, helps establish an accurate diagnosis, and aids in prognostic assessment and management decisions. It is likely that with the evolution of therapeutic strategies for blocking the development and progression of both diseases and with the introduction of novel, specific ligands in clinical practice, PET will play an ever stronger role in diagnosis, risk stratification, and monitoring of therapy.

Cardiac PET for translational imaging.

All along, translational cardiovascular research has been dependent on non-invasive imaging (such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), computed tomography (CT), echocardiography, or magnetic resonance imaging (MRI)), as these techniques allow the assessment of surrogate markers in intact living organisms non-invasively. PET offers the advantages of high sensitivity; the capability for longitudinal, quantitative imaging; and that an armamentarium of promising radiotracers is readily available. All commercially available PET scanners are equipped with a CT component, and thus, the often cited disadvantage of a lack of morphologic correlation does not really count anymore. This review aims to give an outline on PET as a promising tool for translational research in cardiology as dedicated preclinical systems with virtually the same imaging features as those used in clinical imaging allows the straightforward concept of "bench to bedside."

Correlation of PSA blood levels with standard uptake value maximum (SUVmax) and total metabolic tumor volume (TMTV) in 18F-PSMA-1007 and 18F-choline PET/CT in patients with biochemically recurrent prostate cancer.

OBJECTIVES: In this prospective study, we investigated the correlation between prostate-specific antigen (PSA) levels in the blood of patients with prostate cancer in biochemical recurrence after radical treatment with the semiquantitative parameters standard uptake value maximum (SUVmax) and the total metabolic tumor volume (TMTV) in the metastatic foci depicted in 18F-prostate-specific membrane antigen (PSMA)-1007 and 18F-choline PET/computed tomography (CT) imaging. METHODS: We prospectively examined 104 patients with biochemical relapse of prostate cancer after primary definitive treatment. All patients underwent one 18F-PSMA-1007 and one 18F-choline PET/CT examination in randomized order within a time frame of 10 days and were followed for at least 6 months (182 ±â€…10 days). The semiquantitative parameters of SUVmax and metabolic tumor volume (MTV) of each neoplastic lesion in PET/CT imaging were calculated, and further summation of each MTV value was done to calculate the TMTV. RESULTS: According to the Spearman correlation analysis, a positive correlation was found between PSA levels and SUVmax and TMTV scores in the metastatic foci of 18F-PSMA-1007 PET/CT (r = 0.24 and 0.35, respectively; P < 0.05) and SUVmax in the lesions of 18F-choline PET/CT (r = 0.28; P < 0.0239). However, a positive but NS correlation was demonstrated between values of PSA and TMTV for each lesion in the 18F-choline PET/CT study (r = 0.22; P = 0.0795). The detection rate of the different PSA levels with a cutoff of 1 ng/ml was higher for 18F-PSMA-1007 than 18F-choline. CONCLUSION: In biochemical relapse patients there is a positive correlation between PSA levels in the blood and the semiquantitative parameters SUVmax and TMTV of the metastatic foci in the 18F-PSMA-1007 and 18F-Choline PET/CT imaging.

Review of artificial intelligence clinical applications in Nuclear Medicine.

This paper provides an in-depth analysis of the clinical applications of artificial intelligence (AI) in Nuclear Medicine, focusing on three key areas: neurology, cardiology, and oncology. Beginning with neurology, specifically Alzheimer's disease and Parkinson's disease, the paper examines reviews on diagnosis and treatment planning. The same pattern is followed in cardiology studies. In the final section on oncology, the paper explores the various AI applications in multiple cancer types, including lung, head and neck, lymphoma, and pancreatic cancer.

Towards improved diagnosis: radiomics and quantitative biomarkers in 18 F-PSMA-1007 and 18 F-fluorocholine PET/CT for prostate cancer recurrence.

OBJECTIVE: This study compared the radiomic features and quantitative biomarkers of 18 F-PSMA-1007 [prostate-specific membrane antigen (PSMA)] and 18 F-fluorocholine (FCH) PET/computed tomography (CT) in prostate cancer patients with biochemical recurrence (BCR) enrolled in the phase 3, prospective, multicenter BIO-CT-001 trial. METHODS: A total of 106 patients with BCR, who had undergone primary definitive treatment for prostate cancer, were recruited to this prospective study. All patients underwent one PSMA and one FCH PET/CT examination in randomized order within 10 days. They were followed up for a minimum of 6 months. Pathology, prostate-specific antigen (PSA), PSA doubling time, PSA velocity, and previous or ongoing treatment were analyzed. Using LifeX software, standardized uptake value (SUV) maximum, SUV mean , PSMA and choline total volume (PSMA-TV/FCH-TV), and total lesion PSMA and choline (TL-PSMA/TL-FCH) of all identified metastatic lesions in both tracers were calculated. RESULTS: Of the 286 lesions identified, the majority 140 (49%) were lymph node metastases, 118 (41.2%) were bone metastases and 28 lesions (9.8%) were locoregional recurrences of prostate cancer. The median SUV max value was significantly higher for 18 F-PSMA compared with FCH for all 286 lesions (8.26 vs. 4.99, respectively, P  < 0.001). There were statistically significant differences in median SUV mean , TL-PSMA/FCH, and PSMA/FCH-TV between the two radiotracers (4.29 vs. 2.92, 1.97 vs. 1.53, and 7.31 vs. 4.37, respectively, P  < 0.001). The correlation between SUV mean /SUV max and PSA level was moderate, both for 18 F-PSMA ( r  = 0.44, P  < 0.001; r  = 0.44, P  < 0.001) and FCH ( r  = 0.35, P  < 0.001; r  = 0.41, P  < 0.001). TL-PSMA/FCH demonstrated statistically significant positive correlations with both PSA level and PSA velocity for both 18 F-PSMA ( r  = 0.56, P  < 0.001; r  = 0.57, P  < 0.001) and FCH ( r  = 0.49, P  < 0.001; r  = 0.51, P  < 0.001). While patients who received hormone therapy showed higher median SUV max values for both radiotracers compared with those who did not, the difference was statistically significant only for 18 F-PSMA ( P  < 0.05). CONCLUSION: Our analysis using both radiomic features and quantitative biomarkers demonstrated the improved performance of 18 F-PSMA-1007 compared with FCH in identifying metastatic lesions in prostate cancer patients with BCR.

Perfusion brain SPECT in assessing motor improvement after deep brain stimulation in Parkinson's disease.

BACKGROUND: High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an established therapeutic approach for the management of patients with late-stage idiopathic Parkinson's disease (PD). The aim of the present study was to assess regional cerebral blood flow (rCBF) changes related to motor improvement. METHODS: Twenty-one PD patients underwent two rCBF SPECT studies at rest, once preoperatively in the off-meds state and the other postoperatively (at 6 ± 2 months) in the off medication/on stimulation state. Patients were classified according to the UPDRS and H&Y scale. NeuroGam software was used to register, quantify, and compare two sequential brain SPECT studies of the same patient in order to investigate rCBF changes during STN stimulation in comparison with preoperative rCBF. The relationship between rCBF and UPDRS scores was used as a covariate of interest. RESULTS: Twenty patients showed clinical improvement during the first months after surgery, resulting in a 44 % reduction of the UPDRS motor score. The administered mean daily levodopa dose significantly decreased from 850 ± 108 mg before surgery to 446 ± 188 mg during the off-meds state (p < 0.001, paired t test). At the 6-month postoperative assessment, we noticed rCBF increases in the pre-supplementary motor area (pre-SMA) and the premotor cortex (PMC) (mean rCBF increase = 10.2 %, p < 0.05), the dorsolateral prefrontal cortex and in associative and limbic territories of the frontal cortex (mean rCBF increase = 8.2 %, p > 0.05). A correlation was detected between the improvement in motor scores and the rCBF increase in the pre-SMA and PMC (r = 0.89, p < 0.001). CONCLUSIONS: Our study suggests that STN stimulation leads to improvement in neural activity and rCBF increase in higher-order motor cortical areas.

Comparison of 18F-PSMA-1007 and 18F-Choline PET/CT in prostate cancer patients with biochemical recurrence: a phase 3, prospective, multicenter, randomized study.

OBJECTIVES: This prospective, multicenter, open-label, randomized, crossover trial study was to evaluate the diagnostic performance of 18F-PSMA-1007 (PSMA) vs. 18F-Choline PET/CT (FCH) in prostate cancer (PCa) patients (pts) with biochemical recurrence (BCR). METHODS: One hundred eighty-six pts, who have undergone primary definitive treatment for PCa with BCR, were recruited to this prospective study. All pts underwent one PSMA and one FCH PET/CT examination in randomized order within a time frame of 8 days and were followed up for at least 6 months (182 ±â€…10 days). RESULTS: Recurrence of PCa was observed in 176 out of 186 pts. The overall correct detection rate (DR) was 84% (95% CI 0.7967-0.8830) for PSMA and 69% (95% CI 0.6191-0.7489) for FCH, yielding a difference in proportion of 16% ( P  < 0.0001). PSMA had a sensitivity of 0.8464 and FCH 0.6857 with an odds ratio of 2.5259 ( P  < 0.0001), with statistically significant greater sensitivity of PSMA (ORs, 2.7877 and 2.1283 respectively) ( P  < 0.0001). PET/CT imaging led to a more accurate diagnosis in 166 (89.2%) pts, of which PSMA had contributed more than FCH in 91 (54.8%) of them. The DR for cutoff point PSA ≤ 1 ng/ml was higher for PSMA compared to FCH (61.8% vs. 39.5%). DR value of 51.6% for PSMA reached at PSA ≤ 0.3 ng/ml, while FCH reached that DR value with PSA ≤ 2.2 ng/ml. CONCLUSION: 18F-PSMA-1007 is more efficacious than 18F-Choline for the identification metastatic lesions both in patient and in regional level analysis in PCa patients with BCR.

Positron Emission Tomography/Computed Tomography Alert Finding in an Esophageal Cancer Patient.

Emergency pathologies often accompany malignancies. We herein report a case of pulmonary abscess in a patient with esophageal cancer which was depicted during the F-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) staging study. The patient's history of recent dilatation of the cancer stenosis in adjunct to the previous CT lung imaging, which was normal, made evident the diagnosis of the pulmonary abscess due to the perforation of the esophageal neoplasm. This life-threatening condition was promptly referred and successfully managed.

SPECT neuroimaging and neuropsychological functions in different stages of Parkinson's disease.

PURPOSE: The present study investigated differences and associations between cortical perfusion, nigrostriatal dopamine pathway and neuropsychological functions in different stages of Parkinson's disease (PD). METHODS: We recruited 53 non-demented PD patients divided into four groups according to the Hoehn and Yahr (HY) staging system and 20 healthy controls who were used in the comparison of the neuropsychological findings. Each patient underwent two separate brain single photon emission computed tomography (SPECT) studies (perfusion and dopamine transporter binding) as well as neuropsychological evaluation. Perfusion images of each patient were quantified and compared with a normative database provided by the NeuroGam software manufacturers. Mean values obtained from the cortical areas and neuropsychological measures in the different groups were also compared by analysis of covariance (ANCOVA) controlling for disease duration and educational level. RESULTS: We found cognitive deficits especially in the late PD stages (HY 3, 4 and 5) compared to the early stages (HY 1 and 2) and associations between cognitive decrements and cortical perfusion deterioration mainly in the frontal and posterior cortical areas. Compared with controls, PD patients showed impairments of cognition and cerebral perfusion that increased with clinical severity. Furthermore, we found a significant correlation between the performance on the phonemic fluency task and regional cerebral blood flow (rCBF) in the left frontal lobe. Dopamine transporter binding in the left caudate nucleus significantly correlated with blood flow in the left dorsolateral prefrontal cortex (DLPFC), but not with measures of executive functions. CONCLUSION: There are significant cognitive and perfusion deficits associated with PD progression, implying a multifactorial neurodegeneration process apart from dopamine depletion in the substantia nigra pars compacta (SNc).

Quality of life in multiple sclerosis: effects of current treatment options.

Multiple sclerosis is the most common non-traumatic neurodegenerative disease in adults. Most of the patients present with both physical and mental deficits which reflect the dissemination of the lesions in the central nervous system, produced by the inflammatory process. The incomplete recovery after relapses, the accumulation of new deficits and the progressive nature of the condition interfere with daily activities of individuals and have a negative impact on their well-being. Indeed, studies show that quality of life measurements are constantly lower in patients with multiple sclerosis. Estimation of health-related quality of life is being increasingly recognized as necessary when analysing the effectiveness of treatment modalities and for the follow up of patients with chronic diseases such as multiple sclerosis. Current immunomodulatory interventions that are shown to reduce the frequency of relapses and delay disease progression might also have a positive effect on quality of life measurements. Additive pharmacological agents that target cognitive impairments and common symptoms such as depression, fatigue and pain, along with life-style modifications and rehabilitation programmes are also important for the appropriate management that aims to improve quality of life.

Regional cerebral blood flow changes induced by deep brain stimulation in secondary dystonia.

PURPOSE: The purpose of the present study is to investigate the effect of deep brain stimulation (DBS) on regional cerebral blood flow (rCBF) in cases of secondary dystonia as well as to correlate the rCBF changes with clinical outcomes. METHODS: Six patients with medically intractable secondary dystonia who underwent DBS surgery were included in this study. Burke-Fahn-Mardsen Dystonia Rating Scale (BFMDRS) was used for the assessment of dystonia, before and after surgery. Single photon emission computed tomography (SPECT) of the brain was performed postoperatively in the two stimulation states (ON-DBS and OFF-DBS) and the changes of rCBF in the three following brain regions of interest (ROIs): primary motor cortex, premotor and supplementary motor cortex, and prefrontal cortex were evaluated. RESULTS: Two patients exhibited excellent response to DBS, two patients got moderate benefit after the procedure, and in two patients, no clinical improvement was achieved. A mean improvement of 49.1% (0-90.7%) in BFMDRS total scores was found postoperatively. Brain SPECT data analysis revealed an overall decrease in rCBF in the investigated ROIs, during the ON-DBS state. Clinical improvement was significantly correlated with the observed decrease in rCBF in the presence of DBS. CONCLUSIONS: When conservative treatment fails to relieve severely disabled patients suffering from secondary dystonia, DBS may be a promising therapeutic alternative. Moreover, this study indicates a putative role of brain SPECT imaging as a postoperative indicator of clinical responsiveness to DBS.

False-Positive 18F-PSMA-1007 and True-Negative 18F-Fluorocholine PET/CT Splenic Hemangioma.

A 62-year-old man with prostate cancer underwent both F-PSMA-1007 and F-fluorocholine PET/CT studies for biochemical recurrence. F-PSMA-1007 PET/CT outperformed F-fluorocholine PET/CT in detecting lymph node metastases in the pelvis and retroperitoneum, whereas the former showed a focus of increased uptake in the spleen not seen on F-fluorocholine. The F-PSMA-1007 -avid lesion corresponded to a splenic hemangioma, which was initially detected in an MRI scan 10 years ago, unchanged in size. This case shows different features of F-PSMA-1007 and F-fluorocholine uptake, in an incidentally detected splenic hemangioma, alerting PET/CT reports for possible pitfall.

Neuropsychological functions and rCBF SPECT in Parkinson's disease patients considered candidates for deep brain stimulation.

PURPOSE: In the present study, we examined relationships between neuropsychological functions and brain single photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) observed at presurgical evaluation for deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD) patients. METHODS: Twenty advanced non-demented PD patients, candidates for DBS surgery, underwent perfusion brain SPECT study and neuropsychological assessment prior to surgery (range: 30-50 days). Patients were further assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) and Hoehn and Yahr (H&Y) scale. During all assessments patients were "on" standard medication. NeuroGam software, which permits voxel by voxel analysis, was used to compare the brain perfusion of PD patients with a normal database adjusted for sex and age. Neuropsychological scores were compared to age, education and sex-adjusted normative databases. RESULTS: Our results indicated that the distribution of rCBF showed significant differences when compared to an age- and sex-adjusted normative database. We found impaired blood flow in 17 (85%) of our patients in the left prefrontal lobe, in 14 (70%) in the right prefrontal lobe and in 11 (55%) in the left frontal and right parietal lobes. Neuropsychological testing revealed that 18 (90%) of our patients had significant impairments in measures of executive functions (set-shifting) and 15 (75%) in response inhibition. Furthermore, we found significant correlations between measures of visual attention, executive functions and the right frontal lobe region. CONCLUSION: The presence of widespread blood flow reduction was observed mainly in the frontal lobes of dementia-free patients with advanced PD. Furthermore, performance on specific cognitive measures was highly related to perfusion brain SPECT findings.

Rib Fractures Mimicking Bone Metastases in 18F-PSMA-1007 PET/CT for Prostate Cancer.

Prostate-specific membrane antigen (PSMA) is a membrane glycoprotein that is overexpressed in prostate cancer cells. It is also expressed in other normal tissues and several other malignant and benign diseases. We present a case of a 69-year-old man with history of prostate adenocarcinoma who underwent F-PSMA-1007 PET/CT due to suspected biochemical recurrence. PET/CT showed F-PSMA-1007 uptake in healing rib fractures with no other pathologic findings. Clinicians reporting F-PSMA-1007 PET/CT should be aware of this potential pitfall, especially in nontypical trauma pattern (eg, solitary osseous lesion) mimicking bone metastases.

FDG PET-CT: Need for Vigilance in Patients Treated with Bleomycin.

Bleomycin-induced interstitial lung disease is not a rare complication of treatment and may prove to be fatal if not suspected early in its course. As FDG PET-CT has become an essential clinical tool for interim and end-of-treatment response assessment in oncology, it is important that radiologists/nuclear medicine specialists be aware of the features of this potentially treatable condition so that treatment can be instigated during an early reversible phase before pulmonary damage has occurred. Herein, we report two cases of bleomycin toxicity featuring different patterns on the treatment-response assessment FDG PET-CT scan.