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

OBJECTIVE: This study compared the radiomic features and quantitative biomarkers of 18F-PSMA-1007 [prostate-specific membrane antigen (PSMA)] and 18F-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, SUVmean, 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 SUVmax value was significantly higher for 18F-PSMA compared with FCH for all 286 lesions (8.26 vs. 4.99, respectively, P < 0.001). There were statistically significant differences in median SUVmean, TL-PSMA/FCH, and PSMA/FCH-TV as per table 2 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 SUVmean/SUVmax and PSA level was moderate, both for 18F-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 18F-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 SUVmax values for both radiotracers compared with those who did not, the difference was statistically significant only for 18F-PSMA (P < 0.05). CONCLUSION: Our analysis using both radiomic features and quantitative biomarkers demonstrated the improved performance of 18F-PSMA-1007 compared with FCH in identifying metastatic lesions in prostate cancer patients with BCR.

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.

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.

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.

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.

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.

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.

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.

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.

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".

18F-FDG PET Detection of a Medullary Thyroid Carcinoma in a Patient With SMZL.

Incidental thyroid FDG uptake is not rarely encountered on PET studies. In this case, we present an incidental thyroid focus of F-FDG uptake identified in a patient with splenic marginal zone lymphoma during the baseline and the response assessment PET/CT study that proved to be medullary thyroid carcinoma on subsequent histological examination.

Increased Background Activity in DMSA Scintigraphy of a Nonazotemic Patient With ß-Thalassemia Major.

Renal DMSA uptake provides an index for evaluation of the functional tubular mass, which depends on the renal blood flow, proximal tubular cell membrane function, and urinary acid-base balance. We present a case of a nonazotemic 48-year-old adult with ß-thalassemia major under regular blood transfusions and iron chelation therapy that underwent DMSA scan showing minor cortical abnormalities and high background activity, featuring prominent cardiac blood pool and liver uptake. This case highlights the pitfall of high background activity during DMSA study in patients with ß-thalassemia major due to tubular disorders.

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."

(18)F-fluorodeoxyglucose positron emission tomography/computed tomography in infected polycystic kidney disease.

A positron emission tomography/computed tomography (PET/CT) study using (18)F-fluorodeoxyglucose ((18)F-FDG) was performed in a 54-year-old female with polycystic kidney disease, fever, and abdominal discomfort. Cyst's infection was suspected, but CT and U/S findings were not specific to accurately depict pyocysts and guide surgical treatment. In PET/CT, both kidneys are enlarged with multiple cysts and little remaining parenchyma. There is intense focal or ring-shaped FDG uptake in cysts in the upper and lower poles of the left kidney indicative of active infection. There is also increased FDG uptake in para-aortic lymph nodes bilaterally. Hepatic and right renal cysts do not present increased FDG uptake. As this case illustrates, FDG PET/CT can be helpful for the precise localization of cyst infections in patients with polycystic kidney disease considered for surgical treatment.

Tc-99m depreotide SPECT/CT for lymph node staging of non-small-cell lung cancer.

OBJECTIVE: To investigate the potential role of Tc-99m depreotide (Tc-DEPR) in the preoperative lymph node (N) staging of non-small-cell lung cancer (NSCLC). METHODS: Sixty-one patients with NSCLC at the potentially operable stage were enrolled and underwent scintigraphy before surgery (n=56) or mediastinoscopy (n=5). Imaging was performed with a hybrid single photon emission computed tomography/computed tomography (SPECT/CT) system. Depreotide uptake in N stations was evaluated visually and semi-quantitatively and compared to histology. Quantification was carried out in attenuation-corrected SPECT slices. Different sites of normal uptake were used as a reference for comparison with lesional uptake. Receiver operating characteristic analysis was employed to identify the most preferable reference area and the cut-off best discriminating disease-free from disease-involved lymph nodes. RESULTS: With reference to 53 Ν1 hilar and 147 Ν2/Ν3 sampled stations, sensitivity of scintigraphy by visual interpretation was 100 and 94%, specificity 43 and 59% and accuracy 55 and 67%, respectively. No patient was down-staged, but 52% were incorrectly up-staged and 44% were misclassified as inoperable. Compared to scintigraphy, preoperative contrast-enhanced diagnostic CT demonstrated lower sensitivity (36% for hilar and 73% for N2/N3 stations), higher specificity (79 and 75%) and similar accuracy (70 and 75%). Regarding the ultimate N-stage and the prediction of surgical disease, diagnostic CT was wrong in 51 and 34% of cases. Dichotomy of quantitative scintigraphic data by the use of certain N-to-spine ratio cut-offs resulted in a significant increase of specificity (76% for hilar and 89% for N2/N3 stations), while sensitivity remained high (82% in both circumstances) and accuracy for Ν2/Ν3 stations was substantially improved (88%). By this quantitative approach, misclassifications as to the N-stage and patient operability (25 and 16%) were considerably less than that of visual Tc-DEPR and diagnostic CT interpretations. CONCLUSION: Tc-99m depreotide SPECT/CT seems to have a role in the N-staging of NSCLC, mainly because of its high sensitivity and negative predictive value. Quantification of uptake can improve specificity, at a low cost of sensitivity. If F-18 fluoro-deoxyglucose positron emission tomography is not available, this method may be used as a surrogate to conventional staging modalities.

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.

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.