99mTc-DTPA dynamic SPECT/CT renogram in adults: feasibility and diagnostic benefit.

OBJECTIVE: The objective of this study is to investigate the feasibility and potential advantages of 99mTc-DTPA dynamic single photon emission computed tomography/computed tomography (SPECT/CT) renogram in adults. METHODS: Fifty-five patients aged 19-80 years (mean 56.3) were enrolled. The imaging protocol included: day 1: 99mTc-DTPA planar renogram, followed by planar 99mTc-DMSA scan. Day 3: attenuation-corrected dynamic 99mTc-DTPA SPECT renogram [DSPECT(AC)] and Cr-51 ethylenediamine tetraacetic acid (EDTA) glomerular filtration rate (GFR) calculation. DSPECT(AC) included an initial CT scan followed by 12 consecutive SPECT sessions acquired via continuous-mode acquisition for a total of 24 min. Fast SPECT sequences (1-2 s/projection, 60 projections, every 6°) were obtained for the first 8 min, followed by slower acquisitions (3-4 s/projection) during the rest of the study. Renal activity was measured in the total kidney volume by regions of interest drawn on consecutive transaxial slices of the third SPECT, which were then copied on the whole 12-SPECT series. Corresponding time-activity curves were created. DSPECT(AC) parameters were compared with those of planar renogram. The reference method for split renal function was 99mTc-DMSA (geometrical mean of anterior and posterior projection counts) and for GFR the Cr-51 EDTA 2-blood sample clearance method. RESULTS: DSPECT(AC) images were of good quality. There was good correlation between renogram parameters (time to peak activity and NORA20) comparing the two techniques (r = 0.959 and 0.933, respectively). In 21 cases with >30% absolute difference between the two kidneys, spilt renal function calculation by DSPECT(AC) correlated perfectly (r = 0.968) with the reference method, whereas planar renogram was less accurate (r = 0.843). Anatomic information provided by nonenhanced CT offered an integrated structural-functional view valuable for final diagnosis. DSPECT(AC) early kidney uptake as a fraction of injected dose correlated better with reference GFR (r = 0.789) than the Gates' method (r = 0.642). CONCLUSION: 99mTc-DTPA dynamic SPECT/CT renogram is feasible with conventional SPECT/CT systems. It allows accurate split renal function measurement, offers additional anatomical information and can be used for closer approximation of GFR compared with Gates' method.

Age-related variations in trunk composition and patterns of regional bone and soft tissue changes in adult Caucasian women by DXA.

We explored the regional variations in body composition with advancing age in healthy Caucasian females living in the Mediterranean area. The objectives of this study were to establish body composition values for the trunk in healthy women of a Greek origin and to evaluate the effects of aging on the distribution of truncal bone mass, fat mass (FM) and lean mass (LM). Body composition of the trunk and detailed analysis of its anatomical components-the ribs, the thoracic spine, the lumbar spine and the pelvis, and FM and LM ratios--were calculated in 330 women aged 20-85 years, using DXA. Peak bone mineral density (BMD) of the trunk was attained between ages 30 and 33. The overall truncal BMD reduction with age was 20.7% (p < 0.001). Peak %LM of the trunk was achieved at age 20. The overall reduction of %LM with age for the trunk was 9.8% (p < 0.001). Peak %FM of the trunk was attained between ages 68 and 73, and the overall %FM reduction with age was 2.8% (p > 0.05). Multiple comparative analyses showed that the 51-60 years age group was the landmark age for significant changes of truncal bone mass measures across all age groups (p = 0). For truncal LM and FM metrics, multigroup comparative analysis showed the turning point of significant changes in soft tissue was the 41-50 age bracket (p = 0 and p = 0, respectively). In Greek women, truncal %LM exceeded by far %FM across all ages (p = 0). Our results suggest that aging affects body composition of the trunk in ambulatory healthy women of a Greek origin differently, leading to menopausal loss of bone mass, senior adulthood loss of lean mass, and middle-age storage of fat mass. In adult women, these age-related associations between bone and soft tissue metrics on DXA exams carry implications for the attainment of optimal peak values and shifts in body composition overtime, impacting lifelong skeletal health.

Nuclear Medicine and Cancer Theragnostics: Basic Concepts.

Cancer theragnostics is a novel approach that combines diagnostic imaging and radionuclide therapy. It is based on the use of a pair of radiopharmaceuticals, one optimized for positron emission tomography imaging through linkage to a proper radionuclide, and the other bearing an alpha- or beta-emitter isotope that can induce significant damage to cancer cells. In recent years, the use of theragnostics in nuclear medicine clinical practice has increased considerably, and thus investigation has focused on the identification of novel radionuclides that can bind to molecular targets that are typically dysregulated in different cancers. The major advantages of the theragnostic approach include the elimination of multi-step procedures, reduced adverse effects to normal tissues, early diagnosis, better predictive responses, and personalized patient care. This review aims to discuss emerging theragnostic molecules that have been investigated in a series of human malignancies, including gliomas, thyroid cancer, neuroendocrine tumors, cholangiocarcinoma, and prostate cancer, as well as potent and recently introduced molecular targets, like cell-surface receptors, kinases, and cell adhesion proteins. Furthermore, special reference has been made to copper radionuclides as theragnostic agents and their radiopharmaceutical applications since they present promising alternatives to the well-studied gallium-68 and lutetium-177.

The Role of Myocardial Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events at 1 Year Follow-Up: A Single Center's Experience.

BACKGROUND: Myocardial perfusion imaging via single-photon emission computed tomography (SPECT MPI) is a well-established method of diagnosing coronary artery disease (CAD). The purpose of this study was to assess the role of SPECT MPI in predicting major cardiovascular events. METHODS: The study population was composed of 614 consecutive patients (mean age: 67 years, 55% male) referred for SPECT MPI due to symptoms of stable CAD. The SPECT MPI was performed using a single-day protocol. We conducted a follow-up on all patients at 12 months via a telephone interview. RESULTS: The majority of our patients (78%) presented findings suggestive of reversible ischemia, fixed defects or both. Extensive perfusion defects were found in 18% of the population, while LV dilation was found in 7%. During the 12-month follow-up, 16 deaths, 8 non-fatal MIs and 20 non-fatal strokes were recorded. There was no significant association of SPECT findings with the combined endpoint of all-cause death, non-fatal MI and non-fatal stroke. The presence of extensive perfusion defects was an independent predictor of mortality at 12 months (HR: 2.90, 95% CI: 1.05, 8.06, p = 0.041). CONCLUSIONS: In a high-risk patient population with suspected stable CAD, only large reversible perfusion defects in SPECT MPI were independently associated with mortality at 1 year. Further trials are needed to validate our findings and refine the role of SPECT MPI findings in the diagnosis and prognosis of cardiovascular patients.

Myocardial perfusion imaging single photon emission computed tomography may detect silent myocardial ischemia in patient with epilepsy.

BACKGROUND: The aim of the present study was to compare the myocardial perfusion imaging (MPI) with [99mTc]tetrofosmin stress - rest single-photon emission computer tomography (SPECT) of patients with epilepsy with matched control individuals. MATERIAL AND METHODS: All 29 adult epileptic patients were receiving antiepileptic drugs (AEDs) for epilepsy. Thirty-two individuals matched for gender and age consisted of the control group. MPIs SPECT were performed, and myocardial summed scores were obtained during stress (SSS) and rest (SRS) images. Abnormal MPI was considered when SSS was ≥ 4. In addition, the difference (SDS) between SSS and SRS was also assessed, which represents a rate of reversibility after stress. RESULTS: Twenty of 29 (68.97%) patients with epilepsy had abnormal MPI and 14/32 (43.75%) of the controls (p = 0.04). Among males, 18/23 patients and 11/25 controls had abnormal MPI (p = 0.01), with quite a significant difference for mean SSS between male patients and controls (p = 0.002). Furthermore, SDS comparison showed that irreversible abnormalities were more common in patients than in control individuals. A difference of inadequately compensated myocardial ischemia between patients treated with enzyme inducing AEDs and patients treated with valproic acid was also detected. CONCLUSIONS: Single-photon emission computer tomography (SPECT) may detect increased risk for coronary artery disease and further cardiovascular events in patients with epilepsy. Our findings favor the conclusion that SPECT could be used for the early identification of cardiovascular comorbidity in epilepsy.

Hybrid bone SPECT/CT reveals spleen calcification in sickle cell mutation and beta-thalassemia.

We present a case of a 65 years-old male with sickle cell mutation and beta-thalassemia (Hb S/ß-Thal), who had whole-body bone scan evaluation for osteomyelitis. The examination revealed high radiopharmaceutical uptake in the left abdomen. Further evaluation with hybrid single photon emission computed tomography/computed tomography (SPECT/CT) showed calcification of approximately the entire spleen, in the context of sickle cell anemia. This report highlights the role of SPECT/CT in such cases.

Myocardial Ischemia on MPI SPECT in a Patient with Acute Myeloid Leukemia Without Significant Coronary Artery Disease.

Herein, we report the case of a 56-year-old male patient with acute myeloid leukemia (AML) in remission who had asymptomatic myocardial ischemia on myocardial perfusion imaging and transthoracic echocardiography. Angiography did not reveal any significant coronary artery disease. Although the etiology is not entirely clear, this case suggested that myocardial perfusion imaging should be considered in patients with AML who received idarubicin to screen for possible myocardial dysfunction.

Hamstring Muscle Cramp Visualized on Bone Single-Photon Emission Computed Tomography/Computed Tomography Hybrid Imaging.

ABSTRACT: It is well recognized that bone-seeking radiotracers localize in muscles sustaining an injury from various causes (e.g., strenuous physical activity, trauma, hereditary myopathies, inflammatory myositides, medications, electrical burns, etc.). This report presents the case of an active 50-yr-old man (body mass index = 29) that was recently referred to our nuclear medicine department for bone scintigraphy, for the skeletal staging of a newly diagnosed prostate adenocarcinoma. The scan findings were unremarkable for its oncological indication but revealed extraosseous radiotracer absorption in the medial region of the hamstrings bilaterally. Hybrid scintitomography (single-photon emission computed tomography) with computed tomography indicated that this uptake involved the semitendinosus muscle. On a more meticulous repeat history questioning, he recalled experiencing muscle cramps on both posterior thighs 5 days earlier, during intense work-related physical activity (plumbing) under warm environmental conditions. The combination of strenuous exercise with likely dehydration contributed to bilateral self-limiting heat cramps of the hamstrings, leading to an inconsequential localized minor rhabdomyolysis that was discovered coincidentally a few days later during a bone scan. Although extraskeletal absorption of bone-seeking radiotracers in muscles is widely documented as a result of exertion or injury, this is the first report of radiotracer absorption induced by cramping.

Silent severe myocardial ischemia in a past illicit drug user imaged with myocardial perfusion scintigraphy.

Patients with illicit drug use may have deleterious acute and chronic cardiac effects. We present a case of a 42-year-old man, former alcohol and various illicit drugs user, who was admitted to the psychiatric unit for management of psychosis. Because of his previous drug and alcohol history, a cardiological evaluation was performed which revealed silent severe myocardial ischemia detected by myocardial perfusion imaging (MPI). The myocardial ischemia was attributed to coronary microvascular dysfunction, occurring several years after quitting the illicit drugs. This study highlights the potential myocardial ischemia that may occur in patients with previous alcohol and illicit drug use, and the role of MPI, a non-invasive test that can provide important information regarding the myocardial status of such patients, even without obvious cardiac symptoms or findings.

Early-Onset Frontotemporal Dementia-Related Semantic Variant of Primary Progressive Aphasia: Multimodal Evaluation With Brain Perfusion SPECT, SPECT/MRI Coregistration, and MRI Volumetry.

ABSTRACT: Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by cortical and subcortical atrophies, with early involvement of the hippocampus and amygdala. A 58-year-old man with clinical presentation of primary progressive aphasia-particularly its svPPA (semantic variant)-and bilateral asymmetric (left-predominant) anterior temporal lobe atrophy on MRI was referred for brain perfusion SPECT. This revealed bilateral hypoperfusion of the anterior temporal lobe (sustained by software-fused SPECT/MRI), pointing toward FTD rather than Alzheimer disease. Furthermore, voxel-based MRI volumetric analysis confirmed bilateral atrophy affecting the hippocampus and amygdala. Combining SPECT with MRI was supportive of the early-onset FTD-related svPPA diagnosis.

Single photon emission computed tomography myocardial perfusion imaging in patients with moderate to severe psoriosissis.

BACKGROUND: Psoriasis is a chronic inflammatory disorder with an increased risk for coronary artery disease (CAD). This retrospective study aimed to evaluate the rate of myocardial ischaemia in patients with psoriasis subjected to myocardial perfusion imaging (MPI). MATERIAL AND METHODS: Twelve patients with moderate to severe psoriasis that had MPI were compared to 395 MPIs randomly retrieved from our MPIs pool data. All patients had a [99mTc]tetrofosmin stress - rest single-photon emission computer tomography ([99mTc]SPECT). Summed difference scores (SDS) were calculated for stress (SSS), rest (SRS) and their difference (SDS = SSS - SRS). RESULTS: There was no significant difference in the frequency of abnormal MPI SPECT outcomes between patients with vs. without psoriasis (6/12 vs 214/395 respectively; p = 0.778). From the evaluation of SSS, SRS and SDS, only the SDS scores of inadequately compensated resting perfusion defects were significantly lower in patients with psoriasis (p = 0.012). CONCLUSIONS: Patients with moderate-to-severe psoriasis had a similar rate of abnormal SSS scans compared to control patients. However, the SDS scans were significantly lower in patients with psoriasis indicating compromised reversibility of resting perfusion defects. Larger controlled studies are needed to verify these observations.

Vitamin D Deficiency as a Risk Factor for Myocardial Ischemia.

Background and Objectives: Vitamin D (Vit D) deficiency has been implicated in various conditions, including cardiovascular disease. The purpose of this retrospective study was to investigate the incidence of patients with myocardial ischemia in relation to their serum levels of vitamin D. Materials and Methods: A 64-month search (January 2016 to April 2021) in our database of the Nuclear Medicine Laboratory revealed 113 patients who had both myocardial perfusion imaging with single photon emission computed tomography (MPI SPECT) and Vit D measurements. MPI SPECT obtained myocardial images during both stress (summed stress score, SSS) and rest (summed rest score, SRS). Abnormal MPI SPECT was when the SSS was ≥4. Vit D was determined by radioimmunoassay (RIA). Patients with Vit D values <10 ng/mL, 10-29 ng/mL and ≥30 ng/mL were defined as having a deficiency, insufficiency and sufficiency, respectively. Results: Among patients, 46/113 (40.7%) were male and 67/113 (59.3%) were female. Abnormal MPI was found in 58/113 (51.3%) patients. Vit D deficiency was noted in 20/113 (17.7%) patients, insufficiency in 86/113 (76.1%) patients, and normal Vit D was noted in only 7/113 (6.2%) patients. Sixteen of the 20 patients (80%) with Vit D deficiency, and 38/86 (44.2%) with insufficiency had an abnormal MPI SPECT. In contrast, only 1/7 (14.3%) patients with sufficient Vit D levels had an abnormal MPI SPECT. The Mann-Whitney U-test showed that ischemia reduced the values of Vit D. Correlation analysis showed a negative association of Vit D levels with SSS (rho = -0.232, p = 0.014) and SRS (rho = -0.250, p = 0.008). Further evaluation with a Vit D cut off 20 ng/mL retrieved no statistical significance. Finally, Vit D and gender were independently associated with myocardial ischemia. Conclusions: Low Vit D levels may represent a risk factor for myocardial ischemia.

Myocardial perfusion SPECT as a potential mediator on circulating chromogranin A in patients with old myocardial infarction.

OBJECTIVE: Chromogranin A (CgA) is a soluble polypeptide stored within and released from secretory granules of endocrine and other cell types (including cardiomyocytes); CgA appears to be a marker of the overall neuroendocrine activity. Increased levels of serum CgA have been found not only in patients with neuroendocrine neoplasms but also with other malignancies, hypertension, myocardial infarction, heart, or renal failure. SUBJECTS AND METHODS: A population of 307 patients (202 males, 105 females) was enrolled. The study group consisted of 118 individuals (38.4%) with myocardial infarction more than one year old (MI group); the remaining 189 (61.6%) had no known heart disease (control group). All patients underwent myocardial perfusion scintigraphy (MPS) after blood withdrawal for serum CgA measurement. To test whether a possible effect of old infarction on serum CgA is mediated by MPS findings, we employed analysis of covariance for three distinct categories of left ventricular (LV) perfusion deficits as dichotomous predictors: (1) any-type deficits (abnormal MPS); (2) reversible deficits (ischemia); and (3) fixed deficits (scar). RESULTS: In all three MPS conditions, the effect of age, gender, and LV ejection fraction (EFLV) on serum CgA was statistically significant: women exhibited higher CgA levels than men (P=0.008-0.023), whereas increasing age and decreasing EFLV were associated with increasing CgA (all P<0.001). Conversely, no statistically significant differences in mean CgA levels were found between MI patients and normal controls with either abnormal MPS, scar, or ischemia, or their degree and extent. CONCLUSION: Although serum CgA is significantly associated with age, gender, and EFLV in patients with an old MI, no association was found between CgA levels and either old MI history or MPS findings. The verified involvement of circulating CgA in the acute/subacute phase of infarction appears to be blunted in infarctions older than a year.

Is there a role for Gallium-67 SPECT in distinguishing progression and pseudoprogresion in oncologic patients receiving immunotherapy?

Immuno-oncology (IO) with immune checkpoint inhibitors (ICIs) is the new landmark in cancer treatment. However, due to its economical-related burden and the possibility of tumor pseudoprogression with late response patterns, it is imperative to find new ways for early discrimination of patients with IO-sensitive versus IO-resistant disease. ICI-mediated antitumor responses depend on tumor immune infiltration by T-cells capable of recognizing and killing tumor cells. Nevertheless, patients may experience different responses to immunotherapy according to their tumor microenvironment and inflammatory infiltration. T-cell infiltrated tumors are referred to as 'hot' and are potential candidates for a good response to ICIs, whereas 'cold' are those tumors lacking T-cell infiltration and exhibit a narrow likelihood of response to IO therapy. Gallium-67 (67Ga) scintigraphy may hold potential for separating 'hot' from 'cold' tumors, thus providing an imaging tool to distinguish 'hot' ICI-induced pseudoprogression from real early 'cold' progression. Even so, various tumors (lymphomas, lung cancer, breast cancer, hepatoma, malignant melanoma) exhibit an inherent affinity for 67Ga that is independent of the ICI-induced immune infiltration, and this raises issues about false positivity. For that reason, future investigational studies to evaluate the prospective role of this radiotracer in the early prediction of ICI response should be confined to tumors with an inherently low 67Ga affinity (thyroid carcinoma, gastrointestinal and genitourinary tract tumors). We describe our experience with a patient with recurrent metastatic lung adenocarcinoma under ICI therapy that was submitted to 67Ga scanning for a fever of unknown origin and we discuss the aforementioned topics, alongside current imaging trends and future perspectives in the field.

Quality of life and tolerance to mental pain scale in cancer patients subjected to bone scan.

PURPOSE: To evaluate the impact of psychiatric co-morbidities on the quality of life-36 (QoL36) and tolerance to mental pain scale (TMPS) questionnaire of cancer patients administered in the Laboratory of Nuclear Medicine prior to a bone scan to rule out metastatic disease. METHODS: A group of 40 consecutive cancer patients (24 prostate, 12 breast and 4 with other cancers) were subjected to bone scan (BS) to rule out metastatic disease. Each patient received QoL36 and TMPS questionnaire prior to BS. RESULTS: There were low QoL and TMPS scores in all patient groups. The average QoL36 questionnaire score was 43,71 (23-70) (normal values considered >90). The average TMPS scores for prostate cancer patients was 55.42 (21-96), for breast cancer patients 63.42 (44-83) and for the other cancer patients 58.25 (48-68). Female patients with breast cancer had statistically higher tolerance to mental pain compared to patients with prostate cancer. Both tests were independently important for evaluation of the psychological status of the patients. There was no significant correlation of either QoL or TMPS with age, sex or disease duration. CONCLUSIONS: Cancer patients exhibited low QoL and TMPS, independent of sex, age, cancer type and disease duration. Multi-modality psychological support may be needed for these patients.

Assessment of adrenal response in patients with stable cirrhosis and ascites using different short Synacthen tests and definitions.

BACKGROUND AND AIMS: The definition of relative adrenal insufficiency (RAI) in patients with cirrhosis remains controversial. We investigated the serum and salivary cortisol (SalC) response after low-dose and standard-dose Synacthen test in patients with stable cirrhosis and ascites. METHODS: Ninety-five cirrhotic patients with ascites were prospectively evaluated from January 2014 to January 2018. Low-dose [adrenocorticotrophic hormone (ACTH): 1 µg] and standard-dose (ACTH: 250 µg) Synacthen test were successively performed. Paired serum total and saliva cortisol were taken at baseline, 30 min (low-dose test) and 60 min (standard-dose test). Salivary and Δserum total cortisol criteria included post-ACTH SalC < 12.7 ng/ml and/or SalC increase <3 ng/ml and serum total cortisol increase <9 µg/dl, respectively. RESULTS: The prevalence of RAI varied according to the definition used. SalC-defined RAI was significantly more common after low-dose than standard-dose test (54.7% vs. 20%; P < 0.001). Δserum total cortisol-defined RAI was also significantly more frequent after low-dose than standard-dose test (66.3% vs. 24.2%; P < 0.001). Considering low-dose test/SalC criteria as reference diagnostic criteria, standard-dose/salivary and Δserum total cortisol criteria showed low specificity for RAI diagnosis (43.9% and 52.7%, respectively). Survival probability was significantly lower in patients with low-dose test/SalC-defined RAI compared to those without (53.8% vs. 79.1%; P = 0.01). SalC-defined RAI after low-dose test was significantly more common than that defined after standard-dose test (72.7% vs. 30.3%; P < 0.001) among patients who died. CONCLUSION: Low-dose test/SalC definition can identify RAI in about half of patients with stable cirrhosis and ascites and is associated with increased mortality.