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.

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.

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.

Adaptation of Melodic Intonation Therapy to Greek: A Clinical Study in Broca's Aphasia With Brain Perfusion SPECT Validation.

Melodic intonation therapy (MIT) is one of the most well-known treatment methods which is based on pitch and rhythm and was developed to increase verbal output in adults with non-fluent aphasia. Although MIT has been adapted to several languages, in Greece it is almost unknown. The aim of the proposed study is twofold: (1) to translate and adapt the MIT to the Greek language, and (2) to conduct an experimental study in order to examine the effect of MIT on Greek patients with Broca's aphasia. To this aim, a 64-year-old, right-handed male who had a 6-year primary school education level, no musical abilities and poor performance on the recognition of prosody attended the MIT intervention program almost two and a half years after the event of suffering an ischemic stroke. The MIT intervention was administered three times per week for a 12-week period, in which each session lasted from 30 to 40 min. The patient underwent three assessments all using both the Boston Diagnostic Aphasia Examination-Short Form (BDAE-SF) and brain perfusion single-photon emission computed tomography (SPECT); (1) before the MIT, (2) immediately after, and (3) 3 months after the completion of MIT. The results from the BDAE-SF revealed an impressive improvement on both trained and prepositional speech production, immediately after the completion of the MIT, and a stable improved performance 3 months after MIT. The SPECT scan revealed reactivation of the perilesional areas of the left hemisphere, and considerably improved perfusion of the frontal lobe, the anterior temporal lobe, and the upper part of the parietal lobe of the right hemisphere. The improvement persisted and even expanded 3 months after MIT. Therefore, MIT is a promising intervention program and its positive effects last for at least 3 months after the completion of the intervention.

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.

Conversion of Propranolol to Carvedilol Improves Renal Perfusion and Outcome in Patients With Cirrhosis and Ascites.

BACKGROUND: In recent years, concerns have been raised on the potential adverse effects of nonselective beta-blockers, and particularly carvedilol, on renal perfusion and survival in decompensated cirrhosis with ascites. We investigated the long-term impact of converting propranolol to carvedilol on systemic hemodynamics and renal function, and on the outcome of patients with stable cirrhosis and grade II/III nonrefractory ascites. PATIENTS AND METHODS: Ninety-six patients treated with propranolol for esophageal varices' bleeding prophylaxis were prospectively evaluated. These patients were randomized in a 2:1 ratio to switch to carvedilol at 12.5 mg/d (CARVE group; n=64) or continue propranolol (PROPRA group; n=32). Systemic vascular resistance, vasoactive factors, glomerular filtration rate, and renal blood flow were evaluated at baseline before switching to carvedilol and after 6 and 12 months. Further decompensation and survival were evaluated at 2 years. RESULTS: During a 12-month follow-up, carvedilol induced an ongoing improvement of systemic vascular resistance (1372±34 vs. 1254±33 dynes/c/cm5; P=0.02) along with significant decreases in plasma renin activity (4.05±0.66 vs. 6.57±0.98 ng/mL/h; P=0.01) and serum noradrenaline (76.7±8.2 vs. 101.9±10.5 pg/mL; P=0.03) and significant improvement of glomerular filtration rate (87.3±2.7 vs. 78.7±2.3 mL/min; P=0.03) and renal blood flow (703±17 vs. 631±12 mL/min; P=0.03); no significant effects were noted in the PROPRA group. The 2-year occurrence of further decompensation was significantly lower in the CARVE group than in the PROPRA group (10.5% vs. 35.9%; P=0.003); survival at 2 years was significantly higher in the CARVE group (86% vs. 64.1%; P=0.01, respectively). CONCLUSION: Carvedilol at the dose of 12.5 mg/d should be the nonselective beta-blocker treatment of choice in patients with cirrhosis and nonrefractory ascites, as it improves renal perfusion and outcome.

Principles and current trends in the correlative evaluation of glioma with advanced MRI techniques and PET

Cerebral gliomas comprise a heterogeneous group of primary neoplasms of the central nervous system, representing a signifcant cause of cancer morbidity and mortality. Contrast-enhanced magnetic resonance imaging (MRI) is paramount for identifying structural brain abnormalities related to the development of gliomas. Although morphological MRI remains the current standard of care for initial diagnostic workup, surgical planning, monitoring therapy response and surveillance during follow-up, it is rather diffcult to define tumor grade and boundaries and to assess response to radiochemotherapy solely by contrast-enhancement, due to a variety of factors influencing blood-brain barrier (BBB) permeability and contrast agent distribution. The nature of a lesion lies beyond often misleading gross structural patterns, down to the cellular and molecular level, hence the imaging techniques of advanced multimodal MRI and positron emission tomography (PET) have emerged to provide critical non-invasive insight into the underlying biology of primary brain cancer. Out of the various PET radiotracers, labeled amino acids are of particular significance due to their non-dependency on BBB disruption to reach glioma cells and their excellent tumor-to-background contrast. After discussing the basic imaging principles of MR perfusion, diffusion, spectroscopy and PET in glioma, this review focuses on the correlative imaging with amino acid PET and advanced MRI techniques in tumor grading and staging, in guiding stereotactic biopsy and surgical excision and in assessing therapy response, post-therapy surveillance and prognosis. Lastly, a reference is made on the expanding availability of integrated PET/MRI systems and the resulting benefits of simultaneous image acquisition.

Regional Cerebral Blood Flow SPECT and MRI in Logopenic Variant Primary Progressive Aphasia.

We report a 61-year-old woman who presented because of gradually progressive speech disorders. MRI scan revealed left temporal lobe atrophy with ex vacuo dilatation of the temporal horn and atrophy of the left inferior frontal gyrus and the left inferior parietal lobe. These findings in brain perfusion SPECT corresponded to a generalized hypoperfusion of the left hemisphere, particularly prominent on the rear parietal cortex and the temporal lobe. After taking into consideration the clinical presentation and imaging findings on MRI and SPECT, the diagnosis of the logopenic variant of primary progressive aphasia was finally reached.

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.

Imaging of cardiac amyloidosis by (99m)Tc-PYP scintigraphy.

OBJECTIVE: Cardiac amyloidosis (CA) is an underestimated and underdiagnosed cause of cardiac insufficiency. Despite being often considered as a solitary entity attributable to extracellular deposition of fibrillary proteins, there exist at least two different pathophysiologic backgrounds, with different clinical course and treatment. a) In light-chain cardiac amyloidosis (immunoglobulin light-chain amyloidosis-AL) the fibrils consist of light-chain immunoglobulins produced by a clonal plasma cell population in bone marrow. b) In CA related to transthyretin (transthyretin-related amyloidosis - ATTR), whether familial amyloid cardiomyopathy or senile systemic amyloidosis, monomers or dimers of the normally tetrameric protein of transthyretin are deposited in the myocardium. Today, definitive diagnosis of cardiac amyloid disease is based on endomyocardial biopsy in conjunction with immunohistochemical parameters or, in ambiguous cases, with mass spectroscopy. Several radiotracers have been hitherto tried in the detection of CA. SUBJECTS AND METHODS: In this pilot study technetium-99m pyrophosphate ((99m)Tc-PYP) was administered to patients suffering from CA, aiming to differentiate scintigraphically between AL and ATTR. Twelve patients (8 males, aged [mean±SD] 70,6±13,2y; 4 females, aged 65,7±9,9y) were enrolled for the discrimination between AL and ATTR. Diagnosis was confirmed by biopsy combined with the clinical and laboratory evaluation of the patients. Myocardial scintigraphy (planar and tomographic imaging) was conducted at 1, 2 and/or 3h after intravenous administration of 555-925MBq (99m)Tc-PYP. Myocardial radiotracer uptake was evaluated optically and also by a semiquantitative method. Two regions of interest (ROI) were drawn: one over the heart and another over the contralateral hemithorax, to calculate the corresponding heart-to-contralateral (H/CL) count ratio. According to established reference standards, a cut-off H/CL value of 1.5 best discriminates between the two conditions. (99m)Tc-PYP scintigraphy revealed diffuse intense myocardial uptake upon visual evaluation that was also verified semi-quantitatively in 6 patients, all of which had ATTR. Faint or no myocardial tracer uptake was found in 4 patients who were diagnosed with AL. Two AL patients had a borderline positive scan on visual evaluation but their H/CL ratios did not exceed the value of 1.5. In three patients, we also attempted scintigraphy with the tracer pentavalent (99m)Tc-dimercaptosuccinic acid. Results and possible mechanisms of uptake are discussed. The sensitivity and specificity of scintigraphy with (99m)Tc-PYP was high, albeit the small number of patients. IN CONCLUSION: These preliminary results are compatible with current international literature, and demonstrate that scintigraphy with (99m)Tc-PYP may prove a simple, non-invasive and widely available method in the identification of patients with the ATTR subtype, thus optimizing therapeutic decisions.

Estimation of Residual Peritoneal Volume Using Technetium-99m Sulfur Colloid Scintigraphy.

Residual peritoneal volume (RPV) may contribute in the development of ultrafiltration failure in patients with normal transcapillary ultrafiltration. The aim of this study was to estimate the RPV using intraperitoneal technetium-99m Sulfur Colloid (Tc). Twenty patients on peritoneal dialysis were studied. RPV was estimated by: 1) intraperitoneal instillation of Tc (RPV-Tc) and 2) classic Twardowski calculations using endogenous solutes, such as urea (RPV-u), creatinine (RPV-cr), and albumin (RPV-alb). Each method's reproducibility was assessed in a subgroup of patients in two consecutive measurements 48 h apart. Both methods displayed reproducibility (r = 0.93, p = 0.001 for RPVTc and r = 0.90, p = 0.001 for RPV-alb) between days 1 and 2, respectively. We found a statistically significant difference between RPV-Tc and RPV-cr measurements (347.3 ± 116.7 vs. 450.0 ± 67.8 ml; p =0.001) and RPV-u (515.5 ± 49.4 ml; p < 0.001), but not with RPV-alb (400.1 ± 88.2 ml; p = 0.308). A good correlation was observed only between RPV-Tc and RPV-alb (p < 0.001). The Tc method can estimate the RPV as efficiently as the high molecular weight endogenous solute measurement method. It can also provide an imaging estimate of the intraperitoneal distribution of RPV.

Comparison of (99m)tc-tetrofosmin and (99m)tc-sestamibi uptake in glioma cell lines: the role of p-glycoprotein expression.

(99m)Tc-Tetrofosmin ((99m)Tc-TF) and (99m)Tc-Sestamibi ((99m)Tc-MIBI) are SPECT tracers that have been used for brain tumor imaging. Tumor's multidrug resistance phenotype, namely, P-glycoprotein (p-gp), and the multidrug resistance related proteins (MRPs) expression have been suggested to influence both tracers' uptake. In the present study we set out to compare (99m)Tc-TF and (99m)Tc-MIBI uptake in high-grade glioma cell lines and to investigate the influence of gliomas p-gp expression on both tracers' uptake. We used four glioma cell lines (U251MG, A172, U87MG, and T98G). The expression of p-gp protein was evaluated by flow cytometry. Twenty µCi (7.4·10(5) Bq) of (99m)Tc-TF and (99m)Tc-MIBI were used. The radioactivity in the cellular lysate was measured with a dose calibrator. P-gp was significantly expressed only in the U251MG cell line (P < 0.001). In all gliomas cell lines (U251MG, U87MG, A172, and T98G) the (99m)Tc-TF uptake was significantly higher than (99m)Tc-sestamibi. The U251MG cell line, in which significant p-gp expression was documented, exhibited the strongest uptake difference. (99m)Tc-TF uptake was higher than (99m)Tc-MIBI in all studied high-grade glioma cell lines. Thus, (99m)Tc-TF may be superior to (99m)Tc-MIBI for glioma imaging in vivo.

Comparison of diffusion tensor, dynamic susceptibility contrast MRI and (99m)Tc-Tetrofosmin brain SPECT for the detection of recurrent high-grade glioma.

INTRODUCTION: Treatment induced necrosis is a relatively frequent finding in patients treated for high-grade glioma. Differentiation by imaging modalities between glioma recurrence and treatment induced necrosis is not always straightforward. This is a comparative study of diffusion tensor imaging (DTI), dynamic susceptibility contrast MRI and (99m)Tc-Tetrofosmin brain single-photon emission computed tomography (SPECT) for differentiation of recurrent glioma from treatment induced necrosis. METHODS: A prospective study was made of 30 patients treated for high-grade glioma who had suspected recurrent tumor on follow-up MRI. All had been treated by surgical resection of the tumor followed by standard postoperative radiotherapy with chemotherapy. No residual tumor had been found on brain imaging immediately after the initial treatment. All the patients were studied with dynamic susceptibility contrast brain MRI and, within a week, (99m)Tc-Tetrofosmin brain SPECT. RESULTS: Both (99m)Tc-Tetrofosmin brain SPECT and dynamic susceptibility contrast MRI could discriminate between tumor recurrence and treatment induced necrosis with 100% sensitivity and 100% specificity. An apparent diffusion coefficient (ADC) ratio cut-off value of 1.27 could differentiate recurrence from treatment induced necrosis with 65% sensitivity and 100% specificity and a fractional anisotropy (FA) ratio cut-off value of 0.47 could differentiate recurrence from treatment induced necrosis with 57% sensitivity and 100% specificity. A significant correlation was demonstrated between (99m)Tc-Tetrofosmin uptake ratio and rCBV (P=0.003). CONCLUSIONS: Dynamic susceptibility contrast MRI and brain SPECT with (99m)Tc-Tetrofosmin had the same accuracy and may be used to detect recurrent tumor following treatment for glioma. DTI also showed promise for the detection of recurrent tumor, but was inferior to both dynamic susceptibility contrast MRI and brain SPECT.

Heart involvement in systemic sclerosis: a combined echocardiographic and scintigraphic study.

The aim of this study is to investigate systemic sclerosis (SSc) patients without clinically evident heart disease for cardiac abnormalities. SSc patients and age- and sex-matched healthy controls from the hospital staff underwent transthoracic echocardiography for the assessment of the left ventricle (LV) morphology and function and estimation of the pulmonary artery systolic pressure (PASP). Patients further underwent stress-rest myocardial perfusion imaging (MPI) scintigraphy by single-photon emission computed tomography (SPECT). Thirty-seven patients were included (33 women, 19 with diffuse, and 18 with limited SSc). LV hypertrophy was more common in SSc patients than controls (24.3 vs 0 %, p = 0.001). Impaired LV relaxation was found in 45.9 % of patients and 40.5 % controls (p = 0.639). Excluding patients with arterial hypertension, LV hypertrophy was still found in 23.1 % and LV relaxation impairment in 38.5 %. PASP over 30 mmHg was found in 13 patients (35.1 %), 11 of whom had no history of pulmonary arterial hypertension (PAH). Of 35 patients who underwent SPECT, 21 patients (60 %) exhibited reversible LV perfusion defects. Their mean age was 51.8 years; four patients were younger than 40 years old and eight patients younger than 50 years. In all cases, ischemia was graded as mild or moderate and in a single case, graded as significant. Subclinical heart involvement is common in SSc patients even in the younger age groups. LV hypertrophy and impaired relaxation, raised PASP, and ischemia on MPI with SPECT are found in a significant proportion of SSc patients. Careful screening of SSc patients for potential heart involvement and consultation by a cardiologist may be of value.

Correlation of diffusion tensor, dynamic susceptibility contrast MRI and (99m)Tc-Tetrofosmin brain SPECT with tumour grade and Ki-67 immunohistochemistry in glioma.

OBJECTIVE: Assessment of the grade and type of glioma is of paramount importance for prognosis. Tumour proliferative potentials may provide additional information on the behaviour of the tumour, its response to treatment and prognosis. The purpose of this study was to investigate the correlation between diffusion tensor imaging (DTI), dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) and (99m)Tc-Tetrofosmin brain single-photon emission computed tomography (SPECT), and the tumour grade and Ki-67 labelling index in newly diagnosed gliomas. METHODS: Study was made of patients with suspected glioma on brain MRI between December 2010 and January 2012, by DTI, DSC MRI and (99m)Tc-Tetrofosmin brain SPECT. The proliferative activity of each tumour was measured by deriving the Ki-67 proliferation index from immunohistochemical staining of tumour specimens. RESULTS: Glioma was newly diagnosed in 25 patients (17 men, 8 women, aged 19-79 years, median 55 years). The Ki-67 index ranged from 1% to 80% (mean 19.4%). On evaluation of the relationship between the (99m)Tc-Tetrofosmin tumour uptake by gliomas was found to be significantly correlated with cellular proliferation (rho=0.924, p<0.0001). Regarding DTI, significant negative correlation was demonstrated between the apparent diffusion coefficient (ADC) ratio and the Ki-67 index (rho=-0.545, p=0.0087). Significant correlation was also observed between the fractional anisotropy (FA) ratio and the Ki-67 index (rho=0.489, p=0.02). Strong correlation was found between relative cerebral blood volume (rCBV) and Ki-67 index (rho=0.853, p<0.0001), and between the (99m)Tc-Tetrofosmin lesion-to-normal (L/N) uptake ratio and rCBV (rho=0.808, p ≤ 0.0001). Significant negative correlation was demonstrated between the (99m)Tc-Tetrofosmin L/N ratio and ADC ratio (rho=-0.513, p=0.014). These imaging techniques were able to distinguish between low-grade and high-grade gliomas. CONCLUSIONS: Findings on DSC MRI and brain SPECT with (99m)Tc-Tetrofosmin metrics were more closely correlated with glioma cellular proliferation.

Glioblastoma multiforme imaging: the role of nuclear medicine.

Glioblastoma multiforme (GBM) is the most common and most malignant primary brain tumor occurring during adulthood. The incidence of GBM is nearly 5 cases per 100,000 population per year. The standard of care for newly diagnosed GBM includes surgical resection when possible, followed by radiotherapy and concomitant and adjuvant chemotherapy with temozolomide. Imaging modalities used in nuclear medicine, namely positron emission tomography (PET) and single-photon emission computed tomography (SPECT) have been employed towards the evaluation of brain tumors. Herewith, we discuss the value of the above imaging techniques in the assessment of GBM aggressiveness, in the distinction of treatment induced necrosis from glioma recurrence, in the estimation of overall prognosis and in the evaluation of treatment response in patients with GBM.

Increased breast density correlates with the proliferation-seeking radiotracer (99m)Tc(V)-DMSA uptake in florid epithelial hyperplasia and in mixed ductal carcinoma in situ with invasive ductal carcinoma but not in pure invasive ductal carcinoma or in mild epithelial hyperplasia.

The purpose of this study was to assess the relationship of mammographic breast density (BD) and cell proliferation/focal adhesion kinase activation-seeking radiotracer technetium 99m pentavalent dimercaptosuccinic acid (99mTc(V)-DMSA) uptake in women with different breast histologies, that is, mild epithelial hyperplasia (MEH), florid epithelial hyperplasia (FEH), mixed ductal carcinoma in situ with invasive ductal carcinoma (DCIS + IDC), and pure IDC. Fifty-five women with histologically confirmed mammary pathologies were submitted preoperatively to mammography and 99mTc(V)-DMSA scintimammography. The percentage and intensity of 99mTc(V)-DMSA uptake and the percentage of BD were calculated by computer-assisted methods and compared (t-test) between the breast pathologies. In breasts with increased BD, FEH and DCIS + IDC were found. On the contrary, pure IDC and MEH were identified in breasts with significantly lower BD values. In breasts with increased 99mTc(V)-DMSA area and intensity of uptake, FEH was the main lesion found compared to all other histologies. Linear regression analysis between BD and 99mTc(V)-DMSA uptake area and intensity revealed significant coefficients of correlation (r  =  .689, p < .001 and r  =  .582, p < .001, respectively). Increased BD correlates with the presence of FEH and mixed DCIS + IDC but not with pure IDC or MEH. Its close relationship to 99mTc(V)-DMSA, which also showed an affinity to FEH, indicates that stromal microenvironment may constitute a specific substrate leading to progression to different subtypes of cancerous lesions originating from different pathways.