Pier Luigi Guidalotti

Role of 11C-choline PET/CT in the re-staging of prostate cancer patients with biochemical relapse and negative results at bone scintigraphy

AIM to evaluate the utility of (11)C-choline PET/CT in prostate cancer (PC) patients who have demonstrated a biochemical recurrence and a negative bone scintigraphy (BS). MATERIALS AND METHODS 123 consecutive PC patients (mean age 67.6 years; range 54-83) with a biochemical relapse (mean PSA value 3.3ng/mL; range 0.2-25.5) after radical prostatectomy (RP) were included in our retrospective study. Patients underwent a BS that resulted negative and a (11)C-choline PET/CT within 4 months from BS (range: 1 day to 4 months; mean: 2.5 months). Validation of results was established by: (1) a positive biopsy, (2) a positive subsequent BS, CT or MR and (3) a normalization of (11)C-choline uptake after systemic therapy or a progression of the disease. RESULTS (11)C-choline PET/CT was positive in 42/123 patients (34.1%). (11)C-choline PET/CT detected lesions in: bone (10 patients), lymph-nodes (20 patients), bone and lymph nodes (7 patients), bone and lung (1 patient), lymph-nodes and lung (1 patient), local relapse (3 patients). Overall, (11)C-choline PET/CT showed a total of 30 unknown bone lesions in 18/123 (14.6%) patients. CONCLUSION (11)C-choline PET/CT showed a better sensitivity than BS in patients with biochemical relapse after RP: (11)C-choline PET/CT detected unknown bone lesions in 18/123 (14.6%) patients.

Brain circulation during sleep and its relation to extracerebral hemodynamics

Regional cerebral blood flow (rCBF) was measured in rabbits during the sleep-waking cycle, using radioactive microspheres. rCBF does not change significantly in the transition from wakefulness (W) to synchronized sleep (SS), while it significantly increases during desynchronized sleep (DS). No correlation was found between CBF changes and changes in cardiac output or regional blood flows in the transition from SS to DS. This suggests that the CBF increase in DS is not relevantly affected by changes in extracerebral hemodynamic factors.

Identification of TTR-Related Subclinical Amyloidosis With 99mTc-DPD Scintigraphy

We have previously documented that 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) has a high affinity for transthyretin (TTR)-infiltrated myocardium, allowing a differential diagnosis with light-chain cardiac amyloidosis [(1)][1] and other non-amyloidotic cardiomyopathies with a

Lung perfusion in patients with pulmonary hypertension: comparison between MDCT pulmonary angiography with minIP reconstructions and 99mTc-MAA perfusion scan.

Objectives:Alterations in lung perfusion are a well-known feature of pulmonary hypertension (PH) seen on nuclear medicine studies. Abnormal radiotracer distribution in patients with PH may be caused by arterial thromboembolic occlusion, like in chronic thromboembolic pulmonary hypertension, by parenchymal destruction as in interstitial lung disease and pulmonary emphysema or by distal arteriopathy, like in idiopathic pulmonary arterial hypertension and other nonembolic forms. The different imaging pattern on radionuclide perfusion studies represents an important element for differential diagnosis. The aim of this study was to evaluate minimum intensity projection (minIP) images as an alternative to perfusion scintigraphy. We compared lung parenchyma attenuation patterns as depicted in minIP reconstructions with scintigraphic findings of lung perfusion in patients affected by pulmonary hypertension from various etiologies. Methods:One hundred and seven consecutive patients affected by PH of different etiology (37 of those had chronic thromboembolic pulmonary hypertension) who had undergone both multidetector computed tomography pulmonary angiography and 99mTc-MAA perfusion scan were included. Five-millimeter thickness contiguous axial, coronal, and sagittal minIP images were reconstructed from the contrast enhanced computed tomography datasets. Two radiologists evaluated the images and qualitatively graded pulmonary attenuation as homogeneous, inhomogeneous with nonsegmental patchy defects, or inhomogeneous with segmental defects. The presence of parenchymal and pleural alterations was recorded. MinIP perfusion grading results were then compared with those of perfusion scintigraphy. Results:In 87 of 107 patients (81.3%), the attenuation pattern seen on minIP images (39 homogeneous patterns, 13 with nonsegmental patchy defects, and 39 with segmental defects) correlated with the nuclear medicine scans. In the remaining 20 patients (18.7%), the imaging pattern was discordant because of 7 false-positive and 2 false-negative thromboembolic patterns at minIP and 11 false-positive thromboembolic patterns at perfusion scan. Air-trapping and parenchymal disease caused false-positive findings at minIP and perfusion scans, respectively. The sensitivity and specificity of minIP in detection of a chronic thromboembolic perfusion pattern were 94.5% and 90%, whereas perfusion scan had 100% sensitivity and 84% specificity. Conclusion:MinIP reconstructions can identify different patterns of pulmonary parenchymal attenuation, which show high concordance with perfusion patterns seen on radionuclide studies in patients with pulmonary hypertension. MinIP is a promising technique to evaluate lung perfusion in PH and may be used as an alternative to scintigraphy in the diagnostic work-up of these patients.

Defining the Diagnosis in Echocardiographically Suspected Senile Systemic Amyloidosis

Senile systemic amyloidosis (SSA) is a cardiomyopathy mainly affecting elderly men due to intramyocardial deposition of wild-type (nonmutant) transthyretin (TTR) ([1][1]). Since the heart is the only involved organ, SSA—which requires endomyocardial biopsy (EMB) for a definite diagnosis—is often

Etiology of amyloidosis determines myocardial 99mTc-DPD uptake in amyloidotic cardiomyopathy.

Tc-DPD (Tc-3,3-diphosphono-1,2-propanodicarboxylic acid) has a high affinity for transthyretin (TTR)-infiltrated myocardium, allowing a differential diagnosis with light chain cardiac amyloidosis and other nonamyloidotic cardiomyopathies with a hypertrophic phenotype, in which myocardial tracer uptake is low or absent. Myocardial bone tracer uptake in the rarer forms of amyloidosis (eg, apolipoprotein-related) has been rarely studied. We present 4 cases of cardiac amyloidosis that underwent Tc-DPD scintigraphy; myocardial DPD uptake was present in patients with ATTR, wtTTR and apolipoprotein AI and negative in cases with AL and apolipoprotein AII-related disease.

High 99mTc-DPD myocardial uptake in a patient with apolipoprotein AI-related amyloidotic cardiomyopathy

Abstract Amyloidotic cardiomyopathy is still a widely underdiagnosed condition that usually requires endomyocardial biopsy (EMB) for a definite diagnosis. 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) has proven highly sensitive for detecting amyloidotic cardiomyopathy due to transthyretin-related amyloid deposition. Herein we report the first description of the 99mTc-DPD scintigraphy profile in a patient with suspected amyloidotic cardiomyopathy and a final EMB- and genetically-proven diagnosis of familial apolipoprotein AI amyloidosis due to Leu174Ser variant. Abbreviations: AL: light-chain associated amyloidosis; ApoAI: apolipoprotein AI; ATTR: hereditary transthyretin-related amyloidosis; EMB: endomyocardial biopsy; HCM: hypertrophic cardiomyopathy; HR: heart retention; H/WB: heart/whole-body retention ratio; LV: left ventricular; SPECT: single-photon emission computed tomography; SSA: senile systemic amyloidosis; 99mTc-DPD: 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid; TDI: tissue Doppler imaging; TTR: transthyretin.

Short-term thermoregulatory adjustments involving opposite regional temperature changes

Abstract 1. 1. Experimental evidence is presented that short-term thermoregulatory adjustments occurring not far from thermoneutrality, involve temperature changes that are opposite in sign in different body regions. In man, exposure to hot ambient temperature ( T a ), induced a decrease in esophageal and rectal temperatures. In rabbit, exposure to cold T a induced an increase in hypothalamic temperature. 2. 2.|Similar results could be obtained by simulation on a mathematical model of mans thermoregulatory system. 3. 3.|The above results, as well as analogues results described in the literature, can be accounted for by a scheme of interpretation standing on current concepts of thermoregulation. If the gain of the thermoregulatory system is high, thermal stimulation of a region of the body will induce opposite temperature changes in other regions of the body.

NON-INVASIVE IDENTIFICATION OF SENILE SYSTEMIC AMYLOIDOSIS: INCREMENTAL DIAGNOSTIC ROLE OF 99MTC-DPD SCINTIGRAPHY

Background: Senile systemic amyloidosis (SSA), due to intramyocardial deposition of wild-type transthyretin (TTR), is often mistaken as hypertensive heart disease (HHD) or hypertrophic cardiomyopathy (HCM). In patients with amyloidotic cardiomyopathy 99mTc-DPD scintigraphy can differentiate between TTR (mutant and wild-type) and primary amyloidosis. We assessed the diagnostic performance of 99mTc-DPD scintigraphy in the non-invasive identiication of SSA in a clinical context of elderly patients with unexplained concentric left ventricular (LV) “hypertrophy”.

Coexistence of degenerative aortic stenosis and wild type transthyretin-related cardiac amyloidosis: a potentially dangerous association that can be non-invasively identified

Background Degenerative aortic stenosis (AS) and wild type transthyretin (TTR)-related cardiac amyloidosis (wt-ATTR) share a common demographic and clinical profile. It has been recently suggested that the coexistence of wt-ATTR could negatively influence the outcome of elderly patients with aortic stenosis undergoing transcatheter aortic valve replacement (TAVR). TTR-related cardiac amyloidosis can be accurately identified by technetium-99m-3, 3-diphosphono-1, 2 propanodicarboxylic acid (99mTc-DPD) scintigraphy. We decided to investigate the coexistence of cardiac amyloidosis in elderly patients with aortic stenosis referred for aortic valve replacement (TAVR or surgery).