Search

Background This study aims to investigate the incidence and the relative risk factors of retinopathy of prematurity (ROP) and posterior-ROP (P-ROP): ROP in Zone I and posterior Zone II, as well as to analyze the occurrence of surgical treatment of ROP and to evaluate the short term outcome of the disease in Italy. Methods It is a prospective multicenter observational study; all infants with a birth weight (BW) ≤ 750 g and/or a gestational age (GA) ≤27 weeks born between January 1st 2008 and December 31st 2009 in 25 III level Italian neonatal intensive care units were eligible for the study. Results 421 infants were examined: 265 (62.9%) developed ROP and 102 (24.2%) P-ROP. Following the multivariate analysis erythropoietin-therapy (p

Funding Acknowledgements Type of funding sources: None. Background Patients undergoing chemotherapy (CHT) for breast cancer (BC) need a monitoring of cardiac function due to the possible onset of cardiotoxicity. Cardiotoxicity may occur with heart failure but is often asymptomatic and is detectable only by assessing an increase in cardiac volumes (left ventricular end-diastolic (LV-EDV) and end-systolic (LV-ESV) volumes) and/or by a reduction of the left ventricular ejection fraction (LV-EF). The primary purpose of this study was to evaluate the role of gated SPECT myocardial perfusion imaging in this setting. Dosimetric evaluation was also assessed. Methods Seventeen BC patients (mean age 55.93 ± 11.04 years)with invasive ductal carcinoma HER2 + treated with surgery and with an anthracycline-based adjuvant CHT, were enrolled. The trend of cardiac function was assessed by evaluation of LV-EF, LV-EDV and LV-ESV using gSPECT in baseline conditions and at 12, 15 and 52 weeks during treatment and then at 6, 12, 24 and 48 months during follow-up. Each patient was studied 15-20 min after injection of 555 MBq of 99mTc-Tetrofosmin with gSPECT (16 frames/cardiac cycle) using an Infinia Hawkeye IV gamma-camera. Dosimetry was assed according to ICRP reports. Results Two out of the 17 patients enrolled left the protocol: one because of a second tumor and the other due to the appearance of cardiotoxicity. 15 patients completed the study: mean LVEF at baseline was 70.67 ± 5.68. The greatest modification occurred after 15th week of treatment, when mean LV-EF showed a significant decrease to 65.67 ± 8.27, while mean LV-EDV and mean LV-ESV increased from 73.60 ± 16.72 up to 84.73 ± 21.11 and from 21.93 ± 7.17 up to 30.27 ± 14.16, respectively. All parameters progressively returned similar to baseline values at the final examination (after 48th month): mean LV-EF 70.20 ± 5.65, LV-EDV 73.40 ± 16.15 and ESV 22.07 ± 7.50. In one case cardiotoxicity occurred at 15th week: LV-EF decreased from 69 to 47%, LV-EDV increased from 92 up to 142 ml and LV-ESV from 28 up to 75 ml. According to our image protocols, effective dose for gSPECT was 3.83 mSv (ICRP 106). The use of gSPET instead of MUGA (6.47 mSv–ICRP 80) allowed a dose effective saving of 2.64 mSv/each control with a total saving of 21.12 mSv/patient. Conclusions Although the small sample size, gSPECT was demonstrated to be an applicable tool for monitoring cardiac function because it correctly identified BC patient with cardiotoxicity. gSPECT also allowed a significant radiation dose saving compared to MUGA: this is particularly relevant in cardiotoxicity studies that require repeated and close evaluations.

Background and objective Motion due to patient's breathing can introduce heavy bias in PET/CT, both in image quality and quantitation. This paper is a review of the main technical solutions available to manage movement in PET/CT studies: a) Respiratory Gated (RG), b) Motion Free (MF), c) End Expiration (EE), d) Banana Artefact Management (BAM) and e) Data Driven Gating (DDG). Methods The most diffused solutions (RG, MF and EE) are based on LIST mode acquisition of a PET Field of View (4D FOV), centered on the anatomical region of interest; to link PET data not only to time and to spatial position but also to the corresponding breathing phase, the synchronized acquisition of the patient's breathing curve is performed by an external tracking device. Different commercial tools to track and to record patient breathing cycle are available to associate the internal organ motion with a measurable external parameter; for example these systems can measure the pressure on a chest elastic belt, the air flow trough patient nose, the breath-in and breath-out air temperature or the markers movement on the thorax/ abdominal region. Recently DDG techniques are developed to correct respiratory motion without the help of external motion tracking devices and to obtain a comparable result to that based on standard RG protocols. Results The final result of an RG or DDG protocol is a sequence of 3D images showing organs and lesions movement; using the other motion management options a single 3D motion-free image is obtained without motion artefacts and degradation. Compared to the previously described options the BAM solution is not a real motion management protocol but just a Banana Artefact correction technique obtained using an Attenuation Correction Map calculated merging the Whole Body Helical CT with a Cine CT on the diaphragm area. Conclusion The motion management in PET/CT imaging shows benefits in terms of image quality, quantification and lesion detectability and it is useful both in diagnostic and radiotherapy planning.

Background and purpose Cognitively stimulating life experiences and activities are deemed to moderate the clinical impact of brain damage progressively building a neural and cognitive reserve (CR). CR has been studied extensively in various neurodegenerative disorders, but not in corticobasal degeneration (CBD). Methods Using Statistical Parametric Mapping 8, years of education, as a determinant of CR, was correlated with tracer uptake on positron emission tomography with 18 F-fluorodeoxyglucose, as a marker of neurodegeneration, in 35 patients with various phenotypes of CBD, including a cognitive-motor composite score or symptoms duration as covariates for controlling disease stage. Results A cluster of relative hypometabolism was found associated with higher education in the left inferior regions of pre- and post-rolandic gyri and insula, which represent typical loci of neurodegeneration in CBD regardless of clinical presentation. Conclusions The present findings extend to CBD the evidence gathered in other neurodegenerative disorders that a higher CR has a protective effect against the clinical manifestations of brain degeneration.

Purpose: The aim of the present study was to evaluate the added diagnostic value of respiratory-gated 4D18F–FDG PET/CT in liver lesion detection and characterization in a European multicenter retrospective study. Methods: Fifty-six oncological patients (29 males and 27 females, mean age, 61.2 ± 11.2 years) from five European centers, submitted to standard 3D–PET/CT and liver 4D–PET/CT were retrospectively evaluated. Based on visual analysis, liver PET/CT findings were scored as positive, negative, or equivocal both in 3D and 4D PET/CT. The impact of 4D–PET/CT on the confidence in classifying liver lesions was assessed. PET/CT findings were compared to histology and clinical follow-up as standard reference and diagnostic accuracy was calculated for both techniques. At semi-quantitative analysis, SUVmax was calculated for each detected lesion in 3D and 4D–PET/CT. Results: Overall, 72 liver lesions were considered for the analysis. Based on visual analysis in 3D–PET/CT, 32/72 (44.4%) lesions were considered positive, 21/72 (29.2%) negative, and 19/72 (26.4%) equivocal, while in 4D–PET/CT 48/72 (66.7%) lesions were defined positive, 23/72 (31.9%) negative, and 1/72 (1.4%) equivocal. 4D–PET/CT findings increased the confidence in lesion definition in 37/72 lesions (51.4%). Considering 3D equivocal lesions as positive, sensitivity, specificity, and accuracy were 88.9, 70.0, and 83.1%, respectively, while the same figures were 67.7, 90.0, and 73.8% if 3D equivocal findings were included as negative. 4D–PET/CT sensitivity, specificity, and accuracy were 97.8, 90.0, and 95.4%, respectively, considering equivocal lesions as positive and 95.6, 90.0, and 93.8% considering equivocal lesions as negative. The SUVmax of the liver lesions in 4D–PET (mean ± SD, 6.9 ± 3.2) was significantly higher (pÂ

Background and objective Breathing movement can introduce heavy bias in both image quality and quantitation in PET/CT. The aim of this paper is a review of the literature to evaluate the benefit of respiratory gating in terms of image quality, quantification and lesion detectability. Methods A review of the literature published in the last 10 years and dealing with gated PET/CT technique has been performed, focusing on improvement in quantification, lesion detectability and diagnostic accuracy in neoplastic lesion. In addition, the improvement in the definition of radiotherapy planning has been evaluated. Results There is a consistent increase of the Standardized Uptake Value (SUV) in gated PET images when compared to ungated ones, particularly for lesions located in liver and in lung. Respiratory gating can also increase sensitivity, specificity and accuracy of PET/CT. Gated PET/CT can be used for radiation therapy planning, reducing the uncertainty in target definition, optimizing the volume to be treated and reducing the possibility of "missing" during the dose delivery. Moreover, new technologies, able to define the movement of lesions and organs directly from the PET sinogram, can solve some problems that currently are limiting the clinical use of gated PET/CT (i.e.: extended acquisition time, radiation exposure). Conclusion The published literature demonstrated that respiratory gating PET/CT is a valid technique to improve quantification, lesion detectability of lung and liver tumors and can better define the radiotherapy planning of moving lesions and organs. If new technical improvements for motion compensation will be clinically validated, gated technique could be applied routinely in any PET/CT scan.

Purpose: The aim of this study was to compare planning target volume (PTV) defined on respiratory-gated positron emission tomography (PET)/CT (RG-PET/CT) to PTV based on ungated free-breathing CT and to evaluate if RG-PET/CT can be useful to personalize PTV by tailoring the target volume to the lesion motion in lung cancer patients. METHODS: Thirteen lung cancer patients (six men, mean age 70.0 years, 1 small cell lung cancer, 12 non-small cell lung cancer) who were candidates for radiation therapy were prospectively enrolled and submitted to RG-PET/CT. Ungated free-breathing CT images obtained during a PET/CT study were visually contoured by the radiation oncologist to define standard clinical target volumes (CTV1). Standard PTV (PTV1) resulted from CTV1 with the addition of 1-cm expansion of margins in all directions. RG-PET/CT images were contoured by the nuclear medicine physician and radiation oncologist according to a standardized institutional protocol for contouring gated images. Each CT and PET image of the patient's respiratory cycle phases was contoured to obtain the RG-CT-based CTV (CTV2) and the RG-PET/CT-based CTV (CTV3), respectively. RG-CT-based and RG-PET/CT-based PTV (PTV2 and PTV3, respectively) were then derived from gated CTVs with a margin expansion of 7-8 mm in head to feet direction and 5 mm in anterior to posterior and left to right direction. The portions of gated PTV2 and PTV3 geometrically not encompassed in PTV1 (PTV2 out PTV1 and PTV3 out PTV1) were also calculated. RESULTS: Mean ± SD CTV1, CTV2 and CTV3 were 30.5 ± 33.2, 43.1 ± 43.2 and 44.8 ± 45.2 ml, respectively. CTV1 was significantly smaller than CTV2 and CTV3 (p = 0.017 and 0.009 with Student's t test, respectively). No significant difference was found between CTV2 and CTV3. Mean ± SD of PTV1, PTV2 and PTV3 were 118.7 ± 94.1, 93.8 ± 80.2 and 97.0 ± 83.9 ml, respectively. PTV1 was significantly larger than PTV2 and PTV3 (p = 0.038 and 0.043 with Student's t test, respectively). No significant difference was found between PTV2 and PTV3. Mean ± SD values of PTV2 out PTV1 and PTV3 out PTV1 were 12.8 ± 25.4 and 14.3 ± 25.9 ml, respectively. The percentage values of PTV2 out PTV1 and PTV3 out PTV1 were not lower than 10 % of PTV1 in 6/13 cases (46.2 %) and than 20 % in 3/13 cases (23.1 %). CONCLUSION: Our preliminary data showed that RG-PET/CT in lung cancer can affect not only the volume of PTV but also its shape, as demonstrated by the assessment of gated PTVs outside standard PTV. The use of a gating technique is thus crucial for better delineating PTV by tailoring the target volume to the lesion motion in lung cancer patients.

Objective. The aim of this work was to assess robustness and reliability of an adaptive thresholding algorithm for the biological target volume estimation incorporating reconstruction parameters.Method. In a multicenter study, a phantom with spheres of different diameters (6.5–57.4 mm) was filled with18F-FDG at different target-to-background ratios (TBR: 2.5–70) and scanned for different acquisition periods (2–5 min). Image reconstruction algorithms were used varying number of iterations and postreconstruction transaxial smoothing. Optimal thresholds (TS) for volume estimation were determined as percentage of the maximum intensity in the cross section area of the spheres. Multiple regression techniques were used to identify relevant predictors of TS.Results. The goodness of the model fit was high (R2: 0.74–0.92). TBR was the most significant predictor of TS. For all scanners, except the Gemini scanners, FWHM was an independent predictor of TS. Significant differences were observed between scanners of different models, but not between different scanners of the same model. The shrinkage on cross validation was small and indicative of excellent reliability of model estimation.Conclusions. Incorporation of postreconstruction filtering FWHM in an adaptive thresholding algorithm for the BTV estimation allows obtaining a robust and reliable method to be applied to a variety of different scanners, without scanner-specific individual calibration.

Background: This investigation used image data generated by a physical phantom over a wide range of count statistics to evaluate the effectiveness of several of the newer commercially available SPECT reconstruction iterative algorithms (IRR) in improving perfusion defect contrast and spatial resolution, while controlling image noise. Methods: A cardiac phantom was imaged using four different gamma cameras over a wide range of counts statistics (from 6 to 0.8 Mcounts). Images were reconstructed with FBP, OSEM, and the IRR available on site. IRR were applied without corrections (IRR NC), with attenuation correction (IRR AC), scatter correction (IRR SC), and attenuation + scatter corrections (IRR SCAC). Four image performance indices related to spatial resolution, contrast, and image noise were analyzed. Results: IRR NC always determined significant improvements in all indices in comparison to FBP or OSEM. Improvements were emphasized with IRR SC and IRR SCAC. Count reduction from 6 to 1.5 Mcounts did not impair the performances of any of the considered indices. Conclusions: This is the first study comparing the relative performance of different, commercially available, IRR software, over a wide range of count statistics; the additional effect of scatter and attenuation corrections, alone or in combination, was also evaluated. Our results confirm that IRR algorithms produce substantial benefits with respect to conventional FBP or OSEM reconstruction methods, as assessed through different figures of merit, in particular when SC and/or SCAC are also included. © 2013 American Society of Nuclear Cardiology.

Background: Anorexia nervosa commonly arises during adolescence and is associated with more than one medical morbidity. Abnormalities in brain structure (defined as "pseudoatrophy") are common in adolescents with anorexia nervosa; however, their correlations with endocrinological profiles and clinical parameters are still unclear. In particular, no study has described the impact of BMI (body mass index) variations (speed and magnitude of weight loss) on cerebral trophism changes. Methods. Eleven adolescents with anorexia nervosa and 8 healthy controls underwent cerebral MRI (magnetic resonance imaging) examination to obtain global and partial volumes (gray matter, white matter and cerebrospinal fluid) and clinical evaluation. The Mann-Whitney U test was used to compare partial volumes and clinical variables between cases and controls. The Spearman non-parametric test was performed in order to explore correlations between the variables studied. Results: The patients diagnosed with AN showed significantly increased cerebrospinal fluid (CSF) volumes and decreased total gray (GM) and white matter (WM) volumes. The degree of weight loss (deltaBMI) correlated inversely with the GM volume; the increase of CSF compartment correlated directly with the rapidity of weight loss (DeltaBMI/disease duration). Conclusions: This study suggests a correlation between cerebral alterations in AN and the speed and magnitude of weight loss, and outlines its importance for the therapeutic treatment. © 2013 Bomba et al.; licensee BioMed Central Ltd.

Monica Bomba,1,* Anna Riva,1,* Sabrina Morzenti,2 Marco Grimaldi,3 Francesca Neri,1 Renata Nacinovich1 1Child and Adolescent Mental Health Department, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy; 2Medical Physics Department, San Gerardo Hospital, Monza, Italy; 3Department of Radiology, Humanitas Research Hospital, Milan, Italy *These authors contributed equally tothis work Abstract: The recent literature on anorexia nervosa (AN) suggests that functional and structural abnormalities of cortico-limbic areas might play a role in the evolution of the disease. We explored global and regional brain volumes in a cross-sectional and follow-up study on adolescents affected by AN. Eleven adolescents with AN underwent a voxel-based morphometry study at time of diagnosis and immediately after weight recovery. Data were compared to volumes carried out in eight healthy, age and sex matched controls. Subjects with AN showed increased cerebrospinal fluid volumes and decreased white and gray matter volumes, when compared to controls. Moreover, significant regional gray matter decrease in insular cortex and cerebellum was found at time of diagnosis. No regional white matter decrease was found between samples and controls. Correlations between psychological evaluation and insular volumes were explored. After weight recovery gray matter volumes normalized while reduced global white matter volumes persisted. Keywords: anorexia nervosa, adolescent, gray matter, insula, voxel-based morphometry study