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Marina di Pisa, Italy

Sansovini M.,Unit of Radiometabolic Medicine | Severi S.,Unit of Radiometabolic Medicine | Ambrosetti A.,Unit of Radiometabolic Medicine | Monti M.,Unit of Biostatistics and Clinical Trials | And 6 more authors.
Neuroendocrinology | Year: 2013

Background: We evaluated the activity and safety profile of 177Lu-DOTATATE peptide receptor radionuclide therapy (Lu-PRRT) in patients with advanced G1-G2 pancreatic neuroendocrine tumors. Patients and Methods: Fifty-two consecutive patients were treated at two different therapeutic dosages of 18.5 or 27.8 GBq in five cycles, according to the patient's kidney function and bone marrow reserve, which are known to be the critical organs in PRRT. Results: Twenty-six patients received a mean full dosage (FD) of 25.5 GBq (range 20.7-27.8) and 26 a mean reduced dosage (RD) of 17.8 GBq (range 11.1-19.9). Both therapeutic dosages resulted in antitumor activity (disease control rate in the entire case series 81%), with 12% complete response, 27% partial response and 46% stable disease in the FD group, whereas we observed 4% complete response, 15% partial response and 58% stable disease in the RD group. Median progression-free survival was not reached in the FD group and was 20 months in the RD group. No major acute or delayed hematological toxicity occurred. Conclusion:177Lu-DOTATATE peptide receptor radionuclide therapy showed antitumor activity in advanced pancreatic neuroendocrine tumors even at a reduced total activity of 18.5 GBq. However, progression-free survival was significantly longer (p = 0.05) after a total activity of 27.8 GBq, which can thus be considered the recommended dosage in eligible patients. Copyright © 2013 S. Karger AG, Basel. Source

Tessa C.,Versilia Hospital | Lucetti C.,Versilia Hospital | Diciotti S.,University of Florence | Paoli L.,University of Florence | And 8 more authors.
Neuroradiology | Year: 2012

Introduction: Nuclear medicine studies in Parkinson's disease (PD) indicate that nigrostriatal damage causes a widespread cortical hypoactivity assumed to be due to reduced excitatory thalamic outflow. However, so far, functional MRI (fMRI) studies have provided controversial data about this "functional deafferentation" phenomenon. To further clarify this issue, we assessed, with fMRI, de novo drug-naive PD patients using a relatively complex motor task under strictly controlled conditions. Methods: Nineteen de novo PD patients with right-predominant or bilateral symptoms and 13 age-matched healthy volunteers performed continuous writing of "8" figures with the right-dominant hand using a MR-compatible device that enables identification of incorrectly performed tasks and measures the size and the frequency of the "8"s. The data were analyzed with FSL software and correlated with the clinical severity rated according to the Hoehn and Yahr (HY) staging system. Results: Fifteen (89%) of 19 PD patients and 12 (92%) of 13 controls correctly executed the task. PD patients showed significant hypoactivation of the left primary sensorimotor cortex (SM1) and cerebellum and no hyperactive areas as compared to controls. However, activation in SM1 and supplementary motor area bilaterally, in left supramarginal, parietal inferior, parietal superior and frontal superior gyri as well as in right parietal superior and angular gyri paralleled increasing disease severity as assessed with the HY stage. Conclusions: In line with the "deafferentation hypothesis", fMRI demonstrates hypoactivation of the SM1 in the early clinical stage of PD. © Springer-Verlag 2011. Source

Tessa C.,Versilia Hospital | Diciotti S.,University of Florence | Lucetti C.,Versilia Hospital | Baldacci F.,University of Pisa | And 4 more authors.
Parkinsonism and Related Disorders | Year: 2013

Background and purpose: Previous fMRI studies indicated a relationship between changes of the cortical activation pattern and disease severity in Parkinson's disease (PD). Early diagnosis of Parkinson's disease offers the opportunity to evaluate the putative neuroprotective and disease-modifying effects of drugs at a clinical stage when they might be more effective. The aim of this study was to assess motor cortex reorganization at the earliest clinically detectable stage of PD and the effects on it of chronic dopaminergic treatment. Methods: We evaluated with fMRI 11 de novo patients with right unilateral parkinsonism during execution of a controlled hand-tapping task by the unaffected left hand. In 7 of them fMRI examination with the same task was repeated after 6 months of ropinirole administration. Results: At baseline, as compared to control subjects, PD patients showed significant hypoactivation of right sensory-motor cortex (SM1) and hyperactivation of the left parietal superior and inferior gyri and frontal superior gyrus and of the right parietal superior gyrus and precuneus. Ropinirole treatment yielded a significant clinical improvement (mean UPDRS score subitem III 13.4 at baseline, 9.4 at follow-up; p < 0.001 at a paired t-test) which was combined with lower activation in the left parietal superior and inferior gyri and in right parietal and occipital superior gyri with respect to their baseline fMRI examination. Conclusions: Our results indicate that in PD patients changes in cortical activation precede the onset of motor symptoms in the clinically unaffected side and are partially reversed by chronic administration of long acting dopamine agonist ropinirole. © 2012 Elsevier Ltd. Source

Iacconi C.,Azienda Ospedaliero Universitaria Pisana | Giannelli M.,Unit of Medical Physics | Marini C.,Azienda Ospedaliero Universitaria Pisana | Cilotti A.,Azienda Ospedaliero Universitaria Pisana | And 5 more authors.
European Radiology | Year: 2010

Objective: To evaluate the role of mean diffusivity (MD) as a predictive index of the response to chemotherapy in locally advanced breast cancer. Methods: Twenty-one women referred to our institution with a diagnosis of locally advanced breast cancer underwent magnetic resonance imaging (MRI) studies at 1.5 T before beginning and after completing combined neoadjuvant chemotherapy. The examination protocol included an EPI sequence sensitised to diffusion (b-value 1,000 s/mm2) and three-dimensional (3D) coronal T1 sequences before and after intravenous contrast medium. Tumours were delineated by using dynamic MR acquisition before and after chemotherapy. The percentage of tumour volume reduction (PVR) and pre-(MDpre) and post-therapy (MDpost) MD values were computed for each lesion. Results: PVR ≥ 65% was observed in 17/21 patients (responders). MDpre of responders (0.99± 0.27 10-3 mm2/s) was significantly (p=0.025) lower than MDpre of non-responders (1.46±0.33 10-3 mm2/s). Moreover, in patients as a whole PVR significantly correlated (p=0.01, r=-0.54) with MDpre. MDpost (1.26± 0.39 10-3 mm2/s) of responders was significantly(p=0.024) higher than MDpre (0.99±0.27 mm 2 10-3 mm2/s), whereas non-responders MD post(1.00±0.14 10-3 mm2/s) did not increase compared with MDpre(1.46±0.33 10-3 mm 2/s). Conclusions: This preliminary study seems to indicate that low values of pre-chemotherapyMDmay identify, before starting treatment, the patients with higher probability of response in terms of percentage of volume reduction of the lesion. MD may represent a complementary parameter useful to correctly select patients for neoadjuvant chemotherapy. © European Society of Radiology 2009. Source

Giannelli M.,Unit of Medical Physics
Journal of applied clinical medical physics / American College of Medical Physics | Year: 2010

The rotational variance dependence of diffusion tensor imaging (DTI) derived parameters on the number of diffusion weighting directions (N) has been investigated by several Monte Carlo simulation studies. However, the dependence of fractional anisotropy (FA) and mean diffusivity (MD) maps on N, in terms of accuracy and contrast between different anatomical structures, has not been assessed in detail. This experimental study further investigated in vivo the effect of the number of diffusion weighting directions on DTI maps of FA and MD. Human brain FA and MD maps of six healthy subjects were acquired at 1.5T with varying N (6, 11, 19, 27, 55). Then, FA and MD mean values in high (FAH, MDH) and low (FAL, MDL) anisotropy segmented brain regions were measured. Moreover, the contrast-to-signal variance ratio (CVRFA, CVRMD) between the main white matter and the surrounding regions was calculated. Analysis of variance showed that FAL, FAH and CVRFA significantly (p < 0.05) depend on N. In particular, FAL decreased (6%-11%) with N, whereas FAH (1.6%-2.5%) and CVRFA (4%-6.5%) increased with N. MDL, MDH and CVRMD did not significantly (p>0.05) depend on N. Unlike MD values, FA values significantly vary with N. It is noteworthy that the observed variation is opposite in low and high anisotropic regions. In clinical studies, the effect of N may represent a confounding variable for anisotropy measurements and the employment of DTI acquisition schemes with high N (> 20) allows an increased CVR and a better visualization of white matter structures in FA maps. Source

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