Computing Consensus: A Logic for Reasoning About Deliberative Processes Based on Argumentation

Argumentation theory can encode an agent’s assessment of the state of an exchange of points of view. We present a conservative model of multiple agents potentially disagreeing on the views presented during a process of deliberation. We model this process as iteratively adding points of view (arguments), or aspects of points of view. This gives rise to a modal logic, deliberative dynamic logic, which permits us to reason about the possible developments of the deliberative state. The logic we propose applies to all natural semantics of argumentation theory. Furthermore, under a very weak assumption that the consensus considered by a group of agents is faithful to their individual views, we show that model checking these models is feasible, as long as the argumentation frameworks, which may be infinite, does not have infinite branching.acceptedVersio

LAPAROSCOPIC VERSUS LAPAROTOMIC LIVING DONOR NEPHRECTOMY: ASSESSMENT OF GRAFT RENAL FUNCTION BY MEANS OF 99MTC-MAG3 DYNAMIC RENAL SCINTIGRAPHY

Laparoscopic living donor nephrectomy (LLDN) has been claimed to induce an increased risk of acute tubular necrosis for the transplanted kidney as compared to laparotomic living donor nephrectomy (OLDN). LLDN is characterized by longer surgery time, longer warm ischemia time, higher risk of vascular damage and vasoconstriction due to the traction on the vessels during the laparoscopic dissection and prolonged venous compression due to pneumoperitoneum. 99mTc Mag3 scintigraphy has been used to compare graft function between LLDN and OLDN groups. Material and Methods: The immediate post-operative results and the effects of the ischemic insult, in 22 grafts derived from LLDN, transplanted between 2001 to 2006, were evaluated in terms of incidence of delayed graft function (DGF), graft survival, serum creatinine and were compared with 38 grafts derived from OLDN performed between 1992 to 2006. The uptake (corrected for graft depth) of 99mTcMAG3 between first and second minute after injection, acquired on the 5th-7th postoperative day, was used to estimate effective renal plasma flow (ERPF) in both groups. Being the variables not normally distributed (shapiro wilk test), two sample Wilcoxon test (Mann Whitney) have been used to assess differences between groups. Results: Kidneys of the LLDN group suffered a mean of 160 \ub1 35 seconds of warm ischemia time (compared with 22 \ub1 11 sec in OLDN group, p<0.0001) and the mean operating time was 213 \ub1 36 min (vs 270 \ub1 41 min in the OLDN group, p<0.001). Only one PNF occurred in the LLDN group. The incidence of DGF was 4.5% in LLDN vs 2.6% in OLDN. Mean serum creatinine at 1 week post-op was 201 \ub1 164 in the LLDN vs 200 \ub1 119 \ub5mol/L in the OLDN (p=0.49). No difference (p= 0.66) in ERPF mean values between LLDN and OLDN group was demonstrated by a twosample Wilcoxon test. Renal time concentration curve suggested tubular necrosis in 4/22 (18.2%) LLDN patients and in 4/38 (10.5%) OLDN patients. Conclusions: Despite the limited experience at our center in LLDN and the small number of procedures performed per year, the LLDN technique seems to be as safe as OLDN, providing a similar early post-transplant renal function and showing significative difference in the incidence of DGF. The slight difference in the number of acute tubular necrosis between the groups, demonstrated by 99mTc-MAG3 renography, could be due to the low number of patients and should be further investigate

Assessing Response Using Tc99m-MIBI Early after Interstitial Chemotherapy with Carmustine-Loaded Polymers in Glioblastoma Multiforme: Preliminary Results

Introduction. Early signs of response after applying wafers of carmustine-loaded polymers (gliadel) are difficult to assess with imaging because of time-related imaging changes. Tc99m-sestamibi (MIBI) brain single-photon emission tomography (SPET) has reportedly been used to reveal areas of cellularity distinguishing recurrent neoplasm from radionecrosis. Our aim was to explore the role of MIBI SPET in assessing response soon after gliadel application in glioblastoma multiforme (GBM). Methods. We retrospectively reviewed the charts on 28 consecutive patients with a radiological diagnosis of GBM who underwent MIBI SPET/CT before surgery (with intracavitary gliadel placement in 17 patients), soon after surgery, and at 4 months. The area of uptake was selected using a volume of interest that was then mirrored contralaterally to obtain a semiquantitative ratio. Results. After adjusting for ratio at the baseline, the effect of treatment (gliadel versus non-gliadel) was not statistically significant. Soon after surgery, however, 100% of patients treated with gliadel had a decreased ratio, as opposed to 62.5% of patients in the non-gliadel group P=0.0316. The difference between ratios of patients with radical versus partial resection reached statistical significance by a small margin P=0.0528. Conclusions. These data seem to suggest that the MIBI ratio could be a valuable tool for monitoring the effect of gliadel early after surgery

Gleason score at diagnosis predicts the rate of detection of 18F-choline PET/CT performed when biochemical evidence indicates recurrence of prostate cancer: experience with 1,000 patients

The objective of this study was to explore the ability of the initial Gleason score (GS) to predict the rate of detection of recurrent prostate cancer (PCa) with (18)F-choline PET/CT in a large cohort of patients. METHODS: Data from 1,000 patients who had undergone (18)F-choline PET/CT because of biochemical evidence of relapse of PCa between 2004 and 2013 were retrieved from databases at 4 centers. Continuous data were compared by the Student t test or ANOVA, and categoric variables were compared by the χ(2) test. Univariable and multivariable analyses were performed by logistic regression. RESULTS: The GS at diagnosis was less than or equal to 6 in 257 patients, 7 in 347 patients, and greater than 7 in 396 patients. The results of 645 PET/CT scans were positive for PCa recurrence. Eighty-one percent of the positive PET/CT results were found in patients with a PSA level of greater than or equal to 2 ng/mL, 43% were found in patients with a PSA level of 1-2 ng/mL, and 31% were found in patients with a PSA level of less than or equal to 1 ng/mL; 78.8% of patients with positive PET/CT results had a GS of greater than 7. The results of (18)F-choline PET/CT scans were negative in 300 patients; 44% had a GS of less than or equal to 6, 35% had a GS of 7, and 17% had a GS of greater than 7. PET/CT results were rated as doubtful in only 5.5% of patients (median PSA, 1.8 ng/mL). When the GS was greater than 7, the rates of detection of (18)F-choline PET/CT were 51%, 65%, and 91% for a PSA level of less than 1 ng/mL, 1-2 ng/mL, and greater than 2 ng/mL, respectively. In univariable and multivariable analyses, both a GS of 7 and a GS of greater than 7 were independent predictors for positive (18)F-choline PET/CT results (odds ratios, 0.226 and 0.330, respectively; P values for both, <0.001). CONCLUSION: A high GS at diagnosis is a strong predictive factor for positive (18)F-choline PET/CT scan results for recurrent PCa, even when the PSA level is low (i.e., ≤1 ng/mL)

[18F]FDG PET/MRI versus contrast-enhanced MRI in detecting regional HNSCC metastases

Objective: To compare the accuracy of contrast-enhanced MRI using established dimensional and morphological criteria versus integrated [18F]FDG PET/MRI in identifying regional lymph node metastases in patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC). For this purpose, we compare MRI and PET/MRI using the histopathological findings in dissected lymph nodes as the gold standard. Methods: We retrospectively reviewed 26 patients with histologically proven HNSCC who underwent gadolinium-enhanced [18F]FDG PET/MRI as part of their staging. All neck lymph nodes were classified on MRI using dimensional and/or morphological criteria. Then, they were jointly assessed by a nuclear medicine physician and a radiologist using integrated [18F]PET/MR images. ROC curves were obtained to compare the techniques. Lymph node histopathology was considered as the reference standard. Results: Out of 865 lymph nodes, 35 were malignant at histopathology (3 with micro-metastases). Sensitivity and specificity were 48.6% and 99.5% for MRI using dimensional criteria; 60.0% and 99.6% for MRI using morphological criteria; 60.0% and 99.4% for MRI using both; and 74.3% and 97.6% for PET using MR as anatomic localization. The area under the ROC curve was higher for PET and MRI localization (0.859) than for MRI using dimensional (0.740; p &lt; 0.05), or morphological (0.798; p &lt; 0.05), or both criteria (0.797; p &lt; 0.05). PET/MR using a PET SUVmax cutoff of 5.7 combined with MRI using dimensional and/or morphological criteria reached high values for accuracy (98.2%), NPV (98.2%), and PPV (95.2%). Conclusions: Compared with traditional contrast-enhanced MRI or PET alone, integrated PET/MRI could improve diagnostic accuracy in detecting metastatic lymph nodes in patients with HNSCC