Positron Emission Tomography imaging (PET) with 18F-fluoro-2-deoxyglucose (FDG) is a well established method to image brain glucose metabolism in healthy and disease states with application areas in neuro-degenerative and seizure disorders. Epilepsy is one of the most common neurological disorders effecting approximately 1 - 2% of the population. Advances in deep learning have revolutionized quantitative analysis and interpretation of medical images. Increasing availability of large medical imaging databases and sophisticated methods of extracting their discriminative features allows the potential for a greater understanding of the alterations of medical images in varying disease states. Probing medical images latent state presentations allows compressed representations with descriptive attributes to be explored. The auto-encoder and its variants serve this purpose; wherein they naively attempt to learn the identity function to reconstruct the input. Further constraints or regularization on the autoencoder avoid over-fitting to the training data hence boosting the discovery process. An autoencoder trained on a normal healthy database has recently found application areas in anomaly detection of FDG uptake with the magnitude of the reconstruction error serving as a proxy for abnormal brain patterns. In this work we take advantage of the fact that FDG uptake in the healthy subject is usually homogeneous and symmetrical with left-right asymmetries in activity concentration present in patients with hypometabolic epileptogenic regions. We therefore construct a novel autoencoder for anomaly detection in FDG brain PET and utilize a regularizing symmetry term in the loss function. This has the effect of producing increased reconstruction error in the event of an anomaly. The autoencoder is trained on 120 normal volunteers and tested on 3 patients with diagnosed epilepsy, demonstrating an average increase in reconstruction error of 6%, hence greater discriminative power in anomaly identification.

Oesophageal adenocarcinoma has a poor prognosis and relies on multi-modality assessment for accurate nodal staging. The aim of the study was to determine the prognostic significance of nodal concordance between PET/CT and EUS in oesophageal adenocarcinoma. Consecutive patients with oesophageal adenocarcinoma staged between 2010 and 2016 were included. Groups comprising concordant node–negative (C−ve), discordant (DC), and concordant node–positive (C+ve) patients were analysed. Survival analysis using log-rank tests and Cox proportional hazards model was performed. The primary outcome was overall survival. A p value < 0.05 was considered statistically significant. In total, 310 patients (median age = 66.0; interquartile range 59.5–72.5, males = 264) were included. The median overall survival was 23.0 months (95% confidence intervals (CI) 18.73–27.29). There was a significant difference in overall survival between concordance groups (X2 = 44.91, df = 2, p < 0.001). The hazard ratios for overall survival of DC and C+ve patients compared with those of C−ve patients with cT3 tumours were 1.21 (95% CI 0.81–1.79) and 1.79 (95% CI 1.23–2.61), respectively. On multivariable analysis, nodal concordance was significantly and independently associated with overall survival (HR 1.44, 95% CI 1.12–1.83, p = 0.004) and performed better than age at diagnosis (HR 1.02, 95% CI 1.003–1.034, p = 0.016) and current cN-staging methods (HR 1.20, 95% CI 0.978–1.48, p = 0.080). Patients with discordant nodal staging on PET/CT and EUS represent an intermediate-risk group for overall survival. This finding was consistent in patients with cT3 tumours. These findings will assist optimum treatment decisions based upon perceived prognosis for each patient. • Clinicians are commonly faced with results of discordant nodal staging in oesophageal adenocarcinoma. • There is a significant difference in overall survival between patients with negative, discordant, and positive lymph node staging. • Patients with discordant lymph node staging between imaging modalities represent an intermediate-risk group for overall survival.

B. HCC of Sunitinib treated woodchuck showing partially preserved neoplastic cells (lower left) and expensive necrosis in the rest of the section.Mo1928 Chemotherapy With Bevacizumab for Advanced or Metastatic Colorectal Cancer Masaru Hirata [Background] We compared intention to treat analysis, patient survival and complication between FOLFOX+BEV, XELOX+BEV, and FOLFIRI+BEV among advanced or metastatic colorectal cancer patients.[Patients] Patients consisted of 56 cases (41 men and 15 women, 22 rectal cancer and 34 colon cancer, 28 advanced and 28 metastatic, 63.5 years old) who underwent chemotherapy with bevacizumab from July 2007 to June 2013.The location of metastasis were liver (32 cases), lung (13 cases), distant lymphnodes (11 cases), retroperitoneum (7 cases), peritoneum (4 cases), bone (2 cases), and ovary (1 case).[Method] All patients underwent complete resection of the primary carcinoma before chemotherapy.Time to progression analysis and patients survival, which were calculated by Kaplan-Meier method, and complication, were compared between FOLFOX+BEV, XELOX+BEV, and FOLFIRI+BEV group.[Results] 39 cases (69.6 %) out of 56 patients had k-ras wild type cancer and 17 (30.4%) had k-ras mutant type.There was no significant difference about TTP of bevacizumab rgimen between k-ras wild group and k-ras mutant group, althouth k-ras wild group revealed significantly better patients survival.Bevacizumab based chemotherapy was performed as the first line in 41 cases (73.2 %), the second line in 8 cases (14.3 %), and the third line in 7 cases (12.5 %).TTP analysis revealed no significant difference between the first line group and other patients (second or third regimen group).Disease control rate (CR+PR+SD) was 83.3 % in FOLFOX+BEV group, 88.2 % in XELOX+BEV group, and 66.7 % in FOLFIRI+BEV group.Median TTP of FOLFOX+BEV group (225 days) or that of XELOX+BEV group (365 days) was significantly longer than that of FOLFIRI+BEV group (117 days).The rate of grade 3 or 4 adverse events was 3.6 % (1 gastrointestinal perforation and 1 fistula formation).[Discussion] FOLFOX + BEV or XELOX + BEV should be given to advanced or metastatic colorectal cancer at first.

Purpose: F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) is now established as a routine staging investigation of oesophageal cancer (OC). The aim of the study was to determine the prognostic significance of PET/CT defined tumour variables including maximum standardised uptake value (SUVmax), tumour length (TL), metastatic length of disease (MLoD), metabolic tumour volume (MTV), total lesion glycolysis (TLG) and total local nodal metastasis count (PET/CT LNMC).Materials and methods: 103 pre-treatment OC patients (76 adenocarcinoma, 25 squamous cell carcinoma, 1 poorly differentiated and 1 neuroendocrine tumour) were staged using PET/CT. The prognostic value of the measured tumour variables were tested using log-rank analysis of the Kaplan-Meier method and Cox's proportional hazards method. Primary outcome measure was survival from diagnosis.Results: Univariate analysis showed all variables to have strong statistical significance in relation to survival. Multivariate analysis demonstrated three variables that were significantly and independently associated with survival; MLoD (HR 1.035, 95% CI 1.008-1.064, p = 0.011), TLG (HR 1.002, 95% CI 1.000-1.003, p = 0.018) and PET/CT LNMC (HR 0.048-0.633, 95% CI 0.005-2.725, p = 0.015).Conclusion: MLoD, TLG, and PET/CT LNMC are important prognostic indicators in OC. This is the first study to demonstrate an independent statistical association between TLG, MLoD and survival by multivariable analysis, and highlights the value of staging OC patients with PET/CT using functional tumour variables. Crown Copyright (C) 2014 Published by Elsevier Ireland Ltd. All rights reserved.

2000 Objectives To determine whether a time of flight (TOF) reconstruction algorithm leads to qualitative changes in image appearance or quantitative differences in calculated SUV uptake values as compared to a conventional reconstruction algorithm in a phantom model across a range of acquisition times. Methods In two experiments, a NEMA phantom containing six spheres ranging from 37mm to 10mm was filled with a target background ratio of 4.8: 1 and 10:1 respectively. The phantom was imaged in a single three minute list mode acquisition with the data retrospectively divided into two minute, 1.5 minute, one minute and 30 second subsets. Each set of acquisition data was reconstructed with TOF and non TOF algorithms. For each sphere, a qualitative assessment of lesion visibility was made along with measurements of SUV max and SUV mean. Results With the target to background ratio of 10:1, the spheres were all visible on all reconstructions except for the 10mm sphere on the 30 second non TOF acquisition. However on the 4:1 target to background ratio there were significant qualitative and quantitative differences between the TOF and non TOF acquisitions. On the non TOF acquisition, the 10mm sphere could no longer be visualised on acquisitions of 1.5 minutes or less, whereas on the TOF acquisitions, the 10mm sphere was visible on all but the 30 second acquisition. For all of the experiments, the measured SUV mean and SUV max values were consistently lower in the smaller spheres, and this effect was more pronounced on the non TOF acquisition. Conclusions The TOF reconstruction algorithm improves the visualisation of small lesions at lower target to background levels. This effect becomes significant at lower acquisition times. This implies that the use of TOF reconstruction algorithms may allow preserved lesion visualisation with lower administered doses or shorter scan times

A 73-year-old man with thalassemia intermedia presented acutely with abdominal pain and distension. He had previously undergone a splenectomy. A diagnostic computed tomography (CT) scan through the abdomen and pelvis was performed with oral and intravenous contrast. This showed bilateral paravertebral and retrocrural soft tissue masses. It was believed that this was unlikely to be the cause of the patient's acute presentation. Nevertheless, the possibility of lymphoma or extramedullary hematopoiesis was raised. To avoid an invasive diagnostic biopsy, a Tc-99m sulfur colloid scan was performed. Initially, planar images were obtained; however, no clear corresponding colloid uptake was demonstrated. Therefore, a single-photon computed emission tomography (SPECT)/CT examination was performed. This demonstrated uptake of Tc-99m sulfur colloid in the paravertebral masses, confirming that these are likely to represent extramedullary hematopoiesis rather than lymphoma.

An 80-year-old woman presented with a history of right flank pain and tenderness. Her white cell count and C-reactive protein were elevated at 12.3 × 109/L and 108 mg/L respectively. An ultrasound scan of the abdomen showed moderate right sided hydronephrosis without ureteric dilatation and a collection at the lower pole of the kidney. An isotope renogram was performed using Tc-99m mercaptoacetyltriglycine (MAG3) to assess the presence of renal obstruction and to look for evidence of a urinary leak. Planar images revealed partial obstruction of the right kidney and unusual accumulation of tracer inferior to the kidney. SPECT/CT was performed to further evaluate the location of the abnormal tracer accumulation. Fused images demonstrated a posterior perirenal urinoma due to rupture of the collecting system. The patient underwent retrograde ureteric stenting and made an uneventful recovery.