[Gastrointestinal stromal tumors]

Gastrointestinal stromal tumor (GIST) account for 1% of all gastrointestinal neoplasms and are the most common mesenchymal tumor of gastrointestinal tract. There are considered to originate fom the intestinal cell of Cajal, an intestinal pacemaker cell, characterized usually express the KIT protein on immunohistochemistry. The stomach (40-60%) and small intestine (30-40%) are the most common locations. Diagnosis of these tumors is difficult to establish, because symptoms are vague and traditional diagnostic tests are not specific. GISTs shows a wide variety of clinical behaviours ranging fom benign to frankly malignant, making the outcome totally unpredictable. Surgery is the standard treatment of local GIST while Imatinib (tyrosine kinasi inhibitor) is considered as the standard treatment of metastatic disease. Resistence to Imatinib is also becoming a major clinical problem but new tirosyne kinase inibitor are being studied to improve the treatment and survival. The present paper is a review of the salient features of epidemiology, pathophysiology, diagnosis, therapy and prognostic factors of GIS

Neoadjuvant Accelerated Concomitant Boost Radiotherapy and Multidrug Chemotherapy in Locally Advanced Rectal Cancer: A Dose-Escalation Study

OBJECTIVES: To determine the maximal and safely dose of preoperative radiotherapy and concurrently intensified chemotherapy regimen (raltitrexed plus oxaliplatin) in locally advanced rectal cancer patients. METHODS: Patients with cT3-T4 and/or cN 651 or locally recurrent rectal cancer were sequentially assigned to 4 treatment schedules of chemoradiation: standard radiotherapy (50.4 Gy/5.5 wk) plus raltitrexed (cohort A), accelerated radiotherapy (55 Gy/5 wk) plus raltitrexed (cohort B), standard radiotherapy plus raltitrexed and oxaliplatin (cohort C), accelerated radiotherapy plus raltitrexed and oxaliplatin (cohort D). Patients were treated in cohorts of 6 to 12 per group. The maximal tolerated dose was exceeded if more than one-third of patients in a given cohort experienced dose-limiting toxicity (DLT). DLT was defined as any grade 653 toxicity according to the Radiation Therapy Oncology Group criteria. RESULTS: Forty-six consecutive patients were enrolled. In cohort A, 6 patients received the planned treatment with no DLT. In cohort B, 1 of 8 patients experienced a DLT. In cohort C, a DLT occurred in 2 of 6 patients and therefore, a cohort expansion was required. Three of 16 patients treated at this dose level experienced a DLT. In addition, cohort D was expanded and DLT was found in 4 of 16 patients. Therefore, the maximal tolerated dose was not exceeded at any treatment level. CONCLUSIONS: An intensified regimen of chemoradiotherapy delivering raltitrexed and oxaliplatin concurrently with concomitant boost radiotherapy (55 Gy/5 wk) can be safely administered in patients with locally advanced rectal cancer. On the basis of these results, this intensified regimen could be tested in a phase II study

Neoadjuvant Accelerated Concomitant Boost Radiotherapy and Multidrug Chemotherapy in Locally Advanced Rectal Cancer: A Dose-Escalation Study

OBJECTIVES: To determine the maximal and safely dose of preoperative radiotherapy and concurrently intensified chemotherapy regimen (raltitrexed plus oxaliplatin) in locally advanced rectal cancer patients. METHODS: Patients with cT3-T4 and/or cN 651 or locally recurrent rectal cancer were sequentially assigned to 4 treatment schedules of chemoradiation: standard radiotherapy (50.4 Gy/5.5 wk) plus raltitrexed (cohort A), accelerated radiotherapy (55 Gy/5 wk) plus raltitrexed (cohort B), standard radiotherapy plus raltitrexed and oxaliplatin (cohort C), accelerated radiotherapy plus raltitrexed and oxaliplatin (cohort D). Patients were treated in cohorts of 6 to 12 per group. The maximal tolerated dose was exceeded if more than one-third of patients in a given cohort experienced dose-limiting toxicity (DLT). DLT was defined as any grade 653 toxicity according to the Radiation Therapy Oncology Group criteria. RESULTS: Forty-six consecutive patients were enrolled. In cohort A, 6 patients received the planned treatment with no DLT. In cohort B, 1 of 8 patients experienced a DLT. In cohort C, a DLT occurred in 2 of 6 patients and therefore, a cohort expansion was required. Three of 16 patients treated at this dose level experienced a DLT. In addition, cohort D was expanded and DLT was found in 4 of 16 patients. Therefore, the maximal tolerated dose was not exceeded at any treatment level. CONCLUSIONS: An intensified regimen of chemoradiotherapy delivering raltitrexed and oxaliplatin concurrently with concomitant boost radiotherapy (55 Gy/5 wk) can be safely administered in patients with locally advanced rectal cancer. On the basis of these results, this intensified regimen could be tested in a phase II study

Indications and results of pancreatic stump duct occlusion after duodenopancreatectomy

Severe post-operative complications after pancreaticoduodenectomy (PD) are largely due to pancreatic fistula onset. The occlusion of the main pancreatic duct using synthetic glue may prevent these complications. Aim of this study is to describe this technique and to report short- and long-term results as well as the post-operative endocrine and exocrine insufficiency. Two hundred and four patients who underwent PD with occlusion of the main pancreatic duct in a period of 15 years were retrospectively analyzed. Post-operative complications and their management were the main aim of the study with particular focus on pancreatic fistula incidence and its treatment. At 1-year follow-up endocrine and exocrine functions were analyzed. We observed a 54 % pancreatic fistula incidence, most of which (77/204 patients) were a grade A fistula with little change in medical management. Twenty-eight patients developed a grade B fistula while only 2 % of patients (5/204) developed a grade C fistula. Nine patients required re-operation, 5 of whom had a post-operative grade C fistula. Post-operative mortality was 3.4 %. At 1-year follow-up, 31 % of patients developed a post-operative diabetes while exocrine insufficiency was encountered in 88 % of patients. The occlusion of the main pancreatic duct after PD can be considered a relatively safe and easy-to-perform procedure. It should be reserved to selected patients, especially in case of soft pancreatic texture and small pancreatic duct and in elderly patients with comorbidities, in whom pancreatic fistula-related complications could be life threatening

Overview of the JET results

Since the installation of an ITER-like wall, the JET programme has focused on the consolidation of ITER design choices and the preparation for ITER operation, with a specific emphasis given to the bulk tungsten melt experiment, which has been crucial for the final decision on the material choice for the day-one tungsten divertor in ITER. Integrated scenarios have been progressed with the re-establishment of long-pulse, high-confinement H-modes by optimizing the magnetic configuration and the use of ICRH to avoid tungsten impurity accumulation. Stationary discharges with detached divertor conditions and small edge localized modes have been demonstrated by nitrogen seeding. The differences in confinement and pedestal behaviour before and after the ITER-like wall installation have been better characterized towards the development of high fusion yield scenarios in DT. Post-mortem analyses of the plasma-facing components have confirmed the previously reported low fuel retention obtained by gas balance and shown that the pattern of deposition within the divertor has changed significantly with respect to the JET carbon wall campaigns due to the absence of thermally activated chemical erosion of beryllium in contrast to carbon. Transport to remote areas is almost absent and two orders of magnitude less material is found in the divertor

Micro ion beam analysis for the erosion of beryllium marker tiles in a tokamak limiter

Beryllium limiter marker tiles were exposed to plasma in the Joint European Torus to diagnose the erosion of main chamber wall materials. A limiter marker tile consists of a beryllium coating layer (7-9 mu m) on the top of bulk beryllium, with a nickel interlayer (2-3 mu m) between them. The thickness variation of the beryllium coating layer, after exposure to plasma, could indicate the erosion measured by ion beam analysis with backscattering spectrometry. However, interpretations from broad beam backscattering spectra were limited by the non-uniform surface structures. Therefore, micro-ion beam analysis (mu-IBA) with 3 MeV proton beam for Elastic back scattering spectrometry (EBS) and PIXE was used to scan samples. The spot size was in the range of 3-10 mu m. Scanned areas were analysed with scanning electron microscopy (SEM) as well. Combining results from mu-IBA and SEM, we obtained local spectra from carefully chosen areas on which the surface structures were relatively uniform. Local spectra suggested that the scanned area (approximate to 600 mu m x 1200 mu m) contained regions with serious erosion with only 2-3 mu m coating beryllium left, regions with intact marker tile, and droplets with 90% beryllium. The nonuniform erosion, droplets mainly formed by beryllium, and the possible mixture of beryllium and nickel were the major reasons that confused interpretation from broad beam EBS