Comparison of spatial and contrast resolution for cone-beam computed tomography scanners

OBJECTIVE: The purpose was to evaluate the perceived spatial and contrast resolution for a wide range of cone-beam computed tomography (CBCT) devices. STUDY DESIGN: A customized polymethyl methacrylate (PMMA) phantom was developed. Inserts containing a line-pair and rod pattern were used. The phantom was scanned with 13 CBCT devices and 1 multislice CT (MSCT) device using a variety of scanning protocols. The images were presented to 4 observers for scoring. RESULTS: The observer scores showed excellent agreement. A wide range was seen in image quality between CBCT exposure protocols. Compared with the average CBCT scores, the MSCT protocols scored lower for the line-pair insert but higher for the rod insert. CONCLUSIONS: CBCT devices are generally suitable for the visualization of high-contrast structures. Certain exposure protocols can be used for depicting low-contrast structures or fine details. The user should be able to select appropriate exposure protocols according to varying diagnostic requirements.     

Phenotype and genotype frequency of β-thalassemia and sickle cell disease carriers in Halkidiki, Northern Greece

A decade of screening (years 2000 to 2010) for hemoglobinopathies in 3,931 patients was performed at the General Hospital of Poligiros, Halkidiki, Northern Greece. Among the patients examined, 10.8% heterozygotes for β-thalassemia (β-thal) were found, as well as 4.1% with sickle cell disease and 1.2% with double β-thal/Hb S [β6(A3)Glu→Val] heterozygosity. Iron deficiency was observed in 23.4%. The geographical distribution in the region revealed a substantial incidence of hemoglobinopathies even in mountainous areas. This pattern did not follow the typical distribution according to the malaria hypothesis, as incidence did not dovetail with swamp locations recorded in the past. The HBB gene mutations for 85 patients were also analyzed. Most prevalent in Halkidiki, Northern Greece, was the codon 39 (C>T) mutation (27.1%) followed by the IVS-I-110 (G>A) mutation (22.4%); this was in direct contrast to the current distribution of the same mutations seen in the rest of Greece (Greek National Genetic Database, GNGD). This frequency inversion was statistically significant, with the difference from the GNGD being 20.6% for the IVS-I-110 mutation (p <0.0005) and 7.6% for the codon 39 mutation (p = 0.0238). The history of Halkidiki, denoting a clear example of geographical isolation from the rest of the country, may possibly account for a potentially diverse genetical identity of the disease in this region.     

Translational research. New findings and potential future applications in pancreatic adenocarcinoma

The current achievements in pancreatic cancer diagnosis and treatment are disappointing for patients and clinicians alike. Still, in the dawn of 2012, most patients are diagnosed at a late stage where cure is not feasible, with the majority going to succumb within the same year of diagnosis. Thus, the only hope for early and diagnosis and radical treatment is the invention of diagnostic and prognostic tests which might predict accurately patients who may develop this disease and those who have the most aggressive potential, so clinician adopt the appropriate strategy. In this paper we summarize the findings from the three most interesting research abstract as presented at the 2012 American Society of Clinical Oncology Gastrointestinal Cancers Symposium. In particular, we focus on Abstract #160 which shows the diagnostic utility of microRNA serum profiling in pancreatic cancer patients, on Abstract #201 which suggests a potential prognostic role of transforming growth factor (TGF)-beta pathway in advanced pancreatic cancer, and on Abstract #165 which shows that protein S100A4 might be a new, potentially useful, predictive biomarker of gemcitabine efficacy.     

Novel agents in early phase clinical studies on refractory pancreatic cancer

The standard current treatment options in advanced pancreatic cancer have demonstrated minimal or modest only efficacy for the majority of patients. Unfortunately, the mortality and morbidity remain high crying out for better treatments and results. With the exception of erlotinib, which received approval by the Food and Drug Administration of the United States in 2005, no other novel agents have since been added in our treatment quiver. Therefore, the search for novel approaches continuous at the laboratory and clinical level. At the 2012 American Society of Clinical Oncology Gastrointestinal Symposium, results of some interesting early phases clinical studies were presented. First, in Abstract #198, toxicity and efficacy results from the phase I/II study of cixutumumab, an insulin growth factor-1 receptor (IGF-1R) antibody combined with the standard gemcitabine and erlotinib treatment were presented, but the outcomes suggest no real clinical benefit. Second, the early safety and clinical data from the novel monoclonal antibody (ensituximab) against the mucin epitope NPC-1C in pancreatic and colon cancer patients were presented (Abstract #233) and again no particular efficacy was observed. Finally, interesting results which definitely deserve further exploration were presented in Abstract #211, which tested the combination of ipilimumab, an antibody against the cytotoxic T-lymphocyte antigen 4 (CTLA-4), with a cell-based vaccine transfected with the granulocyte macrophage colony-stimulating factor (GM-CSF) gene in advanced refractory pancreatic cancer. Though, it seems we have not yet found the culprit and the solution of this devastating disease, a small step forward might have been achieved.     

Intramedullary nailing of humeral diaphyseal fractures. Is distal locking really necessary?

Purpose:

Distal interlocking is regarded as an inherent part of the antegrade humeral nailing technique, but it exposes both the patient and surgeon to radiation, is time consuming, and has a potential risk of damaging neurovascular structures. We have presented our technique of diaphyseal humeral nailing without any distal interlocking in this paper.

Materials and Methods:

We have presented a series of 64 consecutive patients (33 male and 31 female, mean age: 41.5 years) with humeral shaft fractures treated with antegrade rigid intramedullary nailing without distal interlocking following a strict intra and postoperative protocol. According to the AO classification, there were 36 type A fractures, 22 type B, and 6 type C. Nails were inserted unreamed or by using limited proximal reaming and they were fitted as snuggly as possible into the medullary canal. After impaction of the nail into the fossa, we carefully tested rotational stability of fixation by checking any potential external rotation when the arm was slightly turned externally and left to the gravity forces. We were ready to add distal screws, but that was not required in these cases. Follow-up assessment included fracture union, complications and failures, and the final clinical outcome at minimum 2-year follow-up using the parameters of the constant score.

Results:

All fractures, except two, united between the 4^th and 5^th postoperative month. In one case, nail was exchanged with plate, and, in another, a larger nail was used at a second surgery. Shoulder function according to constant score, at a minimum of 2-year follow-up, was excellent or very good in 93.7% of the patients.

Conclusions:

Provided that some technical issues are followed, the method reduces intraoperative time and radiation exposure and avoids potential damage to neurovascular structures.