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A Bel

Publications and source records attributed to A Bel.

At least 109 records · Page 6Linked to original sources

[Conformal radiotherapy: tomotherapy].

Conformal radiation therapy allows the possibility of delivering high doses at the tumor volume whilst limiting the dose to the surrounding tissues and diminishing the secondary effects. With the example of the conformal radiation therapy used at the AZ VUB (3DCRT and tomotherapy), two treatment plans of a left ethmoid carcinoma will be evaluated and discussed in detail. The treatment of ethmoid cancer is technically difficult for both radiation therapy and surgery because of the anatomic constraints and patterns of local spread. A radiation therapy is scheduled to be delivered after surgical resection of the tumor. The treatment plan for the radiation therapy was calculated on a three-dimensional (3D) treatment planning system based on virtual simulation with a beam's eye view: George Sherouse's Gratis. An effort was made to make the plan as conformal and as homogeneous as possible to deliver a dose of 66 Gy in 33 fractions at the tumor bed with a maximum dose of 56 Gy to the right optic nerve and the chiasma. To establish the clinical utility and potential advantages of tomotherapy over 3DCRT for ethmoid carcinoma, the treatment of this patient was also planned with Peacock Plan. For both treatment plans the isodose distributions and cumulative dose volume histograms (CDVH) were computed. Superimposing the CDVHs yielded similar curves for the target and an obvious improvement for organs at risk such as the chiasma, brainstem and the left eye when applying tomotherapy. These results have also been reflected in the tumor control probabilities (equal for both plans) and the normal tissue complication probabilities (NTCP), yielded significant reductions in NTCP for tomotherapy. The probability of uncomplicated tumor control was 52.7% for tomotherapy against 38.3% for 3DCRT.

Ethmoid Bone↗

Can statins reduce the inflammatory response to cardiopulmonary bypass? A clinical study.

OBJECTIVE: In addition to lowering lipid levels, statins might reduce leukocyte-endothelial cell interactions. Therefore, we assessed whether this effect could limit the inflammatory response to cardiopulmonary bypass (CPB) in cardiac surgical patients. METHODS: Twenty patients undergoing valve or coronary operations with tepid (34 degrees C) CPB were randomized to receive an oral dose of atorvastatin (40 mg the evening before and 40 mg the morning of surgery) or to serve as controls. Pre- and post-CPB blood samples were assayed for neutrophil CD11b surface adhesion molecule and oxidative burst. Plasma levels of interleukins 6 and 8, P-selectin, soluble intercellular adhesion molecule-1, and lactoferrin were measured by enzyme-linked immunosorbent assay (ELISA). In addition, right atrial biopsies were taken before and at the end of CPB, and processed for the expression of the transcription nuclear factor-kappa B (NF-kappaB). RESULTS: The two groups did not differ with regard to pre- and intraoperative data. Except for P-selectin, postbypass values of all markers significantly increased over baseline values, but atorvastatin therapy failed to attenuate the magnitude of this increase. In the two groups, the expression of NF-kappaB significantly (p = 0.004) increased over baseline without group effect. Postoperative clinical outcomes did not differ either between the two groups. CONCLUSION: These data show that acute preoperative statin therapy fails to limit the inflammatory response to CPB; however, the data also document a major upregulation of NF-kappaB during cardiac operations, thereby providing a sound rationale for interventions targeted at inactivating this key component of the inflammatory cascade.

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