Individualising the margins applied to the clinical target volume (CTV) may reduce OAR irradiation without increasing the risk GSK 4529 of geographical miss. We quantified the movement of the pancreas with respiration and evaluated whether individualised margins based on this motion reduced the dose to OARs.
and methods: Planning computed tomography scans were acquired in quiet breathing, held expiration and held inspiration. Organ motion was evaluated from displacement of a reproducible point within the pancreas in all directions. Two sets of plans (standard plan: P(stan); individualised plan incorporating movement data: P(ind)) were generated for each patient. The PTV and doses to OARs were evaluated for both sets of plans.
Results: The mean (standard deviation) movement of the pancreas in the superior-inferior, lateral and anterior-posterior directions were 15.3mm (4.3), 5.2mm (3.5) and 9.7mm (6.1), respectively. The use of individualised margins reduced the mean PTV volume by 33.5% (9.8) (P = 0.0051). The proportional reductions in the percentage of kidney receiving
> 10 Gy, small bowel > 45 Gy and liver > 30 Gy were 63.7% (P = 0.0051), MAPK Inhibitor Library cell line 29.3% (P = 0.0125) and 29.2% (P = 0.0107), respectively. For the same level of OAR constraints, individualised margins allowed dose escalation in six of the 10 patients to a mean dose of 63.2 Gy.
Conclusions: The present study shows a simple way of incorporating organ motion into the planning process and can be adopted by any centre without major strain on healthcare resources. The use of individualised margins
reduced PTV volume and the dose to OARs. This may offer an opportunity Staurosporine in vivo for dose escalation to try and further improve local control. Gwynne, S. et at. (2009). Clinical Oncology 21, 713-719 (C) 2009 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.”
“Meningococcal meningitis (MM) is the most common presentation of meningococcal disease and an important cause of morbidity and mortality worldwide. When MM is associated with shock, early recognition and treatment of shock is essential. No investigation should delay starting antibiotics once the diagnosis is suspected. Corticosteroids can be started at the same time as the antibiotics or just before, but this is not a specific recommendation for MM. Low-dose steroids should be used in meningococcal disease with refractory shock. Altered blood flow, cerebral edema, and raised intracranial pressure are problems that should be considered in all patients with MM and decreased consciousness level. When mechanical ventilation is required, the target carbon dioxide level is 4.0 to 4.5 kPa, with avoidance of hypocapnia. Seizures, although not frequent, can occur in MM and require prompt treatment. Other treatments, such as mannitol and activated protein C, should be avoided. Potential new treatments requiring further investigation include neuroprotection with hypothermia or glycerol.