New York, March 19 : US scientists have developed a new tool to help physicians predict the risk of blood clots in patients with brain tumour. Venous thromboembolisms (VTE), blood clots that form in veins, can be life-threatening for patients with adult-type diffuse gliomas, the most common type of malignant tumour arising in the brain. The novel web-based VTE prediction tool is based on seven factors such as prior history of VTE, hypertension, asthma, elevated white blood cell count, higher glioma grade, increasing patient age and elevated body mass index. To create the risk prediction tool, scientists from Northwestern Medicine analysed arterial blood, tumour tissue and other data from 483 patients with newly diagnosed adult-type diffuse glioma. They published the results in the journal Blood. "For the first time, we have an evidence-based prediction of venous thromboembolism specifically for glioma patients," said Craig M. Horbinski, director of Neuropathology at Northwestern University. "This tool is a web-based calculator. You enter in basic information about the patient and tumour, and get a percent of risk at one, three, six and 12 months," he added. Armed with that information, physicians can weigh the risk of a clot against other risks that come with preemptively administering anticoagulants, which can sometimes cause brain haemorrhages, Horbinski said. "When I informally polled physicians on how they assess the risk of these blood clots, I got various answers," Horbinski said. "It all depends on how aggressive they are about anti-thrombotic prophylaxis. Physicians can give patients heparin up front but often would not know if a particular patient was really at risk of a blood clot or not. Plus, heparin administration is painful and may increase the risk of bleeding in the brain. Before now, there's just never been rigorous evidence to guide that decision-making." Horbinski said he is now planning to conduct a trial with high-risk patients to further validate the tool and provide better guidance on which patients would benefit the most from preventative anticoagulants. /IANS