USA English [change] |  Contact |  MyVarian

New Varian High-Precision X-ray Imaging Device Significantly Reduces Time Needed for Complex Neurosurgical Treatment at Top UK Cancer Center

Clinicians at the UK's Clatterbridge Center for Oncology have carried out their first routine stereotactic neurosurgical treatment using a Varian linear accelerator equipped with a new device for enhancing precision using 3D X-ray images.

A 40-year-old female patient with a solitary brain metastasis received a single session of radiosurgery on a Varian Clinac® linear accelerator equipped with an On-Board Imager™ to track the exact location of the lesion. The On-Board Imager device enabled clinicians at Clatterbridge to pinpoint the location of the tumor using special conebeam CT images and then complete the treatment in less than an hour. Until now, this type of special treatment took up to four hours.

"The time-consuming nature of this sort of treatment has meant that we would normally have had to carry it out in the evening on specialized machines, after our routine work has been completed," says Angela Heaton, research radiographer at Clatterbridge. "It could take up to two hours to check calibrations before we could even begin treating and the whole process could take several hours, which was inconvenient for both the patient and staff and made it a relatively difficult treatment."

She said stereotactic treatments could be further delayed when there was the need for neurosurgeons to attend and screw a head fixation device into the patient's skull in order to keep them in place for up to four hours. Doctors said the new imaging treatment process makes it possible to avoid this uncomfortable and time-consuming step for their patients.

Dr Brian Haylock, the center's clinical director, said the conebeam CT capability would be extremely useful in validating the accuracy of different methods of head fixation used, which is vital in brain treatments. "I was very impressed with the accuracy and ease of use of the On-Board Imager's CBCT imaging capability. It seemed very efficient," he said, following the treatment.

The patient selected for this pioneering treatment had previous whole brain surgery for two brain metastases from an inoperable renal tumour in August last year and although the primary tumor has not progressed, her long-term prognosis is still poor. A new 25mm lesion had recently developed in the right fronto-parietal region of the brain and was causing the onset of facial palsy and headaches from oedema, which meant treating the lesion could greatly improve her quality of life.

Using the Clinac accelerator's 120-leaf multileaf collimator to shape a 1.5cm beam, clinicians delivered a 15Gy stereotactic radiosurgery treatment from eight angles, carefully checking the patient's head position between each treatment field. The entire treatment took less than an hour – about 20 minutes for patient positioning on the couch using a head-frame, two minutes for conebeam CT image acquisition, a further five minutes for online image matching and about 20 minutes for treatment delivery.

"At present we could expect to do between ten and twelve such treatments a year," adds Dr Haylock. "These patients have previously been treated out of hours because of time constraints so this did not become routine. It's now important that we do everything we can to improve the efficiency as well as maintain treatment accuracy and improve patient comfort. That's why we want to move all our stereotactic procedures across to the Varian machine, which also has the versatility to handle routine radiotherapy treatments when it is not being used for neurosurgical cases."

 

Contact Varian Oncology

Varian Oncology Headquarters
Tel: 1.650.424.5700
Contact Us

Events

Print Normal Bigger Large

© 1999-2012 Varian Medical Systems, Inc. All rights reserved.
Production of any of the material contained herein in any format or media without the express written permission of Varian Medical Systems is prohibited.

Product Index A - Z