Radiotherapy Quality Assurance System Analyzes Dose in Isocentric Target Region

Key to this is the capability to perform real dose measurements and analyze the dose in the isocentric target region, the volume of greatest concern.

Advocate Lutheran General Hospital, in the Chicago suburb of Park Ridge, IL, USA, has chosen ScandiDos (Uppsala, Sweden) as the provider of its QA solution for its RapidArc radiotherapy system, developed by Varian Medical Systems. (Palo Alto, CA, USA), and in doing so, becomes the 100th clinical installation of Delta4. The Delta4 system is in clinical use for intensity-modulated radiation therapy (IMRT), arc therapy, and TomoTherapy since 2006 at clinics worldwide.

As Advocate Lutheran General Hospital begins treating patients with RapidArc--one form of volumetric modulated arc therapy (VMAT) or intensity-modulated arc therapy (IMAT), having Delta4 for the pretreatment measurement and analysis of treatment plans will provide clinicians the comfort and confidence to proceed with these new, advanced treatments. Delta4's unique approach to measuring and presenting the dose data in three dimensions allows for quick, easy, and precise analysis of the treatment in relation to the prescription dose to the patient.

The advanced analysis software allows the medical physicist to quickly analyze the measured dose against the treatment plan to determine the significance and cause of deviations in the dose. Because VMAT/IMAT modalities such as RapidArc by Varian Medical Systems employ many more treatment angles than conventional IMRT, an integral part of the analysis of such is the delivery of dose from each of the actual gantry angles that will be delivered to the patient and the independent verification of each gantry angle as an element of the dose analysis. Delta4 is the only volumetric QA system on the market to perform this independent gantry angle verification, and, as such, accounts for this area of potential discrepancy as part of its measurement.

"We are very pleased that Advocate Lutheran General Hospital has chosen Delta4 PT as part of the technology solution to offer advanced radiation treatments to its patients,” stated Brad Dugai, national sales manager at ScandiDos.

"When we installed our first Delta4 in 2006, it was used to verify both IMRT and Arc Therapy treatments. Now, 3 years later, rotational therapy is becoming the new standard radiation therapy and, significantly, our 100th installed system will be used for both TomoTherapy and Varian RapidArc,” said Ingemar Wiberg, VP of sales and marketing at ScandiDos.

Delta4 has been used by linear accelerator manufacturers in the development and validation of arc therapy treatment modalities to include Varian's RapidArc and Elekta's (Stockhom, Sweden) VMAT system.

ScandiDos introduced the new QA standard in advanced radiotherapy by moving into the era of three-dimensional (3D) and 4D volumetric dosimetry. ScandiDos goal is to provide complete dosimetry solutions that enable clinics around the world to implement new treatment modalities satisfying the demand on accuracy in dose verification and patient throughput.

Related Links:
ScandiDos
Varian Medical Systems