QUICK FACTS
At the Thompson Cancer Survival Center, researchers are working with a select few reputable institutions to pioneer Helical TomoTherapy. The TomoTherapy system is groundbreaking in radiation therapy. Physicists in the Radiation Department were involved specifically with verifying the radiation dose delivery within this system. PV-WAVE was then used to return the results of radiation dose delivery quality assurance simulations in the form of an image cube having the same dimensions as a patient’s original image data set.

THE PROBLEM
For those suffering from cancer, radiation is one of the most effective treatments available. The goal of the treatment is to damage the cancer cells enough so that they will ultimately die. Often the radiation treatment is applied to a tumor from many directions in order to target the cancerous cells in the tumor while avoiding the surrounding healthy tissue. However, one of the biggest challenges in radiation therapy is to deliver enough radiation to kill a tumor while not damaging normal tissue.

An important advancement in radiation therapy is Intensity Modulated Radiation Therapy (IMRT). This procedure modifies the size, shape and strength of a radiation beam. In this way, the dose of radiation applied to the tumor kills the cancer cells and spares much more of the healthy tissue. Conventional IMRT is normally applied from 5 to 9 different directions. With a greater number of beam directions, the more efficiently the high dose will be concentrated on the tumor and the chance for side effects will be less.

At the Thompson Cancer Survival Center in Knoxville, Tennessee, researchers are working in conjunction with a select few other institutions to pioneer the applications of image-guided helical tomotherapy (http://www.tomotherapy.com). The TomoTherapy system is groundbreaking technology in radiation therapy. This new technology fuses volumetric megavolt CT imaging with continuous spiral delivery of IMRT to more accurately deliver radiation to the target while sparing nearby healthy tissue.

THE SOLUTION

Physicists in the Radiation Department at Thompson Cancer Survival Center were involved with the first clinical Hi-ART II Helical TomoTherapy system. One of their primary responsibilities was to verify the radiation dose delivery. The technique chosen by the Thompson physics group involved extensive hand manipulation of files to construct an input deck for a 16 dual processor node cluster. The manual process had many areas where errors could have been introduced, so code was written that performed image and file manipulations to construct the input deck for the dose calculation engine.

The results of the dose delivery quality assurance calculations were returned in the form of an image cube having the same dimensions as the test phantom CT image data set. To analyze this data, the physicists turned to PV-WAVE visual data analysis (VDA) software from Visual Numerics. Code was created in PV-WAVE that provided the ability for the user to extract arbitrary slices that corresponded to the planes within the phantom where film was placed. The software then saved these results in a format that could be read by other analysis systems.

The patient treatments and megavolt CT image sets are stored within a database and can be extracted into an XML file that references several binary images. PV-WAVE made it possible to parse the XML file searching for various fields to assist in the visualization of patient specific megavolt CT images, treatment deliveries and dosimetry.

RETURN ON INVESTMENT
The group of physicists found that the powerful graphics and the array oriented computational engine in PV-WAVE provided an efficient means for developing proof of principle concepts and scientific algorithms. "The beauty of PV-WAVE is that one spends approximately 90% of the time developing concepts while only 10% of the time writing code to implement those concepts", said Stephen Mahan, a physicist in the Radiation Department at Thompson Cancer Survival Center. The rapid development, advanced graphics and ease of use have been factors contributing to the success of PV-WAVE in the Helical TomoTherapy system.

WORLD CLASS PRODUCTS, SERVICES, AND SUPPORT
Visual Numerics has provided technical software solutions for numerical analysis and visualization for over 30 years. The company's software products help users understand complex data from a variety of sources and build business-critical applications. Visual Numerics offers two product lines: the IMSL® Numerical Libraries for powerful mathematical and statistical analysis and the PV-WAVE® visual data analysis development environment. Visual Numerics also offers customized consulting services for applications that involve mathematical, statistical, or visual data analysis to meet today’s business analytical needs.