Peregrine Offers More Accurate RT Dose Calculation

SEWICKLEY, Penn—NOMOS Corporation has been granted an exclusive license by the Lawrence Livermore National Laboratory to commercialize its Peregrine technology. Peregrine is a Monte Carlo-based dose calculation system designed specifically for radiation therapy planning (see photo).

Current dose calculation methods approximate the radiation dose distribution in the patient based on dose distributions in water phantoms. Peregrine determines the dose by simulating the actual treatment, using CT scans to provide information on the patient’s anatomy and disease and a mathematical technique called Monte Carlo to predict radiation absorption by the tumor and the healthy surrounding tissue.

The Monte Carlo technique uses radiation transport algorithms developed originally by scientists working on the Manhattan Project to design nuclear weapons. These algorithms predict the path and absorption of radiation particles as they pass through matter. Scientists at the Livermore Laboratory have adapted these algorithms, based on the Lab’s extensive nuclear and atomic databases, for use in radiation oncology.

Trillions of radiation particles enter the body with radiation treatment, and each is affected by the tissue, blood, bone, etc, with which it comes into contact. The Monte Carlo technique tracks up to 100 million representative particles and records the energy deposited by each as it moves through the body (as represented by the patient’s CT scans).

This gives an accurate model of the radiation dose distribution throughout the treatment volume and allows the physician to concentrate radiation doses more accurately to tumors, with decreased doses to healthy tissue.

 “Peregrine is another example of swords being converted into plowshares, as Livermore’s 4 decades of nuclear weapons research into radiation physics will be used to provide improved cancer treatments,” said US Secretary of Energy Bill Richardson. The Livermore Laboratory is managed by the University of California for the Department of Energy.

Only a few years ago, using a super-computer, a Monte Carlo analysis took 200 hours or more for a single patient. Now, Peregrine system software can conduct a Monte Carlo analysis on a patient and produce a 3D dose calculation in about 20 minutes, Ralph Patterson, Peregrine program manager at Livermore, said in a news release.

NOMOS Corporation plans to incorporate Peregrine into the company’s planning systems such as Peacock, its inverse treatment planning system for delivering intensity modulated radiation therapy (IMRT). A stand-alone version will also be developed to work with other treatment planning systems. The company is currently preparing a validation and verification package to submit to the FDA for marketing clearance.

 “Peregrine represents decades of weapons research that will now be used to set a gold standard for radiation calculation, allowing physicians to more accurately pinpoint the target, plan the dose prescription, and deliver higher doses of radiation,” said Anil K. Rastogi, president and CEO of NOMOS.