Feature | September 20, 2010

New Model May Simplify High-Dose Radiosurgery Planning

There is yet no straightforward way to determine the optimal dose level and treatment schedules for high-dose radiation therapies such as stereotactic radiation therapy, used to treat brain and lung cancer, or for high-dose brachytherapy for prostate and other cancers. Radiation oncologists at the Ohio State University Comprehensive Cancer Center-Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC-James) may have solved the problem by developing a new mathematical model that encompasses all dose levels.

Typically, radiation therapy for cancer is given in daily, low doses spread over many weeks. Oncologists often calculate the schedules for these fractionated, low-dose treatment courses using a mathematical model called the linear-quadratic (LQ) Model. The same calculation model is used to evaluate radiation response, interpret clinical data and guide clinical trials.

“Unfortunately the LQ Model doesn’t work well for high-dose radiation therapy,” says co-author Nina Mayr, M.D., professor of radiation oncology at the OSUCCC-James. “Our study resolves this problem by modifying the current method to develop the Generalized LQ (gLQ) Model that covers all dose levels and schedules.”

If verified clinically, the gLQ Model could guide the planning of dose and schedules needed for the newer radiosurgery and stereotactic radiation therapy and high-dose brachytherapy procedures that are increasingly used for cancer patients, she says.

“Developing proper radiation dose schedules for these promising high-dose treatments is very challenging,” Mayr says. “Typically, it involves phase I dose-finding studies and a long, cumbersome process that allows only gradual progression from the pre-clinical and clinical trial stages to broader clinical practice.”

The new gLQ Model could allow oncologists to design radiation dose schedules more efficiently, help researchers conduct clinical trials for specific cancers more quickly and make these high-dose therapies available to cancer patients much sooner, Mayr says.

Fractionated low-dose therapy causes cumulative damage to tumor cells during the many weeks of exposure, while causing minimal damage to hardier normal cells. Patients, however, must return repeatedly to the hospital for many weeks to complete their treatment. High-dose therapy has become possible because of advances in computer and radiation technology. It uses multiple beams of radiation that conform tightly to a tumor’s shape. They converge on the cancer to deliver higher total radiation levels, while sparing normal tissues. This kills more tumor cells per treatment, so far fewer treatments are needed overall.

The new study, published recently in the journal Science Translational Medicine, tested the gLQ Model in cell and animal models and is expected to be evaluated soon in clinical trials.

“Our Generalized LQ Model determines appropriate radiation levels across the entire wide spectrum of doses, from low and high, and from many to very few treatments, which is a new approach,” Mayr says.

Note: First author Dr. Jian Z. Wang, director of the OSUCCC-James Tumor Response Modeling Laboratory in Radiation Oncology, passed away unexpectedly in June 2010. He was largely responsible for developing the Generalized gLQ Model. Other Ohio State researchers involved in this study were Drs. Zhibin Huang, Simon S. Lo and William T.C. Yuh.

Related Content

Insightec Announces Expanded Reach of MR-Guided Focused Ultrasound
News | Focused Ultrasound Therapy | August 22, 2017
Insightec announced recently that worldwide adoption of magnetic resonance (MR)-guided focused ultrasound continues to...
UCLA Study Offers Roadmap to Personalized Therapies for Sarcoma
News | Oncology Diagnostics | August 22, 2017
A new UCLA study is the first to identify patient and tumor characteristics that predict the successful creation of...
Sponsored Content | Videos | Information Technology | August 22, 2017
Melissa Martin, MS, president of the American Association of Physicists in Medicine (AAPM), discusses her vision of t
Sponsored Content | Videos | Proton Therapy | August 21, 2017
Mark Pankuch, Ph.D., director of medical physics at the Northwestern Medicine Chicago Proton Center, discusses the cl
Summit Cancer Center-Boise Treats First Cancer Patients With Accuray Radixact System
News | Image Guided Radiation Therapy (IGRT) | August 21, 2017
Accuray Inc. and the Summit Cancer Center-Boise announced that the center is now treating patients with the Radixact...
MedStar Georgetown Proton Center Selects RayStation for Treatment Planning
News | Treatment Planning | August 17, 2017
August 17, 2017 — The proton center at MedStar Georgetown University Hospital will utilize RayStation for planning on
DOSIsoft Releases ISOgray Proton Therapy Treatment Planning System
Technology | Treatment Planning | August 15, 2017
DOSIsoft SA announced the official release, with CE marking, of ISOgray Treatment Planning System (TPS) release 4.3 for...
First Radixact Results Presented at AAPM 2017
News | Radiation Therapy | August 10, 2017
Accuray Inc. announced that the first studies validating the benefits of the Radixact System were presented at the 59th...
Clinical Data Supports Use of Xoft System for Endometrial Cancer
News | Brachytherapy Systems | August 03, 2017
Researchers presented clinical data supporting use of the Xoft Axxent Electronic Brachytherapy (eBx) System for the...
Overlay Init