· Computer-Based Technique Speeds Radiation Therapy Planning
· Ablation System Linked to Barrett’s Esophagus Cure
· FDA Approves IMCO-STAT Communication Software
· COLD Registry Compiles Cryoablation Patient Data

Computer-Based Technique Speeds Radiation Therapy Planning

Researchers at Rensselaer Polytechnic Institute, Troy, NY, have built a computer program that automates planning for radiation therapy, potentially saving hours of clinician time. A paper published in Physics in Medicine and Biology1 details how the team at Rensselaer—led by Richard Radke, PhD, assistant professor of electrical, computer, and systems engineering—leveraged the power of machine learning to create the system, which trains itself based on data sets consisting of successful historical radiation therapy cases from Memorial Sloan-Kettering Cancer Center, New York.

“We’re focusing on the input and the output,” Radke said. “Over the years, we’ve developed a bunch of algorithms related to this problem. One is a pretty close approximation of the algorithm that the clinic uses to go from an optimization cost function to the plan, and then we’ve developed algorithms to layer on top of that to automatically adjust the parameters of this optimization problem to find good ones so that the human expert doesn’t have to coax the software into doing what they want.”

Using a data set consisting of 36 historical cases of prostate cancer successfully treated with radiation therapy, Radke and student Renzhi Lu trained their program to plan prostate cancer procedures according to approximately 20 commonly used parameters. “There are four or five parameters for every organ that you have to consider,” Radke explained. “The medical physicist knows that some knobs you can leave alone, some you have to turn some of the time, and some you always have to change. The idea is to somehow quantify that intuition instead of having it encapsulated inside a planner’s head.”

Radke’s software was put to the test on 10 patients. “We took 10 of the original 36 scans, and we sent our plans to the hospital and asked the expert medical physicists to look at them and see whether they were acceptable,” he said. “Out of that 10-patient data set, the planners said four of them would be fine, three needed a small amount of [adjustment], and three would take more than 15 minutes of modification to come to something that they found acceptable. So, the number we came to was 70% of the cases would be immediately or almost immediately acceptable.”

Ideally, a more robust prototype could be created through the use of more advanced algorithms and the incorporation of hundreds of cases encompassing a variety of patients. “If we could get access to a hospital’s full database, that would be exciting, because it would make our algorithms more effective,” Radke said. “The more data you have, the better. And you can imagine if you had this operating in the clinic, you could update [the information] every time you planned for a new patient, and that information would feed back into the system and make the next plan even better.”

Radke wants to begin shopping the system around to vendors soon. “We’ve been lucky to work with Memorial Sloan-Kettering, where they treat patients with their own home-written code,” he said. “We’ve had access to a lot of the finer aspects of their algorithms. Next, it would be great to start incorporating our tools into commercial algorithms.”

—C. Vasko


  1. Renzhi L, Radke RJ, Happersett L, et al. Reduced-order parameter optimization for simplifying prostate IMRT planning. Phys Med Biol. 2007;52:849-870.

Ablation System Linked to Barrett’s Esophagus Cure

According to data published in the February issue of Gastrointestinal Endoscopy,1 70% of patients with Barrett’s esophagus were disease-free a year after treatment with a balloon-based ablation system. The multicenter clinical trial analyzed 100 patients diagnosed with the precancerous condition, which is a complication of gastroesophageal reflux disease (GERD) affecting more than 3 million US adults.

Patients were treated with the HALO360 Ablation System, a balloon-based radiofrequency device from BARXX Medical Inc, Sunnyvale, Calif, that removes diseased cells via the controlled application of heat.

“Until now, the patient with Barrett’s esophagus was relegated to a lifetime of frequent endoscopic surveillance procedures to watch for progression to more dangerous forms of the disease, like dysplasia and cancer,” said the study’s first author, Virender K. Sharma, MD, gastroenterologist and associate professor of medicine at Mayo Clinic, Scottsdale, Ariz. “The results of this study suggest that we can safely and proactively eliminate Barrett’s esophagus at the very earliest stage, rather than limiting ourselves to passive observation of the disease for progression.”

After the year-long period of the trial, 70% of the patients showed no symptoms of Barrett’s, and the remaining group had near-complete resolution of the disease. The initial procedures were performed using endoscopy, and follow-up visits included frequent endoscopy with biopsy to ensure that the disease was fully eliminated.

“The results of the AIM [ablation of intestinal metaplasia] trial prompted BARXX Medical to develop a focal ablation device, called the HALO90 Ablation System, which can be used as a complementary therapy to circumferential ablation with the HALO360 device,” said David S. Utley, MD, chief medical officer at BARXX. “The AIM trial has been extended beyond [the published study] in order to remove any residual Barrett’s with the new device. With patient follow-up now approaching 2.5 years for the trial, it is expected that the focal ablation procedure will even further improve the efficacy outcomes of this ablative technology.”

According to the American Cancer Society, esophageal cancer of the type characterized early by Barrett’s is the fastest-growing cancer in the United States in terms of cases per year.

—C. Vasko


  1. Sharma VK, Wang KW, Overholt BF, et al. Balloon-based, circumferential, endoscopic radiofrequency ablation of Barrett’s esophagus: 1-year follow-up of 100 patients. Gastrointest Endosc. 2007;65:185-195.

Designed for implementation in a PACS environment, with the sender using a PACS workstation and the recipient using a Tablet PC or PDA, IMCO-STAT from IMCO Technologies also can establish a dialogue between the radiologist and clinician.

FDA Approves IMCO-STAT Communication Software

The FDA has approved IMCO-STAT wireless communication technology software from IMCO Technologies Corp, Pewaukee, Wis. IMCO-STAT wirelessly transfers data to Tablet PCs or PDAs, includes automatic receipt confirmation and an events log, and is compatible with all DICOM PACS installations. The system also allows for bidirectional communication.

According to IMCO Technologies, IMCO-STAT software exceeds the requirements of the most recent Guidelines and Standards issued by the American College of Radiology, Reston, Va. These benchmarks, published in October 2005, emphasize critical components of reporting nonroutine findings and deal directly with report timeliness, receipt confirmation, and documentation of communication.

IMCO-STAT communicates findings in multiple formats, including images, voice, text, snapshot pictures, handwritten annotations, and streaming video. For more information, visit www.imco-tech.com.

—C. Vasko

COLD Registry Compiles Cryoablation Patient Data

To study the safety and efficacy of cryo-ablation treatment for prostate cancer, J. Stephen Jones, MD, vice chairman of the Glickman Urological Institute of Cleveland Clinic, Cleveland, Ohio, turned to the largest database of cryoablation patients ever compiled—the Cryo On-Line Database (COLD) from Endocare Inc, Irvine, Calif, whose products include a cryoablation device for prostate cancer treatment. The steadily growing registry consists of data from more than 2,000 patients in the United States, and Endocare hopes to reach 5,000 in the near future.

Although the database was built to validate Endocare’s cryoablation device, the COLD registry also enables researchers like Jones to study patients who have undergone cyroablation treatment for prostate cancer. “I think it’s a new way that medicine’s going to be charted,” said Paul LaPine, vice president of marketing for Endocare. “You can compile data across institutions very quickly and be monitoring the results almost in real time.”

The COLD registry from Endocare contains data from more than 2,000 patients who have been treated with cryoablation.

Jones—who presented the results of his research at the annual meeting of the Society of Urologic Oncology, held on November 30-December 2, 2006, in Bethesda, Md—found that in the 1,002 patients he studied, the biochemical survival rate of all patients was 76.1%. He also discovered that 84% of low-risk patients, 70.5% of moderate-risk patients, and 71.7% of high-risk patients showed no biochemical evidence of disease recurrence 5 years following treatment.

According to LaPine, statistics like these were not available previously. “Because of our FDA filing, we didn’t have to go through a lot of rigorous trials with the FDA, which is the typical way a medical device or drug is brought to the market,” he explained. “So, community physicians and academics just started using cryoablation. By collecting and harvesting the results of active physicians using it, we can really bring to bear the evidence that the technology and the procedure are working well.”

The registry allows physicians to enter results into a database developed by KIKA Medical, Boston, a provider of Web-based clinical studies solutions. Patients are assigned an ID number to ensure HIPAA compliance, and data is aggregated in real time. “We can stratify by various demographic features; characteristics of the patient, like age or weight or height; the experience level of the physician; and the technique the doctor used. There’s so much rich data analysis that can come out of it,” LaPine said. “We’re quickly going to amass a very large group of patients from a large number of practitioners, and I think that will provide powerful, irrefutable evidence of how well this therapy is really working.”

The COLD registry’s next big project will be a salvage study involving up to 26 academic centers, all of which will submit data electronically to be compiled and analyzed in real time. “We’ll have some pretty good morbidity data to start compiling pretty quickly,” LaPine noted. “There will be a lot of instantaneous feedback.

“In the past, we would get requests from physicians to help organize data, so someone would go out and do a bunch of work, or we would fund some work for our research efforts, but there was no follow-up, and the data was lost after that,” LaPine continued. “Now we have a repository that will exist, essentially, in perpetuity.”

—C. Vasko