Prostate Cancer Patients Treated Using Enhanced Seed Brachytherapy Software

VariSeed 8.0, developed by Varian Medical Systems (Palo Alto, CA, USA), is an updated version of the company's treatment planning software for low dose rate (LDR) brachytherapy in which radiation doses are delivered by implanting seeds within the prostate.

With VariSeed 8.0, clinicians can use the new software to target individual sectors of the prostate based on biopsy results, according to Rebecca Claydon, software product manager with Varian's brachytherapy business unit. "We have also speeded up the planning process considerably with an improved SeedFinder algorithm," Ms. Claydon said. "The use of a 3D digital reconstructed radiograph [three-dimensional DRR] generated from a CT [computed tomography] allows doctors to more easily see and interactively add or remove proposed seed locations from the treatment plan."

According to Dr. William Bice, recently from the University of Texas Health Science Center at San Antonio (USA) but now practicing at The London Clinic (UK), the main benefit of VariSeed 8.0 over previous versions of the product is its ability to perform sector analysis. "The new version of VariSeed features some significant improvements in several different areas, particularly the ability to target regions using sector analysis," said Dr. Bice. "It is now easier to verify seed locations following source localization and reconstruction using the projection display in VariSeed 8.0."

At Kuopio University Hospital (Finland), brachytherapy physicist Jan-Erik Palmgren performed his first treatment using VariSeed 8.0 in March. "The ease of calibration was excellent and we are evaluating the benefits of sector analysis," he said. "Permanent seed implants are becoming more common in Finland. This is a small country and patients are asking for it because their friends tell them about it. It's very easy for the patient and the treatment is outpatient-based."

"There are some really nice features with VariSeed 8.0 that aid identification and simplify dose planning," said Asa Jamtrot, medical physicist at Karolinska University's South Hospital (Stockholm, Sweden). Physicians at the hospital have treated between 6 and 10 patients using the new system to date.

"It's extremely important to make the planning as easy as possible, particularly when you are in the operating room," Ms. Claydon added. "Our customers have always liked the simple tabular flow of VariSeed, which makes the system so usable, and the new digital connection to BK Medical's Pro Focus scanner improves this workflow even more."

VariSeed 8.0 also offers brachytherapy physicists new and improved contouring tools, including the ability to contour in the sagittal and coronal planes. Contouring the urethra has been simplified by the introduction of the Structure sweep, which is also available in the VariSeed Implant View module for interactive seed placement and dosimetry. For postplanning, the updated system offers a tool that creates a digital reconstruction of the CT image and makes it much simpler to define the seed placement, which has been time-consuming in the past. A typical permanent seed implant involves up to 120 radioactive seeds, each the size of a grain of rice.

The use of permanent seed implants for LDR brachytherapy for early stage prostate cancer has increased in recent years. In this technique, radioactive seeds are positioned in the prostate using needles that are guided into position by ultrasound and a template or grid through which the needles are inserted to control their spacing. From 50 to more than 100 individual seeds may be placed in a single session, using 10 to 20 needles. The seeds or radiation sources then deliver the dose slowly over the following month.

There are more than 1,200 hospital sites worldwide using approximately 1,700 Varian VariSeed software systems for guiding the placement of permanent prostate seed implants in what is called LDR brachytherapy. Use of this technique alone or in combination with external beam radiotherapy is increasing for patients, including about 60,000, or one-third, of U.S. men who are diagnosed annually with prostate cancer.

Varian Medical Systems is a leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy, radiosurgery, proton therapy, and brachytherapy.

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