Innovative new brachytherapy planning tool

Jul 19 2005

An innovative new brachytherapy planning tool from Varian Medical Systems is enabling clinics to streamline prostate cancer treatments and improve patient comfort. The Vitesse system is being used in more than 25 hospitals worldwide to speed up planning and enable treatments to take place within a day, avoiding the need for patients to stay in a hospital overnight.

According to Dr Gyorgy Kovacs, head of the Interdisciplinary Brachytherapy Centre at Kiel University Hospital in Germany -- one of the first departments to introduce the Vitesse system -- treatment planning for HDR (High-Dose-Rate) brachytherapy prostate procedures has been cut from 90 minutes to just 30 minutes per patient.

"As well as the time saving," said Dr Kovacs, "you also find that the dose conformity is better and you are better able to spare adjacent critical organs from unnecessary exposure, so it's not only faster it also results in more effective treatments and higher cure rates."

Clinical evidence suggests that the most effective way of treating high-risk prostate cancer is to deliver high doses of radiation in a highly targeted manner directly to the cancerous tissues. Using the Vitesse HDR brachytherapy system from Varian Medical Systems, clinics are able to accomplish this with just one or two high-dose treatments in a single day.

Delivered alone or in conjunction with external beam radiation therapy, brachytherapy is used primarily for treating breast, prostate and gynaecological cancers, providing patients with new treatment options, and gaining recognition as a viable and highly targeted cancer treatment approach.

Brachytherapy treatments involve the implantation of radioactive sources inside the tumour. There are two types of brachytherapy employed: permanent seed implants and temporary implants. Temporary implants involve using a machine called a High-Dose-Rate afterloader to place radioactive seeds into particular positions within a set of needles that have been temporarily implanted in the prostate. The spatial arrangement of the seeds within the needles is what yields the desired radiation dose distribution with the patient's anatomy.

"Previously, hospitals wishing to employ this temporary implant technique have been hampered by the difficult logistics," said Dave Hall, Varian's Brachytherapy product manager. "The implant takes an hour, the patient goes to recovery, then goes to Radiology for a CT scan, then waits for the physics staff to generate a treatment plan, and then gets the first radiation treatment. Often by then it is too late to get a second radiation dose on the same day and the patient needs to be kept in hospital overnight."

Vitesse, which marries together Varian's VariSeed planning system for seed prostate implants and BrachyVision 3D brachytherapy planning software, is an optional workflow module that allows doctors to quickly acquire prostate images with HDR catheters already in place. This data can then be exported over a digital connection to the BrachyVision software program, meaning doctors can go straight from imaging to treating, sometimes in a single procedure room.

Dr Kovacs and his team at Kiel have carried out more than 400 of these online planned cases over the past eight months, in a process he calls 'Intensity Modulated Brachytherapy' or IMBT. "The learning curve for us has been remarkably short. We were doing offline pre-treatment planning using our own in-house software and we are now at a stage where we can use the Varian software to contour and plan on the actual images, using the Vitesse and BrachyVision programs to adjust the catheter position as necessary."

The clinical team at Kiel uses both GammaMed and VariSource HDR afterloaders from Varian to deliver brachytherapy treatments. As a site with over 20 years' of experience, they have been following treatment outcomes for a long time. Dr Kovacs reports, "excellent results with outcomes comparable to those reported for permanent implants or surgery."

Varian plans to show the latest version of the Vitesse system at the upcoming American Association of Physicists in Medicine meeting in Seattle, Washington, July 24-27, 2005.