In the expansive region of Australasia—which includes Australia, New Zealand and neighboring islands—Auckland Radiation Oncology Centre (ARO) is the first to use Elekta VMAT, treating a patient with prostate cancer using a single 100-second arc of radiation. Such rapid treatments change the entire therapy experience for these patients, who have had to remain completely still for seven minutes during radiation delivery for each of 37 to 39 separate treatment sessions or "fractions."
"When treating prostates, any internal organ motion or patient movement during the fraction is a problem," says John Simpson, Ph.D. chief physicist at ARO, New Zealand's first private radiation oncology center. "Some internal motion is inevitable, and patients are treated with a semi-full bladder at the start of treatment to push the colon upward and away from the radiation field to minimize its exposure. Prolonging treatment duration, therefore, both increases the probability of internal organ motion as well as external movement due to patient discomfort, both of which can hinder treatment accuracy. Adopting a technique that reduces treatment delivery time is an obvious benefit for these patients."
Elekta VMAT was an ideal solution for ARO's prostate cancer patients, who represent nearly one-third (approximately 20 patients) of the center's daily treatment volume of 70 to 80 patients. Since June 7, when the first patient began receiving Elekta VMAT therapy on ARO's Elekta Synergy® treatment system, eight additional patients have begun treatment courses and another two are awaiting therapy.
"Elekta VMAT is now our technique of choice for patients with prostate cancer," says Dr. Simpson, who leads a team that compared the arc therapy technique with its advanced image guided Intensity Modulated Radiation Therapy (IMRT) method. ARO physicists subjected Elekta VMAT to extensive quality assurance testing to ensure both delivery and plan quality were comparable to IMRT.
"It had to meet all the criteria we set for it," he says. "We were very pleased with the way SmartArc planning calculates Elekta VMAT and the way Elekta VMAT delivers the therapy. Intrafraction motion, dose conformance, treatment efficiency and patient comfort are all addressed—and in a few weeks we will attempt to increase prostate therapy volume by reducing the length of the treatment slot."
Currently, the complete prostate treatment session encompasses patient set-up, pre-treatment imaging and Elekta VMAT delivery (100 seconds) for a total of 20 minutes.
"We haven't decreased the treatment slot yet because we want to gain confidence that we will have interruption-free delivery," Dr. Simpson observes. "Once we have this confidence we can start to reduce the timeslots from 20 minutes to 15 minutes. Multiplied by 20 plus patients per day, we will gain an hour-and-a-half, which should help us add more timeslots to increase access to care."
ARO building advanced healthcare enterprise to serve Australasia
Since it opened two years ago, ARO has initiated a steady stream of technology acquisitions aimed at creating a state-of-the-art facility that will complement New Zealand's public health system.
Adding an extra degree of sophistication to ARO's operation, for example, is MOSAIQ®, Elekta's solution for oncology information management.
"We were determined to be paperless from day one, so MOSAIQ was the obvious choice to go along with the Elekta systems," he says. "MOSAIQ is the key component to our efficiency at ARO. We export our VMAT plans from our treatment planning system through MOSAIQ in the same way we do for any other conventional treatment without any additional steps."
ARO currently is embarking on a further advance in its treatment capability with the addition of a second VMAT capable Elekta Synergy system with a suite of add-ons to enable image guided stereotactic radiation therapy, which will begin in 2011.