Clinicians cut VMAT planning times, aim to increase access to rapid radiotherapy for more patients

Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) delivery techniques have dramatically reduced treatment times for thousands of patients. An obstacle to offering this technique to more patients is the time it takes to create a VMAT plan. Physicians at St. James’s University Hospital – the first in the United Kingdom to use Monaco® VMAT clinically – have been able to significantly reduce VMAT planning times, increasing the potential to offer this advanced therapy to greater numbers of patients.

“Our referral rate for radiation therapy is expanding by over seven percent annually,” says St. James’s head of radiotherapy physics Vivian Cosgrove, Ph.D. “We see VMAT as a key way to manage that growth. If we can plan complex radiotherapy quickly and deliver treatment more efficiently with VMAT, then we can treat more patients and derive more benefit from our existing fleet of treatment machines.”

Elekta VMAT is an advanced radiation therapy technique that delivers treatment in one or more continuous high-speed arcs around the patient, enabling the radiation dose to precisely conform to a tumor by modulating the radiation beam’s intensity in multiple small volumes.

The key to rapidly developing Elekta VMAT plans lies in understanding the principles of efficiently producing traditional IMRT plans with step-and-shoot (i.e., non-dynamic) delivery. Medical physics staff at St. James’s have used Monaco since January 2011 to plan head-and-neck IMRT cases.

“Monaco has transformed our IMRT service,” Dr. Cosgrove notes. “After contouring, we can complete a complex plan in two to three hours. This is two to three times quicker than other planning systems we have used. Since we introduced Monaco clinically, we have been able to significantly increase the number of patients receiving intensity modulated treatment: over 260 patients in 2011 and a target to increase this further in 2012.”

That number includes many patients who have received VMAT planned with Monaco, which St. James’s clinicians began performing in August 2011 on one of its 12 Elekta digital accelerators.

VMAT delivery of head-and-neck cases takes 6.5 minutes, half the time of a seven-field step-and-shoot delivery, he says.