Swedish Cancer Institute Sees Major Improvements in Planning VMAT Cases for Cancer Patients with Elekta’s New Monaco 3.20ATLANTA
Planning system’s Segment Shape Optimization boosts VMAT plan quality, increases delivery efficiency by 30-50 percent
In two clinical SBRT cases and retrospective plan comparisons of 10 previously treated patients with cancer, physicists at Swedish Cancer Institute (SCI, Seattle, Wash.) have discovered that Elekta’s latest release of Monaco® treatment planning system – version 3.20 – provides significant benefits in dose conformity, delivery efficiency and sparing of organs-at-risk. SCI has been evaluating Monaco 3.20 since April.
In VMAT planning cases, physicists led by SCI Medical Physicist Daliang Cao, Ph.D., compared Monaco 3.20 with the previous version of Monaco and found that Monaco 3.20 with Segment Shape Optimization™ (SSO) can provide much more uniform target dose without significantly compromising the sparing of critical normal structures. Compared with the previous version, they also observed that Monaco 3.20 reduced beam delivery time by 37 percent (1.3 min.) in some cases.
“In addition, Monaco 3.20 provides similar or better dose distributions, dose conformity and sparing of organs-at-risk compared with our other VMAT planning system,” Dr. Cao reports. “We look forward to putting Monaco 3.20 into routine clinical practice.”
SSO is key to Monaco 3.20
The new Segment Shape Optimization (SSO) enables improved dose conformity, plan quality and delivery efficiency through its proprietary approach to smoothing and clustering segments, then optimizing beam weights and shapes. Powered by the Monte Carlo algorithm, the results are plans that improve sparing of organs-at-risk and dose conformality.
In addition to improved plan quality over the previous Monaco release, with SSO, Monaco VMAT can reduce the number of segments and therefore the amount of MLC leaf motion in the plan. The result is a 30-50 percent improvement in delivery efficiency, according to Dr. Cao.
In SCI’s SBRT cases, Dr. Cao found that Monaco VMAT planning takes just a few hours to obtain a reasonable plan, compared with the 1-2 day process using the center’s existing VMAT planning system.
“The target dose also tends to be more uniform, with less dose spill out,” he says. “In addition, Monaco can provide a sharper dose gradient, which can reduce the dose to nearby critical structures. Conversely, Monaco can maintain the same critical structure dose while providing a higher target dose.”