“Good enough” is not good enough with brain radiosurgery.
When treating multiple brain metastases — the most common indication for stereotactic radiosurgery — every cubic centimeter of healthy brain tissue matters. Radiation exposure to the uninvolved brain can be linked to cognitive decline, loss of executive function, and diminished quality of life.
Yet not all SRS delivery platforms protect the healthy brain equally.
The data is striking.
| Whole-Brain Dose | Varian®TrueBeam® | ZAP-X® |
|---|---|---|
| V12 Gy | 22.90 cc | 1.74 cc |
| V10 Gy | 38.20 cc | 2.35 cc |
| V5 Gy | 332.10 cc | 7.29 cc |
A recent peer-reviewed study* compared whole-brain dose across six leading SRS platforms using a standardized 10-metastases patient dataset. Analyzing how each platform performs in typical and routine clinical practice, the findings reveal dramatic differences in how much healthy brain tissue receives low-dose radiation “spillage.”
Notably, ZAP-X® Gyroscopic Radiosurgery® delivered up to 13.16 times less brain V12 than Varian® TrueBeam® VMAT.
The study authors also observed a nearly 50-fold difference in brain V5 between ZAP-X and multi-purpose C-arm linacs — a gap with potentially profound implications, as emerging radiobiology research suggests even low-dose radiation may alter normal brain circuitry.
What’s the difference?
ZAP-X is purpose-built to minimize collateral exposure. Compared to multi-purpose linacs, ZAP-X benefits from:
- Ultra-low collimator leakage (<0.001% vs. up to 3.0%)
- Shorter source-axis distance (45 cm vs. 100 cm) for tighter beam penumbra
- An SRS-optimized beam energy (3 MV vs. 6 MV) for reduced scatter
- Multi-isocenter, non-coplanar beam delivery that conforms tightly to each target
Download the Study
See the full dosimetric comparison across six SRS platforms — including TrueBeam®, TrueBeam Edge®, CyberKnife® M6, Gamma Knife® Esprit®, Gamma Knife® Icon®, and ZAP-X®.
*Marianayagam NJ, Wang Z, Gutierrez AN, et al. A Comparison of Whole-Brain Dose During Stereotactic Radiosurgery for Multiple Metastases Across Technology Platforms. Cureus 17(9): e92442. doi:10.7759/cureus.92442
Explore the ZAP-X® Gyroscopic Radiosurgery® platform.
MK-20881 / ECO-001769