Cherenkov Output (image) The Geisel School of Medicine at Dartmouth Caption A radiation beam treatment is visualized here in the first in human use of the technique. The blue represents the treatment area. As the dose fades the treatment area becomes a dark gray shadow. The lingering blue in the lower right hand area of the image shows a "hot spot" in the treatment area where adjustments can be made to avoid skin irritation. Credit NCCC Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.