Fig. 2From: Impact of four-dimensional cone-beam computed tomography on target localization for gastric mucosa-associated lymphoid tissue lymphoma radiotherapy: reducing planning target volumeIllustration of how to calculate the covering ratio (CR) of the stomach with PTV structures of 5–30 mm margins, based on the 4D-CBCT images. The CR with PTV structure in the illustration is 70%Back to article page