CyberKnife® Radiosurgery for Pancreatic Lesions
Technical Radiotherapy Notes
The pancreas moves considerably with respiration (16). Because of this, a relatively large margin must be added to the target volume, bringing substantial adjacent sensitive normal tissue into the treatment volume, potentially increasing the risk of radiation injury and limiting the safe dose. Although intensity modulated radiotherapy (IMRT) improves the conformality of the radiation dose distribution around the pancreas, reducing the dose to adjacent tissues compared with standard conformal techniques (14), it still does not effectively deal with the targeting problem created by respiratory-induced tumor motion. Thus, the improved conformal dose distribution still necessarily includes substantial adjacent normal GI tissue, to deal with the respiratory-induced tumor volume excursion issue.

Dose Volume Histogram (DVH)