Creating Guidelines for Reactive and Prophylactic Enteral Feeding in Definitive (Chemo) IMRT for Head-and-Neck Cancer

Abstract

course were consistent within 5% and 1.5% of the planned mean doses for PTvs and CTvs, respectively. For the tighter margin plans, the cumulative mean dose ratios were consistent within 4.3% and 2.3% of the planned mean doses for CTV2 and CTV3, respectively. No significant changes in D95 and D90 for the CTV2/3 cumulative doses in both reference and tighter margin plans were observed. While interfraction anatomical changes introduced minor variations in delivered target doses, improved normal structure sparing was observed in plan_0margin. The averaged planned cord maximum doses in Plan_0margin was 7.6% lower, and the parotid mean doses were 18.9% lower than plan_Ref. Similar dose variations of the delivered dose were seen for the reference and tighter margin plans. The delivered maximum and mean doses for the cord were 20% and 10% higher than the planned doses; a 3.6% higher cumulative mean dose for the parotids was also observed for the delivered dose than the planned doses in both plans. Conclusions: The GPU-based image framework enables real-time dose verification, accumulation and documentation. By imposing tighter PTV margins for level 2 and 3 targets for HN Varian Medical Systems, Inc. F. Honoraria; Accuray Inc., Siemens Medical Solutions, Viewray Inc. M. Steinberg: None. D. Low: None. S. Lee: None.