TY - JOUR
T1 - Impact of Gastric Filling on Radiation Dose Delivered to Gastroesophageal Junction Tumors
AU - Bouchard, Myriam
AU - McAleer, Mary Frances
AU - Starkschall, George
N1 - Funding Information:
Supported by Université de Sherbrooke, Sherbrooke, Qc, Canada (M.B.). M. Bouchard is presently at Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke Qc Canada.
PY - 2010/5/1
Y1 - 2010/5/1
N2 - Purpose: This study examined the impact of gastric filling variation on target coverage of gastroesophageal junction (GEJ) tumors in three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), or IMRT with simultaneous integrated boost (IMRT-SIB) plans. Materials and Methods: Eight patients previously receiving radiation therapy for esophageal cancer had computed tomography (CT) datasets acquired with full stomach (FS) and empty stomach (ES). We generated treatment plans for 3DCRT, IMRT, or IMRT-SIB for each patient on the ES-CT and on the FS-CT datasets. The 3DCRT and IMRT plans were planned to 50.4 Gy to the clinical target volume (CTV), and the same for IMRT-SIB plus 63.0 Gy to the gross tumor volume (GTV). Target coverage was evaluated using dose-volume histogram data for patient treatments simulated with ES-CT sets, assuming treatment on an FS for the entire course, and vice versa. Results: FS volumes were a mean of 3.3 (range, 1.7-7.5) times greater than ES volumes. The volume of the GTV receiving ≥50.4 Gy (V50.4Gy) was 100% in all situations. The planning GTV V63Gy became suboptimal when gastric filling varied, regardless of whether simulation was done on the ES-CT or the FS-CT set. Conclusions: Stomach filling has a negligible impact on prescribed dose delivered to the GEJ GTV, using either 3DCRT or IMRT planning. Thus, local relapses are not likely to be related to variations in gastric filling. Dose escalation for GEJ tumors with IMRT-SIB may require gastric filling monitoring.
AB - Purpose: This study examined the impact of gastric filling variation on target coverage of gastroesophageal junction (GEJ) tumors in three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), or IMRT with simultaneous integrated boost (IMRT-SIB) plans. Materials and Methods: Eight patients previously receiving radiation therapy for esophageal cancer had computed tomography (CT) datasets acquired with full stomach (FS) and empty stomach (ES). We generated treatment plans for 3DCRT, IMRT, or IMRT-SIB for each patient on the ES-CT and on the FS-CT datasets. The 3DCRT and IMRT plans were planned to 50.4 Gy to the clinical target volume (CTV), and the same for IMRT-SIB plus 63.0 Gy to the gross tumor volume (GTV). Target coverage was evaluated using dose-volume histogram data for patient treatments simulated with ES-CT sets, assuming treatment on an FS for the entire course, and vice versa. Results: FS volumes were a mean of 3.3 (range, 1.7-7.5) times greater than ES volumes. The volume of the GTV receiving ≥50.4 Gy (V50.4Gy) was 100% in all situations. The planning GTV V63Gy became suboptimal when gastric filling varied, regardless of whether simulation was done on the ES-CT or the FS-CT set. Conclusions: Stomach filling has a negligible impact on prescribed dose delivered to the GEJ GTV, using either 3DCRT or IMRT planning. Thus, local relapses are not likely to be related to variations in gastric filling. Dose escalation for GEJ tumors with IMRT-SIB may require gastric filling monitoring.
KW - Dose escalation
KW - Gastric filling
KW - Gastroesophageal junction cancer
KW - Intensity-modulated radiation therapy
KW - Radiation therapy treatment planning
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U2 - 10.1016/j.ijrobp.2009.08.026
DO - 10.1016/j.ijrobp.2009.08.026
M3 - Article
C2 - 20092963
AN - SCOPUS:77950570857
SN - 0360-3016
VL - 77
SP - 292
EP - 300
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 1
ER -