TY - JOUR
T1 - Determination of planning target volume for whole stomach irradiation using daily megavoltage computed tomographic images
AU - Johnson, Matthew E.
AU - Pereira, Gisele C.
AU - El Naqa, Issam M.
AU - Goddu, S. Murty
AU - Al-Lozi, Rawan
AU - Apte, Aditya
AU - Mansur, David B.
PY - 2012/10
Y1 - 2012/10
N2 - Purpose: Whole stomach radiation therapy is often used in the management of gastric lymphoma. However, very limited data exist with regard to planning target volume requirements for the whole stomach. This study retrospectively analyzed daily megavoltage computed tomographic (CT) scans of gastric lymphoma patients in order to help determine the interfraction variation of the stomach position. Methods and Materials: Forty-one daily megavoltage CT images from 3 gastric lymphoma patients were used for stomach contouring. Each patient's megavoltage CT images were rigidly registered to their CT simulation data sets, and the margin in each direction that covered at least 95% of the daily stomach volumes was computed using a simple grid search. Patient setup variation was also calculated from the daily patient shifts. The organ motion margin was then added to the setup margin to render the total margin. Results: A uniform margin of 2.2 cm is required to cover 95% of the stomach over the treatment course. However, direction-specific margins were observed from 1.72, 1.88, 0.92, 2.23, 1.90, and 0.86 cm for the right, left, posterior, anterior, superior, and inferior directions, respectively. Conclusions: The results of this study provide helpful 3-dimensional volumetric information to the limited existing data on margin requirements for whole stomach radiation therapy.
AB - Purpose: Whole stomach radiation therapy is often used in the management of gastric lymphoma. However, very limited data exist with regard to planning target volume requirements for the whole stomach. This study retrospectively analyzed daily megavoltage computed tomographic (CT) scans of gastric lymphoma patients in order to help determine the interfraction variation of the stomach position. Methods and Materials: Forty-one daily megavoltage CT images from 3 gastric lymphoma patients were used for stomach contouring. Each patient's megavoltage CT images were rigidly registered to their CT simulation data sets, and the margin in each direction that covered at least 95% of the daily stomach volumes was computed using a simple grid search. Patient setup variation was also calculated from the daily patient shifts. The organ motion margin was then added to the setup margin to render the total margin. Results: A uniform margin of 2.2 cm is required to cover 95% of the stomach over the treatment course. However, direction-specific margins were observed from 1.72, 1.88, 0.92, 2.23, 1.90, and 0.86 cm for the right, left, posterior, anterior, superior, and inferior directions, respectively. Conclusions: The results of this study provide helpful 3-dimensional volumetric information to the limited existing data on margin requirements for whole stomach radiation therapy.
UR - http://www.scopus.com/inward/record.url?scp=84866523397&partnerID=8YFLogxK
U2 - 10.1016/j.prro.2012.02.001
DO - 10.1016/j.prro.2012.02.001
M3 - Article
C2 - 24674190
AN - SCOPUS:84866523397
SN - 1879-8500
VL - 2
SP - e85-e88
JO - Practical Radiation Oncology
JF - Practical Radiation Oncology
IS - 4
ER -