TY - JOUR
T1 - An analysis of anatomic landmark mobility and setup deviations in radiotherapy for lung cancer
AU - Samson, Michael J.
AU - Van Sdaornsen De Koste, John R.
AU - De Boer, Hans C.J.
AU - Tankink, Hans
AU - Verstraate, Marjolein
AU - Essers, Marion
AU - Visser, Andries G.
AU - Senan, Suresh
PY - 1999/3/1
Y1 - 1999/3/1
N2 - Purpose: To identify thoracic structures that exhibit little internal motion during irradiation and to determine setup variations in patients with lung cancer. Methods and Materials: Intrafractional images were generated with an electronic portal-imaging device from the AP fields of 10 patients, during several fractions. To determine the intrafractional mobility of thoracic structures, visible structures were contoured in every image and matched with a reference image by means of a cross-correlation algorithm. Setup variations were determined by comparing portal images with the digitized simulator films using the stable structures as landmarks. Results: Mobility was limited in the lateral direction for the trachea, thoracic wall, paraspinal line, and aortic notch, and in the craniocaudal direction for the clavicle, aortic notch, and thoracic wall. Analysis of patient setup revealed random deviations of 2.0 mm (1 SD) in the lateral direction and 2.8 mm in the craniocaudal direction, while the systematic deviations were 2.5 and 2.0 mm (1 SD) respectively. Conclusions: We have identified thoracic structures that exhibit little internal motion in the frontal plane, and recommend that these structures be used for verifying patient setup during radiotherapy. The daily variation in the setup of lung cancer patients at our center appears to be acceptable.
AB - Purpose: To identify thoracic structures that exhibit little internal motion during irradiation and to determine setup variations in patients with lung cancer. Methods and Materials: Intrafractional images were generated with an electronic portal-imaging device from the AP fields of 10 patients, during several fractions. To determine the intrafractional mobility of thoracic structures, visible structures were contoured in every image and matched with a reference image by means of a cross-correlation algorithm. Setup variations were determined by comparing portal images with the digitized simulator films using the stable structures as landmarks. Results: Mobility was limited in the lateral direction for the trachea, thoracic wall, paraspinal line, and aortic notch, and in the craniocaudal direction for the clavicle, aortic notch, and thoracic wall. Analysis of patient setup revealed random deviations of 2.0 mm (1 SD) in the lateral direction and 2.8 mm in the craniocaudal direction, while the systematic deviations were 2.5 and 2.0 mm (1 SD) respectively. Conclusions: We have identified thoracic structures that exhibit little internal motion in the frontal plane, and recommend that these structures be used for verifying patient setup during radiotherapy. The daily variation in the setup of lung cancer patients at our center appears to be acceptable.
KW - Anatomic landmark mobility
KW - Portal imaging
KW - Radiotherapy
KW - Treatment verification
UR - http://www.scopus.com/inward/record.url?scp=0345435973&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/S0360-3016(98)00467-2
DO - https://doi.org/10.1016/S0360-3016(98)00467-2
M3 - Article
C2 - 10098438
SN - 0360-3016
VL - 43
SP - 827
EP - 832
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 4
ER -