TY - JOUR
T1 - What margins are necessary for incorporating mediastinal nodal mobility into involved-field radiotherapy for lung cancer?
AU - Van Sörnsen de Koste, John R.
AU - Lagerwaard, Frank J.
AU - Nijssen-Visser, Margriet R.J.
AU - Schuchhard-Schipper, Regine
AU - Joosten, Hans
AU - Senan, Suresh
PY - 2002/8/1
Y1 - 2002/8/1
N2 - Purpose: The mobility of mediastinal nodes was studied on multiple CT scans of the thorax from patients with non-small-cell lung cancer. Patients and Methods: A total of 10 enlarged mediastinal nodes/masses were identified in 8 patients with non-small-cell lung cancer. Nodal locations were classified using the Naruke/ATS-LCSG system, and between 3 and 6 scans were available for each site. The CT data sets were coregistered, and the contoured nodes were automatically projected onto the initial planning CT scan. An encompassing nodal volume (ENV) of all contours of a particular node was manually contoured on all scans. Individual nodal volumes were expanded in three dimensions to establish additional margins required to encompass the ENV. Results: The mean volume of nodes studied ranged from 0.8 to 23.2 cc. The addition to individual nodes of a margin of 5 mm was found to result in a mean ENV coverage of ≥95% at all sites. For individual nodes at locations N4R, N5, and N6, however, the coverage ranged from 87.8% to 92.6%. Conclusion: The addition of a margin of 5 mm to individual mediastinal nodes seems to be adequate to account for variations in both contouring and mobility.
AB - Purpose: The mobility of mediastinal nodes was studied on multiple CT scans of the thorax from patients with non-small-cell lung cancer. Patients and Methods: A total of 10 enlarged mediastinal nodes/masses were identified in 8 patients with non-small-cell lung cancer. Nodal locations were classified using the Naruke/ATS-LCSG system, and between 3 and 6 scans were available for each site. The CT data sets were coregistered, and the contoured nodes were automatically projected onto the initial planning CT scan. An encompassing nodal volume (ENV) of all contours of a particular node was manually contoured on all scans. Individual nodal volumes were expanded in three dimensions to establish additional margins required to encompass the ENV. Results: The mean volume of nodes studied ranged from 0.8 to 23.2 cc. The addition to individual nodes of a margin of 5 mm was found to result in a mean ENV coverage of ≥95% at all sites. For individual nodes at locations N4R, N5, and N6, however, the coverage ranged from 87.8% to 92.6%. Conclusion: The addition of a margin of 5 mm to individual mediastinal nodes seems to be adequate to account for variations in both contouring and mobility.
KW - CT scans
KW - Lung cancer
KW - Lymph nodes
KW - Mediastinum
KW - Mobility
UR - http://www.scopus.com/inward/record.url?scp=0036680336&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/S0360-3016(02)02853-5
DO - https://doi.org/10.1016/S0360-3016(02)02853-5
M3 - Article
C2 - 12128122
SN - 0360-3016
VL - 53
SP - 1211
EP - 1215
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 5
ER -