Assessment of Intrafraction Mediastinal and Hilar Lymph Node Movement and Comparison to Lung Tumor Motion Using Four-Dimensional CT

Journal Article · Mon Oct 01 04:00:00 EDT 2007 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2007.05.083· OSTI ID:21036263

Donnelly, Eric D ^[1]; Wei, Lu; Tianyu, Zhao; Lechleiter, Kristen; Nystrom, Michelle; Hubenschmidt, James P; Low, Daniel A; Bradley, Jeffrey D ^[1]

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1. Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States)

Purpose: To quantify the amount of free-breathing motion measured using Four-dimensional (4D) CT scans of mediastinal and hilar lymph nodes and to compare this motion to the primary lung tumor motion. Methods and Materials: Twenty patients with primary lung cancer, radiographically positive lymph nodes, and prior 4D CT scans were retrospectively analyzed. The 4D CT data sets were divided into four respiratory phases, and the primary tumor and radiographically positive nodes were contoured. Geometric and volumetric analysis was performed to analyze the motion of the primary tumors and the lymph nodes. Results: The mean lymph node motion was 2.6 mm in the mediolateral direction, 2.5 mm in the anterior-posterior direction, and 5.2 mm in the cranial-caudal direction with a maximum of 14.4 mm. All lymph nodes were found to move inferiorly during inspiration, with 12.5% of nodes moving more than 1 cm. Lymph nodes located below the carina showed significantly more motion than those above the carina (p = 0.01). In comparing the primary tumor motion to the lymph node motion, no correlation was identified. Conclusions: Four-dimensional CT scans can be used to measure the motion of the primary lung tumor and pathologic lymph nodes encountered during the respiratory cycle. Both the primary lung tumor and the lymph node must to be examined to assess their individual degree of motion. This study demonstrates the need for individualized plans to assess the heterogeneous motion encountered in both primary lung tumors and among lymph node stations.

• OSTI ID: 21036263
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 69; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CARCINOMAS
COMPUTERIZED TOMOGRAPHY
LUNGS
LYMPH NODES
PATIENTS
RADIOTHERAPY
RESPIRATION
VOLUMETRIC ANALYSIS