Impact of different anatomical landmarks on registration in imaging-guided radiation for lung cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To evaluate the impact of different anatomical landmarks on registration in imaging-guided radiation (IGRT) for lung cancer. Methods For 20 patients with non-small cell lung cancer receiving stereotactic body radiotherapy (SBRT) in Fudan University Cancer Hospital, 100 frames of kilo-voltage cone-beam computed tomography scanning were evaluated in this study. The spine, carina and tumor were selected as landmarks for registration, respectively. Results of registration using different landmarks were documented and compared. Results The average set-up errors in the left-right, superiorinferior and anterior-posterior directions were -0. 08 cm ±0. 32 cm, -0. 16 cm ±0. 45 cm and 0. 06 cm ±0. 23 cm with the spine for registration;0. 06 cm ±0. 34 cm, -0. 13 cm ±0. 45 cm and -0. 02 cm±0.23 cm with the carina;and -0. 17 cm ±0.25 cm, 0.03 cm ±0.47 cm and 0. 15 cm ±0.38 cm with tumor. The registration results between using the carina and tumor as landmarks were statistically significant different (q=4.61, P=0. 002 ;q = 2. 23 , P=0. 118;q=3.44, P=0. 017). The registration results were equal when using the spine and tumor as landmarks ( q = 1.85, P = 0. 195; q = 2. 54, P = 0. 075; q = 1.89,P=0. 185), as well as using the carina and tumor as landmarks (q=2.76, P=0. 054;q=0.31, P=0. 826 ;q = 1.55, P = 0. 276). Conclusions For early stage lung cancer, the spine and tumor can be used equally as registration landmarks in imaging-guided SBRT. The carina is not suggested for its poor reproducible position.