Hypofractionated radiotherapy for lung tumors with online cone beam CT guidance and active breathing control

Yali Shen, Hong Zhang, Jin Wang, Renming Zhong, Xiaoqing Jiang, Qinfeng Xu, Xin Wang, Sen Bai, Feng Xu
Radiation Oncology 2010, 5: 19

BACKGROUND: To study the set-up errors, PTV margin and toxicity of cone beam CT (CBCT) guided hypofractionated radiotherapy with active breathing control (ABC) for patients with non-small cell lung cancer (NSCLC) or metastatic tumors in lung.

METHODS: 32 tumors in 20 patients were treated. Based on the location of tumor, dose per fraction given to tumor was divided into three groups: 12 Gy, 8 Gy and 6 Gy. ABC is applied for every patient. During each treatment, patients receive CBCT scan for online set-up correction. The pre- and post-correction setup errors between fractions, the interfractional and intrafractional, set-up errors, PTV margin as well as toxicity are analyzed.

RESULTS: The pre-correction systematic and random errors in the left-right (LR), superior-inferior (SI), anterior-posterior (AP) directions were 3.7 mm and 5.3 mm, 3.1 mm and 2.1 mm, 3.7 mm and 2.8 mm, respectively, while the post-correction residual errors were 0.6 mm and 0.8 mm, 0.8 mm and 0.8 mm, 1.2 mm and 1.3 mm, respectively. There was an obvious intrafractional shift of tumor position. The pre-correction PTV margin was 9.5 mm in LR, 14.1 mm in SI and 8.2 mm in AP direction. After CBCT guided online correction, the PTV margin was markedly reduced in all three directions. The post-correction margins ranged 1.5 to 2.1 mm. The treatment was well tolerated by patients, of whom there were 4 (20%) grade1-2 acute pneumonitis, 3 (15%) grade1 acute esophagitis, 2 (10%) grade1 late pneumonitis and 1 (5%) grade 1 late esophagitis.

CONCLUSION: The positioning errors for lung SBRT using ABC were significant. Online correction with CBCT image guidance should be applied to reduce setup errors and PTV margin, which may reduce radiotherapy toxicity of tissues when ABC was used.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"