Dosimetric Impact of Online Correction via Cone-Beam CT-Based Image Guidance for Stereotactic Lung Radiotherapy

Journal Article · Wed Dec 01 00:00:00 EST 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2010.02.012· OSTI ID:21491525

Galerani, Ana Paula ^[1]; Grills, Inga ^[2]; Hugo, Geoffrey ^[3]; Kestin, Larry; Mohammed, Nasiruddin ^[2]; Chao, K Kenneth ^[4]; Suen, Andrew; Martinez, Alvaro; Yan, Di ^[2]

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1. Department of Radiation Oncology, Clinirad, Angelina Caron Hospital, Curitiba, Parana (Brazil)
2. Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States)
3. Department of Radiation Oncology, Virginia Commonwealth University, VA (United States)
4. Department of Radiation Oncology, Epic Care, Pleasant Hill, CA (United States)

Purpose: To evaluate the dosimetric impact of online cone-beam computed tomography (CBCT) guided correction in lung stereotactic body radiation therapy (SBRT). Methods and Materials: Twenty planning and 162 CBCT images from 20 patients undergoing lung SBRT were analyzed. The precorrection CBCT (CBCT after patient setup, no couch correction) was registered to planning CT using soft tissue; couch shift was applied, with a second CBCT for verification (postcorrection CBCT). Targets and normal structures were delineated on CBCTs: gross tumor volume (GTV), clinical target volume (CTV), cord, esophagus, lung, proximal bronchial tree, and aorta. Dose distributions on all organs manifested on each CBCT were compared with those planned on the CT. Results: Without CBCT guided target position correction, target dose reduced with respect to treatment plan. Mean and standard deviation of treatment dose discrepancy from the plan were -3.2% (4.9%), -2.1% (4.4%), -6.1% (10.7%), and -3.5% (7%) for GTV D{sub 99%}, GTV D{sub 95%}, CTV D{sub 99%}, and CTV D{sub 95%}, respectively. With CBCT correction, the results were -0.4% (2.6%), 0.1% (1.7%), -0.3% (4.2%), and 0.5% (3%). Mean and standard deviation of the difference in normal organ maximum dose were 2.2% (6.5%) before correction and 2.4% (5.9%) after correction for esophagus; 6.1% (14.1%) and 3.8% (8.1%) for cord; 3.1% (17.5%) and 6.2% (9.8%) for proximal bronchial tree; and 17.7% (19.5%) and 14.1% (17%) for aorta. Conclusion: Online CBCT guidance improves the accuracy of target dose delivery for lung SBRT. However, treatment dose to normal tissue can vary regardless of the correction. Normal tissues should be considered during target registration, according to target proximity.

• OSTI ID: 21491525
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 78, Issue 5; Other Information: DOI: 10.1016/j.ijrobp.2010.02.012; PII: S0360-3016(10)00240-3; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AORTA
COMPUTERIZED TOMOGRAPHY
CORRECTIONS
ESOPHAGUS
LUNGS
NEOPLASMS
ON-LINE SYSTEMS
RADIATION DOSE DISTRIBUTIONS
RADIOTHERAPY
ARTERIES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
DISEASES
MEDICINE
NUCLEAR MEDICINE
ORGANS
RADIOLOGY
RESPIRATORY SYSTEM
THERAPY
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