Simple Factors Associated With Radiation-Induced Lung Toxicity After Stereotactic Body Radiation Therapy of the Thorax: A Pooled Analysis of 88 Studies. Int J Radiat Oncol Biol Phys 2016 Aug 01;95(5):1357-1366
Date
06/22/2016Pubmed ID
27325482Pubmed Central ID
PMC5541363DOI
10.1016/j.ijrobp.2016.03.024Scopus ID
2-s2.0-84990847965 (requires institutional sign-in at Scopus site) 160 CitationsAbstract
PURPOSE: To study the risk factors for radiation-induced lung toxicity (RILT) after stereotactic body radiation therapy (SBRT) of the thorax.
METHODS AND MATERIALS: Published studies on lung toxicity in patients with early-stage non-small cell lung cancer (NSCLC) or metastatic lung tumors treated with SBRT were pooled and analyzed. The primary endpoint was RILT, including pneumonitis and fibrosis. Data of RILT and risk factors were extracted from each study, and rates of grade 2 to 5 (G2+) and grade 3 to 5 (G3+) RILT were computed. Patient, tumor, and dosimetric factors were analyzed for their correlation with RILT.
RESULTS: Eighty-eight studies (7752 patients) that reported RILT incidence were eligible. The pooled rates of G2+ and G3+ RILT from all 88 studies were 9.1% (95% confidence interval [CI]: 7.15-11.4) and 1.8% (95% CI: 1.3-2.5), respectively. The median of median tumor sizes was 2.3 (range, 1.4-4.1) cm. Among the factors analyzed, older patient age (P=.044) and larger tumor size (the greatest diameter) were significantly correlated with higher rates of G2+ (P=.049) and G3+ RILT (P=.001). Patients with stage IA versus stage IB NSCLC had significantly lower risks of G2+ RILT (8.3% vs 17.1%, odds ratio = 0.43, 95% CI: 0.29-0.64, P<.0001). Among studies that provided detailed dosimetric data, the pooled analysis demonstrated a significantly higher mean lung dose (MLD) (P=.027) and V20 (P=.019) in patients with G2+ RILT than in those with grade 0 to 1 RILT.
CONCLUSIONS: The overall rate of RILT is relatively low after thoracic SBRT. Older age and larger tumor size are significant adverse risk factors for RILT. Lung dosimetry, specifically lung V20 and MLD, also significantly affect RILT risk.
Author List
Zhao J, Yorke ED, Li L, Kavanagh BD, Li XA, Das S, Miften M, Rimner A, Campbell J, Xue J, Jackson A, Grimm J, Milano MT, Spring Kong FMMESH terms used to index this publication - Major topics in bold
Age DistributionAged
Aged, 80 and over
Carcinoma, Non-Small-Cell Lung
Causality
Comorbidity
Dose-Response Relationship, Radiation
Female
Humans
Incidence
Lung Neoplasms
Male
Middle Aged
Radiation Pneumonitis
Radiosurgery
Radiotherapy Dosage
Reproducibility of Results
Risk Factors
Sensitivity and Specificity
Treatment Outcome
