Simple Factors Associated With Radiation-Induced Lung Toxicity After Stereotactic Body Radiation Therapy of the Thorax: A Pooled Analysis of 88 Studies.
To study the risk factors for radiation-induced lung toxicity (RILT) after stereotactic body radiation therapy (SBRT) of the thorax.



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.



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.



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.
Department of Radiation Oncology, GRU Cancer Center/Medical College of Georgia, Georgia Regents University, Augusta, Georgia; Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Jing
J
Zhao
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
Ellen D
ED
Yorke
Department of Radiation Oncology, GRU Cancer Center/Medical College of Georgia, Georgia Regents University, Augusta, Georgia; Department of Shanghai Cancer Hospital, Fudan University, Shanghai, China.
Ling
L
Li
Department of Radiation Oncology, University of Colorado, Denver, Colorado.
Brian D
BD
Kavanagh
Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin.
X Allen
XA
Li
Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina.
Shiva
S
Das
Department of Radiation Oncology, University of Colorado, Denver, Colorado.
Moyed
M
Miften
Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York City, New York.
Andreas
A
Rimner
Department of Radiation Oncology, GRU Cancer Center/Medical College of Georgia, Georgia Regents University, Augusta, Georgia.
Jeffrey
J
Campbell
Department of Radiation Oncology, MD Anderson Cancer Center at Cooper, Camden, New Jersey.
Jinyu
J
Xue
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
Andrew
A
Jackson
Bott Cancer Center, Holy Redeemer Hospital, Meadowbrook, Pennsylvania.
Jimm
J
Grimm
Department of Radiation Oncology, University of Rochester, Rochester, New York.
Michael T
MT
Milano
Department of Radiation Oncology, GRU Cancer Center/Medical College of Georgia, Georgia Regents University, Augusta, Georgia; Currently at Department of Radiation Oncology, Simon Cancer Center, Indiana University Medical School, Indianapolis, Indiana. Electronic address: fkong@gru.edu.
Feng-Ming
FM
Spring Kong
D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality* / Q000532:radiotherapy*; D015984:Causality; D015897:Comorbidity; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D017564:Radiation Pneumonitis / Q000175:diagnosis / Q000453:epidemiology*; D016634:Radiosurgery / Q000706:statistics & numerical data*; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016896:Treatment Outcome