Organs at Risk Considerations for Thoracic Stereotactic Body Radiation Therapy: What Is Safe for Lung Parenchyma? Int J Radiat Oncol Biol Phys 2021 May 01;110(1):172-187
Date
11/30/2018Pubmed ID
30496880Pubmed Central ID
PMC9454379DOI
10.1016/j.ijrobp.2018.11.028Scopus ID
2-s2.0-85060693490 (requires institutional sign-in at Scopus site) 40 CitationsAbstract
PURPOSE: Stereotactic body radiation therapy (SBRT) has become the standard of care for inoperable early-stage non-small cell lung cancer and is often used for recurrent lung cancer and pulmonary metastases. Radiation-induced lung toxicity (RILT), including radiation pneumonitis and pulmonary fibrosis, is a major concern for which it is important to understand dosimetric and clinical predictors.
METHODS AND MATERIALS: This study was undertaken through the American Association of Physicists in Medicine's Working Group on Biological Effects of Stereotactic Body Radiotherapy. Data from studies of lung SBRT published through the summer of 2016 that provided detailed information about RILT were analyzed.
RESULTS: Ninety-seven studies were ultimately considered. Definitions of the risk organ and complication endpoints as well as dose-volume information presented varied among studies. The risk of RILT, including radiation pneumonitis and pulmonary fibrosis, was reported to be associated with the size and location of the tumor. Patients with interstitial lung disease appear to be especially susceptible to severe RILT. A variety of dosimetric parameters were reported to be associated with RILT. There was no apparent threshold "tolerance dose-volume" level. However, most studies noted safe treatment with a rate of symptomatic RILT of <10% to 15% after lung SBRT with a mean lung dose (MLD) of the combined lungs ≤8 Gy in 3 to 5 fractions and the percent of total lung volume receiving more than 20 Gy (V20) <10% to 15%.
CONCLUSIONS: To allow more rigorous analysis of this complication, future studies should standardize reporting by including standardized endpoint and volume definitions and providing dose-volume information for all patients, with and without RILT.
Author List
Kong FS, Moiseenko V, Zhao J, Milano MT, Li L, Rimner A, Das S, Li XA, Miften M, Liao Z, Martel M, Bentzen SM, Jackson A, Grimm J, Marks LB, Yorke EMESH terms used to index this publication - Major topics in bold
Carcinoma, Non-Small-Cell LungHumans
Lung
Lung Neoplasms
Models, Biological
Models, Theoretical
Organs at Risk
Pulmonary Fibrosis
Radiation Pneumonitis
Radiation Tolerance
Radiosurgery
Radiotherapy Dosage
Re-Irradiation
Risk Factors
Tumor Burden