Local control and toxicity in a large cohort of central lung tumors treated with stereotactic body radiation therapy Journal Article

Authors: Modh, A.; Rimner, A.; Williams, E.; Foster, A.; Shah, M.; Shi, W.; Zhang, Z.; Gelblum, D. Y.; Rosenzweig, K. E.; Yorke, E. D.; Jackson, A.; Wu, A. J.
Article Title: Local control and toxicity in a large cohort of central lung tumors treated with stereotactic body radiation therapy
Abstract: Results One hundred twenty-five patients received SBRT for non-small cell lung cancer (n=103) or metastatic lesions (n=22), using intensity modulated radiation therapy. The most common dose was 45 Gy in 5 fractions. Median follow-up was 17.4 months. Incidence of toxicity ≥ grade 3 was 8.0%, including 5.6% pulmonary toxicity. Sixteen patients (12.8%) experienced esophageal toxicity ≥ grade 2, including 50% of patients in whom PTV overlapped the esophagus. There were 2 treatment-related deaths. Among patients receiving biologically effective dose (BED) ≥80 Gy (n=108), 2-year LF was 21%. On MVA, gross tumor volume (GTV) was significantly associated with LF. None of the studied dose-volume metrics of the lungs, heart, proximal bronchial tree (PBT), or 2 cm expansion of the PBT ("no-fly-zone" [NFZ]) correlated with pulmonary toxicity ≥grade 2. There were no differences in pulmonary toxicity between central tumors located inside the NFZ and those outside the NFZ but with planning target volume (PTV) intersecting the mediastinum. Conclusions Using moderate doses, SBRT for central lung tumors achieves acceptable local control with low rates of severe toxicity. Dosimetric analysis showed no significant correlation between dose to the lungs, heart, or NFZ and severe pulmonary toxicity. Esophageal toxicity may be an underappreciated risk, particularly when PTV overlaps the esophagus. Purpose Stereotactic body radiation therapy (SBRT) in central lung tumors has been associated with higher rates of severe toxicity. We sought to evaluate toxicity and local control in a large cohort and to identify predictive dosimetric parameters. Methods and Materials We identified patients who received SBRT for central tumors according to either of 2 definitions. Local failure (LF) was estimated using a competing risks model, and multivariate analysis (MVA) was used to assess factors associated with LF. We reviewed patient toxicity and applied Cox proportional hazard analysis and log-rank tests to assess whether dose-volume metrics of normal structures correlated with pulmonary toxicity.
Keywords: adult; aged; major clinical study; intensity modulated radiation therapy; conference paper; radiation dose; follow up; tumor localization; lung toxicity; tumor volume; esophagitis; coughing; dyspnea; lung tumor; lung metastasis; dosimetry; cardiotoxicity; local control; cancer control; stereotactic body radiation therapy; radiation pneumonia; non small cell lung cancer; very elderly; human; male; female; tracheobronchial tree
Journal Title: International Journal of Radiation Oncology, Biology, Physics
Volume: 90
Issue: 5
ISSN: 0360-3016
Publisher: Elsevier Inc.  
Date Published: 2014-12-01
Start Page: 1168
End Page: 1176
Language: English
DOI: 10.1016/j.ijrobp.2014.08.008
PROVIDER: scopus
PMCID: PMC4276458
PUBMED: 25303891
Notes: Export Date: 2 February 2015 -- Source: Scopus
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MSK Authors
  1. Zhigang Zhang
    238 Zhang
  2. Weiji Shi
    110 Shi
  3. Daphna Y Gelblum
    78 Gelblum
  4. Andreas Rimner
    253 Rimner
  5. Abraham Jing-Ching Wu
    198 Wu
  6. Andrew Jackson
    166 Jackson
  7. Ellen D Yorke
    314 Yorke
  8. Amanda Foster
    62 Foster
  9. Ankit   Modh
    4 Modh
  10. Mihir Minesh Shah
    1 Shah