Ablative radiotherapy for ultracentral lung cancers: Dosimetric, geometric, and volumetric predictors of outcomes and toxicity.

Autor: Breen WG; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Jeans EB; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Gergelis KR; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Garces YI; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Park SS; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Merrell KW; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Peikert TD; Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, United States., Mansfield AS; Division of Medical Oncology, Mayo Clinic, Rochester, United States., Wigle DA; Division of Thoracic Surgery, Mayo Clinic, Rochester, United States., Harmsen WS; Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, United States., Ellerbusch DC; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Olivier KR; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., John Lucido J 3rd; Department of Radiation Oncology, Mayo Clinic, Rochester, United States., Owen D; Department of Radiation Oncology, Mayo Clinic, Rochester, United States. Electronic address: Owen.Dawn@mayo.edu.
Jazyk: angličtina
Zdroj: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2021 May; Vol. 158, pp. 246-252. Date of Electronic Publication: 2021 Mar 10.
DOI: 10.1016/j.radonc.2021.03.001
Abstrakt: Background: Ultracentral lung cancers arise near the proximal bronchial tree (PBT), trachea, or esophagus, and have been associated with worse outcomes and increased toxicity after radiotherapy. We sought to associate dosimetric and anatomic factors with oncologic outcomes and toxicities.
Methods: One-hundred ten patients treated with ablative, curative-intent radiotherapy for ultracentral, node-negative, non-small cell lung cancer were included. Dosimetric and geometric data obtained using custom software that calculated volumes of target structures and organs-at-risk and measured the shortest vector length between these volumes were associated with outcomes and toxicity.
Results: Common dose/fractionation schemes included 50 Gy in 5 fractions (57%), 60 Gy in 8 fractions (15%), and 48 Gy in 4 fractions (13%). Overall survival at 1, 2, and 5 years was 78%, 57%, and 32%, respectively. Factors significantly associated with death included endobronchial tumor, gross tumor volume (GTV) or planning target volume (PTV) contacting PBT, shorter distance from GTV to PBT or esophagus, volume of PBT receiving prescription dose, higher pericardium max dose, lung V20Gy, and mean lung dose. Local progression at 1, 2, and 5 years was 4%, 16%, and 21%. Factors associated with local progression were lower GTV minimum dose and higher GTV/PTV volume ratio. Acute and late grade 2 + toxicity was seen in 18% and 27%, respectively. Four patients (4%) had fatal toxicity.
Conclusions: Lower GTV minimum dose and smaller volumetric PTV expansions may increase risk of local progression, and should be balanced against normal tissue doses including pericardium maximum dose, lung V20Gy, and mean lung dose.
(Copyright © 2021 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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