skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Regional Normal Lung Tissue Density Changes in Patients Treated With Stereotactic Body Radiation Therapy for Lung Tumors

Abstract

Purpose: To describe regional lung tissue density changes in normal lung tissue of patients with primary and metastatic lung tumors who received stereotactic body radiation therapy (SBRT). Methods and Materials: A total of 179 post-SBRT follow-up computed tomography (CT) scans of 62 patients who received SBRT between 2003 and 2009 were studied. Median prescription dose was 54 Gy (range, 30-60 Gy) in 3 to 5 fractions. SBRT-induced lung density changes on post-SBRT follow-up CT were evaluated at approximately 3, 6, 12, 18, 24, and 30 months after treatment. Dose-response curves (DRC) were generated for SBRT-induced lung damage by averaging CT number (HU) changes for regions of the lungs receiving the same dose at 5-Gy intervals. Results: For all follow-up interval periods, CT numbers linearly increased with dose until 35 Gy and were constant thereafter. For 3, 18, 24, and 30 months, the rate of relative electron density increase with dose was approximately 0.24% per Gy. At 6 months, the rate was also similar below 20 Gy but then rose to 0.6% per Gy above this threshold. After 6 months, DRCs were mostly time-independent. When split between patients treated with 3 fractions of 12 to 20 Gy (median, 20 Gy; averagemore » tumor volume, 12 {+-} 16 cm{sup 3}) and with >3 fractions of 6 to 12.5 Gy (median, 9 Gy; average tumor volume, 30 {+-} 40 cm{sup 3}), DRCs differed significantly. In both cases, CT changes at 3, 18, 24, and 30 months were identical to those of the population DRC; however, patients who received >3 fractions showed 6-month CT changes that were more than twice those for the group that received 3 fractions. Conclusions: This analysis of SBRT-induced normal lung density changes indicates that lung normal tissue has more pronounced self-limited acute effects than late effects. Differences in acute CT changes following treatments in 3 fractions were considerably less than for treatments in >3 fractions.« less

Authors:
 [1]; ; ; ; ;  [1]
  1. Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)
Publication Date:
OSTI Identifier:
22149647
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 84; Journal Issue: 4; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; CAT SCANNING; ELECTRON DENSITY; FIBROSIS; GY RANGE 10-100; LUNGS; METASTASES; NEOPLASMS; PATIENTS; RADIATION DOSES; RADIATION INJURIES; RADIOTHERAPY

Citation Formats

Diot, Quentin, E-mail: quentin.diot@ucdenver.edu, Kavanagh, Brian, Schefter, Tracey, Gaspar, Laurie, Stuhr, Kelly, and Miften, Moyed. Regional Normal Lung Tissue Density Changes in Patients Treated With Stereotactic Body Radiation Therapy for Lung Tumors. United States: N. p., 2012. Web. doi:10.1016/J.IJROBP.2011.11.080.
Diot, Quentin, E-mail: quentin.diot@ucdenver.edu, Kavanagh, Brian, Schefter, Tracey, Gaspar, Laurie, Stuhr, Kelly, & Miften, Moyed. Regional Normal Lung Tissue Density Changes in Patients Treated With Stereotactic Body Radiation Therapy for Lung Tumors. United States. doi:10.1016/J.IJROBP.2011.11.080.
Diot, Quentin, E-mail: quentin.diot@ucdenver.edu, Kavanagh, Brian, Schefter, Tracey, Gaspar, Laurie, Stuhr, Kelly, and Miften, Moyed. Thu . "Regional Normal Lung Tissue Density Changes in Patients Treated With Stereotactic Body Radiation Therapy for Lung Tumors". United States. doi:10.1016/J.IJROBP.2011.11.080.
@article{osti_22149647,
title = {Regional Normal Lung Tissue Density Changes in Patients Treated With Stereotactic Body Radiation Therapy for Lung Tumors},
author = {Diot, Quentin, E-mail: quentin.diot@ucdenver.edu and Kavanagh, Brian and Schefter, Tracey and Gaspar, Laurie and Stuhr, Kelly and Miften, Moyed},
abstractNote = {Purpose: To describe regional lung tissue density changes in normal lung tissue of patients with primary and metastatic lung tumors who received stereotactic body radiation therapy (SBRT). Methods and Materials: A total of 179 post-SBRT follow-up computed tomography (CT) scans of 62 patients who received SBRT between 2003 and 2009 were studied. Median prescription dose was 54 Gy (range, 30-60 Gy) in 3 to 5 fractions. SBRT-induced lung density changes on post-SBRT follow-up CT were evaluated at approximately 3, 6, 12, 18, 24, and 30 months after treatment. Dose-response curves (DRC) were generated for SBRT-induced lung damage by averaging CT number (HU) changes for regions of the lungs receiving the same dose at 5-Gy intervals. Results: For all follow-up interval periods, CT numbers linearly increased with dose until 35 Gy and were constant thereafter. For 3, 18, 24, and 30 months, the rate of relative electron density increase with dose was approximately 0.24% per Gy. At 6 months, the rate was also similar below 20 Gy but then rose to 0.6% per Gy above this threshold. After 6 months, DRCs were mostly time-independent. When split between patients treated with 3 fractions of 12 to 20 Gy (median, 20 Gy; average tumor volume, 12 {+-} 16 cm{sup 3}) and with >3 fractions of 6 to 12.5 Gy (median, 9 Gy; average tumor volume, 30 {+-} 40 cm{sup 3}), DRCs differed significantly. In both cases, CT changes at 3, 18, 24, and 30 months were identical to those of the population DRC; however, patients who received >3 fractions showed 6-month CT changes that were more than twice those for the group that received 3 fractions. Conclusions: This analysis of SBRT-induced normal lung density changes indicates that lung normal tissue has more pronounced self-limited acute effects than late effects. Differences in acute CT changes following treatments in 3 fractions were considerably less than for treatments in >3 fractions.},
doi = {10.1016/J.IJROBP.2011.11.080},
journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 4,
volume = 84,
place = {United States},
year = {2012},
month = {11}
}