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Intensity-modulated radiotherapy for locally advanced non-small-cell lung cancer: a dose-escalation planning study.
- Source :
-
International journal of radiation oncology, biology, physics [Int J Radiat Oncol Biol Phys] 2011 May 01; Vol. 80 (1), pp. 306-13. Date of Electronic Publication: 2010 Oct 01. - Publication Year :
- 2011
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Abstract
- Purpose: To evaluate the potential for dose escalation with intensity-modulated radiotherapy (IMRT) in positron emission tomography-based radiotherapy planning for locally advanced non-small-cell lung cancer (LA-NSCLC).<br />Methods and Materials: For 35 LA-NSCLC patients, three-dimensional conformal radiotherapy and IMRT plans were made to a prescription dose (PD) of 66 Gy in 2-Gy fractions. Dose escalation was performed toward the maximal PD using secondary endpoint constraints for the lung, spinal cord, and heart, with de-escalation according to defined esophageal tolerance. Dose calculation was performed using the Eclipse pencil beam algorithm, and all plans were recalculated using a collapsed cone algorithm. The normal tissue complication probabilities were calculated for the lung (Grade 2 pneumonitis) and esophagus (acute toxicity, grade 2 or greater, and late toxicity).<br />Results: IMRT resulted in statistically significant decreases in the mean lung (p <.0001) and maximal spinal cord (p = .002 and 0005) doses, allowing an average increase in the PD of 8.6-14.2 Gy (p ≤.0001). This advantage was lost after de-escalation within the defined esophageal dose limits. The lung normal tissue complication probabilities were significantly lower for IMRT (p <.0001), even after dose escalation. For esophageal toxicity, IMRT significantly decreased the acute NTCP values at the low dose levels (p = .0009 and p <.0001). After maximal dose escalation, late esophageal tolerance became critical (p <.0001), especially when using IMRT, owing to the parallel increases in the esophageal dose and PD.<br />Conclusion: In LA-NSCLC, IMRT offers the potential to significantly escalate the PD, dependent on the lung and spinal cord tolerance. However, parallel increases in the esophageal dose abolished the advantage, even when using collapsed cone algorithms. This is important to consider in the context of concomitant chemoradiotherapy schedules using IMRT.<br /> (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Subjects :
- Adenocarcinoma diagnostic imaging
Adenocarcinoma pathology
Adenocarcinoma radiotherapy
Adult
Aged
Carcinoma, Large Cell diagnostic imaging
Carcinoma, Large Cell pathology
Carcinoma, Large Cell radiotherapy
Carcinoma, Non-Small-Cell Lung diagnostic imaging
Carcinoma, Non-Small-Cell Lung pathology
Carcinoma, Squamous Cell diagnostic imaging
Carcinoma, Squamous Cell pathology
Carcinoma, Squamous Cell radiotherapy
Esophagus radiation effects
Female
Heart radiation effects
Humans
Lung radiation effects
Lung Neoplasms diagnostic imaging
Lung Neoplasms pathology
Male
Middle Aged
Organs at Risk radiation effects
Probability
Radiation Injuries prevention & control
Radionuclide Imaging
Radiotherapy Dosage
Radiotherapy, Conformal methods
Spinal Cord radiation effects
Carcinoma, Non-Small-Cell Lung radiotherapy
Lung Neoplasms radiotherapy
Radiotherapy Planning, Computer-Assisted methods
Radiotherapy, Intensity-Modulated methods
Subjects
Details
- Language :
- English
- ISSN :
- 1879-355X
- Volume :
- 80
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- International journal of radiation oncology, biology, physics
- Publication Type :
- Academic Journal
- Accession number :
- 20888706
- Full Text :
- https://doi.org/10.1016/j.ijrobp.2010.06.025