Proton therapy radiation pneumonitis local dose-response in esophagus cancer patients.

Abstract

PURPOSE:

This study quantifies pulmonary radiation toxicity in patients who received proton therapy for esophagus cancer.

MATERIALS/METHODS:

We retrospectively studied 100 esophagus cancer patients treated with proton therapy. The linearity of the enhanced FDG uptake vs. proton dose was evaluated using the Akaike Information Criterion (AIC). Pneumonitis symptoms (RP) were assessed using the Common Toxicity Criteria for Adverse Events version 4.0 (CTCAEv4). The interaction of the imaging response with dosimetric parameters and symptoms was evaluated.

RESULTS:

The RP scores were: 0 grade 4/5, 7 grade 3, 20 grade 2, 37 grade 1, and 36 grade 0. Each dosimetric parameter was significantly higher for the symptomatic group. The AIC winning models were 30 linear, 52 linear quadratic, and 18 linear logarithmic. There was no significant difference in the linear coefficient between models. The slope of the FDG vs. proton dose response was 0.022 for the symptomatic and 0.012 for the asymptomatic (p=0.014). Combining dosimetric parameters with the slope did not improve the sensitivity or accuracy in identifying symptomatic cases.

CONCLUSIONS:

The proton radiation dose response on FDG PET/CT imaging exhibited a predominantly linear dose response on modeling. Symptomatic patients had a higher dose response slope.

• Authors: Alfredo E Echeverria, Matthew McCurdy, Richard Castillo, Vincent Bernard, Natalia Velez Ramos, William Buckley, Edward Castillo, Ping Liu, Josue Martinez, Thomas Guerrero
• Journal: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology (Radiother Oncol) Vol. 106 Issue 1 Pg. 124-9 (Jan 2013) ISSN: 1879-0887 [Electronic] Ireland
• PMID: 23127772 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Protons
• Fluorodeoxyglucose F18

Topics

• Adult
• Aged
• Aged, 80 and over
• Dose-Response Relationship, Radiation
• Esophageal Neoplasms (radiotherapy)
• Female
• Fluorodeoxyglucose F18
• Humans
• Male
• Middle Aged
• Multimodal Imaging
• Positron-Emission Tomography
• Proton Therapy
• Protons (adverse effects)
• Radiation Pneumonitis (etiology)
• Retrospective Studies
• Tomography, X-Ray Computed