Esophagus in-field: a new predictor for esophagitis

Area of Science:

• Radiation Oncology
• Medical Physics
• Thoracic Oncology

Background:

• Concurrent chemoradiation (CRT) is a standard treatment for non-small cell lung cancer (NSCLC).
• Esophageal toxicity is a significant concern during CRT for NSCLC.
• Optimizing radiation dose parameters is crucial for reducing treatment-related side effects.

Purpose of the Study:

• To identify optimal radiation dose-volume parameters for minimizing esophageal toxicity in NSCLC patients undergoing CRT.
• To establish predictive dosimetric factors for acute esophagitis and late esophageal stricture.

Main Methods:

• Retrospective analysis of 109 NSCLC patients treated with CRT.
• Contouring of the entire esophagus (Esoph) and esophagus in-field (Esoph(in)).
• Analysis of dose-volume metrics (mean dose, V5-V60) correlated with toxicity using logistic regression.

Main Results:

• 25% of patients experienced grade ≥3 acute esophagitis; 5.5% developed late esophageal stricture.
• Mean dose and V45-V60 correlated with acute esophagitis; V55 and V60 correlated with stricture.
• V55 of Esoph or Esoph(in) was the strongest predictor of toxicity; V55 Esoph(in) <50% predicted reduced acute esophagitis.

Conclusions:

• Esophageal V55 is the best dosimetric predictor of acute esophagitis in NSCLC patients receiving CRT.
• Limiting the esophageal V55 dose may effectively reduce the incidence of acute esophagitis.