Dose-volume histogram parameters and clinical factors associated with pleural effusion after chemoradiotherapy in esophageal cancer patients.

ABSTRACT

PURPOSE: To investigate the dose-volume histogram parameters and clinical factors as predictors of pleural effusion in esophageal cancer patients treated with concurrent chemoradiotherapy (CRT). METHODS AND MATERIALS Forty-three esophageal cancer patients treated with definitive CRT from January 2001 to March 2007 were reviewed retrospectively on the basis of the following criteria pathologically confirmed esophageal cancer, available computed tomography scan for treatment planning, 6-month follow-up after CRT, and radiation dose ≥ 50 Gy. Exclusion criteria were lung metastasis, malignant pleural effusion, and surgery. Mean heart dose, mean total lung dose, and percentages of heart or total lung volume receiving ≥ 10-60 Gy (Heart-V(10) to V(60) and Lung-V(10) to V(60), respectively) were analyzed in relation to pleural effusion. RESULTS: The median follow-up time was 26.9 months (range, 6.7-70.2) after CRT. Of the 43 patients, 15 (35%) developed pleural effusion. By univariate analysis, mean heart dose, Heart-V(10) to V(60), and Lung-V(50) to V(60) were significantly associated with pleural effusion. Poor performance status, primary tumor of the distal esophagus, and age ≥ 65 years were significantly related with pleural effusion. Multivariate analysis identified Heart-V(50) as the strongest predictive factor for pleural effusion (p = 0.01). Patients with Heart-V(50) <20%, 20%≤ Heart-V(50) <40%, and Heart-V(50) ≥ 40% had 6%, 44%, and 64% of pleural effusion, respectively (p < 0.01). CONCLUSION: Heart-V(50) is a useful parameter for assessing the risk of pleural effusion and should be reduced to avoid pleural effusion.