Dosimetric and clinical predictors for radiation-induced esophageal injury.
OBJECTIVE
To evaluate the clinical and three-dimensional dosimetric parameters associated with esophageal injury after radiotherapy (RT) for non-small-cell lung cancer.


METHODS
The records of 254 patients treated for non-small-cell lung cancer between 1992 and 2001 were reviewed. A variety of metrics describing the esophageal dose were extracted. The Radiation Therapy Oncology Group toxicity criteria for grading of esophageal injury were used. The median follow-up time for all patients was 43 months (range, 0.5-120 months). Logistic regression analysis, contingency table analyses, and Fisher's exact tests were used for statistical analysis.


RESULTS
Acute toxicity occurred in 199 (78%) of 254 patients. For acute toxicity of Grade 2 or worse, twice-daily RT, age, nodal stage of N2 or worse, and most dosimetric parameters were predictive. Late toxicity occurred in 17 (7%) of 238 patients. The median and maximal time to the onset of late toxicity was 5 and 40 months after RT, respectively. Late toxicity occurred in 2%, 3%, 17%, 26%, and 100% of patients with acute Grade 0, 1, 2, 3, and 4 toxicity, respectively. For late toxicity, the severity of acute toxicity was most predictive.


CONCLUSIONS
A variety of dosimetric parameters are predictive of acute and late esophageal injury. A strong correlation between the dosimetric parameters prevented a comparison between the predictive abilities of these metrics. The presence of acute injury was the most predictive factor for the development of late injury. Additional studies to define better the predictors of RT-induced esophageal injury are needed.
Ahn
Sung-Ja
SJ
Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
Kahn
Daniel
D
Zhou
Sumin
S
Yu
Xiaoli
X
Hollis
Donna
D
Shafman
Timothy D
TD
Marks
Lawrence B
LB
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000532:radiotherapy*; D004947:Esophagus / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D012044:Regression Analysis; D012189:Retrospective Studies