Maguire et al evaluated patients receiving high dose conformal radiation therapy for lung cancer to identify risk factors for late esophageal toxicity. Recognition of these factors can help in therapy planning and in determining which patients require closer long-term monitoring. The authors are from Duke University in Durham, North Carolina.


Therapy: high dose conformal radiation


Toxicity was measured by RTOG grading, with no patients developing Grades 4 or 5 (necrosis, fistula, perforation, death). Approximately 18% of patients developed Grades 1-3 toxicity (mild to severe fibrosis and difficulty swallowing).


Risk factors for late toxicity:

(1) delivery of > 50 Gy to > 32% of esophageal volume

(1) delivery of > 50 Gy to > 32% of esophageal surface

(3) delivery of > 50 Gy to > 3.2 cm of the entire esophageal circumference

(4) delivery of > 80 Gy to any part of the esophagus

(5) dysphagia prior to radiation therapy


number of risk factors =

= SUM(number of risk factors present)



• minimum number of risk factors: 0

• maximum number of risk factors: 5


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