Quantification of Dose-Volume and Dose-Length Parameters for Cervical Esophageal Stricture in Head and Neck Irradiation with the 3DCRT and IMRT Technique.

Purpose: To quantify and compare dose-volume and dose-length parameters of cervical esophagus between three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT) and to correlate with incidence of cervical strictures in head and neck cancer irradiation with radical intent.

Materials And Methods: Forty consecutive head and neck cancer patients who received radical radiation therapy, either with 3DCRT (n = 20) or IMRT (n = 20), between December 2011 and August 2012 were retrospectively analyzed and followed up for at least 4 years post-treatment completion.

Results: The volumes of cervical esophagus receiving ≥54 Gy (V54) and ≥60 Gy (V60) and lengths receiving circumferential dose of ≥50 Gy (L50) and ≥54 Gy (L54) were significantly higher in patients treated with IMRT as compared to 3DCRT (P ≤ .05). At the end of minimum 4 years' post-treatment, nine patients had documented symptomatic strictures; three patients were treated with 3DCRT and six patients with IMRT technique.

Conclusion: IMRT technique in entire-neck irradiation is associated with increased spillage dose to the cervical esophagus, and thereby increased risk for late sequelae. The cervical esophagus has to be considered as an organ at risk and constraints need to be given in IMRT planning, particularly for lower-neck irradiation.