Dosimetric evaluation of plan quality metrics in IMRT and 3DCRT for esophageal squamous cell carcinoma

Abstract

To perform a comprehensive dosimetric comparison of Intensity-Modulated Radiation Therapy and Three-Dimensional Conformal Radiation Therapy in the treatment of Esophageal Squamous Cell Carcinoma, with emphasis on planning target volume (PTV) coverage and sparing of critical organs at risk (OARs).

A retrospective analysis was conducted on 24 patients with histologically confirmed esophageal squamous cell carcinoma. For each patient, clinically approved IMRT and 3DCRT treatment plans were generated using the Eclipse Treatment Planning System. All plans prescribed 66 Gy to the PTV. Dosimetric evaluation was performed using dose–volume histogram (DVH) parameters, including PTV D50%, mean liver dose, heart D50%, maximum spinal cord dose (D0%), and mean lung dose. Comparative analysis was carried out to assess differences in target coverage and OAR sparing.

Both IMRT and 3DCRT achieved comparable PTV coverage, with mean PTV D50% values of 66.46 Gy and 67.45 Gy, respectively. However, IMRT demonstrated significant reductions in OAR doses. The mean liver dose was reduced by 33.71% (11.35 Gy vs. 17.13 Gy), heart D50% by 30.20% (25.45 Gy vs. 36.45 Gy), spinal cord D0% by 20.87% (36.35 Gy vs. 45.94 Gy), and mean lung dose by 31.80% (16.43 Gy vs. 24.10 Gy) compared to 3DCRT. These findings indicate superior dose conformity and improved normal tissue sparing with IMRT.

IMRT provides comparable target coverage to 3DCRT while significantly reducing radiation dose to critical thoracic and upper abdominal organs. The observed dosimetric advantages suggest that IMRT may contribute to reduced treatment-related toxicity and improved therapeutic ratio in esophageal cancer radiotherapy. These results support the preferential use of IMRT in the management of esophageal squamous cell carcinoma, particularly in settings where organ preservation is critical.