Dosimetric comparison between three-dimensional conformal radiation therapy versus intensity-mod- ulated radiation therapy in non-metastatic esoph- ageal carcinoma patients receiving definitive radia- tion with concurrent chemotherapy: a prospective

Background: Esophageal cancer, a highly aggressive and often fatal gastrointestinal disease, frequently reaches advanced unresectable stages. The standard treatment involves definitive chemoradiation due to concerns about regional failure. To address this, intensified radiation dosages and advanced techniques like Intensity-Modulated Radiation Therapy (IMRT) and Three-Dimensional Conformal Radiation Therapy (3D-CRT) are being explored. This study aimed to compare dosimetric factors in pa- tients with esophageal carcinoma undergoing IMRT versus 3D-CRT treatments. Methods: Twenty patients were alternately assigned to receive either treatment. Each patient’s alternate virtual plan resulted in a total of forty plans. Dosimetric evaluations included coverage of the Planning Target Volume (PTV) and dose-vol- umes of lungs, heart, and spinal cord. Treatment consisted of 50.4 Gy radiation with concurrent weekly paclitaxel and carboplatin chemotherapy. Statistical analysis was conducted using the two-tailed Paired t-Test. Results: Dosimetric evaluations revealed no significant distinctions in PTV param- eters such as maximum dose, minimum dose, mean dose, D2%, D50%, and V95% between IMRT and 3D-CRT plans. However, IMRT exhibited improvements in D98% and Homogeneity Index. While Conformity Index did not differ significantly, IMRT displayed reduced lung irradiation in various aspects such as Dmean, V20, and V30, while 3D-CRT showed lower irradiation in V5 and V10. IMRT effectively spared the heart with lowered heart irradiation in V30. Spinal cord Dmax remained consistent across both techniques. Conclusions: IMRT demonstrated better dose homogeneity and superior lung and heart sparing capabilities compared to 3D-CRT in treating esophageal carcinoma. While both techniques had similar dose conformity, IMRT’s potential to reduce long- term radiation-induced lung and heart complications through improved sparing of these organs is noteworthy.