International Journal of Hematology and Oncology 2018, Vol 28, Num 3 Page(s): 079-085
Field-in-Field Technique Improves the Dosimetric Outcome of Treatment Plans Compared with the Three-Dimensional Conformal Radiation Therapy for Esophageal Cancer Radiotherapy

Behnam GHADIMI1, Nasrollah JABBARI2, Laya KARIMKHANI3, Kamal MOSTAFANEZHAD3

1Urmia University of Medical Sciences, Department of Medical physics and Imaging, Urmia, IRAN
2Urmia University of Medical Sciences, Solid Tumor Research Center, Department of Medical Physics and Imaging, Urmia, IRAN
3Omid Research and Treatment Center, Urmia, IRAN

Keywords: Radiotherapy, Esophageal cancer, Dosimetric parameters, Field in field technique, 3D-CRT technique
The aim of this study was to evaluate and compare the dosimetric parameters of three-dimensional conformal radiotherapy (3D-CRT) and field-in-field (FIF) techniques for patients with esophageal cancer. Twenty (20) patients with esophageal cancer participated in this study. Two planning techniques (FIF and 3D-CRT) were generated for each patient by the TiGRT treatment planning system. Two indices namely: Dose Homogeneity Index (DHI) and Conformity index (CI), as well as maximum dose, mean dose, minimum dose, dose received by 2% of the target volume (D2); dose received by 98% of the target volume (D98); volume received greater than 107% of the prescribed dose (V> 107%); volume received less than 95% of the prescribed dose (V< 95%); Dose received by organ at risks (OARs) and total Monitor Unit (MUs) were used for the comparison. The mean values were then compared using paired sample t-test. The FIF technique reduced the maximum dose and mean dose in the planning target volume (PTV). The FIF technique had higher D98, lower D2 and V< 95%. The FIF plan recorded a better DHI than the 3D-CRT technique. However, the FIF did not show any significant differences in minimum dose, V>107%, CI and MUs compared with the 3D-CRT technique. In addition, the FIF technique demonstrated reduced dose received by the OARs in the treated region. The FIF technique enables better dose distribution in the PTV and reduces dose to OARs in esophageal radiotherapy.