Dosimetric analysis of 3 dimensional conformal radiotherapy with volumetric modulated arc therapy in patients with carcinoma oesophagus – Prospective study

Abstract

: To study the dosimetry and treatment plan of Volumetric Modulated Arc Therapy and 3 Dimensional Conformal Radiotherapy in patients with carcinoma oesophagus. : A prospective study was taken up in Department of Radiotherapy, from October 2017 to June 2019. A total 20 patients who achieved eligibility criteria was taken into study and both 3D CRT (3D Conformal Radiation Therapy)and VMAT(Volumetric Modulated Arc Therapy ) plans was done in all patients. Dosimetric comparison is done between these two techniques. Dose to spinal cord is significantly reduced with VMAT technique when compared to 3D CRT. VMAT plans in this study showed significantly reduced doses to heart, when compared to 3D CRT plans. VMAT plans decrease volume of lung receiving high dose(v20,dmean,v30,v40) compared to 3D CRT but at a cost of delivering low dose to more volume of lung (v5, v10, v15) resulting in serious complications like radiation pneumonitis. VMAT plans are advisable in carcinoma oesophagus patients to achieve reduced doses to OARs(Organs at Risk) like Spinal Cord, Heart & Lung and better target coverage particularly in cervical esophagus where higher doses are planned.