Evaluation of Dose Distribution Indices by using RapidArc Technique for the Treatment of Gynecological Cancer

Abstract

Introduction: This study describes the distribution of radiation doses to investigate the planned target volume (PTV) of gynecological cancers using the RapidArc technique. The optimal treatment plan options are developed by involvement of different dosimetric parameters including Homogeneity index (HI), Conformity index (HI), Uniformity index (UI), Radical dose homogeneity index (rDHI) and Moderate dose homogeneity index (mDHI).
 Method: Thirteen patients diagnosed with gynecological cancer were treated through RapidArc on DHX Varian linear accelerator with 6MV and 15MV photon beams. This therapy was carried out with linac.
 Result: The calculated dosimetric parameters for planning target volume were found in the ranges; HI (1.08 to 1.20), CI (0.985 to 0.997 in RTOG), CI (1.003 to 1.005 in ICRU), UI (1.05 to 1.13), rDHI (0.57 to 0.75) and mDHI (0.88 to 0.93).
 Conclusion: It has been concluded that all the calculated indices are within the range specified by radiation therapy oncology group (RTOG; 1993), International Commission on Radiation Units and Measurements (ICRU) and OLIVER; except in rare cases may be due to complex geometry, tumor volume range, and low radiation dose.This treatment can be further added to calculate other dose indices by using higher energy beams and different prescription doses for different fractions.