Dosimetric Influence of Acuros XB Dose-to-Medium and Dose-to-Water Reporting Modes on Carcinoma Cervix Using Intensity-Modulated Radiation Therapy and Volumetric RapidArc Technique

AIM: We aimed to evaluate the dosimetric influence of Acuros XB (AXB) dose-to-medium (D(m)) and dose-to-water (D(w)) reporting mode on carcinoma cervix using intensity-modulated radiation therapy (IMRT) and RapidArc (RA) technique. MATERIALS AND METHODS: A cohort of thirty patients cared for carcinoma cervix was retrospectively selected for the study. Plans were computed using analytical anisotropic algorithm (AAA), AXB-D(m), and AXB-D(w) algorithms for dosimetric comparison. A paired t-test and Pitman–Morgan dispersion test were executed to appraise the difference in mean values and the inter-patient variability of the differences. RESULTS: The dose–volume parameters were higher for AXB-D(w) in contrast to AAA for IMRT and RA plans, excluding D(98%), minimum dose to planning target volume (PTV) and rectum mean dose (RA). There was no systematic trend observed in dose–volume parameters for PTV and organs at risk (OARs) between AXB-D(m) and AXB-D(w) for IMRT and RA plans. The dose–volume parameters for target were higher for AXB-D(m) in comparison to AAA in IMRT and RA plans, except D(98%) and minimum dose to PTV. Analysis envisaged less inter-patient variability while switching from AAA to AXB-D(m) in comparison to those switching from AAA to AXB-D(w). CONCLUSIONS: The present study reveals the important difference between AAA, AXB-D(m), and AXB-D(w) computations for cervix carcinoma using IMRT and RA techniques. The inter-patient variability and systematic difference in dose–volume parameters computed using AAA, AXB-D(m), and AXB-D(w) algorithms present the possible impact on the dose prescription to PTV and their relative constraints to OARs for IMRT and RA techniques. This may help in the decision-making in clinic while switching from AAA to AXB (D(m) or D(w)) algorithm for cervix carcinoma using IMRT and RA techniques.