Dosimetric analysis of Rapid Arc (VMAT) treatment planning in head and neck cancer for quality assurance treatment

Abstract

neck cancer ,Diametric analysis of Rapid Arc (VMAT) treatment planning in head and neck cancer for quality assurance treatment Aim: Evaluate the plan of simultaneous integrated boost (SIB) fixed intensity modulated radiation therapy (IMRT) and SIB Rapid Arc using dosimetric indices. Material and Method: Twenty-nine patients of nasopharyngeal carcinoma (NPC) were taken for the plan evaluation of SIB rapid arc and SIB IMRT. The plan is evaluated by using conformity index (CI), target coverage (TC), gradient index (GI), external volume Index (EI), homogenity index (HI), dose heterogeneity index (DHI), standard deviation (SD) and unified dosimetric index (UDI). The dose of each planning target volume (PTV) is evaluated by using a mean and median dose of PTVs. The organ at risk dose (OAR) is evaluated by using the mean and maximum dose of OAR. The result is considered statistically significant, if p0.05. Result: CI, TC, GI, EI, and UDI is same for both rapid arc and IMRT. DHI of PTV 54 is better for IMRT as compared to rapid arc and DHI of PTV 60, and PTV 70 is same for both rapid arc and IMRT. HI, SD and sparing of OAR is better for rapid arc as compared to IMRT, The dose of PTV 54 and PTV 60 overdose. The dose of PTV 70 is within the limits of prescribed dose for both rapid arc and IMRT. Conclusion: Rapid arc homogenity, sparing of OAR and SD is better than IMRT. The consumption of time and monitor unit is reduced in the case of rapid arc. Hence, rapid arc is better than IMRT for the treatment of NPC.