The influence of different kVs and phantoms on computed tomography number to relative electron density calibration curve for radiotherapy dose calculation

Objective This study was carried out to analyze the effect of varying kilovoltage peak (kVp) on Hounsfield unit (HU) for various tissue substitutes in two different phantoms and their dosimetric impact dose calculation Monaco treatment planning system version 5.11.02. Methods HU density materials obtained from computed tomography images acquired at kVps (80, 100, 120). Two (CatPhan 503 CIRS 062 M) were used construct suitability tomography. Both scan perform 30 volumetric modulated arc therapy plans. Results No significant variation CatPhan phantom observed with kVp. In contrast, a direct relationship between kVp case phantom, as increases resulted corresponding decrease HU. The maximum deviation found breast tissue. is inversely proportional tissues. There difference ≥22% values highest densities phantoms. Conclusion M more convenient calibration than 503, especially high-density material.