Evaluation of kV-CBCT based 3D dose calculation accuracy and its validation using delivery fluence derived dose metrics in Head and Neck Cancer.

Purpose: The purpose of this study is to evaluate the dosimetric impact of Hounsfield unit (HU) variations in kilovoltage cone-beam computed tomography (kV-CBCT) based 3D dose calculation accuracy in the treatment planning system and its validation using measured treatment delivery dose (MTDD) derived dose metrics for Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiotherapy (IMRT) plans in Head and Neck (HN) Cancer.

Methods: CBCT dose calculation accuracy was evaluated for 8 VMAT plans on inhomogeneous phantom and 40 VMAT and IMRT plans of HN Cancer patients and validated using ArcCHECK diode array MTDD derived 3D dose metric on CT and CBCT.

Results: The mean percentage dose difference between CBCT and CT in TPS (ΔD(CBCT-CT)) and 3DVH (ΔD(CBCT-CT)) were compared for the corresponding evaluation dose metrics (D, D, D, D, D, D, D, D) of all PTVs and OARs in phantom and patients.

Solid state diffusion and amalgamating anionic exchange at a KNaSO phosphors activated with Eu , Dy and Sm rare earth ions to enhance w-LED performance.

In present work, KNa(SO ) phosphors doped with different concentrations of rare earth Eu , Sm and Dy ions (0.05, 0.1, 0.

Luminescence properties of nanocrystalline Mg P O :Eu phosphor.

Thermoluminescence (TL) measurements were carried out on europium (Eu) doped magnesium pyrophosphate (Mg P O ) nanopowders using gamma irradiation in the dose range of 0.1 to 3 kGy. The powder samples were successfully synthesized by chemical co-precipitation synthesis route.