Comparison of point dose verification and portal dosimetry for head and neck intensity modulated radiotherapy plans

Intensity Modulated Radiotherapy (IMRT) can deliver optimal prescribed dose distribution to the target volumes, while reducing doses to normal tissues. The planning process of IMRT is having complex planning and delivering mechanisms and needs accuracy in dose planning and delivery. Errors can lead higher doses to critical organs lying close to the targets. So, advanced radiotherapy demands a high level of quality control of machine and treatment delivery. There are two different way of performing IMRT specific Quality Assurance (QA) - Point dose verification and Absolute and fluence verification using gamma analysis