Intensity modulated radiotherapy (IMRT) in head and neck cancers (HNC) has been in use for around two decades. It has clearly been seen that IMRT results not only in a better dose distribution profile to organs at risk (OAR) when compared to 3 dimensional conformal planning , but also in an improved overall survival, progression free survival , locoregional control and quality of life. IMRT has the unique capability of producing inhomogeneous dose distributions, allowing simultaneous delivery of different doses per fraction to different areas within the treatment field.
It has the potential radiobiological advantage of reducing the impact of accelerated repopulation in tumor clonogens by using simultaneous integrated boost (SIB) technique. Increasing use of IMRT has also witnessed a growing concern regarding second malignancies as a result of an increase in the treatment time, worsening the accuracy of treatment due to increased intra fractional patient motion and reduction of patient throughput with economic consequences. Besides, it also leads to patient discomfort on the treatment couch and affects reproducibility of treatment position.
It has been seen in various studies that techniques like VMAT, first introduced in 2007, results in:
At Dharamshila Hospital & Research Centre, we have state of art VMAT enabled Linear accelerator installed and functional since 2010.
Dr Sheh Rawat
Chief of Radiation Oncology services
Dharamshila Hospital & Research Centre