In the modern IMRT/SBRT era, what should be the appropriate definition for the term "hot spot" in evaluating a plan?   

Do people use it interchangeably with DMax or use the 2cmx2cm definition? I often get pushback from the dosimetrists for plans where the DMax is higher than desired (>110% etc.) and their argument to me is that this is merely a point dose and according to Khan textbook, a "hot spot" is considered clinically significant only if it is outside of the target and more than 2cmx2cm. However, I do not recall seeing this requirement in the recent RTOG protocols (they are mostly max/min dose or % of volume receiving Dose X etc.)



Answer from: Radiation Oncologist at Community Practice