Really stupid question...
Started by samtheman
V stands for volume, V30 means some (specified) percentage of an organ got 30 Gy or more. If there is a number afterwards like V20 < 10 cc then it means that less than 10 cc's of the organ received 20 Gy or more.
Also, since you may not know . . .
Gy = Gray = absorbed dose = the unit which Radiation Oncologists use to prescribe radiation = 1 Joule/kilogram of mass
Also, since you may not know . . .
Gy = Gray = absorbed dose = the unit which Radiation Oncologists use to prescribe radiation = 1 Joule/kilogram of mass
Last edited:
Is there a resource for this stuff? Thanks btw...
Advertisement - Members don't see this ad
I guess a "really stupid question" deserves a "really stupid answer" 🙂
It was politely pointed out that I mis-typed the definion of V20 which should be the volume getting 20 Gy or more so I've modified my initial reply accordingly.
It was politely pointed out that I mis-typed the definion of V20 which should be the volume getting 20 Gy or more so I've modified my initial reply accordingly.
It's worth mentioning that the V(x) designation does not always strictly refer to dose (as in x = 20 = 20 Gy), but occasionally the 'x' will refer to a % of the prescription dose. In prostate brachytherapy, for example, V100 is used and defined within literature reports as the % volume of the prostate getting 100% or more of the prescribed dose. V90 is the % volume of prostate getting at least 90% of the prescribed dose, etc...
That said, V20 particularly in the context of discussion about lung cancer irradiation has a well-accepted meaning, and typically people won't say "V20Gy," they will abbreviate to "V20" and the meaning is known.
That said, V20 particularly in the context of discussion about lung cancer irradiation has a well-accepted meaning, and typically people won't say "V20Gy," they will abbreviate to "V20" and the meaning is known.
