Many (most?) modern linear accelerators have imaging panels behind the beam path (see image [1]) which could be used for dose monitoring although they are primarily used for imaging purposes.  I&#x27;m not sure whether any of these are currently used for dose monitoring.<p>[1] <a href="http:&#x2F;&#x2F;tommytoy.typepad.com&#x2F;.a&#x2F;6a0133f3a4072c970b0147e2ed7f81970b-800wi" rel="nofollow">http:&#x2F;&#x2F;tommytoy.typepad.com&#x2F;.a&#x2F;6a0133f3a4072c970b0147e2ed7f8...</a>