We have abandoned energies of 15MV or greater in our entire clinical enterprise. We do so much IMRT that the risk of neutron production with higher energies is not worth it. Furthermore, multi field IMRT or SBRT eliminate the need for the high energies. Our standard machine configuration is 6MV...

In the IMRT era, energies > 6MVX are moot in my opinion. In addition to the neutron contamination issue already raised above, energies > 10 MVX also have a wider lateral penumbra versus 6 MVX, and will thus not perform as well in the formation of extremely steep IMRT dose gradients. We have th...

The question is whether 15 MV or above would improve dosimetry with IMRT for prostate cancer in comparison to 6MV. Dosimetric studies have shown similar coverage and critical organ DVH with low or high energy for most part. That being said, once in a while you run across a case where based on patien...

In the 3D era, high photon energies meant a lower Dmax and better dose homogeneity, at the expense of a wider penumbra and a wider dose build up at the edges of fields. In the IMRT era, the main determinant of penumbra width and Dmax, is the multi leaf Collimator thickness. A tomotherapy unit with 2...

With great humility I would like to respectfully disagree with the several Experts as it pertains to use of high energy in prostate cancer IMRT. My desire in placing this challenge is to learn from you, and not an attempt to be contrary for contrary’s sake. I have reviewed several ...

Everyone is worried about Neutron contamination, but where in any clinical literature is that relevant?  we all feel better and theoretically it is true, but many, many patients were treated with higher energy therapy over decades, and none the worse off from absorbed or scattered  neutron...

It is simply not necessary to use 18MV photons to achieve satisfactory dosimetry in prostate SBRT. I've not seen any dosimetric comparison showing any semblance of superiority that would make the increased neutron production worthwhile.