3D conformal is an earlier version of IMRT. It can definitely be used in a prophylatic sense as well. Most of us have had bilateral irradiation as well as lymph node targeting, etc. It's been said many times here that one must be a candidate for IMRT and meet certain diagnostic criteria. A lot of the treatment programming IS educated guesswork - that is why it is best to be treated at a comprehensive cancer center. IMRT is a standard of care now. In over 10 years of usage it have proven itself efficacious and almost all of the RO treatment centers have retrofitted or purchased new machines with it (the life span of the typical LINAC is about 5 years).


XRT is not going away - for certain types of tumors and conditions it will remain the treatment of choice. IMRT machines can be readily converted back to XRT by unsnapping the multi-leaf collimator (MLC). In fact when you get the weekly x-ray, they take off the MLC. There is virtually no difference in the ionizing radiation source between the two, only in the targeting methodology.

Interestingly, Proton Beam Therapy (PBT) is SO accurate that they use it in conjunction with IMRT for the marginal areas. I have never heard of a multimodality treatment with both XRT and IMRT.