It is not the treatment of choice at most of the major cancer centers. IMRT is the standard for a reason. It works, and unlike implanted seeds can be mapped to many areas, where the seeds will be put in the tumor area only. The disease frequently puts out small non visible micro metastasis and being able to lightly paint the known areas of movement via IMRT reduces the chance of a recurrence later. Brachytherapy is used more in areas where the disease remains encapsulated/localized for long periods like prostate cancers.