Clinical application of in vitro radiohypersensitivity testing.

The cases of two patients who suffered severe late effects of radiotherapy are reported; each tested positive for elevated in vitro radiohypersensitivity (RHS) but negative for the ataxia-telangiectasia mutation. The first patient underwent surgery and postoperative radiotherapy for lung cancer and subsequently developed fatal myelopathy. The second patient underwent triple-modality therapy for cervical cancer and suffered highly symptomatic pelvic fibrosis. The value of the testing was that it increased the confidence in the diagnosis of radiation effects and enabled suitable treatment to proceed. An increasing role for clinical RHS testing is anticipated.