Generation of "soft x-rays" by using the free electron laser as a proposed means of diagnosing and treating breast cancer.
The diagnosis and treatment of breast lesions may be markedly enhanced by the use of a unique new source of near-monochromatic x-rays. Concentric beams of near-monochromatic x-ray photons may be generated by collision of the free electron laser (FEL) electron beam with the optical beam in an interaction zone that delivers the x-rays to a shirtsleeve environment. The absence of Compton scatter and the photoelectric interaction within tissues improves conspicuity of lesions by two to six times. Increased attenuation of x-rays in malignant vs. normal tissues makes tumors more obvious. K-edge subtraction allows chemical analysis of tumors in vivo--all at radiation doses that are one-tenth to one-fiftieth that delivered by the lowest-dose mammographic x-ray technique available. This allows for an increased sensitivity and specificity and permits prediction of histology, negating necessity for biopsies. Selective bond-breaking at depth in tissues as well as x-ray-activated photodynamic therapy are also being explored.