A new method of cancer diagnosis employing the use of an atomic particle was revealed Monday by Dr. William Herbert Sweet, assistant professor of Surgery, and Dr. Gordon L. Brownell, Massachusetts General Hospital physicist and research associate at M.I.T.

Addressing a group of science writers visiting Boston under the sponsorship of the American Cancer Society, Sweet and Brownell disclosed that surgeons at Massachusetts General Hospital are using a "positron," an atomic particle emitted from material made radio-active in the M.I.T. cyclotron, to detect and locate brain tumors.

They also said that 58 patients with brain cancer have been injected with an isotope of boron, which, they asserted, may "lead to useful treatment by direct rays from the atomic pile at Brookhaven, N.Y." This procedure has been described as "a miniature atomic explosion."

Sweet and Dr. Manucher Javid, Research Fellow in Surgery, explained that the "positron" technique is one of diagnosis while the use of boron may possibly be found of advantage for therapy following surgical operations in which brain tumors have been partially or totally removed.

Since both methods are still in the developmental stage, Sweet expressed caution in discussing how extensive a use might be made of them. But he claimed that if "things moved favorably, wide-spread usage of both might be expected."

Although he refused to commit himself until more information about the results of the boron experiments is available, Sweet admitted it was hoped that some day a point would be reached where the therapy would take the place of surgery, when "it is possible to destroy the morbid tissue without brain injury."