The 160 million electron volt Harvard Cyclotron has recently treated malignant tumors in four patients, and early results indicate that the Cyclotron may be instrumental in the development of cures for cancer, diabetes, and Parkinson's disease.

But, Dr. Raymond K. Kjellberg, instructor in surgery at the Harvard Medical School, told an American Cancer Society symposium that the use of this machine is still in the experimental stages as far as tumor therapy is concerned.

Three of the four patients who were treated are progressing satisfactorily, but more time will be needed before a precise evaluation of the results can be made. The fourth patient, a two-year-old girl, died; but her death was due to a recurrent tumor outside the irradiated zone. However, the accuracy of the Cyclotron does reduce the danger of damaging healthy cells and organs outside the target area.

Since radiation is a potential hazard in space flights, Kjellberg indicated that, "The possible role of biological studies with the proton beam is already of interest to the National Aeronautics and Space Administration."