John T. Lyman

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Heavy charged-particle radiation has unique physical characteristics that offer several advantages over photons and protons for stereotactic radiosurgery of intracranial AVMs. These include improved dose distributions with depth in tissue, small angle of lateral scattering, and sharp distal fall-off of dose in the Bragg ionization peak. Under(More)
Since 1954, 840 patients have been treated at Lawrence Berkeley Laboratory with stereotactic charged-particle radiosurgery of the pituitary gland. The initial 30 patients were treated with proton beams; the subsequent 810 patients were treated with helium ion beams. In the great majority of the 475 patients treated for pituitary tumors, marked and sustained(More)
Forty patients aged 6 to 18 years have now been treated for inoperable intracranial arteriovenous malformations (AVMs) using stereotactic heavy-charged-particle Bragg peak radiosurgery at the Lawrence Berkeley Laboratory 184-inch Synchrocyclotron at the University of California, Berkeley. This paper describes the procedures for selection of patients, the(More)
We have treated over 400 patients with symptomatic inoperable intracranial arteriovenous malformations (AVMs) with stereotactic heavy-charged-particle Bragg peak radiosurgery at the University of California at Berkeley in a collaborative program with Stanford University Medical Center and the University of California Medical Center, San Francisco. A(More)
Therapy with 910 MeV alpha particles provides a treatment with no mortality and an extremely low morbidity and has been highly successful in the control of pituitary hormone hypersecretion and tumor growth. It is possible to deliver radiation doses to the pituitary gland that are sufficiently high to inhibit or destroy the tumor cells that cause abnormal(More)
For the particles and energies considered suitable for radiosurgery, with increasing particle charge, the Bragg peak height reaches a maximum with helium and then decreases, the Bragg peak width narrows, the distal fall-off steepens, and the exit dose increases (Table 1). The helium-ion beam is superior to a proton beam because of the higher peak-plateau(More)
Charged-particle beams (e.g., protons and helium, carbon and neon ions) manifest unique physical properties which offer advantages for neurosurgery and neuroscience research. The beams have Bragg ionization peaks at depth in tissues, and finite range and are readily collimated to any desired cross-sectional size and shape by metal apertures. Since 1954(More)
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