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Biomedical subjects

C O Granda

Publications and source records attributed to C O Granda.

2 recordsLinked to original sources
PubMedDate not supplied

Use of the Clinac-35 for tissue activation in noninvasive measurement of capillary blood flow.

Through adjustment of operating parameters responsible for the acceleration, steering, and focusing of electrons en route to the target, we have extracted a 30-MV x-ray beam from the Clinac-35 linear accelerator that is suitable for use in photon activation -15O decay studies of tissue perfusion. This beam is significantly more efficient than the "standard" 25-MV beam in producing 15O in situ through activation of tissue oxygen, thereby substantially reducing the dose to tissue required to yield a desired initial 15O activity. Production and characteristics of the higher energy beam are discussed, and data obtained from its application to measurement of capillary blood flow in animal tumors are presented and analyzed.

Animals↗
PubMedDate not supplied

Testing of a medical linear accelerator's computer-control system.

In August of 1987, the Radiation Oncology Center at the Mallinckrodt Institute of Radiology became the first academic-medical-center user of Varian's computer-controlled therapy accelerator, a prototype version of the 2100C. Installation was accomplished by the retrofit of a computer system to our two-year-old Clinac 1800. Being well aware of the malfunctions that occurred in other computer-controlled accelerators, we took extraordinary measures to assure proper operation of the new, computerized, system. Our acceptance procedure included tests of (i) mechanical systems (isocentricity, digital readouts, etc.); (ii) radiation parameters (flatness, symmetry, output, etc.); (iii) manual safety systems (emergency off switches, etc.); (iv) the computer console systems (communications integrity, state integrity, etc.); and (v) the interlock systems (some 50 electrical, mechanical, and/or computer-controlled interlocks). As items (i), (ii), and (iii) do not differ significantly from the tests for a non-computer-controlled machine, they will not be discussed here. Rather, this report will concentrate on the methods that were devised to test the computer-control and interlock systems.

Computer Systems↗