University of Virginia Library

Tumor Conquest Aim
Of New Accelerator

With the acquisition of an eight
million electron volt linear accelerator
for treatment of malignant
tumors, the radiation therapy department
at the University Medical
Center has become one of the best
equipped in the East.

Installation of the accelerator,
begun in April, was recently completed
and the accelerator will be
ready for use on patients in
September, said Dr. William Constable,
director of radiation therapy
at the Medical Center.

The accelerator eventually will
be used in treating as many as 40
patients a day, he said. Patients are
expected to be referred from
Virginia, West Virginia, Tennessee,
Kentucky, North Carolina and
Washington.

Using an energy source similar
to that in large radar installations,
the accelerator feeds an electric and
magnetic field into the machine and
accelerates electrons to tremendous
speed. If the electrons are allowed
to hit a gold-plated tungsten target,
high intensity x-rays are produced.
If the largest is removed, the
electrons pass directly into the
body.

The advantage of electron therapy,
says radiation physicist Jack
Wakley, is in its limited penetration.
It can be used to treat
surface malignancies without damaging
underlying tissues.

The x-ray therapy offered by
the linear accelerator will be useful
for treatment of deepseated cancers.
"Since the accelerator is more
powerful than conventional x-ray
units, the patient can be exposed to
radiation for a shorter amount of
time with greater results and fewer
side effects, said Mr. Wakley.

Because precise beams can be
directed at any size surface, including
the whole body, the problem
of missed or overlapped areas in
exposure to radiation is avoided, he
said.

The accelerator stands in a room
with high density concrete walls 36
inches thick. The room's concrete
ceiling is 18 inches thick and weighs
17 tons. Over the accelerator an
inverted pyramid of steel weighing
7 tons adds extra protection. Two
closed circuit television cameras,
one with a zoom lens, show the
technician at the control panel
outside the room exactly what is
going on. Audio contact is maintained
by an intercom system.

The radiation therapy department's
own technicians are being
trained to operate the accelerator
by Dr. Constable and Miss Fay
Hurtt, supervisor of radiation therapy.
Miss Hurtt spent six months in
Manchester, England, at the Christie
Hospital and Holt Radium
Institute learning how to operate
linear accelerators.

Although the primary use of the
accelerator will be clinical, it will
also be used in research programs
involving radiation physics and
radio biology.