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Also referred to as cryosurgery
and cryoablation, prostate cryotherapy is a minimally
invasive surgery capable of using controlled freeze
and thaw cycles to destroy the disease.
Cryotherapy’s Role
in the Treatment of Prostate Cancer
Because cryotherapy is relatively new, that is, lacking
numerous long-term survival rate studies, cryotherapy
is not used as often as radiation therapy for primary
treatment. Cryotherapy, however, is effective in treating
cases of prostate cancer that are radioresistant and
recur as a result. Some doctors believe that the use
of freezing temperatures rather than stronger doses
of radiation therapy is more effective for radioresistant
prostate cancer.
Prostate cryotherapy works because
as cells freeze, ice crystals form inside and around
them. The freezing and thawing processes destroy cells
through dehydration, drastic changes in the pH levels,
or prevention of the flow of red blood cells. Subjecting
the prostate gland to freezing temperatures, specifically
negative 40 degrees Celsius, also activates an anti-tumor
response in the body. An anti-tumor response begins
with the production of anti-bodies that work to eradicate
the tumor.
The History of Cryotherapy
Cryoablation translates literally to “destruction
of tissue by cold.” The concept of using sub-zero
temperatures in the treatment of prostate cancer, especially
on prostatic tissue that is radioresistant, has been
around since the 19th century when mixtures of ice and
salt were applied to the breast or cervix for the treatment
of cancer. Modern cryotherapy began in 1966 with the
use of liquid nitrogen. When cryotherapy was first used,
the surgery was fully invasive. The first form of cryotherapy
involved a perineal incision through which an instrument
called the cryoprobe was placed. Liquid nitrogen was
circulated through the probe to freeze the gland. In
1974, doctors began using a minimally invasive transperineal
approach.
Today, 3rd generation cryotherapy
needles are used more effectively through the guidance
of the transrectal ultrasound. Only recently has the
technology become available that allows a surgeon to
carefully place and form an ice ball that will destroy
the prostatic tissue. The technological advances include
the switch from cryoprobes to cryoneedles, the use of
the transrectal ultrasound for guidance, the switch
from liquid nitrogen to argon and helium gases, and
the use of a warming catheter.
Advantages and Disadvantages
of Cryotherapy
Cryotherapy is an effective primary treatment for those
who are in the early stages of prostate cancer with
low risk for tumor extension. This treatment may also
be an excellent alternative for those who are not good
candidates for radical prostatectomy. Cryotherapy may
be used if EBRT fails and the cancerous prostate cells
are deemed radioresistant. Some advantages of include
the one day in-hospital treatment, though some patients
will stay overnight depending on their general health.
Cryotherapy can also be repeated
if it fails to ablate the cancerous tissue during the
first round of treatment. Patients for whom treatments
fail can also pursue alternatives such as radiation
therapy or prostatectomy. Because cryotherapy is minimally
invasive, patients experience only minimal, if any,
blood loss. One disadvantage is that the long-term data
on cryotherapy is limited, due to its newness as mainstream
prostate cancer treatment.
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