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“Cryotherapy for PCa: The Next Generation Innovative Biofeedback Applications in Urology”
John S. Lam, M.D., Oleg Shvarts, M.D., and Arie S. Belldegrun, M.D. Contemporary Urology, October 2004, Vol. 16, No. 10, 2-12
After 6 to 12 months following primary
cryotherapy,
prostate biopsies
were performed in patients and reported a rate ranging
from 7.7 to 25 percent in several series. It was determined
that certain areas of the prostate and seminal
vesicles were more likely to be sites
of treatment failure. Dr. Shinohara and associates reported
that recurrence was more common in cancers located at
the apex (95%) and seminal vesicles (43.8%), in contrast
to those located in the midgland (4.1%) and base (0%).
Due to a release of intracellular PSA
from cellular necrosis, PSA levels may rise to a very
high value immediately after the procedure. Out of 132
patients, biochemical failure was lowest for those who
achieved PSA nadirs (usually found in 3 months) below
.1ng/mL (21%) but was common in those with higher values.
Within the first 12 months after treatment 96% experienced
biochemical failure and 88% saw biopsy failure.
“Targeted Cryoablation of the Prostate: 7-Year Outcomes in the Primary Treatment of Prostate Cancer”
Duke K. Bahn, Fred Lee, Robert Badalament, Anil Kumar, Jeffrey Greski, And Michael Chernick. UROLOGY 60 (Suppl 2A): 3–11, 2002. © 2002, Elsevier Science Inc.
In this study 590 consecutive prostate
cancer patients were evaluated after approximately 5.43
years following primary targeted cryoablation from March
1993 to September 2001. Patients were treated at Crittenton
Hospital in Rochester, Michigan. Based on the likelihood
of disease relapse, patients were placed into 3 risk
groups; 15.9% low risk, 30.3% medium risk, and 53.7%
high risk. Since the cryotherapy procedure had not matured
to its current state until 1996, not all patients in
this series underwent the same procedural method. Although
all patients were treated with 2 complete freeze-thaw
cycles using a target temperature of -40°C, the
first 350 patients were treated with a liquid
nitrogen cryomachine. An argon-based
cryomachine later replaced liquid nitrogen, yielding
better results. After 7 years the biochemical
disease-free survival rates were as
follows, low risk was 61%, medium risk was 68%, and
high risk was 61%. Prostate cryotherapy patients with
a positive biopsy were 13%, and afterwards 32 patients
underwent repeat cryoablation. Targeted cryoablation
proved, in this study, to equal or surpass morbidity
rates of external-beam radiation, 3-dimensional conformal
radiation, and brachytherapy.
“Five-Year Retrospective, Multi-Institutional Pooled Analysis of Cancer-Related Outcomes After Cryosurgical Ablation of the Prostate”
John P. Long, Duke Bahn, Fred Lee, Katsuto Shinohara, Douglas O. Chinn, And Joseph N. Macaluso, Jr. UROLOGY 57: 518–523, 2001. © 2001, Elsevier Science Inc.
In this study 975 prostate cancer
patients underwent cryosurgical ablation as their primary
therapy from January 1993 to January 1998. Patients
treated at five institutions were pooled for this analysis
including the New England Medical Center, University
of California at San Francisco, Urologic Institute of
New Orleans, Crittenton Hospital, and Alhambra Hospital.
Based on clinical characteristics (such as PSA level,
Gleason
score, and stage),
patients were placed into 3 groups, 25% at low risk,
34% at medium risk, and 41% at high risk. Physicians
tracked patients for a period of 24 months. The 5-year
biochemical relapse-free survival rate for patients
with a PSA less than 0.5ng/mL ranged from 36% to 61%,
compared with patients having a PSA level less than
1.0ng/mL, which ranged from 45% to 76%. The positive
biopsy rate was 18%. Certain complications included
impotence (93%), incontinence (7.5%), rectal fistula
(.5%), and transurethral resection (13%).
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