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Prostate Cancer
Salvage Cryosurgery in Prostate Cancer
a report by
Aaron E Katz, MD
Associate Professor of Clinical Urology, and Vice Chairman of Urology, Columbia University Medical Center
Radiation is a common form of therapy for patients with newly Scientific Background
diagnosed and localized prostate cancer. It has been estimated that Clinically based cryosurgical procedures grounded on well-recognized
nearly one-third of newly diagnosed prostate cancer patients will choose scientific principles support physician-managed destruction of radiation
one form of radiation therapy as their primary treatment. Despite recurrent tumors of the prostate.
11–13
When performed with multiprobe
modifications of delivering radiation to the gland such as intensity devices and advanced imaging techniques, cryosurgery has yielded
modulation, 3D conformal, and computer-assisted brachytherapy, a predictable and effective results in the long-term treatment of prostate
significant number of these patients will have a rise in their serum adenocarcinoma in the primary setting.
14–16
prostate-specific antigen (PSA) value some time after radiation has been
administered. Urologists are often called upon to manage patients with Prostate geometry dictates cryoneedle/cryoprobe (CN/P) placement: CN/P
rising PSA values and radiation-recurrent cancer. are placed to support thermal homogeneity at approximately -40°C
throughout the prostate. Following template-assisted, ultrasound-guided
According to the recent literature, the frequency of biochemical failure placement of CN/P, the physician directs freezing from anterior to posterior
with external-beam radiotherapy ranges from 20 to 66%.
1–8
However, in in the gland. This sequencing supports clear visualization and control of the
the past many investigators used different definitions of biochemical ablative process under transrectal ultrasound (TRUS).
failure. In 1997, the American Society for Therapeutic Radiology and
Oncology (ASTRO) defined biochemical failure as three consecutive PSA The main principle of prostate cryosurgery is a thermal therapy that
level rises separated by three- to four-month intervals (ASTRO panel extracts heat (thermal energy) from the targeted tissue, resulting in a series
consensus statement). More recently, the Phoenix consensus definition, of destructive effects. It has long been recognized that the tissue response
PSA nadir plus 2ng/ml or more, was introduced.
9
Since rising PSA levels from cold injury, which can range from inflammation to total destruction,
can occur with both local and metastatic disease, an elevation does not depends on the severity of freezing. The lesion created by freezing is
necessarily imply that the patient has local recurrence. In addition, a PSA characterized by coagulation necrosis in the central region with a
level elevation may be due to benign causes. These factors make it surrounding, relatively thin, peripheral region in which cell death is
difficult to clearly define a locally salvageable population. Only apparent. Under ultrasound, the ice ball can be clearly seen as a large
approximately one-third of patients with biochemical failure will have hypoechoic region. The outer edge of the ice, which is the warmest part of
local recurrence.
10
If local recurrence is detected early, salvage therapy is the ice, can be monitored as it appears as a hyperechoic rim.
feasible. Recent advances in both technology and the technique of
salvage cryosurgery have led to the ability to eradicate these tumors with Salvage Cryosurgery
a reduction in morbidity. Salvage cryosurgery for curative intent should be strongly considered in men
who have failed radiation therapy. The most appropriate candidates have
documented persistent organ-confined prostate cancer, a PSA <10ng/ml,
Aaron E Katz, MD, is an Associate Professor of Clinical
Urology and Vice Chairman of Urology at Columbia University
and a negative metastatic evaluation.
Medical Center. He is also Director of the Center for Holistic
Urology, which performs basic research and conducts clinical
Patient Selection
trials investigating the role of natural therapies within
urology. Dr Katz is recognized as an expert in the field of
prostate cryosurgery. In the early 1990s he began using Prostate-specific Antigen Levels
cryosurgery to cure prostate cancers, and his pioneering work
The optimal time for intervention in a patient whose post-radiation
in advancing the technology helped Medicare approve of this
therapy for treating radiation-recurrent tumors. He has also applied cryosurgery to the
treatment increases PSA is unclear. A temporary rise in PSA levels after
treatment of small kidney tumors, and performed the ablation both percutaneously and brachytherapy commonly occurs around 20 months after treatment.
17
laparascopically. Dr Katz has published numerous articles, written chapters for medical
This ‘bounce phenomenon’ has also been described in patients following
textbooks, and directed courses at both regional and national levels. Dr Katz also developed a
novel blood test that can detect small numbers of prostate cancer cells in the blood. The test,
external-beam radiotherapy.
18
Although there is no consensus among
reverse transcription polymerase chain reaction (RT-PCR), was the first to allow urological urologists or radiation oncologists as to when to intervene, if it is
cancers to be staged using a molecular assay.
determined that salvage therapy is indicated the clinician should consider
E: AEK4@columbia.edu variables such as pre-existing medical conditions, patient age, and
patient preference.
42 © TOUCH BRIEFINGS 2008