KIDNEY CANCER
CRYOTHERAPY
Kidney Cancer Cryosurgery
Cryotherapy, also called cryoablation and cryosurgery, refers to the use of very cold temperatures to treat disease and is a mainstay therapy for a wide variety of conditions. It is a well-established technology for the treatment of many benign and malignant tumors and lesions, and is also one of the oldest documented forms of medical treatment—the Egyptians used cold to treat inflammation and injuries as early as 2500BC.
Cryotherapy is indicated as a treatment for cortical or peripheral lesions, for solid lesions less than 4cm, and for patients with a single kidney or poor kidney function. Kidney cancer ablation eradicates the cancerous tissue by freezing it. Very precise targeting and control of the energy allows for efficient destruction of tumor cells while leaving healthy kidney tissue intact and functional. To freeze the cancer, special thin
probes called cryoablation
needles are placed into the tumor. Argon
gas is delivered under pressure into a small chamber
inside the tip of the needle where it expands
and cools, reaching a temperature well below -100º
Celsius. This produces an iceball of predictable
size and shape around the needle. This iceball
engulfs the tumor, killing the cancerous cells
as well as a small margin of surrounding tissue
while sparing healthy kidney structures.
A double freeze-thaw cycle is favored, since studies
suggest that consistently larger areas of cell
death are achieved with a double rather than single
freeze-thaw cycle. Ultra-thin thermal
sensors may also be placed at the margin of
the tumor to monitor tissue temperature and help
ensure that the entire tumor is destroyed.
Renal cancer ablation using cryotherapy can be performed through several flexible approaches, so treatment can be customized by the physician to accommodate the patient’s general health as well as the size and location of the tumor. Renal cryosurgery can be performed
during traditional open surgery, although this
approach is rarely used today by experienced kidney
surgeons performing kidney cryoablation.
Open surgery is more painful, has a longer recovery
time and generally results in more complications
than minimally invasive surgery. If an open
procedure is chosen, it is always performed under
general anesthesia and it is recommended that
intraoperative ultrasound be utilized as guidance
for cryoablation
needle placement and positioning.
Laparoscopic-guided cryosurgery
on the kidney is a 1 to 3 hour procedure and is
almost always performed under general anesthesia.
Making 3-4 small incisions, standard laparoscopic
technique is used to visualize the kidney, and
a laparoscopic ultrasound probe is used to monitor
the percutaneous placement of the cryoablation
needle(s) and thermal
sensors into the tumor. Additionally,
the ultrasound probe is used to monitor the tumor
and iceball during the double freeze-thaw process,
ensuring destruction of the entire tumor as well
as the desired margin of surrounding tissue.
Another minimally invasive approach
is percutaneous ablation. With percutaneous access,
no incisions are made. The patient is positioned
in the CT or MRI scanner. The cryoablation
needles and thermal
sensors are inserted through the skin and
positioned in the tumor under the guidance of
CT, MRI or Ultrasound and the entire procedure
is monitored using CT or MRI. Image-guided
percutaneous cryoablation is usually performed
under general anesthesia, but can be done under
light sedation. Percutaneous cryoablation is the
least invasive intervention that can be performed
for kidney cancer.
There are many benefits to kidney cancer
treatment via minimally invasive kidney cryotherapy.
To learn more about the advantages of renal cancer
cryoablation, see the section entitled The
Benefits of Kidney Cryotherapy.
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