Kidney Cancer Treatment - Cryoablation

Most people are born with two bean shaped kidney organs. In the middle of the back, kidneys are located, and just below the rib cage on either side of the spine. Kidneys weigh about 0.5 percent of total body weight or the size of a fist. If one kidney is removed, the remaining one will enlarge within a few months to take over the function of other kidney. Kidneys function to filter blood (Outer layer of each kidney is called the cortex, which contains filtering units for blood), produce urine, ensuring that body tissue receives enough water, regulate blood pressure, stimulate the making of red blood cells (Kidneys secrete a hormone called erthropoietin which stimulates and controls the body's red blood cell production), and maintain body's calcium and vital salts in the blood (Regulating salts level through the production of an enzyme called renin). Twenty percent of the blood, pumped by the heart enters the kidneys from the renal artery. The opening area where upon blood enters the kidney is called the hilus. Every minute, more than one quarter (about one liter) of blood goes to the kidneys. Blood enters the kidney through the cortex, where upon the artery branches (nephrons) into one million tiny filtering units. The processed blood in the kidneys, removed through the renal vein. Wastes and other unwanted substances are removed through the urine (Urine appears yellow because it contains urochrome). Urine flows from the kidneys through the uterus to the bladder. Urine in stored in the bladder (holds about half a liter or two cups of urine at any given time), until it is excreted from the body through the urethra. When the bladder is full, nerve endings in the wall of the bladder will send impulses to the brain, ready to urinate. Urine passes through the urethra and then exists either through the male penis or female vaginal opening. Medical conditions can affect the function of the kidneys and urinary tract, including kidney cancer.

Cancer (malignancy) is a disease or disorder, characterized by uncontrolled division or abnormal growth of cells. Also, categorized by the type of cancer, which can spread to adjacent tissue (metastasis) through the bloodstream (or lymphatic system). Diagnosis of a non - malignant growth is a benign tumor that is not cancerous. Cancer affects people of all ages and the risk increases with age.

Kidney cancer is the eighth most common cancer in men and the tenth in women. Risk factors associated to kidney cancer include smoking, obesity, high blood pressure, long-term dialysis and Von Hippel-Lindau syndrome (Inherited multi-system disorder or disease common to develop renal cell carcinoma). In 2007, The American Cancer Society estimates nearly 52,000 people, diagnosed with kidney cancer, and nearly 13,000 will die. During the past twenty years, diagnosis of kidney cancer has steadily increased. Most common type of kidney cancer (Eighty Percent) is renal cell carcinoma Forms in the lining of the renal tubules in the kidney, that filters the blood and produce urine. Standard treatment has been to surgically remove malignant tumors. Some patients, surgery may not be an option, if the tumor is small or if the patient has underlying medical conditions. Then minimal invasive image guided therapies maybe an effective treatment option. Chemotherapy drugs and radiation are generally ineffective to cure kidney cancer.

In March 2007, during the thirty-second annual meeting of the Society of Interventional Radiology, researchers presented a new method to treat renal cell carcinoma and reported in 2007, issue of Radiology. Mayo Clinic researchers in Minnesota, report that freezing kidney tumors through percutaneous cryoablation, effective treatment for patients that are not good candidates for surgery. The patient is preferable placed under a general anesthesia, often possible with only local anesthesia and conscious sedation. During the procedure, cryoprobe (needle) is filed with argon gas, which results in rapid freezing of the tissue to temperatures minus 100 Celsius (ice ball - Freezes and kills the kidney tumor) and the tissue is then thawed by replacing the organ with helium. The freezing and thawing occurs in two separate cycles, and frozen margin of approximately five millimeters beyond the tumor edge, ensure death of the entire tumor. Small bandages are placed over the skin puncture sites, after the cryoprobes are removed. The patient spends one night in the hospital before returning home. Contrarily, the same procedure can be undertaken by delivering directly to the tumor high intensity heat through radiofrequency ablation. The heat cooks the tumor and leads to cell death. A radiologist uses imaging to pinpoint the tumor and thus avoids going through an adjacent structures or harming healthy tissue. Compared to a laparscopy, requires anesthesia, and multiple abdominal incisions to allow access for the surgical instruments, and a longer recovery time. According to study author J. Louis Hinshaw, M.D, of the University of Wisconsin said: "This early stage research indicates that percutaneous cryoablation in the appropriate patient can effectively kill tumors, while also offering patients a shorter hospital stay, a faster recovery and an excellent safety profile, all at a lower cost (59.5%) than laparoscopy. Unfortunately, not all patients are viable candidates for percutaneous ablation and we work closely with our urology colleagues to ensure that each patient receives the most appropriate treatment." Interventional radiologist (Board certified physicians) specializes in minimally invasive targeted treatments. The Food and Drug Administration has approved both radiofrequency ablation (RFA - Minimally invasive treatment for cancer when surgery is not likely to be successful or has failed.) and cryoablation for use in soft tissue tumors, of which renal cell carcinoma is one.

Radiofrequency ablation is not effective when tumors larger then three centimeters and area being treated, cannot be effectively monitored with computer tomography or ultrasound. Cryoablation effectively treats those large tumors guided by ultrasound. Research Study conducted at the Mayo Clinic between March 12, 2003 and August 4, 2005, confirmed those participants (Twenty-three men and seventeen women with kidney cancer) had chosen cryoablation compared to radiofrequency ablation. Thirty-eight of forty patients did not require repeat treatment.

According to Bradley Leibovich, M.D, study co-author and Mayo Clinic urologist said: "We've seen good results in the initial follow-up with these patients, and hope that the long-term results prove this to be a safe alternative for some kidney tumors." Researchers need at least five to ten years of follow-up examinations to consider cryoablation as curative treatment for kidney cancer.