AB39. Cryotherapy in urologic neolplasms

Abstract: Cryosurgery has a long history dating back to the mid-1800s when James Arnott, an English physician, used a salt and ice mixture to treat cervical and breast carcinoma. Modern cryosurgery began in 1961 with the development of automated equipment by Cooper and Lee. Since then, tumors in various organs have been treated with cryoablation, and probes of various shapes and sizes have been designed to improve tumor accessibility and ablation. During the last decade there has been a resurgence of cryotherapy in the field of urology, particularly in the treatment of malignant lesions of the kidney and prostate.

As a minimally invasive treatment, the cryotherapy appears to be the most durable. Currently, select kidney and prostatic lesions are treated using cryotherapy and clinical series have provided compelling results, promoting interest in renal and prostatic cryoablation. By the advancement of radiographic technology and surgical instrumentation, much of the interest has been promoted along with the movement toward to provide minimally invasive therapeutic options for patients.

The optimal indication for renal cryotherapy is a peripheral, enhancing, well circumscribed lesion less than 4 cm. Along with tumor characteristics, certain patient populations may benefit from kidney cryotherapy. They include elderly patients with comorbidities, particularly hypertension, diabetes, kidney stones, renal insufficiency, cerebrovascular accidents, and congestive heart failure. Other considerations include unique situations such as lesions less than 4 cm in a solitary or transplant kidney, along with certain hereditary conditions such as von Hippel-Lindau disease, tuberous sclerosis, and hereditary papillary renal cell carcinoma. Contraindications to kidney cryoablation include locally advanced and/or metastatic disease and uncontrolled bleeding disorders. Other relative contraindications include lesions contiguous with bowel, great vessels, and/or tumor size of at least 5 cm.

Prostate cryotherapy is the most used in urology and is best performed in glands less than 40 g. It offers the patient a minimally invasive treatment option with low morbidity, minimal blood loss, shorter hospital stay, and a high negative biopsy rate after treatment .Investigators have reported protocols assigning patients to neoadjuvant androgen deprivation to achieve smaller gland sizes before starting treatment. Prostate-specific antigen (PSA) has also been used as a parameter to determine cryotherapy eligibility. Cryosurgery was recognized by AUA as a therapeutic option for localized Pca in 1996.Currently, prostate cryosurgery are not limited to the treatment of localized prostate cancer, it also used as a salvage therapy for patients in whom radiation therapy has failed. At the same time, focal cryoablation of prostate and even its use in the localized advanced prostate cancer are under clinical observation. Contraindications include incontinence, and inflammatory bowel disease. The latter is believed to contribute to a higher incidence of anorectal fistula formation.

Keywords: Cryotherapy; urologic neolplasms; prostate-specific antigen (PSA)