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From: Proceedings 10th World Congress of Cryosurgery
The evolving cryosurgical experience - a review

Abstract: Results of treatment of patients with prostatic carcinoma with standard cryosurgery treatment were not very successful unless the patients treated had favorable lesions with pre-treatment PSA levels below 10. Even so, the results cannot be interpreted until many years of follow-up have occurred because the end PSA level is seldom 0.0, the accepted level for cure. Evolving changes in the protocol for treatment utilizing lower urethral warming temperatures, total freeze of the prostate without the use of a warmer, and with the use of transurethral resection as an integral part of the procedure, have led to improved results which compare favorably to radical surgery.

Introduction: Over the past three and a half years, the author has performed ninety cryosurgical destructive procedures on the prostate to treat prostatic carcinoma. The successes and failures of that technology are presented and the continuing evolution in treatment methodologies are outlined. New treatment protocols based on those results are presented.

Materials and Methods: When cryosurgery of the prostate was begun in this practice, the standard procedure using liquid nitrogen and a 37°C urethral warmer as described by Cohen and Miller and by Onik et. al. Was used. Over time, certain failings of the technology became clear as patient results began to surface. Based on these results, changes in the technique were made to try and improve the results.

Results: It first became obvious that patients who had previous transurethral resection of the prostate did not have successful long-term results from standard cryosurgery. Five of the six patients were felt to be failures and four of these patients had to receive subsequent treatment for rising PSA values. Patients who underwent standard cryosurgery for uncomplicated disease with preoperative PSA levels below 10 did somewhat better with sixteen of twenty-two patients (73%) having sustained PSA levels of 0.3 or less over two years. Only one of these patients, however, had a PSA level of 0.0 which would give a high degree of confidence that long-term cure would be likely. Such results could only be assessed over prolonged periods of ten years or more.

More disturbingly, nineteen patients who underwent standard cryosurgery who had preoperative PSA levels above 10 had no successes with uniform failure in treatment as measured by persistently rising PSA levels in the post-operative period. Most of these patients required subsequent therapy for their disease.

Overall, the success rate for the procedure was only 37% - a dismal result for an otherwise treatable disease. This led the author to try and understand why the technique failed and what could be done to overcome these failures. Theoretically, protection of the urethra with a warming catheter would be likely to prevent cryodestruction of the prostate adjacent to the urethra and this might be a source of tumor preservation. Additionally, the warming catheter would also shield the area above the urethra from the destructive effects of the suburethral central cryoprobe. Two parallel efforts at dealing with these drawbacks were undertaken. In the first group of patients, a room temperature (22°C) warming catheter was used, with the technique otherwise identical to the use of the 370C warmer. In the second group of patients, no warming catheter was used and total destruction of the prostate performed. With patients who underwent room temperature warming of the urethra during the cryodestructive process, five of ten patients (all of whom had pre-op PSA levels below 10, had post-op levels of 0.0 out to at least twelve months. An additional patient has a post-treatment PSA level of 0. 1 at eighteen months and four (40%) were considered failures. This was an improvement (albeit a modest one) over the experience using a 37°C warmer. It should be noted that no complications occurred in this group of patients. Subsequently, five additional patients were operated upon using a room temperature warmer and, immediately following the cryosurgery, a transurethral resection of the prostate done (preserving the bladder neck) to try to eliminate the prostatic urethra and possible residual disease. Four of the five patients have PSA levels at six months or longer of 0.0 and, again, there was no indication of incontinence or other untoward event with these patients. The one patient who deteriorated over time to 0.5 had a pre-op PSA level of 15, and should probably not have had this procedure. The author believes that, for patients with preoperative PSA levels below 10, cryosurgery of the prostate using a room temperature warming catheter, followed by a TUR is a promising technique without evident undue complications which needs to be studied further.

For the selection of patients to undergo total cryosurgical destruction of the prostate, the author chose patients who had either high PSA levels, high grade of tumor, or advanced stage of disease beyond T1c. Nine patients were initially selected, four of whom had PSA levels of I I to 90, three of whom had failure of previous surgical procedures on the prostate, five of whom had stage T2b to T3b lesions, and four of whom had grades 8 or 9 cancers. These patients were followed out to eighteen months, and six of these patients are considered treatment successes with PSA levels of 0.0. Unfortunately, complications were too high for the procedure to be considered viable, because four of the nine patients developed late urinary obstruction and required late TUR at three or more months after the procedure. At that time, the prostatic remnants were hard and leathery and difficult to cut, requiring the use of very high cutting currents to remove. All these patients and an additional patient who had a prior TUR were incontinent.

This led to the decision to remove the cryodestroyed prostate immediately by doing a TUR after the total cryosurgery. The results have been quite dramatic. In twelve patients who underwent total cryosurgery with immediate TM eleven have post-op PSA levels of 0.0 at three to six months. The twelfth has a PSA level of 0. 1. The mean preoperative PSA level in this group of patients was 15.4 (range 1-37). Eight of the patients had PSA levels over 10 and four of these had PSA levels over 20. One patient had to be treated for a bladder neck contracture at three months, following the procedure. Two patients have incontinence (16.7% incidence). One patient had a ruptured bladder requiring surgical drainage when his suprapubic catheter was irrigated too vigorously. This latter complication was deemed avoidable and not directly related to the procedure.

Finally, a comparison was made between our experience in all twenty-one patients who underwent total cryosurgery and eighty-two patients who, in our practice, underwent radical prostatectomy. The table below is instructive. It shows a far higher success rate with total cryosurgery (either with or without TUR) when all patients are measured at the same time following treatment (three to six months).

Summary: For patients with PSA levels below 10, cryosurgery of the prostate using a room temperature warmer and, perhaps utilizing immediate TUR appears to be a reasonable alternative of therapy with no significant complications found to date. For patients with more aggressive disease, total cryosurgery of the prostate with immediate TUR appears to offer better early disease control with similar complications to radical surgery