John Baust

Open Access White Paper/Review Article:
Abstract: Cryoablation has been shown to be an effective therapy for all stages of prostate cancer. Though judged efficacious, complications of treatment and persistent disease, although minimal, show the need for improvement. To this end, research has focused on new technology design for cryosurgical apparatus and imaging techniques. Adjunctive therapy, focusing on increasing cell death by apoptosis, also plays a role in this new direction with the… Show more

Open Access White Paper/Review Article:
Abstract: Cryoablation has been shown to be an effective therapy for all stages of prostate cancer. Though judged efficacious, complications of treatment and persistent disease, although minimal, show the need for improvement. To this end, research has focused on new technology design for cryosurgical apparatus and imaging techniques. Adjunctive therapy, focusing on increasing cell death by apoptosis, also plays a role in this new direction with the intent of increasing cell death in the frozen tissue. Additionally, incorporating methods of protecting adjacent structures, including the urethra, bladder neck sphincter, urogenital diaphragm, neurovascular bundles, and rectum, are critical to achieving a successful outcome and continue to evolve. Several strategies to protect these structures are now commonplace as part of a cryosurgical procedure. These strategies include real-time temperature monitoring, visualization of ice growth during freezing, active heating and even the injection of protective media have emerged as methods to protect these structures. Another more recent procedural application is partial gland ablation or image-targeted focal therapy, developed to maintain cancer control yet minimize the risk of collateral damage to the various structures. Each of these methods has been shown in vitro, in vivo, and clinically to be beneficial. This article describes the directions that cryoablation has taken in an effort to improve procedural efficacy while reducing/eliminating associated co-morbidities.
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While several studies have shown cryoablation to be promising for the treatment of bladder cancer, a lack of basic information pertaining to dosing (minimal lethal temperature) necessary to destroy bladder cancer has limited its use as a primary therapeutic option. Concerns with bladder wall perforation and other side effects have also slowed adoption.

In an effort to detail the effects of freezing on bladder cancer, two human bladder cancer cell lines, SCaBER and UMUC3, were evaluated… Show more

While several studies have shown cryoablation to be promising for the treatment of bladder cancer, a lack of basic information pertaining to dosing (minimal lethal temperature) necessary to destroy bladder cancer has limited its use as a primary therapeutic option. Concerns with bladder wall perforation and other side effects have also slowed adoption.

In an effort to detail the effects of freezing on bladder cancer, two human bladder cancer cell lines, SCaBER and UMUC3, were evaluated in vitro. The data show that a single 5 minute freeze to -10°C did not affect cell viability, whereas -15°C and -20°C results in a significant reduction in viability 1 day post freeze to <20%. These populations, however, were able to recover in culture. A complete loss of cell viability was found following a single freeze at -25°C. Application of a repeat (double) freeze resulted in complete cell death at -20°C. In addition to freezing alone, studies investigating the impact of adjunctive low dose (1 µM) cisplatin pre-treatment (30 minutes and 24 hours) in combination with freezing were conducted. The combination of 30 minute cisplatin pre-treatment and mild (-15°C) freezing resulted in complete cell death. This suggests that subclinical doses of cisplatin may be synergistically effective when combined with freezing.

The data describe a potential combinatorial chemo/cryo therapeutic strategy for the treatment of bladder cancer. Show less