Faculty Bibliography

BACKGROUND: As the acceptance of cryoablative therapies for the treatment of non-metastatic cancers continues to grow, avenues for novel cryosurgical technologies and approaches have opened. Within the field of genitourinary tumors, cryosurgical treatments of bladder cancers remain largely investigational. Current modalities employ percutaneous needles or transurethral cryoballoons or sprays, and while results have been promising, each technology is limited to specific types and stages of cancers. OBJECTIVE: This study evaluated a new, self-contained transurethral cryocatheter, FrostBite-BC, for its potential to treat bladder cancer. METHODS: Thermal characteristics and ablative capacity were assessed using calorimetry, isothermal analyses, in vitro 3-dimensional tissue engineered models (TEMs), and a pilot in vivo porcine study. RESULTS: Isotherm assessment revealed surface temperatures below -20^â—¦ C within 9 sec. In vitro TEMs studies demonstrated attainment of ≤-20^â—¦ C at 6.1 mm and 8.2 mm in diameter following single and double 2 min freezes, respectively. Fluorescent imaging 24 hr post-thaw revealed uniform, ablative volumes of 326.2 mm³ and 397.9 mm³ following a single or double 2 min freeze. In vivo results demonstrated the consistent generation of ablative areas. Lesion depth was found to correlate with freeze time wherein 15 sec freezes resulted in ablation confined to the sub-mucosa and ≥30 sec full thickness ablation of the bladder wall. CONCLUSIONS: These studies demonstrate the potential of the FrostBite-BC cryocatheter as a treatment option for bladder cancer. Although preliminary, the outcomes of these studies were encouraging, and support the continued investigation into the potential of the FrostBite-BC cryocatheter as a next generation, minimally invasive cryoablative technology.

PURPOSE/OBJECTIVE:To determine the composition and site of initiation of bacterial biofilm location on indwelling urinary catheters, and to track biofilm progression over time. MATERIALS & METHODS/METHODS:Indwelling urinary catheters were collected from two tertiary care centers following removal from patients. Indwelling time was noted, and catheters were de-identified. Catheters were sectioned, stained for biofilms, and analyzed using spectrophotometry and visualization. Biofilm colonization patterns were analyzed using descriptive statistical analyses and bacterial composition was determined using next-generation sequencing. RESULTS:33 catheters from 26 males and 7 females were collected with indwelling times ranging from 15 minutes to 43 days and analyzed. Biofilm colonization was consistently high on the region of the balloon throughout indwelling times. After week 1, the distal third of the catheter had higher biofilm colonization than the proximal third (week 2: p=0.034). At all indwelling times, the intraluminal surface of the catheter had greater biofilm colonization than the outer surface. Next-generation sequencing detected potential uropathogenic bacteria in 10 of 10 analyzed samples. CONCLUSIONS:The catheter balloon, its distal aspect, and its lumen were the predominant locations of biofilms, comprised of uropathogenic bacteria. Strategies to prevent or treat biofilms should be targeted to these areas.

BACKGROUND:Technological advancements have led to the success of minimally invasive treatment modalities for prostate cancer such as CyberKnife and Cryotherapy. Here, we investigate patient-reported urinary function, bowel habits, and sexual function in patients following CyberKnife (CK) or Cryotherapy treatment, and compare them with active holistic surveillance (AHS) patients. METHODS:An IRB-approved institutional database was retrospectively reviewed for patients who underwent CK, Cryotherapy, or AHS. Quality of life (QoL) survey responses were collected every three months and the mean function scores were analyzed in yearly intervals over the 4 years post-treatment. RESULTS:279 patients (767 survey sets) were included in the study. There was no difference among groups in urinary function scores. The CyberKnife group had significantly lower bowel habit scores in the early years following treatment (year 2 mean difference: -5.4, P < 0.01) but returned to AHS level scores by year 4. Cryotherapy patients exhibited initially lower, but not statistically significant, bowel function scores, which then improved and approached those of AHS. Both CyberKnife (year 1 mean difference: -26.7, P < 0.001) and Cryotherapy groups (-35.4, P < 0.001) had early lower sexual function scores relative to AHS, but then gradually improved and were not significantly different from AHS by the third year post-treatment. A history of hormonal therapy was associated with a lower sexual function scores relative to those patients who did not receive hormones in both CyberKnife (-18.45, P < 0.01) and Cryotherapy patients (-14.6, P < 0.05). CONCLUSIONS:After initial lower bowel habits and sexual function scores, CyberKnife or Cryotherapy-treated patients had no significant difference in QoL relative to AHS patients. These results highlight the benefit of CyberKnife and Cryotherapy in the management of organ-confined prostate cancer.

OBJECTIVE:To investigate the effects of focal (hemiablation) or total cryotherapy and minimum tumor temperature on patient-reported quality of life (QoL) in patients with prostate cancer. METHODS:An Institutional Review Board-approved database was reviewed for patients who underwent cryotherapy or active surveillance (AS). QoL questionnaire responses were collected and scores were analyzed for differences between focal and total cryotherapy and between very cold (<-76°C) and moderate-cold (≥-76°C) minimum tumor temperatures. RESULTS:A total of 197 patients responded to a total of 547 questionnaires. Focal and total cryotherapy patients had initially lower sexual function scores relative to AS (year 1 mean difference focal: -31.7, P <.001; total: -48.1, P <.001). Focal cryotherapy was associated with a more rapid improvement in sexual function. Both focal and total cryotherapy sexual function scores were not statistically significantly different from the AS cohort by postprocedural year 4. Very cold and moderate-cold temperatures led to initially lower sexual function scores relative to AS (year 1 very cold: -38.1, P <.001; moderate-cold: -30.7, P <.001). Moderate-cold temperature scores improved more rapidly than those of very cold temperature. Neither very cold nor moderate-cold temperatures had a statistically significant difference in sexual function scores relative to AS by postprocedural year 4. Urinary function and bowel habits were not significantly different between focal and total cryotherapy and between very cold and moderate-cold temperature groups. CONCLUSION:Focal cryotherapy and moderate-cold (≥-76°C) temperature were associated with favorable sexual function relative to total cryotherapy and very cold temperature, respectively. No significant differences in urinary function or bowel habits were observed between groups.