Hypothermic Cooling Measured by Thermal Magnetic Resonance Imaging; Feasibility and Implications for Virtual Imaging in the Urogenital Pelvis.

OBJECTIVE: To study the combination of thermal magnetic resonance imaging (MRI) and novel hypothermic cooling, via an endorectal cooling balloon (ECB), to assess the effective dispersion and temperature drop in pelvic tissue to potentially reduce inflammatory cascade in surgical applications. METHODS: Three male subjects, before undergoing robot-assisted radical prostatectomy, were cooled via an ECB, rendered MRI compatible for patient safety before ECB hypothermia. MRI studies were performed using a 3T scanner and included T2-weighted anatomic scan for the pelvic structures, followed by a temperature mapping scan. The sequence was performed repeatedly during the cooling experiment, whereas the phase data were collected using an integrated MR-high-intensity focused ultrasound workstation in real time. Pelvic cooling was instituted with a cooling console located outside the MRI magnet room. RESULTS: The feasibility of pelvic cooling measured a temperature drop of the ECB of 20-25 degrees in real time was achieved after an initial time delay of 10-15 seconds for the ECB to cool. The thermal MRI anatomic images of the prostate and neurovascular bundle demonstrate cooling at this interface to be 10-15 degrees, and also that cooling extends into the prostate itself ~5 degrees, and disperses into the pelvic region as well. CONCLUSION: An MRI-compatible ECB coupled with thermal MRI is a feasible method to assess effective hypothermic diffusion and saturation to pelvic structures. By inference, hypothermia-induced rectal cooling could potentially reduce inflammation, scarring, and fistula in radical prostatectomy, as well as other urologic tissue procedures of high-intensity focused ultrasound, external beam radiation therapy, radioactive seed implants, transurethral microwave therapy, and transurethral resection of the prostate.

Limitations of the National Comprehensive Cancer Network® (NCCN®) Guidelines for Prediction of Limited Life Expectancy in Men with Prostate Cancer.

PURPOSE: National Comprehensive Cancer Network prostate cancer guidelines for the prediction of life expectancy recommend subtracting 50% of life table predicted longevity for those in the lowest quartile of health. However, it is unclear how to identify these men and if their survival is uniform. MATERIALS AND METHODS: We sampled records of 1,482 men diagnosed with prostate cancer from 1998 to 2004 at 2 VA hospitals. We identified men in the lowest quartile of health by age using Charlson scores, calculated their NCCN predicted life expectancy, and compared this with observed median survival in aggregate and across comorbidity subgroups. RESULTS: Men with Charlson scores of 2+ (age less than 75 years) and 3+ (age 75 years or older) comprised the lowest quartile of health. Among those younger than 65, 65 to 69, 70 to 74, 75 to 79 and 80 years or older, observed survival vs NCCN predicted life expectancy in years was similar at 10.4 vs 11.1, 10.0 vs 7.8, 6.2 vs 6.4, 4.4 vs 4.9 and 3.7 vs 3.3, respectively. Yet within the lowest quartile there was significant heterogeneity in survival among men with differing Charlson scores. For example, men age 65 to 69 years with Charlson scores 2, 3 and 4+ had an observed median survival greater than 13.3, 9.4 and 4.3 years, respectively. NCCN guidelines misclassified 10-year life expectancy in 24% and 56% of men age less than 65 and 65 to 69 years, and 5-year life expectancy in 18% of men age 70 to 74 years. CONCLUSIONS: While NCCN predictions matched observed survival on average for the lowest quartile of health, there was substantial heterogeneity in survival by Charlson scores. More granular assessments of life expectancy should be used for those at highest risk for mortality.