Gowardhan Bharat, Greene Damien
Department of Urology, Sunderland Royal Hospital, Sunderland, UK.
BJU Int. 2007 Aug;100(2):295-302. doi: 10.1111/j.1464-410X.2007.06983.x. Epub 2007 May 19.
To assess the characteristics of two new developments in cryotherapy for the prostate, IceRods (Oncura, Amersham, UK; 17 G cryoneedles with an advanced heat exchanger which produces a precise ice-ball comparable in size to those with larger diameter cryoneedles) and the Multitemp 1601 temperature monitoring system (TMS, InvivoSense, Trondheim, Norway) probes, in an in vitro model and in a clinical setting, to assess their usefulness, focusing in particular on the TMS probes.
PATIENTS, MATERIALS AND METHODS: We assessed the temperature profile and performance of the IceRods in several different configurations, in conjunction with the TMS probes for temperature mapping, in a phantom prostate model. Subsequently 20 patients with prostate cancer were treated with cryosurgery either as a primary or secondary treatment for radiation failure; all had a standard treatment protocol. The temperatures throughout the procedure were recorded accurately and analysed. RESULTS The IceRods were better able to freeze tissue, reaching lower temperatures than conventional cryoneedles. The IceRods were also capable of forming ice-balls with a maximum diameter of >6 cm after freezing at full power for 10 min. The TMS probes depicted real-time temperature gradients over either four or eight points in a linear array, enabling more thorough monitoring of the temperature changes during a treatment cycle. In the clinical setting, in all 20 patients, therapeutic freezing of <-40 degrees C was achieved in both the cycles. Temperatures of approximately - 40 degrees C were attained in the area just outside the prostate, as measured by the TMS probes, but with variation along the longitudinal axis. The rectal and external urinary sphincter temperatures did not fall below 0 degrees C at any of the points along the eight-point temperature probe, but there was variation in temperature along the prostate.
IceRods and the TMS probes are clinically useful, requiring fewer cryoneedles and with more efficient temperature monitoring; this would be expected to reduce morbidity and increase safety without compromising an adequate oncological outcome. The IceRods were useful in larger prostates of >3.5 cm long, which obviated the need for a 'pull-back' technique. The TMS probes showed convincingly the variation in temperatures along one line, suggesting that single-point temperature monitoring might not accurately depict the lowest temperatures reached during treatment, which is particularly important in the rectum. This is a significant development in cryosurgery and would make the procedure safer, reproducible and allow interested clinicians to learn the technique safely and more quickly.
在体外模型和临床环境中评估前列腺冷冻治疗的两项新进展，即IceRods（Oncura公司，英国阿默舍姆；17G冷冻针，带有先进的热交换器，可产生与较大直径冷冻针大小相当的精确冰球）和Multitemp 1601温度监测系统（TMS，InvivoSense公司，挪威特隆赫姆）探头，以评估它们的实用性，尤其关注TMS探头。
患者、材料与方法：我们在模拟前列腺模型中，结合用于温度测绘的TMS探头，评估了IceRods在几种不同配置下的温度分布和性能。随后，20例前列腺癌患者接受了冷冻手术，作为放疗失败的初次或二次治疗；所有患者均采用标准治疗方案。准确记录并分析了整个手术过程中的温度。结果IceRods能够更好地冷冻组织，达到比传统冷冻针更低的温度。IceRods在全功率冷冻10分钟后还能够形成最大直径>6 cm的冰球。TMS探头可描绘线性阵列中四个或八个点的实时温度梯度，从而能够更全面地监测治疗周期中的温度变化。在临床环境中，所有20例患者在两个周期中均实现了<-40℃的治疗性冷冻。根据TMS探头测量，前列腺外部区域的温度达到约-40℃，但沿纵轴存在变化。在八点温度探头沿线的任何点，直肠和外括约肌温度均未低于0℃，但前列腺沿线的温度存在变化。
IceRods和TMS探头在临床上有用，所需冷冻针更少，温度监测更有效；预计这将降低发病率并提高安全性，同时不影响充分的肿瘤学治疗效果。IceRods对长度>3.5 cm的较大前列腺有用，无需“回拉”技术。TMS探头令人信服地显示了沿一条线的温度变化，表明单点温度监测可能无法准确描绘治疗期间达到的最低温度，这在直肠中尤为重要。这是冷冻手术的一项重大进展，将使该手术更安全、可重复，并使感兴趣的临床医生能够更安全、更快地学习该技术。
