Thermal dosimetry characteristics of deep regional heating of non-muscle invasive bladder cancer. (May 2014)

• Record Type: Journal Article
• Authors: Juang, Titania; Stauffer, Paul R.; Craciunescu, Oana A.; Maccarini, Paolo F.; Yuan, Yu; Das, Shiva K.; Dewhirst, Mark W.; Inman, Brant A.; Vujaskovic, Zeljko
• Is Part Of: International journal of hyperthermia. Volume 30:Number 3(2014)
• Page Start: 176
• Page End: 183
• Publication Date: 2014-05
• Subjects: Thermotherapy -- Periodicals; 615.832
• DOI: 10.3109/02656736.2014.898338
• Languages: English
• ISSNs: 0265-6736

Abstract

<abstract> <title>Abstract</title> <p> <italic>Purpose</italic>: The aim of this paper is to report thermal dosimetry characteristics of external deep regional pelvic hyperthermia combined with intravesical mitomycin C (MMC) for treating bladder cancer following transurethral resection of bladder tumour, and to use thermal data to evaluate reliability of delivering the prescribed hyperthermia dose to bladder tissue. <italic>Materials and methods</italic>: A total of 14 patients were treated with MMC and deep regional hyperthermia (BSD-2000, Sigma Ellipse or Sigma 60). The hyperthermia objective was 42° ± 2 °C to bladder tissue for ≥40 min per treatment. Temperatures were monitored with thermistor probes and recorded values were used to calculate thermal dose and evaluate treatment. Anatomical characteristics were examined for possible correlations with heating. <italic>Results</italic>: Combined with BSD-2000 standard treatment planning and patient feedback, real-time temperature monitoring allowed thermal steering of heat sufficient to attain the prescribed thermal dose to bladder tissue within patient tolerance in 91.6% of treatments. Mean treatment time for bladder tissue >40 °C was 61.9 ± 11.4 min and mean thermal dose was 21.3 ± 16.5 CEM43. Average thermal doses obtained in normal tissues were 1.6 ± 1.2 CEM43 for the rectum and 0.8 ± 1.3 CEM43 in superficial normal tissues. No significant correlation was seen between patient anatomical characteristics and thermal dose achieved in bladder tissue. <italic>Conclusions</italic>: This study demonstrates that a hyperthermia prescription of 42° ± 2 °C for 40–60 min can be delivered safely to bladder tissue with external radiofrequency phased array applicators for a typical range of patient sizes. Using the available thermometry and treatment planning, the BSD-2000 hyperthermia system was shown to be an effective method of focusing heat regionally around the bladder with good patient tolerance.</p> </abstract>