Experimental evaluation of multiple use of interstitial laser probes

Purpose: During the last few remaining years, interstitial thermotherapy wi th laser applications has gained momentum in therapeutical usage. One probl em however, is the limited durability of the expensive probes. The aim of t his study was to determine whether avoidance of carbonisation of the laser probes leads to a reduction in transmission following application of higher laser energies. Material and Method: Nd:YAG-Laser was used for application to a pig's kidne y in vitro probes with quartz caps. After 9900 joules, transmission was mea sured and compared to a reference probe without a quartz cap. Results: By avoiding carbonisation effects, we could apply 49 500 joules wi thout a decrease in transmission (transmission quotient 1.02-1.07). When ca rbonisation occurred, however, the doses transmitted decreased significantl y. Conclusions: This procedure becomes cost effective when the probes are ster ilised and re-used and carbonisation effects avoided.