A plesiotherapy technique for the post-operative treatment of skin cancer using Ir192 microselectron.

Abstract

We describe a technique of post-operative irradiation of skin cancer using pleiotherapy with Ir192 high dose rate afterloading system (Microselectron, Nucletron). The clinically defined area is drawn on the skin and the ‘skin applicator’ is then placed orientated so that  the drown skin area is encompassed within the  catheter defined surface. Using a thin pewter wire, the skin drown area is copied on the air-adjacent surface of the applicator. Ex-vivo CT-simulation follows. The data are then transferred to the radiotherapy planning computer and the catheters are virtually reconstructed.  The isodose curve chosen to prescribe the dose is 3-5mm away from the skin-touching area.  Three fractions of 8Gy are scheduled, 1 week apart, delivering a radiobiological equivalent of 48Gy of standard radiotherapy within 2 weeks. Our preliminary experience shows excellent early skin tolerance. The study is on-going to assess efficacy and late effects.