Thermoluminescence dosimetry in evaluation of liquid super(32)P sources for intravascular brachytherapy

Several new types of miniature (1 and 2 mm diameter) thermoluminescence (TL) detectors were elaborated and tested aiming at dosimetry of liquid [ super(32)P] sodium phosphate sources suggested for intravascular brachytherapy. They were prepared using LiF:Mg,Cu,P and LiF:Mg,Ti TL materials in a two-layer technique with the effective thickness below 0.1 mm. Dosimetric measurements were carried out in tissue-equivalent polymethyl methacrylate (PMMA) phantoms, with TL detectors placed at various distances around angioplasty balloons filled with aqueous solution of Na sub(2)H super(32)PO sub(4). Of particular interest was the response of detectors placed at shortest distances from the balloon surface. All types of the TL detectors used in trials showed very good spatial resolution and dose readings were consistent for all detector types, even at the steepest parts of the dose-distance curve. In our opinion, the new TL detectors can be recommended for measurements of dose distribution around liquid radiation sources.