['Intracoronary gamma or beta radiation from centrally located sources at the time of overstretch balloon injury inhibits neointimal proliferation. In an effort to deliver homogeneous, centered radiation fields in a technically straightforward fashion, we studied the effects of a beta-emitting solution used as a balloon inflation fluid to deliver radiation at the time of coronary injury.', 'Twenty-one coronary arteries in 13 juvenile swine underwent irradiation (control and 11 or 25 Gy media dose). Radiation was delivered using a perfusion balloon inflated with an Re-188 solution. Subsequently, overdilatation percutaneous transluminal coronary angioplasty was performed at the pretreated segment. Histopathologic and histomorphometric analysis was performed at 30 days after injury on the entire irradiated artery.', 'Balloon overdilation was associated with significant vascular injury and marked neointimal proliferation in control and low-dose (11 Gy)-treated arteries. High-dose radiation (25 Gy) significantly inhibited neointima formation compared with controls (neointimal area: 0.49 +/- 0.29 mm2 vs. 1.51 +/- 0.22 mm2, respectively; p = 0.02) and low-dose radiation (neointimal area 1.75 +/- 0.54 mm2, p > 0.1 compared with controls).'] Does radioactive beta-emitting solution-filled balloon treatment prevent porcine coronary restenosis?