Purpose: To evaluate the results of endovascular brachytherapy using beta-emitting radio-istopes for in-stent restenosis in coronary arteries at Lausanne.Materials and Methods: From July 1998 on, we have treated 136 patients with endovascular brachytherapy. We report here the results on the 98 patients with in-stent restenosis. The remaining patients are not included because they present or with de novo lesions or with an insufficient follow-up.The endovascular brachytherapy has been applied with two systems: in 92 patients we have used the Beta-Cath device from Novoste® (30 mm source train of strontium-90 seeds; activity of 3.7 GBq; half-life of 28.8 years) and in 6 patients the RDX from Radiance® (33 mm balloon with integrated in the layers the solid 32P; activity of 0.7 GBq; half-life of 14.3 days; balloon diameter range 2.5, 3.0 and 3.5 mm). Both isotopes are beta-emitting. The dose for Novoste is 18-24 Gy according to vessel diameter with a dwell time below 300 secs, and for RDX 20Gy at 1 mm from the balloon surface with a dwell time range 240-720 secs.Results: Ninety eight patients are reported; the mean age of the treated population is 58.4 (+/- 12.1). Twenty three patients are female. 35 patients present unstable angina. For two patients the reintervention has been done for two vessels. The in-stent restenosis pattern is diffuse, it means more than 10 mm in total lenght, in 73% of the cases. The targets are located in the left anterior descending artery (LAD) in 45 patients, in the left circumflex (LCx) in 13 patients, in the right coronary artery (RCA) in 37 patients and in vein grafts in 7 patients. A new stent implant has been performed in 10 lesions. The procedural success rate, it means the application of the planned dose without any in-hospital complication, is 96%. Three procedural failures have occurred in the first series of 50 patients. Geographical miss defined as underdosage at the edges of the target, has been observed in 14 lesions amongst the first 30 patients. For the latter 68 patients, no geographic miss has been registered mainly to a greater care taken to cover the whole site of the vesssel submitted to the barotrauma during the angioplasty. The initial source train lenght used was 30 mm. In the second part of our clinical experience the 40 mm and 60 mm source of Novoste® became available. During the 24-hours hospitalization following the procedure, only one patient required a repeat PTCA. After a mean follow-up of 11 months an event occurred in 8 patients; we registered three deaths (cancer, preexisting heart failure and a death due to a car accident secondary to cardiac arrest). Target vessel revascularisation has been required in 5 patients.Conclusion: Endovascular brachytherapy is considered a standard for in-stent restenosis. We report a series of 100 applications done in 98 patients. The technique is feasible, safe and the short term results are excellent. The difference in the rate of geographical missses clearly illustrates a learning curve effect and optimisation of technical characteristics of available systems. At the present time the dose prescription is based on vessel measurements made by intravascular ultrasound. Purpose: To evaluate the results of endovascular brachytherapy using beta-emitting radio-istopes for in-stent restenosis in coronary arteries at Lausanne. Materials and Methods: From July 1998 on, we have treated 136 patients with endovascular brachytherapy. We report here the results on the 98 patients with in-stent restenosis. The remaining patients are not included because they present or with de novo lesions or with an insufficient follow-up.The endovascular brachytherapy has been applied with two systems: in 92 patients we have used the Beta-Cath device from Novoste® (30 mm source train of strontium-90 seeds; activity of 3.7 GBq; half-life of 28.8 years) and in 6 patients the RDX from Radiance® (33 mm balloon with integrated in the layers the solid 32P; activity of 0.7 GBq; half-life of 14.3 days; balloon diameter range 2.5, 3.0 and 3.5 mm). Both isotopes are beta-emitting. The dose for Novoste is 18-24 Gy according to vessel diameter with a dwell time below 300 secs, and for RDX 20Gy at 1 mm from the balloon surface with a dwell time range 240-720 secs. Results: Ninety eight patients are reported; the mean age of the treated population is 58.4 (+/- 12.1). Twenty three patients are female. 35 patients present unstable angina. For two patients the reintervention has been done for two vessels. The in-stent restenosis pattern is diffuse, it means more than 10 mm in total lenght, in 73% of the cases. The targets are located in the left anterior descending artery (LAD) in 45 patients, in the left circumflex (LCx) in 13 patients, in the right coronary artery (RCA) in 37 patients and in vein grafts in 7 patients. A new stent implant has been performed in 10 lesions. The procedural success rate, it means the application of the planned dose without any in-hospital complication, is 96%. Three procedural failures have occurred in the first series of 50 patients. Geographical miss defined as underdosage at the edges of the target, has been observed in 14 lesions amongst the first 30 patients. For the latter 68 patients, no geographic miss has been registered mainly to a greater care taken to cover the whole site of the vesssel submitted to the barotrauma during the angioplasty. The initial source train lenght used was 30 mm. In the second part of our clinical experience the 40 mm and 60 mm source of Novoste® became available. During the 24-hours hospitalization following the procedure, only one patient required a repeat PTCA. After a mean follow-up of 11 months an event occurred in 8 patients; we registered three deaths (cancer, preexisting heart failure and a death due to a car accident secondary to cardiac arrest). Target vessel revascularisation has been required in 5 patients. Conclusion: Endovascular brachytherapy is considered a standard for in-stent restenosis. We report a series of 100 applications done in 98 patients. The technique is feasible, safe and the short term results are excellent. The difference in the rate of geographical missses clearly illustrates a learning curve effect and optimisation of technical characteristics of available systems. At the present time the dose prescription is based on vessel measurements made by intravascular ultrasound.

The study presented in this article raises the problems of the integration of recently graduated nurses in the hospital from the point of view of a culture difference between the two socialisation worlds: more reflexive standards of behaviour and culture in the schools (emphasis on analysis, knowledge, care actions argumentation...) and more instrumental ones in the hospitals (emphasis on efficiency, work organisation, operationality...). An enquiry by means of interviews with recent graduates from different schools (open, semi-open and closed questions) enables to successively analyse the skills they consider to have acquired at school, the ones they consider as required by the hospital and the differences they feel between hospital and school concerning the enhanced skills. The results show a significant discrepancy between the ideal of the interviewed nurses and the reality of their work within the institutional constraints of the hospital.