33 Endovascular Brachytherapy

646 Endovascular Brachytherapy

Fig 32.7: The Guidant Galileo System during irradiation of a coronary vessel. The delivery catheter is connected to the front side of the system. A touch-screen is indicating the treatment parameters and the remaining dwell time.

7.1.2.3 The Novoste Beta-Cath™ Intracoronary Beta Radiation System The delivery unit for the radioactive Sr-90/Y-90 source train consists of a quartz source container for shielding and a hydraulic system, operated by an external syringe. Source delivery is manual. The delivery unit is equipped with electronic interlocks for safety and lead indicators for optimal fluid pressure and location of the sources. Due to the half life of 28 years, replacement of sources due to source decay is not necessary. However, for maintenance and update of the device by the manufacturer, there is an exchange of sources twice a year. Two devices containing source trains are available with 12, 16 or 24 seeds, each 2.5 mm resulting in an ASL of 30, 40 or 60 mm. The solid Sr-90/Y-90 mixture is encapsulated in a seed cylinder of 0.64 mm outer diameter with an activity of 0.13 GBq each. Additionally, there are two radio-opaque gold seeds at each end of the source train.

Fig 32.8. The Novoste BetaCath System is used by manual fluid pressure using a syringe fixed to the delivery device. The delivery catheter is connected with a lock system. When not in use the sources are located in a safe and are visible through a shielded window.