Page 31 - Brachytherapy

Remote afterloading devices are used in both interstitial and

intracavitary clinical applications. The anatomic sites commonly

treated with these devices are similar to those treated with

conventional brachytherapy procedures. The essential components

of all remote afterloading systems are:

(i) A safe to house the radioactive source; 1970- Cobalt RALSTON (Diameter 3mm)

(ii) Radioactive sources, single or multiple;

(iii) A local or remote operating console;

(iv) A source control and drive mechanism;

(v) Source transfer guide tubes and treatment applicators;

(vi) A treatment planning computer.

The three commonly used radioactive sources in remote

afterloading devices are 60Co, 137Cs and 192Ir. Currently the

most commonly used source for afterloading is 192Ir, because of

its medium average g ray energy (~400 keV) and its high specific

activity. However, its relatively short half-life is a distinct

disadvantage, since frequent replacement of sources is required 1990- Ir-192 RALS (Diameter 1.1mm) 2000-Cobalt RALS (Diameter 1.1mm)

(typically three to four times per year).
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