Source of Support: None, Conflict of Interest: None
The aim of the present study was to carry out the physical measurements such as depth dose around a high activity lr-192 source and derive the radial dose factors and compare with the published data. A
commercial computer controlled 3-D water phantom system (WPS) was used with an ion chamber of 0.125 cc (PTW, Freiburg, Germany). The chamber was 1 cm long and 0.55 cm diameter and enclosed in a 100 cm long rubber tube. The chamber was connected to an electrometer and operated at a voltage of 300 V. The ionization measurements were made along the perpendicular bisector of the source at a regular interval. Depth dose curve was obtained and radial dose factors were derived. This study improves our confidence in measurement using 3-dimensional WPS and the small size detectors coupled with the electrometer. The present radial dose factors, g(r) values, may be used in clinical situations where secondary dose at other parts of the body located at larger distances are warranted.