J Korean Soc Ther Radiol.  1992 Jun;10(1):85-94.

The dosimetric Properties of Electron Beam Using Lyon Intraoperative Device for Intraoperative Radiation Therapy

• Kim KJ
• Park KR
• Lee JY
• Kim HY
• Sung KJ
• Chu SS

Abstract

We have studied the dosimetric properties of electron beam using Lyon intraoperative device for intraoperative radiation therapy. The dosimetry data had compiled in such a way that a quick and correct decision regarding the cone shape, energy, and accurate calculations could be made. Using 3 dimensional water phantom, we have got the following data: cone output ratios, surface dose, dmax, dgo, flatness, symmetry, beam profiles, isodose curve, and SSD correction factors. The cone output ratios were measured with straight and bevelled cone, respectively. As the cone size and the energy were reduced, the cone output ratios decreased rapidly. With the flattening filter, the surface dose increased by electron beam to 85.3%, 89.2%, and 93.4%, for 6MeV, 9MeV, and 12MeV, respectively. It is important to increase the surface dose to 90% or more. Inspite of diminishing dose rate and beam penetration, this flattening filter increases the treatment volume significantly. With the combination of the three levels collimation and the flattening filter, we achieved good homogeneity of the beam and better flatness and the diameter of the 90% isodose curve was increased. It is important to increase the area that is included in the 90% isodose level. The value of measured and calculated SSD correction factors did not agree over the clinically important range from 100cm to 110cm .

Keyword

Intraoperative Radiotherapy; Electron Beams; Dosimetry; Lyon Intraoperative Device

MeSH Terms

Silver Sulfadiazine
Water
Silver Sulfadiazine
Water