Evaluation of intermediate energy photons for radiation therapy.
Published: 2006
Language: eng
Number of pages: 134
ISBN-13: 9780494161579
Description: This theoretical study examines the reduced beam penumbra of intermediate energy photons (100 keV- 1 MeV) and evaluates their clinical benefit. Using the Monte Carlo N-Particle transport code MCNP-4C, the contribution to radiological penumbra from photon scatter is shown to be negligible for small fields (&le; 4x4cm2); secondary electron spread is the main contributor. Intermediate energy photon beams interact with tissue atoms to liberate low energy secondary electrons that have an extremely short range. Radiological penumbra is about 300 mum for 300 keV photons on a small field. A MCNP-4C generated 800 kV photon spectrum was input in a modified version of the Pinnacle treatment planning system. Treatment plans for a hypothetical, small brain lesion were produced using the 800 kV spectrum and were compared to plans from a 6 MV machine by means of Dose Volume Histograms.	The 800 kV plans show better sparing of an adjacent critical structure.
Notes: Source: Masters Abstracts International, Volume: 44-06, page: 2727.

Thesis (M.Sc.)--University of Toronto, 2006.

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