Details

Autor(en) / Beteiligte

• Stathakis, Sotirios
• Esquivel, Carlos
• Gutierrez, Alonso
• Buckey, Courtney R.
• Papanikolaou, Niko

Titel

Treatment planning and delivery of IMRT using 6 and 18MV photon beams without flattening filter

Ist Teil von

• Applied radiation and isotopes, 2009-09, Vol.67 (9), p.1629-1637

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2009

Quelle

MEDLINE

Beschreibungen/Notizen

• In light of the increasing use of intensity modulated radiation therapy (IMRT) in modern radiotherapy practice, the use of a flattening filter may no longer be necessary. Commissioning data have been measured for a Varian 23EX linear accelerator with 6 and 18MV photon energies without a flattening filter. Measurements collected for the commissioning of the linac included percent depth dose curves and profiles for field sizes ranging from 2×2 to 40×40cm2 as defined by the jaws and multileaf collimator. Machine total scatter factors were measured and calculated. Measurements were used to model the unflattened beams with the Pinnacle3 treatment planning system. IMRT plans for prostate, lung, brain and head and neck cancer cases were generated using the flattening filter and flattening filter-free beams. From our results, no difference in the quality of the treatment plans between the flat and unflattened photon beams was noted. There was however a significant decrease in the number of monitor units required for unflattened beam treatment plans due to the increase in linac output—approximately two times and four times higher for the 6 and 18MV, respectively.