Evaluation of doses in the Wernicke and Broca's areas using two different technique in patients with right frontal glioblastoma multiforme

Broca’s and Wernicke’s areas, which are important language areas of brain, are commonly irradiated in patients with right frontal lobe glioblastomamultiforme (GBM). We aimed to compare two different treatment planning techniques in terms of the doses in the Broca’s and Wernicke’s areas for the patients with right frontal GBM.
Two different treatment planning techniques of right frontal GBM were generated for Rando phantom: two field technique using parallel opposed beams and three field techniques. Both plans were compared for doses in planning target volume (PTV), Broca’s and Wernicke’s areas. Additionally to test the accuracy of treatment planning system (TPS) dose calculation thermoluminescent dosimeters (TLD) were used.
The three field technique allowed the lower doses in the Broca’s and Wernickes’s areas. The doses calculated in the Broca’sand Wernicke’s areas were 0.98% ± 0.03 and 0.09% ± 0.06 of the isocenter dose with three field and 1.06% ± 0.04 and 0.133% ± 0.03 of the isocenter dose with two field techniques respectively. When the doses measured by TLD and calculated with TPS were compared the differences were 3.23% and 2.92 % for Broca’s area, and 4.12 % and 3.95% for Wernicke’s area for two field and three field techniques respectively.
There was a good agreement between TPS and TLD calculations for both techniques. Three field techniques seem to be more advantageous than two field technique with respect to doses of Broca’s and Wernicke’s areas. However this finding should be clarified with further clinical studies.