Program Information
Dosimetric Comparison of Different Treatment Modalities for Bilateral Breast Cancer
B Ispir1*, G Ugurluer2 , Y Akdeniz1 , I Kaptan1 , M Serin2 , (1) Acibadem Adana Hospital, Adana, ,(2) Acibadem University Faculty of Medicine, Adana.
Presentations
SU-I-GPD-J-15 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: To compare the dosimetric characteristics of three different treatment techniques VMAT, IMRT and 3DCRT for Synchronous Bilateral Breast Cancer (SBBC).
Methods: Eight patients diagnosed with SBBC were selected. CT images were imported to treatment planning system (Eclipse Helios v11). 3DCRT plans used two tangent beams with wedge. Both two double half arc VMAT (two isocentric) and two 7-field IMRT (two isocentric) plans were generated for each patients using the same defined tumor volumes, OAR volumes, dose, fractionation, and optimization constraints. AAA was utilized for calculation of the treatment plans. The evaluations analyzed DVH findings of the target volumes and OAR.
Results: In terms of coverage of the target volume did not differ between treatment planning techniques except that PTV V110 higher rise in the value of IMRT plans.The volume of the lung receiving 20 Gy was 19.63% for VMAT, 20.79 % for IMRT and 18.69 % for 3DCRT (p>0.05), V5 value was 70.63%, 67.74% and 30.84% (p≤0.05), respectively. The mean dose of heart was 1162.09±215.02 cGy for VMAT, 1203.63±268.15 cGy for IMRT and 661.33±194.11 cGy for 3DCRT (p≤0.05); V25 value 10.55%, 10.81% and 7.44% (p>0.05); V45 was 0.55%, 0.29% and 3.11% (p≤0.05) respectively. Monitor units were obtained 774.13, 2291.25 and 596.88 (MU) for VMAT, IMRT and 3DCRT, respectively. The IMRT plans had a statistically significant increase in MU compared with the YART plans (p≤0.05).
Conclusion: There were no difference covered in the PTV when compared to the techniques of VMAT, IMRT and 3DCRT for patients. The volume of the lung receiving 5 Gy was higher for VMAT and IMRT than 3DCRT. However, there was no statistically significant difference for lung of V20. While the mean dose of heart was decreased for 3DCRT, the volume of the heart receiving 45 Gy is reduced for VMAT and IMRT plans.
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