Room: ePoster Forums
Purpose: to analyze the dose verification results of 611 cases of breast cancer after breast conserving surgery who were treated using combined radiation technique, and provide reference for the design and improvement of the clinical treatment plan of this type of patients.
Methods: a retrospective analysis of dose verification results for 611 cases of breast cancer after breast conserving surgery using 3D-conformal and intensity-modulated combined radiation technique, All patients were treated with Siemens Artiste Linac, the verification results including 367 absolute dose cases and 244 plane dose verification cases. All plans were designed by 25 fractions with 2.0 Gy fraction dose in pinnacle treatment planning system. The plans were composed of two 3D-conformal tangent fields and IMRT fields. The conformal tangent fields covered 70%-80% fraction dose and the IMRT fields covered the left dose. The absolute dose verification were measured in solid water using IBA dose 1 electrometer and IBA FC65 ionization chamber, and the dose deviation â‰¤Â± 3% was defined to pass; Plane dose verification were done by IBA Matrix 2-dimensional chamer-matirix. the gamma pass rate by 3%, / 3 mm, the pass rate â‰¥95% was defined as up to standard.
Results: The absolute dose verification results was: -1.71% Â± 1.12%; the plane dose verification results was -97.0% Â± 2%.
Conclusion: More than 98% of the mixed beams irradiation plansâ€™ absolute dose verification or plane dose verification results could be up to standard, the cases which could not met the standard could be also validated by a small modified using the technique, As a matter of fact, combined the conformal fields with intensity modulated fields irradiation technique for breast cancer patients with breast conserving surgery is an effective technique for breast cancer radiotherapy, it has higher radiation dose and better dose distribution for treatment targets than normal treatment technique.