目的：比較評估兩種不同模式-- (1) 以劑量- 體積基礎優化條件為主的強度調控放射治療計劃
（DV-based IMRT plan, 簡稱 DV-plan），(2) 以DV-based優化條件為主，並以廣義等效均勻劑量（generalized equilibrium uniform dose, gEUD-based）優化條件為輔的強度調控放射治療計劃（DV-gEUD-based IMRT plan, 簡稱 DV-gEUD-plan）對於雙邊乳癌病患治療之間的差異。材料與方法：本研究採用 6 位疾病分期為 T2~T4 的雙邊乳癌病患，使用 Pinnacle3（version 8.0m, Philips, Fitchburg, WI）治療計劃系統分別規劃 DV-based 與 DV-gEUD 計劃進行比較，並在配備有 120 葉多葉式準直儀的 Varian 21 EX Linac（Varian Medical Systems, Milpitas, CA）機器執行治療。計劃靶體積（planning target volume, PTV）的劑量處方為 50.4 Gy，進行 28 次的分次治療。利用劑量指標評估量化計劃結果，包括 PTV 的順形指標（conformity index, CI）、勻稱指標
（homogeneity index, HI）和腫瘤控制率（tumor control probability, TCP）；危及器官（包括心、肺臟）的V20 Gy與 V30 Gy體積、平均劑量與正常組織副作用發生率（normal tissue complicationprobability, NTCP）。同時，評估治療計劃執行的正確率。結果：DV- 與 DV-gEUD-plan 都能符合 PTV 包覆率的要求，PTV 順形指標和勻稱指標在兩計劃表現相當，而 DV-gEUD-plan 具有減少危及器官劑量的優勢：心臟、肺臟的平均劑量與肺臟 V20 Gy、心臟 V30 Gy在 DV-gEUD-plan 都比 DV-plan 低（p值小於0.05）。另外，兩種計劃
Gamma（Γ3 mm, 3%）分析結果都有 95.5%以上的通過率。結論：DV-gEUD-plan 結合 DV- 與 gEUD-based 的目標函數，可以創建更好的計劃結果。這種混合的方法，可以減少 DV-plan 試誤的次數，同時保留 gEUD-plan 所提供的最佳劑量分佈。

Purpose : To compare the planning performance between dose-volume-based IMRT plans (DV-based IMRT plan, (DV-plan) ) and DV-plan with generalized equivalent uniform dose (gEUD) optimization (DV-gEUD-based IMRT plan, (DV-gEUD-plan) ) on bilateral breast cancer (BBC).Materials and Methods : Six consecutive BBC patients (staged: T2~T4) were planed using the planning system of the Pinnacle3 (version 8.0m, Philips, Fitchburg, WI) to compare the performance of DV- and DV-gEUD plans. The plan was delivered on a Varian 21 EX Linac (Varian Medical Systems, Milpitas, CA) equipped with a 120-leaf multileaf collimator. The prescribed doses were 50.4Gy/28 fractions to the planned target volume (PTV). The dosimetric parameters used included the conformity index (CI), homogeneity index (HI) and tumor control probability (TCP) for the PTV; and V20 Gy and V30Gy for the total lung and heart, respectively; and mean dose, normal tissue complication
probability (NTCP) for the both OARs. The planning delivery accuracy was checked.Results : Both techniques fulfilled the objectives on target coverage. A comparable CI and HI of the PTV were observed on both plans. For the OARs, a significantly superior normal tissue sparing was
observed in DV-gEUD-plan. The DV-gEUD-plan has smaller mean dose of lung and heart, V20 Gy of lung , and V30 Gy of heart (p< 0.05) with respect to the DV-plan. Both plans presented a high QA pass rate (>95.5%) of the Γ3mm, 3% criterion.Conclusions : A better plan (DV-gEUD-plan) can be obtained through a combination of DV- and gEUD-based objective function. This hybrid approach can reduce the number of trial and error in DV-plan processing while retaining a better dose distribution which gEUD-plan can provide.