目的：此篇研究目的為比較根除性全乳切除與乳房保存手術後乳癌病患、接受輔助性放射治療之肺部接受體積／劑量。材料與方法：從2009年7月至2010年10月，我們收集了116位轉介至本科接受輔助性放射、治療的乳癌病態。其中77位接受乳房保存手術，39位接受根除性全乳切除。我們使用治療計畫系統去評估在不同劑量下肺部所接受到的體積，並發覺是否會受手術方法或其他因素所影響。我們分別使用two sample t-test and one-way analysis of variance去執行單變項與多變項統計分析。結果：單變項統計分析顯示接受乳房保存手術、早期腫瘤、或治療照野未包括上鎖骨區域的病患有統計學上顯著性的較低之平均百分比肺部照射體積，而病灶側對在較高劑量下的平均百分比肺部照射體積似有影響。進一步多變項統計分析則顯示腫瘤期數不再是明顯因子，而病灶側與上鎖骨區域照野對於各劑量下的肺部體積是有意義的預測因子。手術方法對於較高劑量下的肺部照射體積有影響。結論：此篇研究顯示當給與術後輔助性放射治療時，接受乳房保存手術之乳癌病患比全乳切除之病態、可以得到較低的肺部照射劑量／體積。

Purpose: The aim of this study is to compare irradiated lung volume/dose for breast cancer patients receiving adjuvant radiotherapy after modified radical mastectomy or breast conservative surgery.Materials & Method: Between July 2009 and October 2010, we collected 116 breast cancer patients who were referred to our department for adjuvant radiotherapy. Seventy-seven received breast conservative surgery and 39 received modified radical mastectomy. We used a treatment planning system to estimate the irradiated lung volume at different dose levels and to discover if different surgical methods or any other factors affected irradiated volume. For statistics, we used two sample t-test and one-way analysis of variance to perform the univariate and multivariate analyses, respectively.Results: The results from the univariate analysis showed that patients receiving breast conservative surgery, with earlier stage, or without suprac1avicular coverage had a significantly lower mean percentage of irradiated lung volume compared to patients receiving modified radical mastectomy, with advanced stage, or with supraclavicular coverage. Left side lesion was a borderline factor in predicting the higher mean percentages of lung volumes at higher dose levels. In the multivariate analysis; however, the stage was not a significant factor. On the other hand, lesion side and supraclavicular coverage were statistically significant factors for lung volumes, and surgical methods affected lung volumes at the higher doses.Conclusion: Patients with breast conservative surgery appear to have a lower irradiated lung volume/dose compared to patients with modified radical mastectomy when post-operative adjuvant radiation is indicated.