以回顧性探討 20 位乳癌病患，以 4D CT 掃描所重組的吸氣相位、吐氣相位、自然呼吸及深吸氣閉氣技術的影像，分別施以混合式治療技術及傳統切線式治療技術兩種不同的治療計畫。其處方劑量為每日 1.8 格雷共 28次，總劑量 50.4 格雷。以劑量體積圖觀察肺臟 V25.2及心臟 V30的差異。結果發現，無論於哪種治療計畫下，深吸氣閉氣技術可以明顯降低肺臟 V25.2及心臟 V30。病患每日治療位置的再現性，以紀錄每日治療前，預習性深吸氣閉氣，其中心點位移距離來觀察。結果在上下、左右、前後三個方向其標準差大部分(83.3%)小於 0.2 cm，顯示每日中心點位移在合理範圍內，可以視為吸氣量再現性是符合期待的。另外記錄深吸氣閉氣技術時，病人每次的呼吸潮氣量，觀察其穩定度差異，結果介於 ± 2.3 % 到 ± 8.6 % 。綜觀看來，深吸氣閉氣可以將危急器官推離開輻射照野，程度上雖因人而異但好好訓練病人做胸式吸氣，並建議閉氣閥值≧ 1 l，心臟與肺臟受輻射照射的體積會明顯減少，進而減少生物效應產生的機率。

This study is to review the reconstructed 4D-CT images of various phases of inspiration, expiration, free breathing
and deep inspiration breathing-hold (DIBH) technique among 20 breast cancer patients who have been treated either by
hybrid treatment plan or by conventional tangential radiation treatment. The prescribed daily dosage is 1.8 Gy for 28
sessions which yield the total of 50.4 Gy. By observing the variation of lungV25.2 and heart V30 through the dose-volume
histogram, it can be concluded that DIBH can evidently lower both lung V25.2 and heart V30. The daily reproducibility of
the treatment target location can be examined by observing the daily offset distance of the center between the daily DIBH
prep-practice and treatment. Most (83%) of the standard deviations on the 3 axes of anterior-posterior, superior-inferior
and left-right are within 0.2 cm which indicates the mis-location is within a reasonable range and can the reproducibility
of inspiration volume conforms the expectation. Through the records of each tidal volume while patients are practicing
DIBH, the stability can be examined. The result shows the deviation is within ± 2.3 % and ± 8.6 %. It can be concluded
that DIBH can influence the relocation of critical organs away from the radiation coverage for various degree among
different patients. Well DIBH training to the patients with threshold ≧ 1 liter can massively reduce the irradiated volume
of the lung and the heart, and further reduce the chance of bio-effect.