乳癌放射治療對正常組織的影響

Normal Tissue Doses of Radiation from Radiotherapy of Breast Cancer

陳弘政(Hung-Cheng Chen) ； 葉健一(Jam-I Yeh) ； 葉啟源(Chi-Yuan Yeh) ； 賴允亮(Yuen-Liang Lai) ； 陳文政(Wen-Cheng Chen)

《放射治療與腫瘤學》 2卷4期 (1995/12) Pp. 337-344

https://doi.org/10.6316/TRO/199502(4)337

摘要

目的；在放射治療期間，照射範圍外的正常器官及組織，不可避免地必定會接受到一些散射劑量。為了作為臨床上評估的需要。我們以人形假體作為實驗病人，針對乳癌放射治療時，其他正常器官所接受的劑量進行測量。
材料與方法：所使用的機器包括直線加速器(6MV)和鈷六十治療機，測量的器官有腦、眼球、唾液腺、甲狀腺、肺、胃、胰臟、腎、卵巢、睪丸及對側乳房等。
結果：測量的結果顯示；當一側乳房以6MV的X射線照射5000 Gy的腫瘤劑量時，除了對側乳房之外其它器官的散射劑量在6~246 cGy之間。對側乳房則分別以直線加速器(6MV)和鈷六十治療機及加上不同角度的楔形濾片(wedge)在十種不同情況下作測量，其散射劑量約在64~425 cGy之間，而且使用的wedge角度越大對側乳房的劑量就越高。
結論：從本實驗的結果我們有以下結論：1)越遠離照射部位的器官接受的散射劑量越低。2)使用楔濾片將會增加對側乳房的散射劑量。3)使用的楔形濾片角度越大。對側乳房的散射劑量也越高。

關鍵字

乳癌放射治療 ； 正常器官 ； 腫瘤劑量 ； 散射劑量

並列摘要

Purpose: Incidental radiation, outside of the treatment field, is an unavoidable consequence of radiotherapy. For the use of clinical evaluation, scatter radiation to normal tissue was measured with an Alderson anthromorphic phantom simulating breast cancer radiotherapy.
Material and method: Treatment machines included a Mitsubishi linear accelerator (6 MV) and a AECL Cobalt-60 teletherapy unit. The scatter dose to the brain, eye, salivary gland, thyroid gland, lung, stomach, pancreas, kidney, ovary, testis, and opposite breast was measured. Result: Measurement results indicated that if the affected breast received 5000 cGy tumor dose by irradiation with 6 MV X-ray then the other organs except the opposite breast would absorb a scatter dose ranging between 6 cGy to 246 cGy. Incidental radiation to the opposite breast was measured under 10 different situations using diverse wedges on the linear accelerator (6 MV) and a Cobalt.60 teletherapy unit. The measured scatter dose to the opposite breast ranged from 64 cGy to 425 cGy. We also found out that larger wedge angles deliver a higher scatter dose to the opposite breast.
Conclusion: From the result of our experiment, we conclude: 1) The scatter dose outside of the primary beam decreased with increasing distance from the irradiated site. 2) When wedges were used, the scatter dose to opposite breast increased, 3) Using the larger wedge angle would deliver the higher scatter dose to opposite breast.

並列關鍵字

Breast cancer radiotherapy ； Normal tissue ； Tumor dose ； Scatter dose