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最近遇到一位老杯杯一直來亂吵亂鬧
又去衛生局亂告,
說他三年前做牙科治療,醫師沒告知他照牙科X光會得腦膜瘤,
他最近走路會跌倒.....PALA....PALA...
一堆老人本來就會有的症狀,他全歸咎於照牙科X光.
老娘看了他所附的所謂【證據】,
原來是來自於2012年4月出版的﹝經濟學人﹞的報導.
(說馬總統是笨蛋的那本刊物.)
5/200000=萬分之2.5
老娘覺得這研究有點問題,若調查發現腦膜瘤患者搭過飛機的人,是非腦膜瘤患者沒搭過飛機的人的2倍。大家是不是從此不要再搭飛機了?
出門會發生車禍的機率比呆在家發生車禍的機率高百萬倍,大家是不是從此不要再出門了?
希望衛生主管機關接到這種申訴,直接告訴病人去看精神科,不要叫醫院再給他什麼公文回復了,因為跟這種人怎麼解釋也說不通,徒然浪費醫師的時間,消耗醫療人員服務的熱忱.
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放射線人體吸收劑量單位為毫西弗(mSv)
1000毫西弗(mSv)為1西弗(Sv)
一.根據行政院原子能委員會公布:
| 情 況 | 劑 量 |
1. | 一般民眾年劑量限值為 （不含天然背景輻射及醫療劑量） | 1 mSv/年 |
2. | 台灣每人接受天然背景輻射劑年劑量值為 (天然背景輻射來自:宇宙射線、食物、地表輻射、氧氣) | 1.6 mSv/年 |
3. | 搭飛機台北往返美國西岸一趟 | 1.09 mSv |
4. | 每天抽30支香菸 | 13 mSv/年 |
5. | 輻射工作人員年劑量限值 | 20 mSv/年 |
6. | 全身一次急性曝露____Sv就會噁心、嘔吐 | 1~2 Sv |
7. | 全身一次急性曝露____Sv就會死亡 | ＞6 Sv |
＊國際放射防護委員會（ICRP）建議:
1. | 個人年等效劑量上限為 | 5 mSv（毫西弗）/年 |
2. | 一旦確定懷孕，胎兒每月接受之輻射劑量不可超過 | 0.5 毫西弗 |
3. | 整個懷孕過程，母親腹部表皮的輻射劑量不可超過 | 2 毫西弗 |
4. | 一次曝露在____毫西弗時，會變成暫時不孕 | 100 毫西弗 |
5. | _____毫西弗以上將會成為永久性不孕 | 2000 毫西弗 |
牙醫診斷型X光攝影所產生輻射劑量之綜合評估
Radiation Dose Evaluation with Dental Radiographies
王士元
S.Y. Wang
生物醫學影像暨放射科學系暨研究所
關鍵詞:
有效劑量;全口根尖片攝影;
Keyword:
effective dose;periapical series;
摘要:
中文摘要 於牙醫臨床上，使用X光的基本目標即是在獲得病人最佳影像診斷資訊的前提下，使病人、醫務人員及民眾接受到最少量的輻射劑量。儘管如此一般牙科病患針對牙科X光攝影，所可能造成人體輻射生物效應仍有相當程度的疑慮。 在本研究中，我們針對全國牙醫師診斷設備，就其相關照射條件、工作場合之輻射環境、工作人員及病患所接受之輻射劑量，做一有系統之量測、分析研究，並與現行之規章法令相互比較與驗證。本研究使用加馬輻射線偵測儀與Barracuda-多功能之輻射測量儀；做為量測牙醫型診斷設備之輸出與滲漏輻射之量測工具，並使用熱發光劑量計 (Thermoluminescent Dosimeter, TLD-100H)，來量測工作環境、工作人員之輻射吸收劑量以及病患於接受攝影時，其有效劑量的量測與評估等。 本研究於各項照射條件及硬體參數設定下，所得到的測量結果與現行之相關法規做一相互比較，其結果如下
：(1) X光機之滲漏輻射：量測結果為21.31 ± 15.24 mR/h，符合法規需低於規定值100 mR/h。(2) 濾片厚度：傳統型牙醫用X光機，其平均濾片厚度為1.95 ± 0.3 mmAl，符合法規70kVp以下必須大於規定值1.5 mmAl鋁厚當量； 環口型牙醫X光機，其平均濾片厚度為2.66 ± 0.11 mmAl，符合法規70kVp以上必須大於規定值2.5 mmAl鋁厚當量。(3) 管電壓：X光能量為60 kVp之傳統型X光機，其設定值與輸出值之平均誤差為2.5%，其中最大誤差值為6.5%，最小誤差值為0.2%，均符合法規小於限定值7%。(4) 照射時間：傳統型X光機之暴露時間範圍：0.5~1.5 sec，平均誤差：7.3%，最大誤差值：8.5%，最小誤差值：0.7%，均符合法規小於限定值10%。(5) 靶至皮膚距離：所量測之X光機，其圓形筒體(cone)平均長度為14.75 ± 0.5 cm，並推算防護管套平均長度為18.63 ± 2.63 cm；因此靶至皮膚距離，均合於法規需大於18公分之規定。(6) 射柱直徑：X光機之圓形筒體直徑均在6 cm內，
合於法規有用射柱在圓錐體尖端之直徑不得大於7.6 cm。(7) 人員劑量部份為：(i) 牙醫師之年劑量約為1.44 ± 1.08 mSv /年；(ii) 助理人員之年劑量約為2.04 ± 1.8 mSv /年，均遠低於法規限定一年內之有效等效劑量不得超過50mSv之規定。(8) 輻射屏蔽：利用熱發光劑量計(TLD)量測國內各牙醫診所之X光室，屏蔽外之輻射劑量值，平均量測結果為：22.70 ± 17.44 μGy /月，遠低於非管制區的限制值。 由上述結果得知，目前國內牙醫診所所使用之X光設備，無論其管電壓，照射時間等條件均符合於現行法規之限值內。此外，在人員與環境劑量評估方面；本研究
也發現牙醫師與助理人員之年累積輻射劑量值均遠低於現行法規之規定；另外在模擬病患於接受牙科各式攝影法中，其有效劑量最高值為55μSv，最低值僅有5μSv。 本篇研究報告除了提
供目前國內各牙醫臨床診所，針對其X光診斷設備與相關工作輻射環境等有更進ㄧ步之了解外，也提供相關主管機關於日後於管理與監督時之參考；另外從本研究結果，亦可使一般病患瞭解，接受牙醫X光攝影檢查應不致於對身體造成過量的輻射劑量。
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http://www.ada.org/news/6979.aspx
美國牙醫協會對該篇研究報告之評論如下:
April 13, 2012
Experts question X-ray study
Association with brain tumors based on patient recall of radiographs
By Jean Williams, ADA News staff
A study published online April 10 associating dental radiographs with brain tumors has stirred media attention and questions from experts on the study’s methodology.
The study published in Cancer, an American Cancer Society peer-reviewed journal, found that people with meningiomas (typically benign brain tumors) are more likely to report that they’ve had certain dental X-ray examinations in their lifetimes.
In a press statement following publication of the study online by Cancer, the ADA referred to ADA recommendations for prescribing radiographs, which help dentists determine how to keep radiation exposure as low as reasonably achievable.
“The ADA has reviewed the study and notes that the results rely on the individuals’ memories of having dental X-rays taken years earlier,” said the April 10 statement. “Studies have shown that the ability to recall information is often imperfect. Therefore, the results of studies that use this design can be unreliable because they are affected by what scientists call ‘recall bias.’”
The ADA released its statement in tandem with the lifting of the press embargo on the study. U.S. News and World Report and MSNBC interviewed Dr. Matthew Messina, a practicing dentist in Ohio and an ADA media spokesperson. Several other media outlets cited the ADA’s recommendations on dental X-rays, which can be viewed at ADA.org. (Click the Public Resources tab, Oral Health Topics, Radiography/X-ray and Dentist Version to find The Selection of Patients for Dental Radiographic Examinations.)
In “Dental X-rays and Risk of Meningioma,” the authors, led by researcher and neurosurgeon Elizabeth B. Claus, M.D., of Yale University School of Medicine and Brigham and Women’s Hospital, conclude that “exposure to some dental X-rays performed in the past, when radiation exposure was greater than in the current era, appears to be associated with an increased risk of intracranial meningioma.”
Using anecdotal evidence, the population-based, case-control study compared dental and therapeutic radiation histories in 1,433 patients who had intracranial meningiomas diagnosed between ages 20 and 79 with a control group of 1,350 patients. Data collection involved interviews and questionnaires and relied on the patients’ recall of details related to dental care received over their lifetimes.
According to the study report, “Participants were asked to report the number of times they had received bitewing, full-mouth, or panoramic films” during four stages in life: before age 10, between ages 10 and 19, between ages 20 and 49, and up to age 50.
Dr. Alan G. Lurie, a radiation biologist and head of radiology at the University of Connecticut School of Dental Medicine, has many concerns about the study’s design and outcomes. “I think it is a very flawed study,” said Dr. Lurie, who is also president of the American Academy of Oral and Maxillofacial Radiology.
He characterized at least one outcome of the study—reflected in a table that related meningioma risk to types of dental X-ray examination—as “radiobiologically impossible.”
Said Dr. Lurie, “They have a table, Table 2, in which they ask the question, ‘Ever had a bitewing,’ and the odds ratio risk from a bitewing ranges from 1.2 to 2.0, depending on the age group. Then they asked ‘Ever had full mouth’ series, and the odds ratio risk from a full mouth series ranged from 1.0 to 1.2.
“That is biologically not possible because the full mouth series has two to four bitewings plus another 10 to 16 periapicals. A full mouth series, just to round things off, is 20 intraoral X-rays of which two to four are bitewings. They are showing that one bitewing has 50 to 100 percent greater risk than a full mouth series that has multiple bitewings plus a bunch of other films.”
Explaining this gross internal discrepancy is difficult, as the epidemiologic and statistical methods are widely accepted, Dr. Lurie said. He attributes the perceived discrepancy in the data to possible recall bias in the patients involved in the study.
“Epidemiologists are very aware of this bias,” Dr. Lurie said. “What happens is you’re asking people to remember what kind of dental X-rays they had 10, 20, 30 or 40 years ago, and how frequently they had those X-rays. It’s anecdotal, and the argument is that it’s just as anecdotal for the group without meningiomas as it is for the group with meningiomas. That is not necessarily true.”
Individuals who had meningiomas and had surgery for them in this study population may be more likely to remember having had X-rays than individuals who did not have meningiomas, Dr. Lurie said.
Dr. Lurie emphasized that his comments on the dental X-rays study are his own.
In addition, AAOMR’s official statement similarly took issue with the study’s validity. Dr. Ernest Lam, associate professor of oral and maxillofacial radiology/biological and diagnostic sciences at University of Toronto Faculty of Dentistry, and Dr. Jie Yang, professor of oral and maxillofacial radiology at Temple University Kornberg School of Dentistry, are the statement’s authors.
“A number of irreconcilable data collection and consistency problems highlight serious flaws in the study and render the conclusions invalid,” the AAOMR statement concluded.
The statement also said: “Absorbed doses from dental radiography have declined upwards of 60 percent in recent years as a result of faster X-ray film speed, the development of digital sensor technology, X-ray beam collimation and patient shielding. Given that these and other factors were not known to the subjects or reported, it is impossible to recreate a dose-response relationship between the radiation doses subjects received and the development of meningioma.”
View the AAOMR statement online.
A broad range of local, national and international media reported news of the dental X-rays study, including ABC World News with Diane Sawyer, CBS This Morning, Good Morning America, USA Today, The Sun (United Kingdom), The Daily Mail (United Kingdom) and others.
The study can be viewed online free of charge online.
The ADA in November 2010, with the support of an educational grant from Schick Technologies Inc., distributed Safe Use of Radiographs in Dentistry, a full-color poster that ADA members can order free from schicktech.com or by calling Emily Brown at 1-718-482-2131.
Also, members may take the ADA Online CE course: Radiographic Examinations: Choosing the Right Patients and Equipment, which can be accessed at adaceonline.org.
Visit ADA.org for additional resources on dental X-rays.
研究：牙科X光易致腦膜瘤
2012-04-17 Web only 作者：經濟學人
如果你是那種擔心照牙科X光會影響健康的人，耶魯大學Elizabeth Claus的研究顯示，你可能是對的。富有國家裡，每20萬個男人就有5人患有腦膜瘤，女性患病率則是男性的2倍；只有2%的腦膜瘤是惡性腫瘤，但良性腦膜瘤還是會致命，約30%的人會在診斷出良性腦膜瘤後5年內死亡。
由過去的研究來看，腦膜瘤最重要的成因是游離輻射，而在今日，游離輻射最重要的來源既非核戰、也不是放射線治療，而是牙科的X光。令人意外的是，這方面的研究並不多，Claus博士和她的同事試圖填補這個缺口，他們研究了1433名患有腦膜瘤的美國人，並與1350名年齡、性別、居住地組成相似、但沒有腦膜瘤的人進行比較。
結果發現，腦膜瘤患者曾接受過至少一次牙科X光照射的機會，是非腦膜瘤患者的2倍。更讓人擔心的是，曾在十歲以下接受過環口放射線影像檢查（panorex）的人，出現腦膜瘤的機率是正常風險的4.9倍。
Claus博士指出，過去30多年，牙科X光的輻射劑量已經減少約一半；少部分牙醫改用輻射量更低的數位式檢查，但其他牙醫則使用錐束電腦斷層等輻射水準較高的新技術。
此外，美國牙醫協會的指導方針指出，健康成人每二或三年最多只能接受一次牙科咬翼片X光檢查，沒有相關症狀的病人也不該接受X光檢查。但如果Claus博士的研究對象沒有說謊，那就表示部分牙醫並未遵照此指導方針；大多數研究對象表示自己每年至少接受一次X光檢查。X光有其危險性，牙醫應該只在必要時使用，擔心健康的病人也不見得是在胡思亂想。（黃維德譯）
