????豪洛捷公司發言人大衛?丹尼爾森表示，沒有得到滿足的需要正在激發起新的需求。該公司的數字化層析X射線照相組合系統于2月份獲得美國食品及藥物管理局（FDA）的批準。這種機器的外形和運行機理與典型的乳房X線照相系統非常類似，但它包含了一個高射傳感器，這種傳感器能夠掃描1毫米的乳房組織表層，進而拍攝出乳房的三維圖像。雖然通用電氣公司在2000年開發出數字化乳房X線照相術，并由此成為這一領域的開拓者，但豪洛捷公司現在是這一產業的領導者，每月銷售的乳房X線照相系統占全美銷售量的65%。

????通用電氣公司的SenoBright系統也于10月份獲得了美國食品及藥物管理局（FDA）的批準。除了傳統的乳房X線掃描以外，該系統還采用對比手法，產生出一種效果得以增強的二次圖像。這種對比可以讓人們更清晰地解讀圖像，非常類似于采用核磁共振成像進行后續檢查所獲得的效果。雖然通用電氣公司預期這項新技術的陽性檢測結果出錯率將“顯著”低于當前的乳房X線照相系統，但它依然無法檢測出某個腫塊是否發生了癌變，而一些醫生認為這正是新技術能否成功的重要指標。

????據美國癌癥協會（American Cancer Society）統計，美國今年大約有30萬名婦女被診斷出患有乳腺癌。紀念斯隆-凱特琳癌癥中心（Memorial Sloan-Kettering Cancer Center）乳腺成像部主任伊麗莎白?莫里斯認為，雖然頻繁的篩查和早期檢測可以降低死亡率，降幅最高可達30%，但乳房X線照相術的“黃金標準”遠遠不夠完善。她說，普通乳房組織中20%的癌病變無法通過乳房X線照片檢測出，對于乳房組織更緊密的女性，這一比例甚至高達50%。即使X線真的發現了異常，復診時也有差不多70%的病人發現這些病變并非陽性，這意味著她們并沒有患上癌癥。“我完全無法確認，三維成像技術是否能夠帶來顯著的變化，改變這個行業的現狀，”莫里斯說。“最重要的問題是，我們什么時候能夠植入某種東西，可以讓我們看清楚癌病變的位置，同時進行靶向治療。”

????MD安德森癌癥中心（MD Anderson Cancer Center）的約翰?黑茲爾認同這種看法。他說，實際上，這也是MD安德森癌癥中心今年8月份同意對愛德華?弗林的磁性納米顆粒技術進行臨床前評估的原因所在。不同于普通的乳房X線照相系統（它只能檢測出至少由1億個癌細胞構成的腫塊），弗林的納米顆粒技術能夠檢測出由10萬個癌細胞構成的腫塊，而且經過目前的編程，可檢測出的細胞數量將降低至1,2000個。等到這種技術正式投入商用時，它能夠在癌細胞發展至第一階段之前就將其檢測出來，可檢測出的細胞數量將降至“幾千個”，Senior Scientifics公司【現在已隸屬于曼哈頓科學公司（Manhattan Scientifics）】總裁杰拉爾德?格拉夫說。“成像技術這條路根本就是錯的。治療癌癥不應該盯著形態，而應尋找某種細胞。”

????弗林的技術不是生成某個癌細胞大腫塊的圖像，而是在納米粒子附著于癌細胞時發出磁信號。通過這種技術，醫生們不僅可以觀察到癌細胞的位置，還可以掌握它們的數量。盡管這種技術目前還遠遠無法獲得食品及藥物管理局的批準，弗林的夢想很有可能到若干年之后方能實現，但弗林聲稱，他的工作朝著正確的方向又邁出了一步。

????譯者：任文科

????Demand is being stoked by unmet needs, according to David Danielson, a spokesperson for Hologic. In February, the company received FDA approval for its digital tomosynthesis system. The machine looks and works similarly to a typical mammography system, but includes an overhead sensor, which takes a 3D image of the breast by scanning 1-millimeter layers of breast tissue. While GE pioneered the mammography industry in 2000 when it developed the digital mammogram, Hologic is now the industry leader, selling about 65% of mammography systems in the U.S. each month.

????In October, GE received FDA approval for its so-called SenoBright. That system uses contrast to produce an enhanced secondary image in addition to a traditional mammography scan. The contrast allows for a clearer reading of the image, much like you would get in a follow up MRI scan. While the company says it expects the new technology to have a "significantly" lower false positive rate than current mammography systems, it still can't detect whether a mass is cancerous -- a factor some physicians feel is key to new technologies.

????Nearly 300,000 women in the U.S. were diagnosed with breast cancer this year, according to the American Cancer Society. While frequent screening and early detection can lower the mortality rate by up to 30%, the mammography "gold standard" is far from perfect, says Elizabeth Morris, chief of breast imaging at Memorial Sloan-Kettering Cancer Center. Mammograms miss about 20% of cancers in normal breast tissue, and up to 50% in denser breast tissues, she says. And even if the x-ray does manage to pick up an abnormality, roughly 70% of those patients called back will be a false positive, meaning they don't have cancer. "I'm just not sure 3D imaging is going to be a huge game changer," Morris says. "The holy grail is when we're able to inject something that allows us to see where the cancer is and does targeted therapy at the same time."

????John Hazle of MD Anderson Cancer Center agrees. In fact, that's the reason, he says, MD Anderson signed on for a pre-clinical evaluation of Edward Flynn's magnetic nano-particle technology in August this year. Unlike a mammogram, which can only detect a mass of at least 100 million cancer cells, Flynn's nano-particle technology can detect cancer at a mass of 100,000 cells, and is currently being programmed to detect down to 12,000 cells. By the time it's ready for commercial use, it could detect cancer before stage one -- down to "a few thousand cells" says Gerald Grafe, president of Senior Scientifics, now a division of Manhattan Scientifics (MHTX). "Imaging is fundamentally the wrong approach. In cancer, you're not after the shape, you're looking for a kind of cell," Grafe argues.

????Instead of producing an image of a large mass of cancer cells, Flynn's technology produces a magnetic signal when the nano-particles attach to cancer cells. This allows physicians to see not only where the cancer is, but also how many cells there are. While the technology is nowhere near FDA approval, and it'll likely be several years before Flynn's dreams come to fruition, Flynn claims his work is just one more step toward the right approach.