How can technology developed at CERN for high-energy physics bring state-of-the-art radiotherapy to a hospital just along the lakeside in Lausanne?
在歐洲核研究組織(CERN： European Organization for Nuclear Research)為高能物理開發的技術，如何能將最先進的放射療法帶往，就在瑞士洛桑市日內瓦湖畔的一家醫院？
The technologies in question include high-performance electron accelerator components and simulation tools originally designed for CERN’s Compact Linear Collider (CLIC). Now, a collaboration between CERN and Lausanne University Hospital (CHUV) plans to use these to create a system for clinical delivery of FLASH radiotherapy.
這些正被討論的技術包括，高性能的電子加速器組件及原本為CERN設計之緊湊型線性對撞機(CLIC)的模擬工具。目前，CERN與瑞士洛桑大學醫院(CHUV)之間的一項合作，計劃使用上述技術，來為超高劑量率(FLASH)放射療法的臨床遞送，創建一種系統。
FLASH radiotherapy, which involves delivering therapeutic radiation at ultrahigh dose rates of 40 Gy/s and above, vastly decreases normal tissue toxicity while maintaining anti-tumour activity. Of particular note, FLASH should enable dose escalation, potentially offering a new option for cancers that are resistant to treatment.
涉及以40格雷/秒(Gy：gray，國際通用的輻射劑量單位)及以上之超高劑量率，遞送治療性輻射能的超高劑量率放射療法，大大降低對正常組織的毒性，同時維持抗腫瘤的放射性。特別值得注意的是，超高劑量率竟會使劑量能逐步上升，潛在上能為對治療具抵抗力的癌腫，提供一項新選擇。
“In all experiments so far, we observed that normal tissues are spared with this type of radiation,” says Jean Bourhis, head of radiation oncology at CHUV. “It’s a really reproducible effect. And there is no sparing of the tumour.”
瑞士洛桑大學醫院放射腫瘤科主任，Jean Bourhis宣稱：「在迄今的所有試驗中，他們觀察到，正常組織不會受到這類型輻射的傷害。這是一種真正可複製的效能。且沒有不被傷害的腫瘤。」
Bourhis pioneered the development of FLASH radiotherapy, leading the team at CHUV that performed the first FLASH treatment in a human patient in 2018. The patient in question had a resistant superficial skin cancer and was treated with low-energy electrons of roughly 10 MeV.
超高劑量率放射治療的發展先驅，Bourhis是2018年，瑞士洛桑大學醫院於一名人類病患中，進行首度超高劑量率放射治療的團隊領導人。該名正被討論的病人，罹患一種具抵抗力的淺層皮膚癌，且經使用大約10 MeV(百萬電子伏特)的低能電子治療。
Next, he would like to translate the impressive observations seen in an experimental setting into clinical trials. To treat larger tumours at depths of up to 20 cm in the patient, however, will require much higher energy electron beams.
接下來，他想將在此實驗環境中，令人印象深刻的觀察結果，轉移到臨床試驗。不過，為了治療病患中，深達20公分的較大腫瘤，將需要更高能量的電子束。
“A clinical FLASH system must have a high accelerating gradient to achieve the beam energies needed to access deeper-seated tumours, energies in the range of 100 MeV,” explains Walter Wuensch, a senior researcher at CERN.
CERN資深研究員，Walter Wuensch解釋：「臨床超高劑量率系統必需具有高加速梯度，來達到治療較深部腫瘤的所需。也就是，在100 MeV範圍內的電子束能量。」
This ability to accelerate beams in a very short distance, he notes, was one of the technologies designed for CLIC. The other key aspect of the high-energy physics study was to deliver a high current in a well-controlled and extremely stable beam – another important requirement for FLASH.
他強調，在很短距離中，加速電子束的能耐，是為緊湊型線性對撞機設計的諸多技術之一。高能物理研究的另一項關鍵層面，是在控制良好且極度穩定的電子束中，輸送大電流。這是超高劑量率的另一項重要必需條件。
“For some years, CERN has been studying accelerator technology for a possible high-energy physics facility,” says Wuensch. “We have developed prototypes and shown their feasibility and performance. So it was with real excitement that we found out about the needs of CHUV. After some initial discussions it became clear that what we had developed for CLIC seemed an almost perfect match for what is needed for a FLASH facility.”
Wuensch宣稱：「多年來，為了一種可能的高能物理設備，歐洲核研究組織一直在進行研究加速器技術。他們已經研發出原型設備，且證實了其可行性及性能。因此，真的很振奮，他們解決了瑞士洛桑大學醫院的此些需求。在一些初步討論之後，很顯然，他們為緊湊型線性對撞機所開發的，對超高劑量率設備所需而言，似乎是一項幾乎完美的匹配。」
The CERN–CHUV partnership has now finished the first phase of its study: moving from an initial idea to creating a conceptual design for the proposed FLASH facility. The next step will be to develop this baseline design in more detail to optimize the system for patient treatments.
目前，歐洲核研究組織與瑞士洛桑大學醫院的合作，已經完成其第一階段研究：從最初的構想進展到，產生提議之超高劑量率設備的一種概念設計。下一階段將是更詳盡地開發此基線設計，來最佳化用於治療患者的系統。
The team also hopes to collaborate with an industry partner in the radiotherapy field. Alongside, while the machine is being prepared, CHUV will start to prepare the required teams and infrastructure, and submit applications to regulatory agencies so that the treatment can reach patients as soon as possible.
在此放射治療領域上，該團隊也期盼與產業界夥伴合作。同時，在這種機械裝置正被製造時，瑞士洛桑大學醫院將開始籌組，所需的團隊及基層組織，並向管理機構提出申請，以便此療法能盡早及於病患。
Bourhis predicts that the FLASH facility should be operational within two to three years, at which point the team plans to embark on proof-of-concept in clinical trials. He notes that after these trials, the system could be transferable to other hospitals.
Bourhis預言，這種超高劑量率設備，應該能在兩到三年內正常運作。團隊計劃在那時候，於臨床試驗中，開始進行概念驗證。他強調，在此些試驗之後，該種系統或許能轉移到其他醫院。
The system will be 2–2.5 times larger than a conventional radiotherapy machine, but should still be compact enough to fit into existing hospital infrastructure. The cost of the first protoype system (being installed in CHUV) is estimated to be about €25m; though if manufacturing scales up, this price should come down.
該種系統會比傳統放射治療機械裝置大2到2.5倍，不過仍然會緊湊足以安裝於現有醫院基礎設備中。第一部原型裝置(被安裝於瑞士洛桑大學醫院)的成本，估計大約2500萬歐元。倘若大量製造，此價格應會下降。
FLASH treatments, however, only require the patient to undergo two or three radiation fractions, compared with 20 or 30 for standard radiotherapy. As such, Wuensch suggests that the eventual cost-per-treatment could be competitive in absolute terms with classical radiotherapy.
不過，相較於標準放射療法的20或30個輻射級分(輻射總劑量通常分為多個，被稱為及分的較小劑量)，超高劑量率治療的病患，僅需經歷兩或三個輻射級分。就此，Wuensch暗示，最終的每次治療費用，與傳統放射療法相較下，會是絕對明確具競爭力。
原文網址：https://physicsworld.com/a/cern-accelerator-technology-to-underpin-flash-radiotherapy-facility/
翻譯：許東榮
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