5月7日，美國食品藥品監(jiān)督管理局（FDA）最終敲定了兩份指南文件，旨在確保X光設(shè)備性能標(biāo)準(zhǔn)與國際標(biāo)準(zhǔn)以及美國聯(lián)邦熒光透視設(shè)備性能標(biāo)準(zhǔn)保持一致。

指南1：《符合IEC標(biāo)準(zhǔn)的醫(yī)用X光成像設(shè)備》（Medical X-Ray Imaging Devices Conformance with IEC Standards）

FDA希望將《電子產(chǎn)品輻射控制》（EPRC）所規(guī)定的性能標(biāo)準(zhǔn)與國際電工委員會（IEC）的標(biāo)準(zhǔn)保持一致，從而有助于對X光成像設(shè)備的遞交申請進(jìn)行更加一致有效的監(jiān)管審查。

“FDA已經(jīng)確定，符合某些IEC標(biāo)準(zhǔn)的行業(yè)，至少能提供與某些EPRC監(jiān)管標(biāo)準(zhǔn)相同水平的公眾健康和電子輻射安全防護(hù)。”該指南草案于2016年8月對外發(fā)布，而這份6頁的指南文件為其最終版本。

但是，由于FDA最近提出了一項規(guī)則，而根據(jù)該規(guī)則的規(guī)定,將取消X光成像設(shè)備的報告要求，因此FDA決定，指南草案中概述的一項擬議政策（即：將符合IEC標(biāo)準(zhǔn)的X光成像設(shè)備視為等同符合EPRC報告要求）應(yīng)從最終指南文件中刪除。

“FDA之所以做出這一決定，是為了避免出現(xiàn)因制定某些很快會被最終規(guī)則所取代的臨時程序而造成的混亂局面，”FDA表示。“然而，如該指南第五節(jié)所述，F(xiàn)DA認(rèn)為，提交相關(guān)標(biāo)準(zhǔn)符合性聲明以及產(chǎn)品報告中21 CFR 1002.10(a)和(b)所要求的型號標(biāo)識，足以滿足21 CFR 1002.10所規(guī)定的產(chǎn)品報告的要求，從而可以減少不必要的重復(fù)工作。”

制造商需要提交關(guān)于符合該指南中確定的IEC標(biāo)準(zhǔn)、勘誤表和修正條款的聲明，表明其已經(jīng)制定了針對電子產(chǎn)品輻射發(fā)射方面的設(shè)計規(guī)范。一旦X光診斷系統(tǒng)不符合針對電子產(chǎn)品輻射發(fā)射方面的設(shè)計規(guī)范，則表明該系統(tǒng)存在電子產(chǎn)品缺陷。因此FDA也提醒業(yè)界，如果X光成像設(shè)備不符合任何與電子產(chǎn)品輻射相關(guān)的要求（如制造商聲明符合的IEC標(biāo)準(zhǔn)、勘誤表或修正條款），則表明該設(shè)備存在電子產(chǎn)品缺陷，F(xiàn)DA將對該制造商發(fā)出缺陷通知書，并要求其回購、修理或置換此設(shè)備。

指南2：《針對某些熒光透視設(shè)備要求的政策說明》（Policy Clarification for Certain Fluoroscopic Equipment Requirements）

該指南草案于2014年9月對外發(fā)布，而這份6頁的指南文件為其最終版本，涉及美國聯(lián)邦關(guān)于透視設(shè)備性能標(biāo)準(zhǔn)的三個方面。這三個方面分別為：熒光透視照射時間、圖像凍結(jié)（last image hold，LIH）和緊急熒光透視模式。

▍器官保存設(shè)備

除了以上兩份關(guān)于X光成像設(shè)備的指南文件外，同日，F(xiàn)DA還最終定稿了另一份指南文件（《利用動物研究評估器官保存設(shè)備》（Utilizing Animal Studies to Evaluate Organ Preservation Devices））。在這份最終指南文件中，提供了利用動物研究評估器官保存設(shè)備的最佳實踐建議。

“FDA認(rèn)識到，隨著這類技術(shù)的迅速發(fā)展，利用動物研究評估器官保存設(shè)備的最佳實踐也在不斷發(fā)展。不過，該指南文件并不具有全面性或規(guī)定性。相反，該文件旨在突出說明FDA關(guān)于如何利用動物移植模型來評估器官保存技術(shù)的初步想法，同時還要謹(jǐn)慎考慮采取最不繁瑣的監(jiān)管原則，”美國FDA表示。

FDA Finalizes Two Guidances to Align X-Ray Imaging Devices With International Standards

The US Food and Drug Administration (FDA) on Tuesday finalized two guidance documents related to harmonizing X-ray device performance standards with international standards, and federal performance standards for fluoroscopic equipment.

On the harmonization front, FDA is looking to align performance standards prescribed by the Electronic Product Radiation Control (EPRC) with standards from the International Electrotechnical Commission (IEC) to help to ensure more efficient and consistent regulatory review of submissions for X-ray imaging equipment.

“FDA has determined that industry conformance to certain IEC standards would provide, at a minimum, the same level of protection of the public health and safety from electronic radiation as certain EPRC regulatory standards,” the agency said. The 6-page guidance finalized a draft from August 2016.

But because a recently proposed rule would eliminate the reporting requirements for X-ray imaging devices, FDA determined that the proposed policy outlined in the draft guidance, which stated that X-ray imaging devices that conform to IEC standards would be considered to have met the EPRC reporting requirements, should be removed from the final version.

“This decision was made to avoid the confusion inherent in establishing an interim procedure that would shortly be superseded by the final rule,” FDA said. “However, as stated in section V. of the guidance, FDA believes that submission of a declaration of conformity to the appropriate standards, and model identification as required by 21 CFR 1002.10(a) and (b), in a product report, would be sufficient to meet the requirements of a product report under 21 CFR 1002.10, thus reducing duplication.”

But FDA also cautions industry that failing to meet any requirements relating to the emission of electronic product radiation of an IEC standard, corrigenda or amendment to which a manufacturer declares conformance is an electronic product defect and is cause for notification and repurchase, repair or replacement.

The other 6-page guidance, which finalizes a draft from September 2014, addresses three aspects of the federal performance standard for fluoroscopic equipment. The three aspects include: Fluoroscopic Irradiation Time, Last-Image Hold and Emergency Fluoroscopy Mode.

▍Organ Preservation Devices

In addition to the two guidance documents on X-ray devices, FDA also finalized another guidance on Tuesday providing recommendations regarding best practices for utilizing animal studies for the evaluation of organ preservation devices.

“FDA recognizes that best practices for conducting animal studies to evaluate organ preservation devices are evolving with the rapid advancements in such technologies. This guidance is not intended to be comprehensive or prescriptive. Instead, it aims to highlight FDA's initial thoughts on how animal transplant models can be utilized to evaluate organ preservation technologies, with careful considerations of regulatory least burdensome principles,” the agency said.