5月7日，美国食品药品监督管理局（FDA）最终敲定了两份指南文件，旨在确保X光设备性能标准与国际标准以及美国联邦荧光透视设备性能标准保持一致。

指南1：《符合IEC标准的医用X光成像设备》（Medical X-Ray Imaging Devices Conformance with IEC Standards）

FDA希望将《电子产品辐射控制》（EPRC）所规定的性能标准与国际电工委员会（IEC）的标准保持一致，从而有助于对X光成像设备的递交申请进行更加一致有效的监管审查。

“FDA已经确定，符合某些IEC标准的行业，至少能提供与某些EPRC监管标准相同水平的公众健康和电子辐射安全防护。”该指南草案于2016年8月对外发布，而这份6页的指南文件为其最终版本。

但是，由于FDA最近提出了一项规则，而根据该规则的规定,将取消X光成像设备的报告要求，因此FDA决定，指南草案中概述的一项拟议政策（即：将符合IEC标准的X光成像设备视为等同符合EPRC报告要求）应从最终指南文件中删除。

“FDA之所以做出这一决定，是为了避免出现因制定某些很快会被最终规则所取代的临时程序而造成的混乱局面，”FDA表示。“然而，如该指南第五节所述，FDA认为，提交相关标准符合性声明以及产品报告中21 CFR 1002.10(a)和(b)所要求的型号标识，足以满足21 CFR 1002.10所规定的产品报告的要求，从而可以减少不必要的重复工作。”

制造商需要提交关于符合该指南中确定的IEC标准、勘误表和修正条款的声明，表明其已经制定了针对电子产品辐射发射方面的设计规范。一旦X光诊断系统不符合针对电子产品辐射发射方面的设计规范，则表明该系统存在电子产品缺陷。因此FDA也提醒业界，如果X光成像设备不符合任何与电子产品辐射相关的要求（如制造商声明符合的IEC标准、勘误表或修正条款），则表明该设备存在电子产品缺陷，FDA将对该制造商发出缺陷通知书，并要求其回购、修理或置换此设备。

指南2：《针对某些荧光透视设备要求的政策说明》（Policy Clarification for Certain Fluoroscopic Equipment Requirements）

该指南草案于2014年9月对外发布，而这份6页的指南文件为其最终版本，涉及美国联邦关于透视设备性能标准的三个方面。这三个方面分别为：荧光透视照射时间、图像冻结（last image hold，LIH）和紧急荧光透视模式。

▍器官保存设备

除了以上两份关于X光成像设备的指南文件外，同日，FDA还最终定稿了另一份指南文件（《利用动物研究评估器官保存设备》（Utilizing Animal Studies to Evaluate Organ Preservation Devices））。在这份最终指南文件中，提供了利用动物研究评估器官保存设备的最佳实践建议。

“FDA认识到，随着这类技术的迅速发展，利用动物研究评估器官保存设备的最佳实践也在不断发展。不过，该指南文件并不具有全面性或规定性。相反，该文件旨在突出说明FDA关于如何利用动物移植模型来评估器官保存技术的初步想法，同时还要谨慎考虑采取最不繁琐的监管原则，”美国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eliminate the reporting requirements for X-ray imaging devices, FDA determined that the proposed policy outlined in the draft guidance, which stated that X-ray imaging devices that conform to IEC standards would be considered to have met the EPRC reporting requirements, should be removed from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.