Radiopharmaceuticals

概述

放射性药物是含有少量放射性物质的药物。医务人员使用这类药物来诊断和治疗许多疾病和状况。

如果用于诊断，放射性药物会在影像学检查前注入体内。药物在受累部位浓聚。成像设备中的摄像机可以检测到辐射。检查拍摄的图像显示摄取药物的身体部位。

如果用于治疗，会将辐射更强的放射性药物注入体内。药物会到达需要治疗的部位并释放辐射。药物将辐射直接照射到需要治疗的身体部位。

使用放射性药物诊断和治疗疾病属于被称为核医学的医疗护理领域。

Types of radiopharmaceuticals

Many radiopharmaceuticals exist. Each contains a radioactive substance called a radionuclide, which is an isotope that gives off radiation. Some radionuclides naturally seek out certain kinds of cells and can be used on their own. Other radionuclides need help getting to the right place. In those cases, the radionuclides are attached to a substance that targets certain cells. This substance carries the radiation to the target cells.

Radiopharmaceuticals can be used for diagnosis, treatment or both. The difference between those used for diagnosis and those used for therapy is the type and amount of radiation given off. In general, the radioactivity in therapeutic radiopharmaceuticals lasts longer and gives a higher dose of radiation in order to treat disease.

Diagnostic radiopharmaceuticals are used with imaging tests to help diagnose diseases and conditions. Radiopharmaceuticals used for diagnosis are called radioactive tracers. They also are called radiotracers. Imaging tests that use radiotracers are sometimes called nuclear medicine imaging tests or molecular imaging tests. Examples include single-photon emission computerized tomography (SPECT) scans and positron emission tomography (PET) scans.

Examples of nuclear medicine imaging tests include:

• Bone scan.
• Choline C-11 PET scan.
• Hepatobiliary iminodiacetic acid (HIDA) scan.
• Molecular breast imaging.
• Nuclear cardiology stress test.
• Parathyroid scan.
• Positron emission tomography (PET) scan.
• Prostate-specific membrane antigen (PSMA) PET scan.
• Single-photon emission computerized tomography (SPECT) scan.

Therapeutic radiopharmaceuticals are used to treat diseases and conditions. These treatments are sometimes called radiopharmaceutical therapy, nuclear medicine therapy, peptide receptor radionuclide therapy (PRRT), radioligand therapy and targeted radiotherapy.

Examples of radiopharmaceutical therapies include:

• Bone-seeking therapy with radium Ra-223 (Xofigo).
• PRRT with lutetium Lu-177 dotatate (Lutathera).
• PSMA therapy with lutetium Lu-177 vipivotide tetraxetan (Pluvicto).
• Radioactive iodine therapy with sodium iodide I-131 (Hicon).
• Radioimmunotherapy with yttrium Y-90 and ibritumomab tiuxetan (Zevalin).

Theranostic radiopharmaceuticals are medicines that help with both diagnosis and treatment. The diagnostic form of the medicine shows where the disease is in the body. It helps the healthcare team see if the treatment is likely to work. The therapeutic form targets those same areas to deliver treatment.

One example is PSMA therapy for prostate cancer. This treatment targets prostate cancer cells that make a protein called prostate-specific membrane antigen (PSMA). To see if treatment might work, the healthcare team does a PSMA PET scan with a diagnostic radiopharmaceutical that targets PSMA. If the cancer cells take up a lot of the medicine, it's a good sign that the treatment may work. The therapy uses a radiopharmaceutical that targets PSMA, but with a higher dose of radiation to treat the cancer.

目的

Radiopharmaceuticals are used to diagnose and treat many different diseases and conditions.

诊断用放射性药物

核医学成像使用被称为放射性示踪剂的放射性药物来诊断疾病和医疗状况。这种成像技术生成的图像能够帮助医护团队了解身体功能状况。它不同于 X 线检查和 CT 扫描，这两种检查显示的是关切部位的外观。核医学成像可以提供有关细胞和组织运作状况的线索。

如果其他检查无法提供足够信息，医务人员可能建议进行核医学成像。核医学成像可能有助于避免进行更具侵入性的医疗程序。它还可能在解剖成像检查（例如 X 线检查或 CT 扫描）显示出异常之前就发现疾病迹象。

核医学成像可能诊断的医疗状况包括：

• 脑部状况。 脑部 PET 和脑部 SPECT 等检查可能有助于诊断阿尔茨海默病、脑肿瘤、帕金森病、认知功能衰退、癫痫发作、卒中、特发性震颤及其他脑部状况。
• 心脏状况。 心脏 PET 和心脏 SPECT 等检查可能有助于诊断心力衰竭、冠状动脉疾病、心脏淀粉样变性、心脏结节病及其他心脏状况。
• 癌症。 PET 扫描用于诊断多种癌症，包括前列腺癌、乳腺癌、胰腺癌、皮肤癌、膀胱癌、肾癌等。PET 扫描还可能有助于发现癌症已经扩散到淋巴结或身体其他部位的迹象。该扫描还可以评估治疗是否有效。
• 甲状腺状况。 包括甲状腺癌、甲状腺功能亢进症、甲状腺结节、甲状腺炎及其他状况。
• 甲状旁腺状况。 核医学检查（例如 SPECT 和 PET）可能有助于精准定位位置异常的甲状旁腺。这可能有助于甲状旁腺功能亢进症的治疗。
• 胆囊和胆管状况。 核医学胆道扫描可能有助于诊断胆囊炎、胆囊癌、胆囊手术并发症及其他状况。
• 骨骼状况。 骨扫描和其他核医学成像检查可能有助于诊断骨折、骨感染、关节炎、骨癌、骨转移及其他骨骼状况。
• 其他状况。 可能包括肺部状况、肾脏状况、淋巴水肿、感染、内部出血和脑脊液漏。

治疗用放射性药物

放射性药物疗法将辐射直接递送至靶细胞。药物经体内循环到达靶部位。药物到位后，其放射性部分释放 α 粒子或 β 粒子。这些高能粒子的传播距离有限，因此辐射主要作用于靶区。辐射导致细胞内的 DNA 断裂，从而造成细胞死亡。

使用放射性药物疗法治疗的医疗状况包括：

• 扩散到骨骼的癌症。 镭 Ra-223（Xofigo）可以辅助治疗扩散到骨骼的前列腺癌。它含有一种放射性同位素，靶向作用于被癌症侵蚀的骨骼区域。
• 淋巴瘤。 钇 Y-90 和替伊妥欧单抗（Zevalin）可以辅助治疗淋巴瘤。该疗法使用一种靶向 CD20（淋巴瘤细胞上的一种蛋白质）的物质。
• 神经内分泌肿瘤。 镥 Lu-177 dotatate （Lutathera）用于治疗晚期神经内分泌肿瘤，包括胰腺神经内分泌肿瘤和类癌瘤。该药物含有一种物质，可以靶向含有生长抑素这种化学物质的受体的癌细胞。
• 前列腺癌。 镥 Lu-177 特昔维匹肽（Pluvicto）可辅助治疗其他疗法不起作用的转移性前列腺癌。该药物含有一种靶向 PSMA（前列腺癌细胞上的一种蛋白质）的物质。
• 甲状腺状况。 碘化钠 I-131（Hicon）可以辅助治疗甲状腺癌和甲状腺功能亢进症。这种治疗方法有时被称为放射性碘疗法。它使用一种可被甲状腺细胞自然吸收的放射性碘。

放射性药物疗法是癌症研究的一个活跃领域。目前正在针对许多其他治疗方法开展研究。

风险

Radiopharmaceuticals are safe medicines. As with all medicines, they have some risks and side effects. The side effects may depend on whether the radiopharmaceutical is used for diagnosis or treatment.

All radiopharmaceuticals contain a small amount of a radioactive substance, which exposes you to radiation. For imaging tests, radiotracers usually have a very low dose of radiation. It's usually not enough to cause any side effects. Radiopharmaceutical therapy typically uses higher doses in order to treat disease. This level of radiation can cause side effects such as feeling very tired, dry mouth, and nausea and vomiting.

Healthcare professionals use the lowest amount of radiation that's needed to get accurate results or effective treatment. They make sure the benefits outweigh the possible risks. High doses of radiation raise the risk of cancer, so healthcare professionals use a safe low dose. If you are concerned about radiation, talk about it with your healthcare team.

Radiotracer side effects

Side effects of radiopharmaceuticals used for diagnosis depend on the medicine you receive and how it's given.

In general, side effects may include:

• A metallic taste in the mouth.
• An area of blood called a hematoma that forms around the spot where the needle goes into the skin.
• Headache.
• Nausea and vomiting.
• Skin irritation around the place where the needle goes into the skin.

Radiopharmaceutical therapy side effects

Side effects of radiopharmaceuticals used for treatment may depend on the reason for the treatment and what medicine you receive. Ask your healthcare professional what you can expect.

In general, side effects may include:

• Allergic reaction to the medicine.
• Diarrhea.
• Dry mouth.
• Feeling very tired and weak.
• Infertility.
• Joint and muscle pain.
• Kidney damage.
• Liver damage.
• Low blood cell counts, which can raise the risk of infections and easy bruising.
• Nausea and vomiting.
• Short-term increase in cancer pain before it starts to get better.
• Slightly increased risk of cancer in the future.
• Throat pain, with treatments for thyroid conditions.

如何进行准备

Follow any instructions your healthcare team may give you to help you prepare for receiving a radiopharmaceutical. Your care team might give you instructions about:

• Food and drink. Some tests and procedures might require you to stop eating and drinking for several hours before your appointment. Some might require you to follow a specific diet. Others might ask you to drink more fluids before your test or procedure.
• Medicines. For most tests, your care team might tell you to continue taking your medicines as usual. Some treatments might require changing how you take your medicines. Follow the instructions from your care team.
• Clothing. In general, wear comfortable clothing to your appointment. For an imaging test, you might need to change into a gown, so wear clothes that are easy to get on and off.

Before your test or treatment, tell your healthcare team:

• About any allergies or bad reactions you've had to any medicines, foods, iodine or latex.
• About any medicines you take, including medicines that you can buy without a prescription, as well as any vitamins or supplements that you take.
• If you are pregnant or breastfeeding.

可能出现的情况

在涉及放射性药物的医疗程序中，可能发生的情况取决于实施医疗程序的原因。

诊断用放射性药物

用于核成像的放射性药物通常通过手臂静脉给药。有些在皮下或是神经周围注射。还有一些通过吞服或吸入给药。

输入放射性示踪剂后，您可能需要等待一段时间才能进行成像检查。这让放射性示踪剂有时间在您的体内循环。有些检查的等待时间很短。还有些检查可能要等几个小时。少数放射性示踪剂需要等待一天或更长时间。因此可能让您先行离开，改天再返回进行成像检查。

进行成像检查时，您可能需要去配有成像设备的检查室。进行检查的医务人员可能让您躺在一张平坦的检查台上。有些检查（例如 PET 扫描）的检查台会缓慢通过含有扫描仪的设备。其他检查（例如 SPECT 扫描）的检查台则保持静止，由扫描仪围绕您移动。

核成像扫描不会引发疼痛。您可能需要在扫描过程中保持静止，这可能引起不适。如果您感到非常不适，请告知正在监测您的医务人员。

扫描结束后，您需要静候，等待医护团队查看扫描结果。医护团队将审核扫描结果，确认不需要再增加扫描。经医护团队确认完成检查后，您即可离开并恢复日常活动。

核成像可能需要一个小时或更长时间。时间长短取决于您进行的检查。检查的扫描环节通常不会花很长时间。但其他环节（例如等待放射性示踪剂在体内循环）会延长整个就诊过程。

核成像结束后，辐射物通常会通过尿液和粪便快速排出体外。喝水有助于排出体内的放射性示踪剂。对于大多数放射性示踪剂，辐射会在几天内消失。

Radiopharmaceuticals for treatment

Most people receiving radiopharmaceutical therapy don't need to stay in the hospital. However, some treatments may require a hospital stay. Ask your healthcare team what you can expect during your treatment.

Most treatments are given through a vein. You might feel a pinch as a healthcare professional puts a needle into your skin. This usually doesn't hurt. You typically won't feel anything as the medicine goes into your body. Radioactive iodine therapy for hyperthyroidism and thyroid cancer comes as a liquid or capsule that you swallow.

Some radiopharmaceutical treatments are given once. Others are repeated several weeks apart for a set number of sessions.

An appointment for radiopharmaceutical therapy usually takes a few hours. Sometimes it takes all day. Ask your healthcare team what you can expect. Bring something to help you pass the time.

You can go home after your treatment. Your care team may ask that you not go to work or to social activities for a few days.

After treatment, the radiation leaves through body fluids, such as urine, stool, sweat and tears. Most of this happens soon after treatment. Your healthcare team gives you instructions to follow to help you limit radiation exposure to others for the first few days after treatment. Instructions may include:

• Avoid close contact with children and people who are pregnant.
• Do not have sexual contact. When it's safe to resume sexual activity, you may need to use birth control for several months after treatment.
• Sleep alone.
• Use a separate toilet from others in your home, if possible, and flush the toilet twice each time you use it.

Once most of the radiation leaves your body, it's safe to go back to your life as usual. A low level of radiation stays in the body for a few months. This low level isn't harmful to others. But it can be found with detectors such as those at airports, train stations, border crossings and other high-security places. Your healthcare team may give you a letter or card to carry with you that explains your treatment.

结果

Ask your healthcare team when you can expect to know the results of your radiopharmaceutical test or treatment. Nuclear imaging results might be available soon after your test. It often takes time to know the results of radiopharmaceutical therapy.

核成像检查结果

核成像检查结果在放射学报告中提供。报告由负责解读图像的医生撰写。这位医生可能是核医学医生或放射科医生。报告供安排检查的医务人员查看，因此往往含有一些可能晦涩难懂的医学术语。

放射学报告通常包括：

• 检查类型及实施方法，包括所使用的放射性药物和成像设备的类型。
• 检查原因，包括重要病史以及您此前其他检查的结果。
• 检查结果显示的内容，包括放射性示踪剂在体内的摄取部位。摄取是指放射性示踪剂在细胞内浓聚的部位。非预期部位出现摄取可能是疾病的体征。健康组织摄取部分示踪剂是正常现象。这被称为生理性放射性示踪剂摄取，通常不是疾病的征兆。
• 结果的含义（可能被描述为印象）以及建议进行的后续检查。

Radiopharmaceutical therapy results

Results of radiopharmaceutical therapy treatments may take time. Ask your healthcare professional what you can expect. You might have imaging tests to check how well the treatment is working.

临床试验

探索 Mayo Clinic 的研究 测试新的治疗、干预与检查方法，旨在预防、检测、治疗或控制这种疾病。