[Fat Bear Science] I heard that this "cancer detection magic tool" can make the tumor nowhere to hide with just a scan?

Malignant tumors are like "silent killers".

Often the disease is discovered in the middle or late stages.

However, in recent years,

There is a magical device in the nuclear medicine field that has gained great fame.

Legend has it that he can see through diseases with his sharp eyes.

Help doctors “nip tumors in the bud”.

What kind of magical artifact is this?

What are the functions?

What should I pay attention to before and after the examination?

Chongqing University Cancer Hospital

Chen Xiaoliang, Director of Nuclear Medicine Department

Reveal the true face of PET/CT for you!

■

Chen Xiaoliang

Director of Nuclear Medicine Department, Chongqing University Cancer Hospital

Chief Physician

Expert profile: Standing member of the Tumor Nuclear Medicine Professional Committee of the Chinese Anti-Cancer Association, Chairman of the Clinical Nuclear Medicine Professional Committee of the Chongqing Medical Biotechnology Association, Vice Chairman of the Nuclear Medicine Branch of the Chongqing Medical Association, and member of the PET Group of the Chinese Nuclear Medicine Society.

Professional expertise: He is good at molecular imaging diagnosis, iodine-131 treatment of differentiated thyroid cancer, strontium-89 treatment of bone metastases and other radionuclide therapy techniques.

PET/CT examination: A powerful combination, the effect of 1+1>2

Everyone is very familiar with CT examination, so what is PET/CT?

As we all know, CT examination is based on anatomical imaging, which can accurately describe the anatomical characteristics of the lesion, such as shape, size and location. PET examination is mainly based on functional metabolic imaging, which can macroscopically display the functions, metabolism and other characteristics of various tissues and organs in the body and lesion cells.

Director Chen Xiaoliang said that PET-CT is a combination of positron emission tomography and X-ray computed tomography. PET/CT examination combines the advantages of both. During the examination, the patient undergoes a rapid whole-body scan and obtains CT anatomical images and PET functional metabolic images at the same time. The two images complement each other. Doctors can simultaneously understand the functional metabolic information and morphological changes of the examined parts of the human body, which helps to determine whether the lesions are benign or malignant, and to discover earlier or hidden small lesions, making the examination more accurate.

In short, ordinary CT is like a camera that can see through things, mainly detecting the size and distribution of lesions in the human body, but it cannot tell whether the lesions are active. Just like an egg, CT focuses on the shape and size, while PET/CT not only focuses on the size, but can also tell whether the egg is raw or cooked, which has a better guiding significance for the subsequent treatment of the lesion.

▲ The red part in the above picture is a hidden small lesion

What are the advantages of PET/CT?

Early

PET/CT can detect hidden metabolic changes in tiny tumor lesions before they undergo obvious anatomical changes. In theory, it can diagnose tumor lesions of 2-5 mm or smaller.

precise

Its examination results are more accurate than those of PET, SPECT, ECT or CT alone.

fast

A full-body rapid examination only takes about 20 minutes, and you can visually see the affected parts of the body and the conditions of the disease.

High value

The cost of treating early-stage tumors is 1-5 times less than that of late-stage tumors, and the survival time is increased by 1-5 times, or even 10 times.

Security

The relevant standards state that there will be no restrictions on radiation doses for visitors, family members and other people around PET-CT examinees.

Therefore, PET/CT is of great significance to people at high risk of cancer, suspected cancer patients, and confirmed cancer patients.

PET/CT: A magical tool for cancer detection

PET/CT is so powerful, so what problems can it diagnose?

Director Chen Xiaoliang introduced that in terms of tumor diagnosis, PET/CT can monitor the development of your tumor in all directions:

When a tumor is highly suspected, it helps find the primary lesion and provides accurate biopsy positioning for early diagnosis.

For patients who have been diagnosed with tumor metastases, further research can be done to find the primary tumor site.

Determine the extent of tumor invasion and differentiate between benign and malignant tumors.

It helps in the accurate staging of malignant tumors before surgery, radiotherapy and chemotherapy, and assists doctors in choosing appropriate treatment plans.

Guide radiotherapy planning and determine the biological target area for tumor radiotherapy.

In addition to early diagnosis, detection, and monitoring of tumors, what other functions does PET/CT have?

Evaluation of efficacy

The attending physician also needs to evaluate the efficacy of the treatment through PET/CT examinations and guide the doctor to adjust the treatment plan in a timely manner. Inactive lesions only need to be observed, while active lesions require further treatment.

Neurological disorders

PET/CT can be used to locate epileptic foci, evaluate brain function after ischemic cerebrovascular disease, stroke, cerebral thrombosis or cerebral hemorrhage, and the changes in hemodynamics before and after cerebral ischemia.

Cardiovascular disease

PET/CT can detect the location and extent of myocardial ischemia in coronary heart disease, accurately evaluate myocardial vitality, determine whether thrombolytic therapy, coronary stent placement or coronary artery bypass surgery is needed, and evaluate the treatment effect through pre- and post-treatment imaging comparison.

What should I do before and after a PET/CT scan?

Before the test

Since PET/CT is a functional test based on glucose metabolism, if the patient needs to undergo this test, they should make adequate preparations before the test:

▲ Before the scan, patients need to fast for 4-6 hours so that the drug can be fully absorbed by the body.

▲ Before the examination, diabetic patients should consult a doctor to determine the accurate fasting schedule, oral hypoglycemic drugs or insulin usage, etc., so that the examination can proceed smoothly.

▲ Patients should avoid strenuous exercise within 24 hours before the examination.

▲ Please try to wear comfortable and loose clothing, and do not wear metal underwear. Women please do not wear dresses, metal, jade and other accessories.

After the inspection

When the examiner does PET/CT, the radionuclide drug 18F-FDG is injected. How long will it stay in our body?

Director Chen Xiaoliang said that about 12 hours after 18F-FDG enters the human body, its radioactivity can be ignored, and 18F-FDG is mainly excreted from the kidneys. Therefore, after a PET/CT examination, you should drink more boiled water and urinate more often to help shorten the drug's residence time in the body. In addition, please flush the toilet more often after defecation.

Introduction to Nuclear Medicine

The Nuclear Medicine Department of the Affiliated Tumor Hospital of Chongqing University and Chongqing Tumor Hospital was established in 1990. It was the first department in Chongqing to carry out SPECT examinations. The department currently has three major diagnosis and treatment centers, namely the PET/CT Center, the SPECT/CT Center, and the Nuclear Medicine Treatment Center, as well as a Positron Drug Preparation Center and a Nuclear Medicine Laboratory. It mainly carries out PET/CT, SPECT/CT imaging diagnosis and radionuclide therapy projects.

The Department of Nuclear Medicine of the Affiliated Tumor Hospital of Chongqing University is currently the chairman unit of the Clinical Nuclear Medicine Committee of Chongqing Pharmaceutical Biotechnology Association, the vice chairman unit of the Nuclear Medicine Branch of Chongqing Medical Association, and the member unit of the PET Group of the Nuclear Medicine Branch of the Chinese Medical Association.

The department has won one third prize for scientific research achievements at the provincial and ministerial level, and has completed and is conducting two provincial and ministerial scientific research projects. The medical staff of the department has rich experience in diagnosis and treatment and strong technical strength. In 2020, the department completed 18,693 SPECT examinations and 5,564 PETCT examinations. At the same time, radionuclide therapy projects such as iodine-131 treatment of differentiated thyroid cancer, strontium-89 treatment of bone metastases, phosphorus-32 treatment of malignant pleural effusion, iodine-125 particle tumor implantation treatment, and radium-223 treatment of prostate cancer bone metastasis have been carried out.

The department has always adhered to the hospital's core culture of being kind, progressive, moral and learning-oriented, and strives to provide every patient with more efficient and higher-quality medical services!

Text/Fat Bear Photos/Partially from the Internet (Please contact us to delete if there is any infringement) Review/Nuclear Medicine Department

Member of China Medical We-Media Alliance

Science Popularization China Co-construction Base

Chongqing Science Popularization Base/Chongqing Health Promotion Hospital

Chongqing Science and Technology Communication and Popularization Project

National Health Commission National Basic Public Health Service Health Literacy Project