At the end of 2011, the Ministry of Health proposed in a document to standardize the use of PET-CT to protect patients' legitimate rights and interests, and required that the positive rate of its examinations be no less than 70%. This statement means that PET-CT must be used symptomatically in the future. In practice, the percentage of cancer detected through PET-CT medical checkups in each medical institution does not exceed 2%. What exactly is driving 98% of healthy people to spend nearly $10,000 to take unnecessary risks?
PET---CT used to do profiteering physical examination business, PET---CT used for healthy people physical examination has historically received mixed reviews, real experts never support healthy people to do, engaged in PET---CT doctors will not themselves or let their families to do.
"This is mainly due to the low tumor detection rate." Chinese Medical Association Nuclear Medicine Branch Chairman, PLA 301 Hospital Nuclear Medicine Professor Tian Jiahe said, before the relevant statistics at home and abroad are in 1% -2%, in recent years in 301 Hospital to do PET-CT among the 20% of people for physical examination, which detected malignant tumors of 1.3%, in addition to 20% of the people to check out other potential diseases such as coronary heart disease.
For healthy people to use PET-
CT physical examination, Tian Jiahe's attitude is "do not advocate, nor oppose". But Tian found that some of his peers preferred to do the most direct health economics evaluation - using PET-CT to make money.
Domestic PET-CT examination costs vary, to the whole body examination, for example, Shanghai, a unified price of 7,500 yuan, Guangzhou is 8,000 - 10,000 yuan ranging, and "Beijing is the most expensive", for 10,000-15,000 yuan. Beijing is the most expensive, at 10,000-15,000 yuan. The website of the intermediary said that the group purchase of more than 5 people can help to apply for a 10% discount.
The head of the nuclear medicine department of a well-known hospital in Beijing told the Southern Weekend reporter that the operating cost of PET-CT is quite high, with an import price of more than 20 million yuan, plus personnel, maintenance fees and other costs, the cost is about 30 million yuan. However, due to the hospital's abundant supply of patients, only in 2011 a PET-CT revenue reached 45 million yuan, a year that is to recover costs.
Dr. Lin Hongwei, an oncology surgeon at PLA Hospital 306, was the first to publicly criticize PET-CT on Weibo for being "abused," calling out, "PET-CT is not for health checkups.
He once asked many
doctors, "Would you let your healthy family members go for a PET-CT checkup?" The answer was usually "no."
You can ask the doctor next to you
, "Would he do it? Would he ask his family to check?
Concealed and ignored risks
In fact, the risks of PET-CT have been concealed by practitioners in the face of the extraordinary popularity of PET-CT, the safety of which has long been questioned. an April 2009 article in Radiology pointed out that radiation dose studies in Hong Kong and the United States have shown that whole-body PET-CT scans are now accompanied by high radiation doses and carcinogenicity. significant radiation dose and cancer risk.
A study in the April 2009 issue of Radiological Society of North America's Radiological Medicine reported that whole-body PET-CT scans are associated with substantial radiation doses and cancer risk.
Professor Pek-LanKhong, head of the Department of Diagnostic Radiology at the University of Hong Kong, and other researchers used three major PET-CT instruments, and the results showed that the radiation dose ranged from 13-32 millisieverts; the "incidence of cancers associated with PET-CT" ranged from 0.2% - 0.8%, and the higher the age, the higher the incidence of cancer. 0.8%, and the lower the age, the greater the risk.
Therefore, the researchers recommend that PET-CT should be performed only when there is a good clinical reason to do so, and that steps should be taken to minimize the dose.
Professor Robert E. Reiman of the Department of Radiation Safety at Duke University Medical Center in the UK said in an interview with Southern Weekend, "It is well recognized in the scientific community that damage to the body from radiation accumulates as the number of times it is exposed to radiation increases. Therefore, each PET-CT examination increases the risk, which will eventually bring about a significant dose of radiation over time".Robert E. Reiman emphasized that the risk to which children are exposed will be even greater.
However, few appointment sites actively advise that people who have just had a
PET-CT exam, as a potential source of radiation, should avoid excessive contact with pregnant women and children for a short period of time.
Japan was the first and most widely used country to use
PET-CT for medical checkups, giving rise to an international "medical checkup tourism" service. The service is now attracting a large number of Chinese people as well. But even in Japan, the controversy over PET-CT checkups has not been avoided.
"There is not enough evidence on the cost-benefit of medical checkups with PET-CT." Kota Kohta Katanoda, director of the Statistical Analysis Division at the National Cancer Center in Japan, said, "Currently PET-CT medical checkups are mainly driven by the interests of some medical institutions, and we are still waiting for more
evidence and will not promote it as a guideline."
A paper published in the 2007 Asia-Pacific Journal of Tumor Prevention expressed an even more negative view. It found that the positive predictive value of PET-CT was only 3.3% when it was used to examine healthy Japanese aged 50-59. That is, nearly 97% of patients found to have tumor abnormalities by PET-CT physical examination were not patients with true malignant tumors.
At the newly held 2012 European Annual Congress of Radiology, a multicenter study showed that PET-CT is not superior to CT or MR*** vibration in these two areas.
The Canadian Health Services Research Foundation, a not-for-profit organization funded by the Canadian government, also noted that PET-CT scans not only do not prevent cancer-related deaths, but also put patients at risk. A good test should be susceptible and specific, with a low error rate, according to the foundation's report. It should be able to reduce mortality from a disease and should not expose people to undue harm.
"There is no evidence that PET-CT scans prevent cancer
related deaths." After combing through a number of papers in recent years assessing the effectiveness of PET-CT physical exams, this report states, "PET-CT scanning is neither susceptible nor specific, and it imposes a large number of risks on patients, including unnecessary exams, excessive radiation exposure, and a very high error rate. In addition, it increases the chances of overmedication."
A doctor's view with scientific ethics
A chief physician of the Department of Gastrointestinal Oncology at the Beijing Cancer Hospital pointed out that PET-CT has a blind spot in detecting lesions in hollow organs (stomach, intestines, etc.), and therefore it does not replace routine exams such as gastroscopy and enteroscopy.
Ouyang Xuenong, director of the oncology department at Fuzhou General Hospital of Nanjing Military Region, said: "It is generally not recommended as a physical examination for healthy people. Because this test costs a lot of money, radiation, in the discovery of cavity organ (such as esophagus, stomach, intestines, etc.) lesions there are blind spots, can not replace the gastroscopy and colonoscopy."
The aforementioned doctors of the Tertiary Cancer Hospital pointed out that PET-CT examination can not replace CT and MRI examination. "Each test has its advantages. Sometimes when we do PET-CT examination, we will also ask the patient to have further CT, MRI or even ultrasound examination."
The truth is that PET-CT exams don't check for all tumors. In the diagnosis of primary liver cancer, PET-CT is not as effective.
Some arguments even challenge the need for health checkups as a whole. "Regular medical checkups for healthy people need to be questioned in themselves." A radiologist at Peking Union Medical College Hospital told Caixin's New Century, "PET-CT is able to detect some very small swellings, but sometimes even if they are detected, they are meaningless. Because it is too small to be detected, such a test can only cause anxiety in patients, triggering another round of unnecessary tests."
In fact, despite the rapid advances in imaging, there is still only one "gold standard" for determining
whether a tumor is malignant, which is the pathological examination of the diseased tissue. "New tests are coming out all the time, and the images are getting clearer and clearer, but is that necessarily a good thing?"
Professor Qiao Youlin, a tumor epidemiologist at the Chinese Academy of Medical Sciences and Peking Union Medical College, also took a negative view of the use of PET-CT for medical checkups in the general population. He pointed out that many cancers currently have mature, simple and inexpensive detection methods, while PET-CT examinations are too expensive and risky "to have the value of promoting them to the entire population."
"It is definitely not good medical practice to subject every healthy human body to a PET-CT scan." Prof. David W. Townsend of the National University of Singapore, who was one of the first in the world to participate in PET-CT research, told Southern Weekend.
When I visited a cancer detection center in Finland, I specifically inquired about the scope of PET-CT use, and was told by the director, Professor Markku Mattila, that PET-CT would not be used casually for medical examinations. "It's no use even if you have money, it has to be done only after other instruments have been checked and the doctor thinks it's necessary."
"It's not because of the price, but because of the risk." Cornelis A. Hoefnagel, an expert in the Department of Nuclear Medicine at the Netherlands Cancer Institute, said, "With a PET-CT checkup like the one in Japan, you might only check 3 people out of 100. It's not worth putting the other 97 people at risk for radiation for the sake of 3 people."
Radiation dose of PET-CT
The contrast agent used in PET-CT examination is generally the radioisotope of fluorine-18 (18F-FDG), and according to the measurement of the injection of 0.1 mCi/kg of body weight, the measurement of the radioisotope injected into the examined person will not be more than 10 mCi in general.That is to say, the radiation dose of doing 1 whole-body PET-CT Check the amount of radiation is about 10-32 mSv, the average person receives 1000-2000 microsieverts of natural radiation per year, (Note: 1000 microsieverts = 1 millisieverts, Japan's Fukushima Daiichi nuclear power plant leakage of the accident level 5, the second day of the nuclear power plant near the 1.1 kilometers, the radiation level of 351.4 microsieverts per hour! )
The simplest analogy: a full-body checkup with PET-CT, equivalent to 30 years of radiation for a normal person, is accepted in one hour. It is equivalent to standing for a day on the second day of the leak at the Fukushima nuclear power plant in Japan.
Afterword: On the issue of PET-CT, many leaders and bosses have asked me whether it is good or not, because they have heard how advanced it is, how good it is, and today I finally at 1:00 in the morning, PET-CT is hidden and not known radiation written out, but also a popular science.