主题：PET/CT在恶性肿瘤中的应用 -- 良金百辟

3年前，Memorial Sloan-Kettering Cancer Center（MSKCC，纪念斯隆－凯特琳癌症中心）--- a cancer treatment and research institution founded in 1884 as the New York Cancer Hospital.As of 2010, U.S. News & World Report ranks MSKCC as the #2 cancer hospital in the country.----的 Mithat Gnen（Director, PET Imaging in MSKCC）和Heiko Schder（Associate Attending Biostatistician）发表的一篇文章（Screening for Cancer with PET and PET/CT: Potential and Limitations Journal of Nuclear Medicine Vol. 48 No. 1 (Suppl) 4S-18S）中提到一个很有趣的测试：

In preparation for writing this article, we conducted a (nonscientific) survey among residents, fellows, technologists, and pharmacists within the Nuclear Medicine Service at Memorial Sloan-Kettering Cancer Center, asking the following questions: Do you think that whole-body PET screening is effective in detecting cancer at an early, potentially curable state? Should whole-body 18F-FDG PET be marketed as a screening study to healthy, asymptomatic individuals? Would you be willing to have a whole-body 18F-FDG PET screening examination? All 20 participants answered the first question with "yes." Although nobody seemed to favor marketing PET or PET/CT as a screening tool to the public, at least 14 individuals were curious enough to undergo a screening PET examination if it were offered to them at no cost (1 additional fellow stated "yes, if I were over the age of 50"). It is likely that similar results would be obtained if this survey were presented to a larger group of health care professionals.

这个可能代表了美国部分大型癌症中心的部分医生关于PET/CT用于癌症筛查的部分意见吧。（避免误导，切切！）

确实， 这个是核医学专业人士发在核医学杂志的文章，有自卖自夸之嫌，但是毕竟核医学圈子不是封闭于医学界之外的自娱自乐的小团体，以他的身份（Heiko Schder,，http://www.mskcc.org/prg/prg/bios/687.cfm）,要是纯粹瞎掰一个民意测试的话，不担心砸了自己或者MSKCC的招牌吗？

来自非影像学专业的权威数据可以提供旁证：(JNCCN, 关于10年来PET在美国的使用量)

*The use of positron emission tomography (PET scanning) is increasing rapidly in the United States.The most common use of PET scanning is related to oncology, especially in staging and managing lymphoma, lung cancer, and colorectal cancer.*

闲话少说，为什么在美国，乃至于全世界，PET/CT的在肿瘤中的应用都越来越广泛？

VALUE OF PET/CT“

/CT is more accurate in detecting cancer and provides fewer equivocal findings than PET alone (80–83), CT alone, or separately acquired PET and CT studies in a head-to-head comparison (84). For cancer staging, PET/CT is also more accurate than either modality alone, as shown for lung cancer (85,86), colorectal cancer (83), and lymphoma (87). Antoch et al. investigated the TNM staging accuracy of PET/CT in 260 patients with a variety of malignancies (88). Histopathologic and clinical follow-up at 311 ± 125 d (mean ± SD) served as a standard of reference. PET/CT had a significantly higher TNM staging accuracy (84%) than side-by-side PET plus CT (75%), CT alone (63%), or PET alone (64%). Values were slightly different for T, N, and M staging, but the same general trend toward superior accuracy of PET/CT was observed.

these studies suggested that PET/CT might be more sensitive and specific for cancer detection than either modality alone”

但是 PET/CT也有自己的问题

1. 费用

2. RADIATION DOSIMETRY CONCERNS：“adiation from an ever-increasing number of medical imaging studies is clearly a concern, but in the overall debate about screening CT and PET, it is only a minor contributing factor. If the efficacy of these studies for reducing cancer mortality could be proven, then concerns about radiation dose might be of lesser importance as long as the principle of "as low as reasonably achievable" is upheld. However, because there is currently no such evidence, dosimetry concerns remain an additional factor in cautioning against indiscriminate screening efforts.”

3. LEGAL IMPLICATIONS

（看来没有大的损害）

他在文中的意见并不在一般人群中推荐PET/CT用于肿瘤筛查，不过留了一个尾巴：Whether either test （PET/CT or whole-body CT or whole-body PET) can be effective and cost-effective for cancer screening in certain high-risk groups remains to be determined.

那么什么是 某些高危人群 呢？

是那个小调查里面的家伙写的50岁以上人群吗？还是在前边一个帖子里提到的 60岁以上 吸烟史 家族史 慢性炎症等易患因素 还是前边一些帖子里面认为的 任何人任何时候都不该用做筛查

现在没有人知道。

不过，值得注意的是， 中国的社区医疗体系不发达。人们尤其是老年人 没有自己的私人医生，少有快速传递自己健康信息的渠道。而且，环境和心理近年来的巨大变化等等，使得我趋向于放宽这个"高危人群" 而不是缩窄。

美国普通人和奥巴马，巴菲特不会是同样的体检标准。区别在于第一 有没有钱 第二 医保计划包括不包括---实际上还是有没有钱

所以，关于不考虑花费的情况下PET/CT可否应用于老年人体检，没有定论，见仁见智。

我的意见是60岁以上 吸烟史 家族史 慢性炎症等易患因素的老年人 在具有良好的医疗条件的时候（可以很好的解读结果，判断下一步采取何种措施等等） 每5年做一次， 可能利大于弊。

PET/CT在筛查中的作用 只是它在肿瘤中的应用的极小的一部分。如果大家有兴趣 可以继续关注下文