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Chapter 14 -- Medical Applications of Nuclear Technology

Chapter 14 -- Medical Applications of Nuclear Technology. Xiaodong He Radiotherapy Center Shanghai Pulmonary Hospit al.

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Chapter 14 -- Medical Applications of Nuclear Technology

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  1. Chapter 14 -- Medical Applications of Nuclear Technology Xiaodong He Radiotherapy Center Shanghai Pulmonary Hospital

  2. Just after the moment of discovery of X rays, the importance of X rays in medical diagnosis was immediately apparent , and within months of its discovery, the bactericidal action of X rays and their ability to destroy tumors were revealed. prologue

  3. Today, both diagnostic and therapeutic medicine as well as medical research depend critically on many increasingly sophisticated applications of nuclear radiation and radioisotopes.

  4. Medical Applications of Nuclear Technology Radiation Oncology 放射肿瘤 治疗学 Nuclear medicine 核医学 Radiation Image + NMR Medical Applications of Nuclear Technology are constituted by three parts above.

  5. Nuclear medicine in vitro Radioimmunoassay，RIA 体 内 γ Camera ，Bone Scanning Single Photon Emission Computerized Tomography SPECT Positron Emission Tomography PET/CT Radionuclide Therapy Tumor, hyperthyroidism甲亢,etc. Radionuclide analysis in vitro + in vivo

  6. According to the radioactive isotope analysis results of the Oak Ridge(橡树岭) lab: In one year, 98% of the atoms of organism (human body) is replaced. The body does not have a constant material. And, in certain time the materials inside body are to produce thousands of times biological chemical reactions every second. Radionuclide analysis for human species

  7. Radioimmunoassay （more compactly as RIA 放射免疫技术） RIA as a kind of technology take the both advantages of accuracy and sensitivity of the radioactive isotope measurement and the specificity of the reaction of antigen and antibody. It is a new in vitro technology for ultra trace (10-9~10-15g) material detection. 放射免疫技术为一种将放射性同位素测量的高度灵敏性、精确性和抗原抗体反应的特异性相结合的体外测定超微量(10-9~10-15g)物质的新技术。

  8. Broadly, all the assay technologies via immune reactions by antigen and antibody which tagged by radioactive isotopescan be called RIA 广义来说，凡是应用放射性同位素标记的抗原或抗体，通过免疫反应测定的技术，都可称为放射免疫技术 。 So far has development to the fifth generation of RIA technology. It is characterised by the combination of magnetic particles and RIA or IRMA (immunoradiometric assay) .

  9. PET / CTPositron emission tomography + CT PET/CT is a perfect fusing of PET and CT. It can Provide detailed lesion function and metabolic information of moleculars by PET , and in the same time, provide the accurate lesion anatomic localization by CT. It is characterised by sensitivity, accuration, specific and accurate location. It is extensive used in radiotherapy, and also be called the “high-tech coronal of Modern medicine”.

  10. The Mechanics of PET The clinicalimaging process of PET is as followes: a. Mark the radioactive isotopes which can emit positrons (such as F-18) to compounds which be gonna to participate in tissue blood flow, or in metabolic process. b. Inject the tagged compounds into human body.

  11. c. Theemission positron from radio-isotope can shift 1 mm in human body, and then combined with an electron in tissues and annihilate to produce two equal energy (511 KeV) and opposite γ photons. It was recognized that detection of these photons, using the property that they are emitted simultaneously in opposite directions, would permit description, in three dimensions, of the distribution of the radionuclides in the body.

  12. Sketch map of PET PET imaging of an object surrounded by a ring of detectors. Annihilation photons γaare recorded by detectors on opposite sides of the ring, the relative intensities allow determination of the mass thickness of the distances L1 and L2 in the patient through which these photons travel.

  13. d. Annihilation photons leaving the body are detected by an array of detectors that surround the patient. Events are recorded only when two detectors each detect an annihilation photon simultaneously, i.e., within 10 to 25 ns of each other. Events separated further in time are not recorded.

  14. The line joining the two recording detectors is a line of response (LOR) along which the annihilation photons have traveled and on which the positron decay occurred. This coincident detection technique allows a determination of the direction of the annihilation photons without the physical collimation needed in SPECT. For this reason coincident detection is often called electronic collimation.

  15. PMT：光电倍增管(Photo Multiplier Tube) BGO： 锗酸铋(Bismuth Germanium Oxide）

  16. Radiation Imaging & NMR X ray Radiography, and DSA （Digital subtraction angiography 数字减影血管造影术） Computed Tomography （CT） 计算机断层成像 Magnetic Resonance Imaging （NMR） Function NMR，NMR spectrum analysation 4D fast CT and 4D fastNMR

  17. Background & Rationale • Convolution 线性系统h(t)，输入e(t)，输出y(t)

  18. 卷积的来源： • 物理中类似对于冲量不变的研究。在用t做横坐标、F做纵坐标的坐标系中，就如同一个面积不变的长方形，底边被挤的越窄，高度被挤的越高。在数学中它可以被挤到无限高，但即使它无限瘦、无限高、但它仍然保持面积不变。 • 可以对它进行积分，求面积。于是“卷积” 这个数学怪物就这样诞生了。

  19. 卷积可以描述为一个过程

  20. 卷积可以描述为一个过程 • 这两个可认为是经典的衍射问题，信号处理也会遇到类似的问题。

  21. 在晶体X射线衍射中，实验测量出的衍射峰的线形h，包括两部分：晶体的贡献f和衍射仪器的贡献g，h、f和g三者的关系满足卷积运算：在晶体X射线衍射中，实验测量出的衍射峰的线形h，包括两部分：晶体的贡献f和衍射仪器的贡献g，h、f和g三者的关系满足卷积运算：

  22. 讲卷积离不开傅立叶变换。 • 在晶体衍射里，傅立叶变换关联着两个完全不同的空间：现实的笛卡儿空间和倒易的衍射空间。

  23. Fourier transformation • 傅里叶变换能将满足一定条件的某个函数表示成三角函数（正弦和/或余弦函数）或者它们的积分的线性组合。 • Two features： 1. 傅立叶变换是线性算子,若赋予适当的范数,它还是酉算子； 2. 正弦基函数是微分运算的本征函数,从而使得线性微分方程的求解可以转化为常系数的代数方程的求解.在线性时变复杂的卷积运算为简单的乘积运算,从而提供了计算卷积的一种简单手段。

  24. Laplace transformation • 拉氏变换的物理意义：建立了时域和复频域之间的联系。 • 其数学意义：将微分方程转化为代数方程，简化了计算。

  25. 傅氏与拉氏变换的区别在于，拉氏变换是处理微分方程的，它的最初目的是将微分运算转化为容易求解的代数运算。而fourier变换是将连续的时间域信号转变到频率域；它可以说是laplace变换的特例；傅氏与拉氏变换的区别在于，拉氏变换是处理微分方程的，它的最初目的是将微分运算转化为容易求解的代数运算。而fourier变换是将连续的时间域信号转变到频率域；它可以说是laplace变换的特例； 拉氏存在条件比fourier变换要宽，是将连续的时间域信号变换到复频率域（整个复平面，而fourier变换此时可看成仅在jΩ轴）；

  26. Z变换则是连续信号经过理想采样之后的离散信号的laplace变换，再令z=esT时的变换结果（T为采样周期），所对应的域为数字复频率域，此时数字频率ω=ΩT。Z变换则是连续信号经过理想采样之后的离散信号的laplace变换，再令z=esT时的变换结果（T为采样周期），所对应的域为数字复频率域，此时数字频率ω=ΩT。 • 它与拉氏变换一样，都是将时域映射到频域。 • 拉普拉斯变换与Z变换的联系；其本质区别在于拉氏变换处理的是时间上连续的问题，Z变换处理的是时间上分立的问题。

  27. Question 1 • What is the main difference between fourier transformation and laplace transformation ? main difference：laplace transformation is in whole complex plane，and fourier transformation is just in imaginary axis. • Question 2 • What is the physical and mathematical significance of laplace transformation? physical significance: It establishes the relationship between the time domain and complex frequency domain. mathematical significance: Converts differential equation to Algebraic equation, so as to simplify the calculation.

  28. NMR • 原子核在外磁场作用下发生能级分裂,在一定射频场作用下吸收其能量发生能级跃迁的现象。 塞曼能级分裂 射频脉冲 E = hν radio frequency pulse, RF 核磁共振

  29. The quantum mechanical describes for NMR

  30. 小结

  31. Background & Rational • Quantum mechanics • Fourier transformation

  32. Radiation Oncology Teletherapy Brachytherapy

  33. P, C Teletherapy X rays Electrons Elements used in teleradiotherapy

  34. 4DRT CRT IMRT Teletherapy Techniques used in teleradiotherapy

  35. Iodine BNCT boron neutron capture therapy Ir-192 Cobalt-60 Brachytherapy Elements used in brachytherapy

  36. (125)I implantation Brachytherapy 碘近距离粒子种植放疗 Brachytherapy 近距离放疗 After loading radiotherapy 后装放疗 Intracavity afterloading radiotherapy 腔内后装放疗 Techniques applied in brachyradiotherapy Seeds implant Interstitial implant brachytherapy 组织间插植

  37. After-loading Intracavitary unit 后装治疗机 A点：宫颈口旁2cm 上2cm B点：A点外3cm

  38. Paris Dosimetry System巴黎剂量学系统 植入辐射源呈直线型、彼此相互平行、各线源等分中心位于同一平面、各源相互等间距、排布呈正方形或等边三角形、源的线性活度均匀且等值、线源与过中心点的平面垂直。

  39. Interstitial Radiation组织间插植治疗

  40. Synopsis of the Tele-radiotherapy外放射治疗简介

  41. What is Radiotherapy (RT) RT is a clinical subject of treating cancers by applying the theories and means of high energy rays to irradiate tumor targets. 研究、应用高能放射线治疗肿瘤的原理和方法的临床治疗学科

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