metrology at nim · 2019. 11. 13. · progress of radiation medicine metrology at nim...

Progress of radiation medicine metrology at NIM

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Zhang Jian

Division of Ionizing Radiation metrology, NIM

Progress of radiation medicine

metrology at NIM


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Outline

1. radiation medicine application in China

2. Radiodiagnosis metrology

3. Radiotherapy metrology

4. Nuclear medicine metrology

5. Collaboration with NRC

proton

neutron


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Radiodiagnosis 放射诊断

• More than 400 million radioactive diagnosis per year in China.

• Around 21,600 CT scanners in 2016 (increase 2300 sets per year)

Metrology requirement:

To get better image quality with low radiation dose. 低个人剂量，高质量图像

Quantity:

Air kerma, Air kerma area product, Air kerma Length, kVp, mAs, HVL

Discovery of X-ray

CT Scanner


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Radiotherapy 放射治疗

Gansu heavy ion hospital

• 3.8 million tumor patients is confirmed per year in China, 60-70% patients need radiotherapy.

• 1413 hospitals for radiotherapy • LINAC: 1931 sets, Co-60: 96 sets; • X knife: 171 sets, γ knife: 210 sets; • Brachytherapy 439 sets; • 919,339 radiotherapy per year • Proton and carbon therapy started to

treat patient, 7 centers are establishing. 低正常组织剂量，高肿瘤靶区剂量

Metrology requirement: • The radiotherapy techniques developing

rapidly and require high accuracy and more complicated dosimetry measurement.

Shanghai Proton and Heavy Ion Center

Superconductivity Cyclotron radiotherapy facility


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Nuclear medicine 核医学

PET/CT Blending image

The use of short-lived radionuclides as a tool for diseases diagnosis (SPECT/PET) and

treatment, particularly cancer, continues to rise at a rapid rate recent years.

Around 300 PET-CT in China in 2016, increasing 40 sets per year

Metrology requirement: 放射性核素计量

• Development of systems for performing activity measurements for short-lived

radionuclides

• Quantitative nuclear medicine Positron Emission Tomography


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Outline

1. Radiation medicine application in China

2. Radiodiagnosis metrology




proton

neutron


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Primary standard of air kerma mammography X-ray

Primary standard of air kerma in 10-60kV X-ray

BIPM.RI(I)-K7 BIPM.RI(I)-K2 BIPM.RI(I)-K3

Primary standard of air kerma in 60-250kV X-ray

Metrology in Radiodiagnosis 放射诊断计量

Air kerma, Air kerma area product, Air kerma Length kV, mA, Image Quality

National standard in kV, Image Quality

Supplemental comparison

Semiconductor detector and ionizing chamber for diagnosis Phantom 放射诊断用半导体探测器和电离室剂量计的校准


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Primary standard for (10-60)kV X-rays 低能X射线基准

NIM designed and manufactured a parallel plate type free air chamber to realize air kerma of x-rays from 10kV to 60kV. The relative expanded uncertainty is around 0.28%. In 2010, we finished the APMP.RI(I)-K2 comparison.

基准装置及国际比对


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Primary standard for (60-250)kV X-rays 中能X射线基准

For (60-250)kV X-rays, we established a new free air chamber(as shown in picture). The relative expanded uncertainty is around 0.22%. APMP.RI(I)-K2 comparison is finished in July, 2016, and BIPM.RI(I)-K3 comparison is finished in 2017.



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Primary standard for mammography 乳腺X射线基准

Mammography is the process of using low-energy X-rays to examine the human breast, The goal of mammography is the early detection of breast cancer. In 2014, we designed a new cylindrical type Free Air Chamber for mammography x-rays to establish the traceability.

Spectrum by simulation 基准装置


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Secondary standard for diagnostic x-ray 诊断X射线标准

The secondary standard for diagnostic x-ray is to offer calibration services for the air kerma, potential of x-ray generator(kVp) of semi-conductor detector and ionizing radiation chamber.

High voltage divider

放射诊断国家标准


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Standard for Image quality control in radiography 放射影像质控标准

To develop technical performance standards for x-ray diagnosis, focusing particularly on image quality: Spatial Resolution, Contrast Sensitivity.

Industrial CT for image quality research

Phantom 图像质控标准


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Outline


2. Radioactive diagnosis metrology




proton

neutron


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Primary standards for Radiotherapy 放疗基准体系

(4-25) MV LINAC 60Co

BIPM.RI(I)-K6 BIPM.RI(I)-K1 BIPM.RI(I)-K4

60Co 192Ir

BIPM.RI(I)-K8

X-ray

BIPM.RI(I)-K9

Primary standard in Air kerma Primary standard in absorbed dose to water

BIPM.RI(I)-K2,K3

X-Ray

Ionizing chamber used in radiotherapy

Trace

放疗电离室剂量计校准


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0.975

0.980

0.985

0.990

0.995

1.000

1.005

1.010

1.015

1.020

1.025

PTB

(BIP

M.R

I(I)-K4)

Nuc

. Malay

sia

AEC

KRIS

S

NMIJ (B

IPM.R

I(I)-K4)

NMIS

A

DMSC

BARC

NIM

BATA

N

INER

ARPANSA (B

IPM.R

I(I)-K4)

NRL

NIS

Primary standard of 60Co water absorbed dose 60Co水吸收剂量基准

• Water absorbed dose measured by graphite calorimeter and cavity ionization chamber.

• Took part the APMP.RI(I)-K4 comparison. • Finished the comparison with IAEA on 2015

for the SSDL network.



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Water Calorimeter for high energy photon absorbed dose 加速器光子水吸收剂量基准

In collaborating with NRC, NIM is developing a primary standard for absorbed dose to water at radiotherapy dose levels. The developing standard for water absorbed dose is based on a water calorimeter and is designed to operate in Co-60 and megavoltage photon beams from a linear accelerator.

The draft B of the BIPM.RI(I)-K6 comparison was finished.

Attempt to measure the high energy electron (18MeV) with calorimeter core used for the photons.


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Dosimetry for Small and composite fields 小野与复杂野剂量学

• Determine the range of the dimension for

the small field dosimetry;

• Determine the absorbed dose

measurement method for small field

dosimetry;

• Establish the reference radiation condition

for small field dosimetry; Research the

transfer method for small field dosimetry;

• Determine the available scope of the

absorbed dose measurement method in

small field dosimetry.

与临床剂量结合，进行放射剂量学研究


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Proton and heavy ion dosimetry 质子重离子剂量学

Heavy ion radiotherapy in Lanzhou Proton radiotherapy in Shanghai

• Proton and heavy ion have been used for radiotherapy in China, there are 3 radiotherapy centers for heavy ion and 4 centers for proton.

• To develop absorbed dose standard for proton and heavy ion based on calorimeter under the cooperation with radiotherapy center.

Bragg peak used for radiotherapy 应对我国质子重离子临床应用的计量需求


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Collaborate with medical physic society 与医学物理领域的合作

Participate in the quality assure (QA) workshop of radiotherapy for the hospital in Beijing every year. Peking union medical college hospital take charge of the radiotherapy QA center of Beijing .

Supply the training course to the medical physicist in china by the collaboration with medical physic society.

Apply the national fund together with cancer centers and the CDC of China, focus on the radiotherapy dosimetry research.

与医学物理学会，精确放疗学会合作


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Outline






proton

neutron


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Radioactivity metrology 医用核素计量

Radioactivity meter

Secondary standards

Primary standards for

standardization

Diagnosis

Treatment

• Tc-99m, half life about 6h, widely applied for imaging in SPECT • F-18, half life about 1.8h; Ga-68, half life about 67.8min used for

imaging in PET

• I-131, half life about 8d, applied for thyroid disease treatment • Ra-223, half life about 11.4d; Y-90, half life about 2.67d widely

applied for the treatment of liver cancer

短寿命医用核素量传链条


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A new and more realistic TDCR model by Penelope 液闪三双符合比方法（LNHB合作）

With more detailed geometrical and material descriptions for

optical chamber, chamber cap, photomultipliers

5000 10000 15000 20000 25000 30000 35000

1E-10

1E-8

1E-6

1E-4

0.01

1

pro

ba

bili

ty d

en

sity

deposited energy/ev

probability density

TDCR

(2D view)

TDCR

(3D view) An example of the computed absorption spectrum for

the interaction of γ ray with a liquid scintillator

国际水平的放射性核素测量方法


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Completed the standardization for nuclides Tc-99m 锝活度测量与国际比对

• Standardization of Tc-99m activity by

primary standard

• Calibration of 4πγ ionization chamber

• Participated in the BIPM.RI(II)-K4.Tc-

99m international comparison, and

equivalence achieved

• Provide services for activity meter and

SPECT for medical diagnosis

Comparison results for Tc-99m

锝99m的测量与国际比对


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90Y seperation from 90Sr and the impurity measurement 钇锶分离与杂质测量

• 90Y (Iridium)was separated from 90Sr(Strontium)using an extraction

chromatographic resin consisting of DtBuCH18C6,2mimNTf2 and a

polymer.

• After the separation, the activity ratio of 90Sr/90Y was less than

0.002%;

Yu Zou, Juncheng Liang, Taiwei Chu, Crown ether-ionic liquid-based extraction chromatographic

resin for separation of 90Y from 90Sr, 2016,J Radioanal Nucl Chem, Doi.10.1007/s 10967-016-5142-5


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Outline






proton

neutron


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NRC and NIM

NRC in Ottawa and NIM in Beijing


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Overview of technique exchange in recent year 近年来技术交流

Agreement signed

2012.12 NRC staff visited NIM

2013.6-11

2015.5

2016.1

NRC staff visited NIM

2017.2

NIM staff worked in NRC

2016.2

NRC and NIM signed MoU

NIM staff visited NRC

2017.5 Meeting today


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metrology at nim · 2019. 11. 13. · progress of radiation medicine metrology at nim...

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