Proton therapy is able to more precisely target radiation dose to tumor tissues while minimizing dose to surrounding healthy tissues. Photon therapy deposits radiation throughout the tissues it passes through, whereas proton therapy deposits most of its energy at a specific depth called the Bragg peak. This allows protons to deliver a high radiation dose to the tumor with little exit dose, improving treatment of cancers near critical structures.
Particle beam – proton,neutron & heavy ion therapyAswathi c p
particle therapy is advanced external beam therapy used to treat cancer , which uses beams of protons or other charged particles such as helium, carbon or other ions instead of photons. charged particles have different depth-dose distributions compared to photons. They deposit most of their energy in the last final millimeters of their trajectory (when their speed slows). This results in a sharp and localized peak of dose, known as the Bragg peak.
Particle beam – proton,neutron & heavy ion therapyAswathi c p
particle therapy is advanced external beam therapy used to treat cancer , which uses beams of protons or other charged particles such as helium, carbon or other ions instead of photons. charged particles have different depth-dose distributions compared to photons. They deposit most of their energy in the last final millimeters of their trajectory (when their speed slows). This results in a sharp and localized peak of dose, known as the Bragg peak.
A summary of recent innovations in radiation oncology focussing on the priniciples of different techniques and their application. An overview of clinical results has also been given
In 2000 IAEA published another International Code of Practice.
“Absorbed Dose Determination in External Beam Radiotherapy” (Technical Report Series No. 398)
Recommending procedures to obtain the absorbed dose in water from measurements made with an ionisation chamber in external beam radiotherapy (EBRT).
A summary of recent innovations in radiation oncology focussing on the priniciples of different techniques and their application. An overview of clinical results has also been given
In 2000 IAEA published another International Code of Practice.
“Absorbed Dose Determination in External Beam Radiotherapy” (Technical Report Series No. 398)
Recommending procedures to obtain the absorbed dose in water from measurements made with an ionisation chamber in external beam radiotherapy (EBRT).
This slide includes physical, biological properties of proton and its advantage over the photon. It also provides information from beam production to treatment planning system of proton therapy, its potential applications, cost effectiveness and demerits.
The evolution of radiation treatment planning and delivery, with innovative techniques (3DCRT, IMRT, IGRT, IGBT), particle therapy allowing for better definition of target and sensitive structure volumes and more precise quantification of dose, has introduced more complexity into the evaluation of radiation effects on OARs.
Transmission of X-ray through body tissues linear energy transfer..pptxDr. Dheeraj Kumar
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Linear Energy Transfer (LET) is a fundamental concept in the study of radiation biology and the effects of ionizing radiation on living tissues.
In this present, we answer the following questions
What is Proton Therapy?
Why use proton therapy?
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And what are the limitations in using proton therapy?
radioactivity is the act of emitting radiation spontaneously. This is done by an atomic nucleus that, for some reason, is unstable; it "wants" to give up some energy in order to shift to a more stable configuration.
The Bohr model of the atom consists of a dense
positive nucleus surrounded by electrons in
shells. The nucleus contains nucleons which
are either protons or neutrons. The proton has
a positive charge and an atomic mass of 1 AMU.
The neutron has zero charge and an atomic
mass of 1 AMU. The atomic number (Z) is
equal to the number of protons in the nucleus.
The atomic mass (A) is equal to the sum of the
neutrons and protons in the nucleus. The electron has a negative charge and a mass of almost
zero. Electrons in an atom only move in specifi c orbits. Each orbit or shell has its own binding energy. The binding energy is the energy
required to remove an electron from its shell.
The shells closer to the nucleus have higher
binding energies. Ionization occurs when an
electron is removed from an atom. This results
in an ion pair made up of one positive and
one negative ion. Ionizing radiation consists
of electromagnetic and particulate radiations
with enough energy to ionize atoms. X-rays
and gamma rays are forms of electromagnetic
radiation. Alpha and beta radiations are forms of
particulate radiation.
There are two systems of radiation units, the
SI and the conventional. The units of exposure
are the roentgen (R) and the coulombs per
kilogram (C/kg). The units of dose are the gray
and the rad. The units of the effective dose are
the sievert and the rem.
Elements with similar electron shell structures have similar chemical properties. Isotopes
are elements with the same atomic number but
different atomic masses. Isotopes have the same
chemical properties. The atomic weight of an
element is the average of the atomic masses of
naturally occurring isotopes. When elements
are arranged in order of increasing atomic number, they form the periodic table of elements.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
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Azure Interview Questions and Answers PDF By ScholarHat
proton therapy
1.
2. Types of Radiations
X-rays• α-particles• neutrons•
γ-rays• β-particles•
β+-particles•
Protons•
Carry enough energy which if deposited
in matter can produce ions
3.
4. Radiation therapy idea
Selective cell destruction (cancer)
How it can be done?
By destroying the cell using Energy
High energy particles damage a cell by altering it’s atom
Cause the atom’s electron to become excited and then ionized
Enzymes repair this damage
• But cancer cell slower than healthy cell
So, the end results (during radiation exposure )
More cancer cell end up dying more than healthy cell
5. Reminder
• Absorbed dose D is the energy (joules) deposited per
unit mass (kg) of target material, D = dE/dm.
• The special unit of absorbed dose D is the Gray (Gy)
≡ 1 Joule/kg
• In biological systems
• Radiation Biologic effects dependent on “the
spatial distribution of energy deposition” (LET)
Linear Energy Transfer is energy deposited per unit path
length = dE/dx with units ev/cm
6. Overview of presentation
• Photon therapy (briefly)
• Proton therapy (in detailed)
• How it works ?
• The remarkable phenomenon of physics “Bragg peak”
• Delivery of the beam (how it can be useful )
• How it can be produced ? (synchrotron)
• RBE of protons .
• Proton therapy Vs Photon therapy .(summary)
7. The desirable goal
In order to treat cancer :
The main goal is to delivers a defined dose distribution
within the target volume and none out side it.
Now
Let’s see what type of radiation
would be the
Best??
9. Interactions of Photons
There are 3 modes:
• Photo-electric effect.
Entire energy transfer from
photon to an atomic electron .
• Compton effect.
Fraction of energy transferred to
Compton electrons.
• Pair production.
11. Exponential behaviour
• It falls exponentially
E E o exp( en x)
• Number of photon gets
attenuated
as depth increases .
• As their number decreases,
the dose that they deposit
decreases also
(proportionately ).
12. Photon’s therapy failure
• Based on “how radiation
interacts with matter”
The failure is :
Most of the radiation is
deposited on healthy tissue.
Cause of failure !!
• They are not easy to control
Why ?
(low mass & high energy)
“Low LET”
15. Short story
• “A man with a vision “
In 1946 Harvard physicist ,
Robert Wilson suggested:
• Protons can be used clinically .
• Maximum radiation dose can
be placed into the tumor .
• Proton therapy provides
sparing of healthy tissues .
16. Characteristics of protons
• Subatomic particle .
• Stable , positively charged .
• Heavy particle with mass 1800
that of electron.
• Very little scattered as they
travel through tissue .
• Travel in straight lines.
Which leads to very
Mp=1.672621636(83)×10−27 kg
Me= 9.10938215(45)×10−31 kg different modes of interactions
with matter .
Let’s see!!!!!!
17. Interactions of Protons
• Coulomb interactions with
atomic electrons .
Electronic (ionization ,excitation)
• Coulomb interactions with
atomic nuclei .
“multiple Coulomb scattering.”
• Nuclear interactions with
atomic nuclei .
Elastic nuclear collision
Non elastic nuclear collision
18. Key fact
Different modes of interactions
Means
Different dose distributions
19. The shape of dose distribution
It means that :
• Low entrance dose
(plateau)
• Maximum dose at depth
(Bragg peak)
• Rapid distal dose fall-off
But
Why this shape of
distribution ?
Let’s see
20. Remarkable phenomena
“Bragg peak”
Protons have the ability of
loosing little energy when
entering tissue .
But depositing more and
more as they slow
down…..
Finally, depositing a heavy
dose of radiation just
before they stop ,
giving rise to the
so-called Bragg peak
21. Energy loss “dE/dx profiles
• a proton’s linear rate of
energy loss “linear energy
transfer” (LET)
• is given by the Bethe-
Block formula:
23. Bragg peak dependence on
energy
• The range is( the depth
of penetration
from the front surface to the
distal point on the Bragg
peak)
• Bragg peak
depends on the initial
energy of the protons so
the greater the energy, the
greater the range
24. There is a problem
Is the current shape of
Bragg peak could provide
the tumor with uniform
dose ?
No, it can’t.
Because
The Bragg peak is too narrow
to fit the shape & depth of
the tumor
25. Is there a solution ?
So, how to make the beam of proton useful for
treatment?
Is it possible to shape the beam to fit the
shape of the tumor ?
Let’s see!!!!!
26. Smart Idea
• The spread-out Bragg peak
(SOBP):
• Extending the dose in depth
means
An extension in depth can be
Superposition of Bragg-peaks by
achieved by proton beams energy variation
of successively
delivering not just one, but
many Bragg peaks each
with different range (energy)
energy variation
27. Beam delivery system Nozzle
There are two main approaches
( techniques) for shaping the
beam : (both laterally and in
depth)
1) passive scattering.
2)Scanned beam.
29. Shaping the beam Laterally
The beam is spread
laterally to clinically
useful size by
double – scatterer
and compensator
30. Tailoring the beam in depth:
the range modulator (fan like
The modulator spins
around in front of the
proton beam pulling the
beam back and forward
causing a flat topped
dose distribution
providing the tumor with a
uniform dose.
31. Scanned beam
• Expand the lateral
dimensions of a proton
beam by using the
electromagnetic
technique to scan the beam
laterally & in shape .
32. Synchrotrons The engine)
• What is Synchrotron
mission ?
• They produce the proton
beam .
• It is a modified Cyclotrons.
synchrotron provides energy
variation by extracting the
protons when they have
reached the desired
energy.
34. A word about Treatment plane
How do you know what
to include and what to
exclude in treating
deep –seated tumors
with radiation?
By using number of
imaging tools
(CT,MRI,PET….)
Gives ability to see
To image
To map
35. Relative Biological Effectiveness
of proton
RBE is the ratio of the dose of reference radiation beam
(e.g., photons) to that of test beam (e.g., protons)
required to produce a defined biological response .
• Is used to compare the biologic effects of various
radiation sources .
Protons has exactly the same biologic effects as X-rays!!
Because the calculated RBE is 1.1
The bottom line is that the only difference between
protons and standard X-rays lies in the physical
properties of the beam and not in the biologic effects
in tissue.
36. SUMMARY
• Photon therapy Proton therapy
the interactions are stochastic . they are deterministic events .
they not easy to control . They easier to control .
At point of entrance,
It receive large amount of dose. It receive very small dose .
As they reached the tumor,
Continue to pass through tissue a sharp burst of energy released
at tumor and none beyond it.
Used for treat superficial tumors. ideal for tumors in or near
critical structures (brain, heart,
eye) pediatric cancers.
37. References and sites
• Radiation Oncology A Physicist's-Eye View: Michael
Goitein .
• Radiation therapy physics: William R Hendee &
Geoffrey .
• Sites:
• www.wikipedia.org
• Loma Linda University Medical Center
www.llu.edu
• www.mpri.org
• www.proton-therapy.org
• http://www.varian.com/