This document discusses the components and workflow of a linear accelerator (LINAC) for radiation therapy. It describes the key components of early LINACs from the 1950s, improvements in second and third generation models in the 1960s-1980s, and the main internal components of current LINACs including the electron gun, accelerating waveguide, treatment head, bending magnet, target, collimators, and monitoring systems. The document also briefly discusses the electron beam mode and auxiliary systems that support LINAC operation.
TISSUE PHANTOM RATIO - THE PHOTON BEAM QUALITY INDEXVictor Ekpo
TPR(20,10) is the recommended photon beam quality index by IAEA TRS-398 for megavoltage clinical photons generated by linear accelerators. This presentation goes through the basics of Tissue Phantom Ratio (TPR).
TISSUE PHANTOM RATIO - THE PHOTON BEAM QUALITY INDEXVictor Ekpo
TPR(20,10) is the recommended photon beam quality index by IAEA TRS-398 for megavoltage clinical photons generated by linear accelerators. This presentation goes through the basics of Tissue Phantom Ratio (TPR).
This seminar is presented as a part of weekly journal club and seminar regularly conducted at Apollo hospital,Kolkata Department of Radiation oncology.
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
This seminar is presented as a part of weekly journal club and seminar regularly conducted at Apollo hospital,Kolkata Department of Radiation oncology.
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
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
1. By DR. MARIYA KIKALI
DNB RESIDENT, RADIATION ONCOLOGY
WORKFLOW OF LINEAR ACCELERATOR
2. FLOW OF PRESENTATION
1. Introduction
2. Different generations of LINAC
3. Components of LINAC-
a) Magneteron
b) Klystron
c) Electron gun
d) Accelerating waveguide
e) Treatment head
f) Auxillary system
3. LINEAR ACCELERATOR
• It is a device that uses high-frequency electromagnetic waves to
accelerate charged particles such as electrons to high energies
through a linear tube.
• The high-energy electron beam itself can be used for treating
superficial tumors.
• Or it can be made to strike a target to produce X-rays for
treating deep-seated tumors.
4. EARLY ACCELERATORS
• 1953 Linac-based radiation therapy for
cancer began with treatment of the first
patient in London at Hammersmith Hospital.
• 1956 In the United States , first patient was
treated for retinoblastoma at Stanford
university, California.
• The Linac had an 8 MV x-ray beam with
limited gantry motion
• These linacs were large and bulky
5. 2ND GENERATION LINACS
• These were isocentric Units,
which can rotate 360 degrees
around gantry axis.
• Built between 1962 and 1982.
• Improved precision and
accuracy of dose delivery.
6. 3RD GENERATION LINACS
• Better accelerator waveguides
and bending magnet systems
• More beam modifying
accessories.
• Wide range of beam energies,
dose rates field sizes and
operating modes.
• Higher reliability
• Computer driven.
9. 1. POWER SUPPLY: Provides DC supply to modulator.
2. MODULATOR: Supplies high voltage negative pulses from main supply
to microwave source and electron gun.
• Dose rate is regulated by varying the pulse repetition frequency.
3. MICROWAVE SOURCE :
• Magnetron
• Klystron
COMPONENTS OF LINAC
10. MAGNETRON
• It produces microwaves.
• It functions as a high-power oscillator, generating microwave
pulses
• The frequency of the microwaves within each pulse is about
3,000 MHz
• Magnetrons operate at a 2-MW peak power output to power low-
energy linacs (6 MV or less)
12. MAGNETRON- FUNCTION
Central cathode is heated by an inner filament
The electron are generated by thermionic emission
Static magnetic field is applied perpendicular to the plane of the
cross section of the cavities + a pulsed DC electric field is
applied between the cathode and the anode
Electrons emitted from the cathode are accelerated toward the
anode
Under the simultaneous influence of the magnetic field, the
electrons move in complex spirals toward the resonant cavities
Radiating energy in the
form of microwaves
13. KLYSTRON
• It is a microwave amplifier
(not a microwave producer)
• It is driven by a low-power
microwave oscillator
• Higher-energy linacs use
klystrons
14. KLYSTRON- STRUCTURE &
FUNCTION
Velocity modulation: Velocity of electron is altered by the action of electric
field in the buncher cavity produced by low power microwave
Electrons on arriving in the catcher cavity suffer deceleration due to
retarding electric field, thus kinetic energy(KE) of electrons is converted
into high-power microwaves
16. ACCELERATING WAVEGUIDE
• Uses electromagnetic RF wave to
accelerate electrons to very high
velocities onto target or electron
window
• Types-
1. Travelling waveguide- The
traveling wave structures require a
terminating, or “dummy,” load to
absorb the residual power at the
end of the structure, thus
preventing a backward reflected
wave
2. Standing waveguide- Provide
maximum reflection of the waves at
both ends of the structure so that
the combination of forward and
reverse traveling waves will give
rise to stationary waves
Cutaway view of a standing wave accelerating
waveguide for a 6 MV linac
17. TREATMENT HEAD
Contains components designed to
shape and monitor the treatment
beams.
They include:
• Bending magnet
• Target
• Primary collimator
• Beam flattening filter/ scattering
foil
• Ion chambers
• Secondary collimators and
• One or more slots for trays,
wedges, blocks and compensators
18.
19. BENDING MAGNET
• Changes the direction of the
electron beam, downwards- towards
the patient
• Bends the pulsed electron beam
towards the target for X-rays or
scattering foil for electron
treatments
• Produces different beam paths for
different energies
• Needed for energies greater than 6
MeV.
20. BENDING MAGNET
Three systems for electron
beam bending :
a) 90˚ bending,
b) 270 ˚ bending and
c) slalom system incorporating
two 45˚ magnets and a
112.5˚ magnet
21. TARGET
The target material:
• Tungsten for electron energies upto 10 MeV
• Higher energies - Aluminium
PRIMARY COLLIMATOR
Defines maximum field size.
(40X40cms)
Limits the beam only in the direction of isocentre and cut off in
all other directions.
22. FLATTENING FILTER
Photon dose distribution produced
by a linac is strongly forward
peaked
Flattening filter is inserted in the
path of beam to make the beam
uniform across the field.
Material: Lead, tungsten, uranium
steel, aluminium or a combination.
23. MONITORING SYSTEM- ION CHAMBER
The function of the ion chamber is to monitor dose rate,
integrated dose, and field symmetry.
The monitor chambers in the treatment head are usually sealed
so that their response is not influenced by temperature and
pressure of the outside air.
24. SECONDARY COLLIMATOR
Consist of four blocks, two forming the upper and two forming
the lower jaws of the collimator
It helps to generate the field shape of any size according to
treatment planning – square or rectangular
High density material like lead or tungsten alloy
Thick enough to absorb 98% of the main beam
3 types of secondary collimators :
1. Symmetric
2. Independent
3. Multileaf
25. MULTI LEAF COLLIMATOR(MLC)
• MLC consists of a large number of collimating blocks or leafs
that can be driven automatically, independent of each other, to
generate a field of any shape.
• The thickness of leaves along the beam direction is sufficient to
provide acceptably low beam transmission (less than 2%).
• Typical MLC systems consist of 60 to 80 pairs
• The individual leaf has a width of 1 cm or less as projected at the
isocenter
• The leaves are made of tungsten alloy
28. SCATTERING FOIL
• It is mounted on a rotating carousel or sliding drawer for ease of
mechanical positioning into the beam, as required
• In the electron mode of linac operation, electron beam, instead
of striking the target, is made to strike an electron scattering foil
• Use- 1. To spread the beam
2. To get a uniform electron fluence across the treatment
field.
• Consists of a thin high-Z metallic foil (e.g., lead, tantalum)
29. AUXILIARY SYSTEM
1. Vacuum pumping system- for accelerating guide and the RF
generator;
2. Water cooling system- used for cooling the accelerating guide,
target, circulator and RF generator;
3. An optional air pressure system- for pneumatic movement of the
target and other beam shaping components;
4. Shielding against leakage radiation.
30. TREATMENT COUCH
• The treatment couch or table is where patient lays still to receive the
radiation treatment
• It moves up/down, right/left and in/out
• Robotic couches are being used in some linacs for 3 more degree of
freedom
• Made with carbon fibre top