The document provides information on the principles of brachytherapy including its definition, history, advantages, disadvantages, and types. It discusses the different classifications of brachytherapy based on duration of implant, source placement, source loading pattern, and dose rate. Key details about low-dose rate, high-dose rate, and pulsed-dose rate brachytherapy are provided. Common brachytherapy sources and applicators are also described.
LDR and HDR Brachytherapy: A Primer for non radiation oncologistsSantam Chakraborty
A small presentation I made for a 30 minutes class comparing and contrasting LDR and HDR brachytherapy. Good for a person with non radiation oncology background to grasp the basics.
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
A review of advances in Brachytherapy treatment planning and delivery in last decade or so, with main focus on brachytherapy for Prostate cancer, Breast cancer and Cervical cancer
The vmat vs other recent radiotherapy techniquesM'dee Phechudi
VMAT is a new type of intensity-modulated radiation therapy (IMRT) treatment technique that uses the same hardware (i.e. a digital linear accelerator) as used for IMRT or conformal treatment, but delivers the radiotherapy treatment using a rotational or arc geometry rather than several static beams.
This technique uses continuous modulation (i.e. moving the collimator leaves) of the multileaf collimator (MLC) fields, continuous change of the fluence rate (the intensity of the X rays) and gantry rotation speed across a single or multiple 360 degree rotations
This ppt explains about Electronic Brachytherapy which is a very special type of Brachytherapy in Radiation therapy. This presentation also demonstrates classifications of brachytherapy, Sources used for Brachytherapy, Advantages and disadvantages of electronic Brachytherapy, Different companies providing Electronic Brachytherapy machines and it portraits working method and components of Electronic Brachytherapy Machine.
LDR and HDR Brachytherapy: A Primer for non radiation oncologistsSantam Chakraborty
A small presentation I made for a 30 minutes class comparing and contrasting LDR and HDR brachytherapy. Good for a person with non radiation oncology background to grasp the basics.
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
A review of advances in Brachytherapy treatment planning and delivery in last decade or so, with main focus on brachytherapy for Prostate cancer, Breast cancer and Cervical cancer
The vmat vs other recent radiotherapy techniquesM'dee Phechudi
VMAT is a new type of intensity-modulated radiation therapy (IMRT) treatment technique that uses the same hardware (i.e. a digital linear accelerator) as used for IMRT or conformal treatment, but delivers the radiotherapy treatment using a rotational or arc geometry rather than several static beams.
This technique uses continuous modulation (i.e. moving the collimator leaves) of the multileaf collimator (MLC) fields, continuous change of the fluence rate (the intensity of the X rays) and gantry rotation speed across a single or multiple 360 degree rotations
This ppt explains about Electronic Brachytherapy which is a very special type of Brachytherapy in Radiation therapy. This presentation also demonstrates classifications of brachytherapy, Sources used for Brachytherapy, Advantages and disadvantages of electronic Brachytherapy, Different companies providing Electronic Brachytherapy machines and it portraits working method and components of Electronic Brachytherapy Machine.
Modern Medical Application methodologies: Brachytherapy, Neutron Capture Ther...Haider Ali Malik
Brachytherapy (also referred to as Curie therapy) is defined as a short-distance treatment of malignant disease with radiation emanating from small sealed (encapsulated)
Neutron capture therapy (NCT) is a nonsurgical therapeutic modality for treating locally invasive malignant tumors such as primary brain tumors, and recurrent head and neck cancer.
Proton therapy, or proton radiotherapy, is a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often to treat cancer.
IORT uses a high single-fraction radiation dose (10-30 Gy) is delivered during surgery to a surgically-exposed tumour bed, immediately after a chunk of the tumour has been surgically excised. This slide includes topics like APBI, IOERT, IOHDR.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
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.
Title: Sense of Taste
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 structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
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.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
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.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
2. DEFINITION
Derives from the Greek word ‘brachy’ – meaning short-distance
Brachytherapy involves placing small radiation sources internally, either
into or immediately next to the tumor in a geometrical fashion , allowing
precise radiation dose delivery (1)
1) Stewart AJ & Jones B. In Devlin Brachytherapy: Applications and techniques. 2007.
3. HISTORY
1896 :- Radioactivity was described by Becquerel
1898 :- Marie curie extracted radium from pitchblende ore
1901 :- Danlos and Bloc performed first radium implant
1931 :- The term brachytherapy proposed first time by Forsell
1940-1950 :- Brachytherapy rules were developed and followed
1953 :- Aterloading technique first introduced by Henschke in New
York – removed hazard of radiation exposure. Also Ir-192 used first
time by Henschke
1953 :- LDR brachytherapy became the gold standard
1968 :- HDR brachytherapy was introduced
1970s :- Brachytherapy is established as a safe and effective
standard of care for many gynecological cancers
4. ADVANTAGES
High dose of radiation is delivered to tumor in short time.So
biologically very effective
Normal tissue spared due to rapid dose fall off
Better tumor control
Radiation morbidity minimal
Acute reactions appear when treatment is over; so no
treatment breaks. Also radiation reactions localized &
manageable
Treatment time short – reduces risk of tumor repopulation
Therapeutic ratio high
5. DISADVANTAGES
Invasive procedure
Radiation hazard due to radioisotopes (in olden days due to
preloading techniques, now risk decreased )
General anesthesia required
Dose inhomogeneity is higher than EBRT (but acceptable if
rules followed)
Because of greater conformity, small errors in source
placement can lead to extreme changes from the intended
dose distribution
6. TYPES OF BRACHYTHERAPY
Classification
Based on Duration of implant
Based on Source position
Based on Source loading pattern
Based on Dose rate
7. TYPES OF BRACHYTHERAPY
Classification
Based on Duration of implant
Based on Source placement
Based on source loading pattern
Based on Dose rate
8. DURATION OF IMPLANT
Temporary- Dose is delivered over a short period of time
and the sources are removed after the prescribed dose has
been reached. The specific treatment duration will depend on
many different factors, including the required rate of dose
delivery and the type, size and location of the cancer. Eg :-
Cs137, Ir192
Permanent- also known as seed implantation, involves placing
small LDR radioactive seeds or pellets (about the size of a grain of rice) in
the tumor or treatment site and leaving them there permanently to
gradually decay. Eg :- I125 ,Pd103, Au198
13. TYPES OF BRACHYTHERAPY
Classification
Based on Duration of implant
Based on Source placement
Based on Source loading pattern
Based on Dose rate
14. Interstitial - the sources are placed directly in the target
tissue of the affected site, such as the prostate or breast.
Contact - involves placement of the radiation source in a
space next to the target tissue.
Intracavitary – Consists of positioning applicators bearing radioactive sources
into the body cavity in close proximity to target tissue eg :- Cervix
Intraluminal – Consists of inserting single line source into a body lumen to treat
its surface &adjacent tissue.
Surface (Mould) – (Plesiocurie/Mould therapy) Consists of an applicator
containing array of radioactive sources designed to deliver a uniform dose
distribution to skin/mucosal surface.
Intravascular – Inserting a single line source to Blood vessels to treat the
layers of blood vessel
19. TYPES OF BRACHYTHERAPY
Classification
Based on Duration of implant
Based on Source placement
Based on Source loading pattern
Based on Dose rate
20. Pre-loading :- Inserting needles/tubes containing radioactive material directly
into the tumor
After-loading :- First, the non-radioactive tubes inserted into tumor
Manual After Loading :- Ir192 wires, sources manipulated into applicator by means of forceps
& hand-held tools
Remote After Loading :- consists of pneumatically or motor-driven source transport system
21. PRELOADING (PROS & CONS)
Advantage:
– Loose & flexible system(can be inserted even in distorted cervix)
– Excellent clinical result
– Cheap
– Long term results with least morbidity (due toLDR)
• Disadvantages:
– Hasty application -Improper geometry in dose distribution
– Loose system – high chance of slipping of applicators – improper geometry
– Application needed special instruments to maintain distance.
– Radiation hazard
– Optimization not possible
22. AFTER LOADING (MANUAL)
Advantages
Circumvents radiation protection problems of preloading
Allows better applicator placement and verification prior to source placement.
Radiation hazard can be minimized in the OT/bystanders as patient loaded
in ward.
Advantages of preloading remain as practised at LDR.
Disadvantages:
specialized applicators are required.
24. Advantages :
No radiation hazard
Accurate applicator placement
-ideal geometry maintained
-dose homogeneity achieved
-better dose distribution
Information on source positions available
Individualization & optimization of treatment possible
Higher precision , better control
Decreased treatment time- opd treatment possible
Chances of source loss nil .
Disadvantages :
Costly
AFTER LOADING (REMOTE)
27. Emergency
button
Hand cranks if
everything else fails
Safe, holding the active
source and a dummy source
Optopair to verify
source position
Indexer face
with 18
source
channels
Transfer
tube
connector
Stepper motor
with shaft encoder (additional
DC motor available for source
retraction in case of failure)
Indexer
Radiation monitor
30. TYPES OF BRACHYTHERAPY
Classification
Based on Duration of implant
Based on Source placement
Based on Source loading pattern
Based on Dose rate
31. Low-dose rate(LDR)- Emit radiation at a rate of 0.4–2 Gy/hour.
Medium-dose rate (MDR)- characterized by a medium rate of dose
delivery, ranging between 2-12 Gy/hour.
High-dose rate (HDR)-when the rate of dose delivery exceeds
12 Gy/h.
Pulsed-dose rate (PDR) - involves short pulses of radiation, typically
once an hour, to simulate the overall rate and effectiveness of LDR
treatment. (1ci)
Ultra low dose rate - Dose range 0.03 to 0.3 Gy/Hr
32. HDR V/S LDR
Advantages :-
Radiation protection
Allows shorter treatments times
HDR sources are of smaller diameter than the cesium sources that are
used for intracavitary LDR ,hence reduced need of Anaesthesia
HDR makes treatment dose distribution optimization possible
Disadvantage
Radiobiological
Limited experience
The economic disadvantage
Greater potential risks
35. KEY ELEMENT
Obsolete or historical
226Ra, 222Rn
• Currently used sealed sources
137 Cs, 192Ir, 60Co, 125I, 103Pd,198Au, 90Sr.
• Developmental sealed sources
241Am, 169Yb, 252Cf,145Sm.
36. IDEAL ISOTOPE
Easily available & Cost effective
Gamma ray energy high enough to avoid increased energy deposition in bone & low
enough to minimise radiation protection requirements
Preferably monoenergetic: Optimum 300 KeV to 400 KeV(max=600 kev)
Absence of charged particle emission or it should be easily screened (Beta energy
as low as possible: filtration)
Half life such that correction for decay during treatment is minimal
– Moderate (few years) T1/2 for removable implants
– Shorter T1/2 for permanent implants
Moderate gamma ray constant (determines activity & output) &also determine
shielding required.
37. No daughter product; No gaseous disintegration product to prevent physical damage
to source and to avoid source contamination
High Specific Activity (Ci/gm) to allow fabrication of smaller sources & to achieve
higher output (adequate photon yield)
Material available is insoluble & non-toxic form
Sources can be made in different shapes & sizes: Tubes, needle, wire, rod, beads
etc.
Should withstand sterilization process
Disposable without radiation hazard to environment
Isotropic: same magnitude in all directions around the source
No self attenuation
41. PATIENT SELECTION
Small size tumors (3 – 5 cm)
Depth of penetration/thickness < 1.5 – 2 cm
Histology: moderately radiosensitive tumors (ca squamous cell) ; some
adenocarcinomas
Early stage (localized to organ)
No nodal/distant metastasis
Location : accessible site with relatively maintained anatomy
Absence of local infection & inflammation
42. RULES OF THE GAME
Interstitial
• Manchester
• Quimby
• Paris
• Memorial
Intracavitary
• Manchester
• Paris
• Stockholm
Surface/Mould
• Manchester
Objectives:-
•To determine the distribution & type of radiation sources to provide optimum dose
distribution
•To provide complete dose distribution in irradiated volume
Components :-
•Distribution rules
•Dose specification and optimization
•Dose calculation aid
43. PARAMETERS MANCHESTER QUIMBY PARIS COMPUTER
Linear strength Variable Constant Constant Constant
Source
distribution
Planar implant:(periphery)
Area <25 cm- 2/3 Ra;
25-100 cm- ½ Ra; >100 cm-
1/3
Volume
implant::Cylinder:belt-4
parts,core-2,end-1
Sphere:shell-6,core-2
Cube :each side-1,core-2
Uniform
Uniform
Uniform
Line sources
parallel
planes
Uniform
Line sources
Parallel or
cylinderic
volumes
Spacing line
source
Constant approx. 1 cm apart
from each other or from
crossing ends
Same as
Manchester
Constant,
Selective
Separation 8-
15 mm
Constant
Selective
Crossing needles Required to enhance dose at
implant ends
Same Crossing
needles not
used;active
length 30-
40% longer
Crossing
needles not
used;active
length 30-40%
longer
46. Breast
Indications: Boost after BCS & EBRT
Postoperative interstitial irradiation alone of
the primary tumor site after BCS in selected
low risk T1 and small T2N0 (PBI)
Chest wall recurrences
As sole modality As Boost to EBRT
Patient choice: cannot come for 5-6 wks treatment :
Distance
Lack of time
Close, positive or unknown margins
Elderly, frail, poor health patient EIC
Large breasts: unacceptable toxicity Younger patients
Deep tumour in large breast
Irregularly thick target vol.
47. T.V.: Primary Tumor site + 2-3 cm margin
Dose: As Boost: 10-20 Gy LDR
AS PBI: 45-50 Gy in 4-5 days LDR (30-70 cGy/hour)
34 Gy/10#, 2# per day HDR
Technique:
Localization of PTV: Surgical clips (at least 6)
USG, CT or MRI localization, Intraop USG
During primary surgery
Guide needle technique or
Plastic tube technique using Template
Double plane implant
Skin to source distance: Minimum 5 mm
48.
49. INTRACAVITARY
MANCHESTER SYSTEM
To define the treatment in terms of dose to a point.
Criteria of the point:
Anatomically comparable
Position
where the dosage is not highly sensitive to small alteration in applicator position
Allows correlation of the dose levels with the clinical effects
To design a set of applicators and their loading which would give the same
dose rate irrespective of the combination of applicators used
To formulate a set of rules regarding the activity, relationship and
positioning of the radium sources in the uterine tumors and the vaginal
ovoids , for the desired dose rate
50. POINT A
PARACERVICAL TRIANGLE where initial lesion of radiation
necrosis occurs
Area in the medial edge of broad ligament where the uterine
vessel cross over the ureter
The point A -fixed point 2cm lateral to the center of uterine
canal and 2 cm above from the mucosa of the lateral fornix
POINT B
Rate of dose fall-off laterally
Imp. Calculating total dose-Combined with EBRT
Proximity to important OBTURATOR LNs
Same level as point A but 5 cm from midline
Dose ~20-25 % of the dose at point A
51.
52. MIND IT !!
In order that point A receives same dosage rate no matter which ovoid combination is used ,it is
necessary to have different radium loading for each applicator size
Dose rate 57.5 R/hr to point A
Not more than 1/3 dose to point A must be delivered from vaginal radium
Largest possible ovoid should be used to reduce dose to mucosa
Longest possible tandem (not > 6 cm)
Better lateral throw off
Smaller dose to mucosa
Dose to point A- 8000R
Dose to uterus wall -30,000R
Dose to vaginal mucosa-20,000R
Dose to recto-vaginal septum- 6750 R
Dose limitation
BLADDER <80 Gy
RECTUM <75 Gy
53. IDEAL APPLICATION
Tandem
1/3 of the way between S1 –S2 and the symphysis pubis
Midway between the bladder and S1 -S2
Bisect the ovoids
Marker seeds should be placed in the cervix
Ovoids
against the cervix (marker seeds)
Largest
Separated by 0.5-1.0 mm
Axis of the tandem-central
Bladder and rectum -should be packed away from the implant
54. PARIS SYSTEM
Single application of radium
Two cork colpostats (cylinder) and an intrauterine tube
Delivers a dose of 7000- 8000 mg-hrs of radium over a period of five
days(45R/hr) (5500mg/hr
Equal amount of radium used in the uterus and the vagina
Intrauterine sources
3 radioactive sources, with source strengths in the ratio of 1:1:0.5
colpostats
sources with the same strength as the topmost uterine source
55. STOCKHOLM SYSTEM
Fractionated course of radiation delivered over a period of one month.
Usually 2-3 applications, each for a period of 20- 30 hours (repeated 3weekly)
Intravaginal boxes -lead or gold
Intrauterine tube -flexible rubber
Unequal loading
30 - 90 mg of radium in uterus
60 - 80 mg in vagina
Total prescribed dose -6500-7100 mg Ra
4500 mg Ra contributed by the vaginal box (dose rate-110R/hr or
2500mg/hr/#)
56. DRAWBACKS OF STOCKHOLM AND PARIS SYSTEM
Long treatment time
Discomfort to the patient
No dose prescription
57. ICRU 38
DOSIMETRIC INFORMATION FOR REPORTING
Complete description
Technique
Time-dose pattern
Treatment prescription
Total Reference Air Kerma
Dose description
Prescription points/surface
Reference dose in central plane
Mean central /peripheral dose
Volumes: Treated/ point A/ reference volume
Dose to Organs at Risk : bladder, rectum
58. REFERENCE VOLUME
Dimensions of the volume included in the corresponding isodose
The recommended dose 60 Gy
TREATED VOLUME
Pear and Banana shape
Received the dose appropriate to achieve the purpose of the treatment, e.g., tumor
eradication or palliation, within the limits of acceptable complications
IRRADIATED VOLUME
Volumes surrounding the Treated Volume
Encompassed by a lower isodose to be specified, e.g., 90 – 50% of the dose
defining the Treated Volume
Reporting irradiated volumes may be useful for interpretation of side effects outside