Techniques and Applications Test 1

CQI (continuous quality improvement)

looks at why the system caused the person to make that mistake (or why something works)

decrease costs, increase customer satisfaction, ensure quality throughout the healthcare organization

What does QI do?

TJC (The joint commison)

independent, not for profit organization dedicated to improving the quality of care in healthcare settings

Accreditation is not required but desired by most

ACRO (american college of radiation oncology)

ACR (american college of radiology)

ASTRO (american society for radiation oncology)

• APEx (accreditation program for excellence)

4 Rad Oncology accreditation agencies

quality

The totality of features and characteristics of a radiation therapy process that bear on its ability to satisfy stated or implied needs of the patient

QA (quality assurance)

what actions need to be taken to meet quality

TQM (total quality managment)

more customer service centered (what does this do for them?)

CQI

continuous quality improvement

QC (Quality control)

the tests/tasks you do

Quality indicators

the actual tolerances (#’s)

Who is on the QI team?

Physicians (oncologists), physicists, engineers, dosimetrists, radiation therapists, oncology nurses, support staff

research

strong scientific evidence demonstrates that performing the evidence based care process improves health outcomes (either directly or by reducing risk)

accuracy

measure should be capable of indicating whether the process has been delivered with sufficient effectiveness to make improved outcomes likely

Adverse effects

implementing the measure has little or no chance of inducing unintended consequences

TNM

Tumor, nodes, mets

PSA

Prostate specific antigen (lab value), higher levels when there is an issue

DRE

Digital rectal exam

consultation, simulation, RT planning, treatment, follow ups

Steps of radiation therapy

American association of physisicts in medicine

AAPM

SRS

stereotactic radiosurgery (more cranium)

SBRT

stereotactic body radiotherapy (rest of the body)

Megavolt vs Kilovolt

megavolt is used for treatment (shows grainy images) - compton

kilovolt is used for simulation and localization (shows structures better) - photoelectric

Homogenity results must be within how many HU (Housefield units)

5 HU

PSA

patient support assembly (the couch)

Co-60 monthly tolerance

2% monthly tolerance

Who does daily, monthly, and yearly QC tests

daily - therapists

monthly - physicists & dosimetrists

annual - physicists

optical devices

lasers, field defining lines

dose volume histogram

graphical summary used in rad therapy to show the dose delivered to a specific volume of tissue

DRR

digitally reconstructed radiograph

tumor localization

determining the extent of the tumor and the location of critical structures

Treatment verification

using diagnostic quality radiographs of each treatment field from the initial simulation procedure

(radiographs used to compare against port films)

conventional sim

designed to simulate the mechanical, geometrical, and optical conditions of various treatments units

IGRT

image guided radiographic therapy

isocenter

what everything rotates around

what is the only non divergent part of the beam

central axis

Monitor units (mu)

radiation output (dose)

100 cm

distance to maintain from source

SSD vs SAD

SSD (source to skin distance) - requires pt to be moved to maintain 100 cm

SAD (source to axis distance) - gantry can rotate and maintain 100 cm

IEC vs Varian

IEC - 0 degrees on top and 180 on bottom

Varian - 180 degrees on top and 0 on bottom

Field defining wires

define treatment field (biggest area possible is 40 × 40 at 100 cm)

Reticule

provides hash marks on field

ODI (Optical distance indicator)

light based ruler projected on pt’s skin

OFD (OID)

object to field distance

SFD

source to field distance

TFD

target to field distance

seperation

intrafield distance

6%

how many degrees of freedom for table movement

pitch

movement of couch in trendelenburg and reverse trendelenburg position

quality improvement

continuous study and improvement of the process of providing healthcare services

when are tattoos a good idea

when retreatment is needed

lead vs concrete vs borate polyethylene shielding

Lead doesn’t take up much space an can’t block neutron radiation

Concrete takes more space but blocks neutrons due to water in it

borated polyethylene is best shielding

conventional ct

using a simulator that was not 3-D (2-D)

virtual simulation

current method

can print out DRR’s

uses CT and computer software

bore size of CT machine for rad therapy

80-90 cm

5 mm

slice thickness can’t be more than 5 mm

pitch

“couch movement in longituinal per 360 degree rotation of the tube / half beam width”

how fast pt is translating through machine

interpolation

mathematical method that estimates unknown value that falls directly between 2 known pts

amount of detectors in conventional vs ct sim

1 detector in conventional

multiple in ct

amount of detectors per cm vs 1 degree in ct sim

1-8 detectors per cm

1-5 per 1 degree

pros and cons of spiral ct sim

pro - shorter scan time = less pt motion = reduces dose (slices can be taken of any part and any thickness)

cons - higher processing time, higher noise on image if pt moves, doesn’t reconstruct on z axis

respiratory gating

watching the tumor move while breathing

deformable fusion

when overlaping images don’t match (like PET and CT)

2 purposes of CT sim

target localization (and critical structures) allows skin marks to be given

ability to generate DRR’s

1 a week minumum

how often are port films taken

HU (hounsfield units) / CT numbers

attenuation rates or tissue density differences displayed as pixels of different shades of gray

range from +1000 to -1000

HU unit for air

-1000

HU units for water

0

HU units for CSF

15

HU units for blood

20H

HU units for gray matter

40

HU units for muscle

50

HU units for bone

650 - 700

patient positioning

weakest link in treatment

1-2 times

missing tumor can result in failure

10% or more reduction in dose =

could determine if pt is cured

3 types of immobilization devices

Patient positioning aids

simple immobilization devices

complex immobilization devices

immobilization device purpose

help set the pt up easier and to prevent movement

(need to last entire treatment otherwise have to re sim)

patient positioning aids

not custom

ex: head holder, prone pillow, arm board, sand bags

simple immobilization devices

helps restrict pt but won’t hold position for them

(doesn’t completely restrict movement)

ex: bite block, arm stretcher,

complex immobilization devices

custom

ex: alpha cradle, vac bag, aquaplast mask, aquaplast breast

when making complex immobilization devices check for…

bulky clothes because those change day to day, shoes, metal, that they aren’t chewing anything

ionizing vs non-ionizing

ionizing - x-rays

non-ionizing - MRI, ultrasound

lymphangiogram

injection of dye into vessels (usually between toes),

helps detect blocks/leaks in lymph vessels, find cancer, or diagnose conditions like lymphedema or lymphoma

Nuc med vs PET

uses different tracers and cameras

both help determine physiologyl

CT w/ PET

changed lung cancer treatment

Ipsilateral

on the same side

Contralateral

on the opposite side

median sagittal vs parasagittal

median sagittal = equal parts

parasagittal = unequal parts

4 types of body habitus

hypersthenic (5%)

sthenic (48-50%)

hyposthenic (35%)

asthenic (10-12%)

2 main body cavities

posterior/dorsal - can be divided further into cranial and spinal cavity

anterior/ventral - splits into thoracic cavity and abdominal/pelvic cavity divided by diaphragm

chondriac

cartilage

9 regions of abdomen

3 main functions of lymph nodes

1) Drains tissue spaces of interstitial fluid that escapes from blood capillaries and loose connective tissues, filters it, and returns it to the bloodstream

2) absorbs fats and transports them to the bloodstream

3) major role in the body’s defense/immunity

lymph node length

1-25 mm in length

afferent

adds lymph (more of these than efferent)

efferent

takes it away (less of these, larger in diameter than afferent)

lymphedema

excessive fluid

lymph node anatomy

lymphatic flow

tissue fluid - lymph - lymphatic capillary - afferent lymphatic vessel - lymph node - efferent lymphatic vessel - lymphatic trunk - collecting duct - subclavian vein

spleen

largest lymph node in the body

filters all blood