Prelim Flashcards
A practice of exposing a disease to various
types of radiation while also trying to
protect the unaffected parts of the patient’s
body from radiation exposure.
• Treatment of a disease particularly malignant
tumors or cancer using ionizing radiation
Radiation Therapy
General Objectives:
§ “
To deliver maximum dose to the tumor
while giving the minimum dose to the
surrounding normal tissues or cells
3 aims of radiation theraphy
Curative
Prophylactic
Palliative
– to prolong the life of the patient
and provide the best quality of life.
Palliative
– to prevent distant metastases
Prophylactic
Four Specific Modes of Treatment
Surgery
Radiotheraphy
Cytotoxic Drugs
Hormones treatment
2 classffication of treatment
Radical, Palliative
Multiple beam radiation)
the attempt, heroic, if necessary, to
remove all malignancy present
Radical
(simple) – if radical
treatment is thought to be
impossible, the aim is to relieve
symptoms
Palliative
Amount of dose given is dependent on:
Size, extent and type of tumor
4 Persons Involved in Radiation Therapy
Medical physicists
Radiation dosimetrist
Radiation therapist
Oncology Nurse
‒ Study of tumors
Oncology
medical specialty involving
the treatment of
cancerous lesions using
ionizing radiation.
Radiation Oncology ‒
Doctor of medicine
specializing in use of ionizing
radiation in the treatment of
disease and prescribes the
quantity of radiation and
determines the anatomic
region/s to be treated
Radiation Oncologist ‒
‒ doctor of
medicine specializing in
the study of tumors.
Oncologist
• is responsible for calibration and maintenance
of the radiation-producing equipment.
• The physicist also advises the physician about
dosage calculation and complex treatment
technique.
Medical physicists
• The person responsible for the calculation of the
proper radiation treatment dose who assist the
radiation oncologist in designing the individual
treatment plans
Medical dosimetrist
• Educating patient about potential radiation side effects and assisting patients with the management of the side effects.
Oncology Nurse
2 types of Radiation Therapy
- External Beam Radiation Therapy (EBRT)
- Brachytherapy
4 several variation of normal growth
Hypertrophy
Neoplasia
Hyperplasia
Metaplasia
of organ the as in heart muscle when the heart has to work against increase resistance
Hypertrophy
Replacement of cell type not normally present in an organ
Metaplasia
Cells are more numerous and more tightly packed with a high incidence of mitosis
Hyperplasia
means swelling and was originally use for enlargement due to injury, inflammation
Neoplasia
Radiation delivered once a day in ___
Total: __
Average treatment: __ times
Radiation absorbed unit: __
Fraction
30
25
Gy
- Devises a plan for delivering the treatments , on a manner to best meet the physician’s goal of irradiating the tumor while protecting vital normal structures.
Medical Dosimetrists
o - trained to assist, take directions from radiation oncologists in the use of ionizing radiation
- Responsible for obtaining radiograph that localize the area to be treated administering the treatment keeping the accurate record of the dose delivered each day and monitors the patient’s physical and emotional being
RADIATION THERAPISTS
2 broad classes of neoplasms tumors
Benign/ simple
Malignant/ cancerous
6 types of Carcinogens: CRIHWV
Chronic irritation
Radiation
Infection
Hormones
Worms
Viruses
o - soot, smoke, asbestos
Chronic Irritation
o - xray, atomic bombs, radioactive mineral ores
Radiation
- spread of cancer may occur in several ways.: LOCAL INVASIONS; LYMPHATIC VESSELS; BLOOD VESSELS; ACROSS CAVITIES.
METASTASES
The geographical estimation of the extent to which any tumor has
spread
▪ It determines the spread of cancer
Staging of Cancer
Stage __: local lymph nodes invaded
2
Stage __: Blood borne metastases present
4
Stage __: tumor confined to organ of origin
1
Stage __: Distant nodes invaded or local spread beyond organ or origin
3
Another system of staging used internationally:
TNM SYSTEM
T- local extension of primary __
N- condition of regional lymph ____
M- presence of ____ beyond regional lymph nodes
TUMOR
NODES
METASTASES
- neoplasms/ swelling of any nature.
oma
3 THERAPEUTIC DECISION ( Ways of CANCER TREATMENT)
Surgery
Chemo & Radiotherapy
• - radiotherapy technique in which the source of radiation is at some distance from the patient
Teletherapy Method or External Beam Radiation Therapy
- placement of radioactive substance or nuclides in or on neoplasm to deliver cancercidal dose
Brachytherapy or Plesiotherapy
All treatment planning requires definition of the tumor
volume and treatment volume (target volume).
Treatment Planning Volume
TREATMENT PLANNING
- all known disease,
including abnormally enlarged lymph nodes.
Gross Tumor Volume (GTV)
provides margins
around TV to allow for internal target motion, other
anatomic motion during treatment.
Planning Target Volume (PTV)-
- encompasses TV plus regions considered to harbor potential microscopic diseases.
Clinical Target Volume (CTV)
METASTASES- spread of cancer may occur in several ways.: LLBA
LOCAL INVASIONS; LYMPHATIC VESSELS; BLOOD VESSELS; ACROSS CAVITIES.
- prevent distant metastases ( treatment of some parts of body that is suspected of harboring tumor cell but without symptoms.)
Prophylactic
– TO CURE ( no probability of long term survival after adequate therapy, some side of therapy
Curative
- to prolong the life of the patient
and provide the best quality of life
( no hope of total eradication of the tumor, done to relieve suffering and to prolong life.)
Palliative
4 specific modes of treatment ( SRCH)
SURGERY, RADIOTHERAPHY, CYTOTOXIC DRUGS, HORMONES THERAPY
• - removal of tumor+ sorrounding tissues.
•
SURGERY
- uses drugs taken by mouth / injected into vein
CHEMOTHERAPY
