RADIATION THERAPY Flashcards
Medical use of ionizing radiation as part of cancer treatment to kill or disable malignant tumors.
RADIATION THERAPY
A medical doctor specializing in the use of ionizing radiation to treat diseases.
radiation oncologist
Prescribes radiation dose and determines the regions for treatment.
radiation oncologist
Responsible for equipment calibration, maintenance, and dosage advice.
medical physicist
Plans treatments to target tumors while protecting vital structures.
medical dosimetrist
Administers treatments, maintains records, and monitors patient well-being.
radiation therapist
Define adjuvant therapy in radiation treatment.
therapy to destroy leftover microscopic cancer cells post-surgery to prevent recurrence.
What is neoadjuvant therapy?
Pre-surgical therapy to shrink tumors, making surgery less extensive.
What is palliative radiation treatment?
Aims to relieve symptoms and improve the quality of life in advanced cancer cases.
What is metastasis?
The spread of cancer from the primary tumor to other body sites.
Name the three pathways of malignant neoplasm spread.
Seeding, lymphatic spread, and hematogenous spread.
Transport of tumor cells via lymph nodes to other body parts, common in carcinomas.
lymphatic spread
Spread via blood, typical for sarcomas and some carcinomas, following venous flow.
hematogenous spread
What is remission?
A period or stage where cancer signs and symptoms are absent.
What is complete remission?
All cancer signs and symptoms are gone.
Tumor size is reduced but not entirely gone.
partial remission
What qualifies a patient as “cured” of cancer?
Being free of signs and symptoms for five years.
Define “second primary cancer.”
A new cancer unrelated to the previous one.
What is local recurrence?
Return of cancer at the original site.
What is regional recurrence?
Return of cancer in nearby lymph nodes or tissues.
What is distant recurrence?
Cancer reappears at a site far from the original location.
Name the three major subtypes of cancer.
Carcinoma, sarcoma, and lymphoma.
Define carcinoma.
Cancer originating from epithelial tissue.
Define sarcoma.
Cancer originating from connective tissue.
Define lymphoma.
Cancer involving blood-forming tissues.
Name three external cancer risk factors.
Chemical exposure, viruses, and ionizing radiation.
Name three internal cancer risk factors.
Hormones, genetic mutations, and immune system disorders.
List general cancer symptoms.
Weight loss, fever, fatigue, pain, skin changes, and bowel/bladder function changes.
What is a biopsy?
Removal of tissue to determine the presence or extent of disease.
Name the types of biopsy.
Surgical, excisional, incisional, fine needle aspiration, and core needle.
What does tumor grading assess?
The tumor’s appearance under a microscope to indicate its aggressiveness.
What does tumor staging assess?
The extent of tumor spread in the body.
What does the TNM system stand for?
Tumor size (T), Node involvement (N), and Metastasis (M).
What is Stage 0 cancer?
Occult lesion with no clinical evidence of cancer.
What is Stage I cancer?
Small lesion confined to the organ of origin without lymphatic or vascular spread.
Describe Stage II cancer.
Tumor <5 cm with local tissue invasion and lymph node involvement but no metastasis.
Describe Stage III cancer.
Tumor >5 cm with deeper structure invasion and lymph involvement but no metastasis.
What is Stage IV cancer?
Extensive lesion with distant metastasis.
List the steps in tumor localization simulation.
Patient immobilization, tumor volume definition, treatment planning, and verification.
Name two immobilization devices used in radiation therapy.
Thermoplastic mask and alpha cradle.
What is thermoplastic mask used for?
Immobilizing the head by molding to its shape when heated.
What is alpha cradle used for?
Immobilizing the head and extremities using a styro-like material.
Name the three types of radiation therapy.
EBRT (Teletherapy), Brachytherapy, and Systemic Radioisotope Therapy.
Define EBRT or Teletherapy.
External beam treatment with radiation emitted from a machine.
Device for treating lesions near the skin surface (50-120 kVp).
superficial machine
Treats moderately superficial tissues using 250 kVp.
orthovoltage radiation therapy
An electron accelerator using magnetic induction, also producing photons.
Betatron
What is Cobalt-60 used for?
Radiation therapy with a gamma-emitting isotope.
Name the machine developed in 1925 for radiation therapy.
Linac (Linear accelerator).
What does 2DXRT stand for?
Two-dimensional conventional external beam radiotherapy.
Define 3DCRT.
3D Conformal Radiotherapy using multileaf collimators.
What is 4DXRT or IGRT?
Image-guided, real-time radiotherapy.
What is IMRT?
Intensity Modulated Radiotherapy.
A precise form of radiotherapy, often using gamma knives.
stereotactic radiosurgery
Radiation therapy using particles like protons or neutrons.
particle therapy
Treatment involving placement of radioactive material inside the patient.
brachytherapy
Name three techniques of brachytherapy.
Mould, intracavitary, and interstitial.
What is HDR brachytherapy?
High-dose rate brachytherapy delivering >1200 cGy/hr in minutes.
What is LDR brachytherapy?
Low-dose rate brachytherapy delivering 40-500 cGy/hr over days.
Radiation delivered through infusion or ingestion.
systemic radioisotope therapy
Name a clinical application of megavoltage radiation.
Treating laryngeal cancer with 6300-6500 cGy over six weeks.
What radiation is used for epiglottis treatment?
Post-op dose of 4000-4500 cGy.
Define the dose for subglottis cancer.
4500 cGy.
How is skin cancer treated with radiation?
Superficial radiation delivering 4000-5000 cGy over 3-4 weeks.
What is the typical dose for medulloblastoma?
4500 cGy for the brain, 3500-4500 cGy for the spinal cord.
Define the radiation dose for oral cavity cancer.
6000 cGy over four weeks using orthovoltage.
Radiation dose for lung cancer treatment?
5000-6000 cGy with 10 MeV.
What dose is used for prostate cancer radiation therapy?
7600 cGy using a megavoltage beam.
What dose is used for cervical cancer radiation therapy?
4500-5000 cGy over five weeks.
Typical dose for Hodgkin’s disease radiation therapy?
disease radiation therapy? 3000-4000 cGy using megavoltage.
Breast cancer radiation therapy dose?
5000 cGy over five weeks.
What is a hotspot in radiation therapy?
An area receiving excessive radiation dose.
Encapsulated radioactive material for precise delivery.
sealed source
Placement of the radioactive source near the lesion.
mould technique
Radioactive source placed inside a body cavity.
intracavitary brachytherapy
Radioactive source implanted directly into a tumor.
interstitial brachytherapy
Typical duration of LDR brachytherapy?
Three to four days.
Typical duration of HDR brachytherapy?
10-20 minutes per session.
How is systemic therapy administered?
By infusion or ingestion of radioactive material.
What is the purpose of treatment planning?
To define tissue volume within the radiation field.
Define seeding in metastasis.
Cancer spread via body cavity surfaces.
Define prophylactic radiation treatment.
Preventive therapy to stop cancer growth and spread.
Educates patients on side effects and assists in management.
oncology nurse
Define “microscopic disease” in oncology.
Cancer not detectable with imaging but present at the cellular level.
What is radiation’s primary biological target?
DNA of cells.
What is the function of a collimator in 3DCRT?
Shapes the radiation beam to match the tumor.
Treatment aimed at eliminating cancer entirely.
curative treatment.
Custom-made devices for beam shaping in radiotherapy.
cerrobend blocks
What is IGRT’s advantage over traditional therapy?
Real-time imaging for higher accuracy.
What is the typical SSD for Cobalt-60 therapy?
80 cm.
What is the role of electron beams in radiotherapy?
Treat superficial tumors due to limited tissue penetration.
Define multi-leaf collimator.
A device to shape radiation beams in advanced therapies.
What is the half-life of Technetium-99m
6 hours
What is the half-life of iodine-131?
8 days
What is the half-life of iodine-123
13.2 hours
What is the half-life of radium 223
11.4 days
What is the half-life of radium 226
1,600 years
What is the half-life of carbon 14
5730 years
What is the half-life of iridium 192
73.83 dys
What is the half-life of cobalt 60
5.26 years
What is the half-life of cesium 137
30 years
What is the half-life of strontium 90
28.8-29.1 years
What is the half-life of molybdenum-99
66.02 hours
What is the half-life of gold-197
2.7 days
What is the half-life of technetium-99
211,000 years
What is the half-life of xenon-133
5.245 days
What is the half-life of tahllium-201
73.1 hours
