10: Radiation Oncology

Question 1

What are direct effects of radiation therapy?

Answer 1

Physical damage that is caused within the cells by the excitation and ionization of atoms or molecules

biological damage that is brought about by damage to critical cellular genetic material

Question 2

What factors are needed to determine type of radiation therapy?

Answer 2

type/size/location of cancer in the body
proximity of cancer to normal tissues, structures and organs
distance the radiation has to travel
individuals gen health, PMH, age, Performance status
use of other cancer therapies

Question 3

What are the different types of radiation?

Answer 3

External beam radiation therapy (EBRT) or teletherapy - delivered from outside the body

Brachytherapy or internal radiation therapy - delivered by sealed sources of radiation temporarily or permanently placed inside a body cavity, tissue or surface

Radiopharmaceutical therapy - unsealed sources of radiation to treat cancer systemically

Question 4

What are the different types of External Beam RT (EBRT)?

Answer 4

3-dementional conformal RT (3D-CRT)

Intensity-modulated radiation therapy (IMRT)

Image-guided radiation therapy (IGRT)

Stereotactic radiosurgery and stereotactic RT (SRS or SRT)

Total Body Irradiation (TBI)

Intraoperative radiation therapy (IORT)

Question 5

Explain the different types of dosage for EBRT

Answer 5

Normal – standard dose, given once/day

Hypofractionation – smaller doses, more than once/day

Hypofractionation – larger doses, given once/day, often to reduce the number of total fractions

Accelerated Fractionation – doses given in larger daily or weekly doses to reduce the number of weeks in a prescribed treatment

Question 6

Define Brachytherapy, what are the different types?

Answer 6

Involves temporarily or permanent placement of radioactive material directly into tumors or next to tumors by placing “seeds” in specialized applicators like needles or catheters

Interstitial - placed into the tumor (Breast, gyn, ENT, lung, prostate, rectal)
Intracavitary - source placed directly into a surgical or body cavity near a tumor (Gyn–cervical, endometrial, and ENT)
Contact - placed on external surface (skin)

Question 7

Acute and Late-Occurring side effects of Brachytherapy - Breast

Answer 7

No known nutrition-related side effects

Question 8

Acute and Late-Occurring side effects of Brachytherapy - GYN

Answer 8

Acute: N, D, discomfort when urinating

Late: D, bladder irritation

Question 9

Acute and Late-Occurring side effects of Brachytherapy - Esophagus

Answer 9

Acute: Esophagitis, dysphagia, odynophagia

Late: Esophageal stenosis, Fibrosis, ulcerations

Question 10

Acute and Late-Occurring side effects of Brachytherapy - Prostate

Answer 10

Acute: discomfort when urinating, D, Cramping/bloating, Flatulence, Proctitis

Late: Urinary stricture, incontinence, D

Question 11

Acute and Late-Occurring side effects of Brachytherapy - Tongue

Answer 11

Acute: mucositis, Xerostomia, taste alterations

Late: Xerostomia, mucosal fibrosis, ulcerations

Question 12

Acute and Late-Occurring side effects of EBRT - ENT

Answer 12

Acute: fatigue, hair loss, mouth changes (dysgeusia, oral mucositis, xerostomia), skin changes (erythema, pruritis, moist desquamation), throat changes (dysphagia, odynophagia, esophagitis), thick saliva, oral infections, stiffness of the jaw, and earaches

Late: trismus, dental decay, permanent xerostomia, alterations in taste and smell, osteoradionecrosis, mucosal sensitivity
Late esophagus: esophageal stenosis, fibrosis, or necrosis

Question 13

Acute and Late-Occurring side effects of EBRT - Breast

Answer 13

Acute: fatigue, hair loss, skin changes (erythema, pruritis, moist desquamation), tenderness, and swelling of breast

Late: no significant late

Question 14

Acute and Late-Occurring side effects of EBRT - Pelvis/Rectum

Answer 14

Acute: D, fatigue, hair loss, sexuality and fertility changes, skin changes (erythema, pruritis, moist desquamation), urinary and bladder changes (frequency, cystitis, incontinence) and rectal bleeding

Late– Urinary: hematuria, cystitis
Sexual organs: changes in menstruation, symptoms of menopause, infertility, erectile dysfunction

Question 15

Acute and Late-Occurring side effects of EBRT - Brain

Answer 15

Acute: fatigue, hair loss, N/V, skin changes (erythema, pruritis, moist desquamation), headache, and blurry vision

Late: headache, leukoencephalopathy (cognitive impairment and change in memory/attention), dementia

Question 16

Acute and Late-Occurring side effects of EBRT - Chest

Answer 16

Acute: fatigue, hair loss, N/V, skin changes (erythema, pruritis, moist desquamation), throat changes (dysphagia, odynophagia, esophagitis), cough, and dyspnea

Late: Esophagus:
Pulmonary: dyspnea, cough, pneumonitis
Cardio: angina on exertion, pericarditis, cardiac enlargement, congestive heart failure

Question 17

Acute and Late-Occurring side effects of EBRT - Stomach and Abdomen

Answer 17

Acute: D, fatigue, hair loss, N/V, sexuality and fertility changes, skin changes (erythema, pruritis, moist desquamation), and urinary and bladder changes (frequency, cystitis, incontinence)

Late: GI - D, malabsorption, chronic enteritis or colitis, intestinal changes (stricture, ulceration, obstruction, perforation, fistula), proctitis