Radiotherapy in Symptom Management Flashcards

1
Q

Radiation : MOA

A
  • ionizing radiation damages DNA
  • Xrays or linear accelerator
  • gamma rays from radioactive source
  • Direct damage to DNA:
    • base deletions, breaks
  • Indirect damage:
    • toxic free radicals from interaction of radiation and water
    • damage to endothelial cells
    • apoptosis
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2
Q

Radical Radiotherapy

A
  • cure
  • minimizing long term damage to normal tissue
  • radiation dose is built up with daily treatment over several weeks
  • can accelerate or hyperfractionate
  • 6-8 weeks in duration
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3
Q

Palliative Radiotherapy

A
  • aim is control of symptoms with minimal acute radiation reaction
  • majority of tumour cells killed (60-80%) in first 1-2 doses
  • short courses, low doses = less acute reaction
  • minimizes late damage to normal tissues
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4
Q

Radiation treatment planning

A
  • Immobilization:
    • face masks, etc
  • Treatment volume dosing
    • CT sim
  • Dosimetric planning
  • Verification
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5
Q

Types of radiation therapy

A
  • External beam radiation (electrons)
    • Xrays
    • linear accelerator
  • Brachytherapy
    • radiactive sources placed directly onto or into treatment area
    • iridium, cobalt
  • Systemic radioisotopes
    • target specific tissue or pathophysiology
    • radioiodine for thyroid cancer
    • strontium for bone mets
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6
Q

Acute side effects of radiation (during treatment - several weeks)

A
  • from loss of epithelial cells
  • skin erythema, desquamation
  • mucositis
  • esopahgitis
  • non infectious cystitis
  • GI irritation
  • skin infection
  • usually recovers in weeks
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7
Q

Late side effects of radiation

A
  • Vascular damage, tissue ischemia
  • Skin
    • atrophy, fibrosis
    • telangectasias, necrosis
  • GI tract
    • stricture
    • bleeding, telangectasias
    • perforation
    • malabsorption
    • enteritis, colitis, proctitis
  • Bladder
    • bleeding
    • strictures
    • fistulae
  • Oral cavity:
    • mucosal atrophy
    • bleeding
    • caries
    • mandibular necrosis
  • Lung:
    • fibrosis
  • Eye:
    • cataract, dry eye
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8
Q

Management of radiation side effects: SKIN

A
  • desquamation rare in palliative doses
  • do not use talcum, gentian violet –> metallic salts increase skin reaction
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9
Q

Management of radiation side effects : MUCOSITIS

A
  • chlorhexidine mouthwash
  • anticandidals
  • NG feeds
  • oral hygiene and dental assessment for curative intent radiation
  • avoid alcohol and smoking
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10
Q

Management of other radiation side effects

A
  • Pneumonitis : steroids and antibiotics
  • GI : nausea management
  • Cystitis : analgesics, rule out infection, flomax, buscopan
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11
Q

Radiotherapy and symptom control : general indications

A
  1. Pain
  • Bone
  • visceral
  • Neuropathic
  1. Local pressure
  • SCC
  • Cranial nerve palsies
  1. Obstruction
  • Bronchus
  • Esophagus
  • SVC
  • Hydrocephalus
  • limb swelling
  1. Bleeding
  • hemoptysis
  • hematuria
  • vaginal bleeding
  • rectal bleeding
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12
Q

Radiation for bone pain

A
  • bone pain
  • pressure on nerves
  • pathological fracture
  • Effective within days to weeks, durable response of months-years
  • Can re-treat with good response
  • Single fraction :
    • more pain flares
    • higher rate of retreatment
  • Multiple fractions:
    • to treat path fracture
    • spinal cord compression
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13
Q

Wide field treatment for bony mets

A
  • multiple sites of disease and pain
  • diffuse
  • Wide field RT: up to half the body at a time
  • Greater toxicity: GI, bone marrow suppression, fatigue, pneumonitis
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14
Q

Radioactive isotopes for bony pain

A
  • isotopes concentrate at bone met sites
  • focal release of beta particles, gamma release
  • Strontium-89
  • Samarium
  • as effective as EBRT, fewer side effects
  • AE : thrombocytopenia, neutropenia
  • analgesia onset - MONTHS
  • Expensive
  • renal excretion, must be continent of urine to prevent contamination

Indications:

  • multiple painful bony mets
  • local radiation not feasible
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15
Q

How does radiation acheive pain control?

A
  • not clear
  • tumour shrinkage may not occur
  • osteoclast activation?
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16
Q

Pain flare after radiation

A
  • first few days
  • 1-2 days duration
  • dexamethasone
  • opioids
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17
Q

Radiation for pathological fracture

A
  • if surgery not indicated or possible
  • Post operative internal fixation
    • prevents progression
  • if widespread disease, limited prognosis, good pain control –> no RT
18
Q

Radiation for SCC

A
  • Dexamethasone 4 mg qid
  • Lymphoma and SCLC - primary treatment is chemo
  • Surgery first if:
    • good PPS
    • solitary mets
    • single level cord compression
    • extensive vertebral collapse into spinal canal
  • Radiation post op
  • primary radiotherapy is surgery not indicated or wanted
19
Q

Radiation for Brain mets

A
  • Dexamethasone 4-8 mg daily
  • Solitary brain met - surgery or SBRT and post op RT
  • WBRT for mutiple diffuse mets
    • palliation of headache, motor and sensory loss, confusin in 80%
    • median survival < 6 months
  • brain mets = widespread advanced disease
  • Need careful patient selection and discussion of goals of care

Acute toxicity WBRT : alopecia x2-3 months

Long term toxicity WBRT : neurocog impairment

20
Q

Meningeal carcinomatosis and RT

A
  • Pre terminal event
  • survival few weeks if untreated
  • multifocal radiculopathy, cranial neuropathy, headache, backache
  • raised ICP
  • breast, lung, leukemia, lymphoma
  • WBRT and whole spinal RT extends prognosis from weeks to maybe short months, all taken up with treatment
  • Skull case for CN or spinal cord nerve roots for sx control may be indicated
21
Q

Brain mets RT decision algorithm

A
  • Good PPS
    • multiple mets
      • WBRT
    • solitary /oligomet
      • surgical?
      • non surgical - radiosurgery, WBRT
    • lymphoma, SCLC, germ cell tumour
      • chemotherapy
  • Poor PPS
    • supportive care
22
Q

Other neurological symptoms that may benefit from Radiation

A
  • Cranial nerve palsies - skull base effective
  • Peripheral nerves - lumbosacral nerve roots, apical lung tumours, brachial pleus, lymph nodes
  • Choroidal and orbital mets
  • Cerebral lymphoma - HIV, WBRT role in question
23
Q

Obstructive symptoms : SVCO

A
  • Occlusion by external compression
  • intraluminal thrombosis
  • direct invasion of vessel
  • Lung cancer, lymphoma
  • Presentation:
    • headaches
    • somnolence
    • dizziness
    • edema
    • dysphagia
    • dyspnea
    • cough
    • hoarseness
    • engorgement and dilation of facial veins
    • facial edema
24
Q

SVCO management general

A
  • steroidse
  • SVC stent
  • Chemo for SCLC germ cell, lymphoma
  • Radiotherapy
25
Bronchial obstruction
* central airway obstruction * bronchial carcinoma, extrinsic compression by mediastinum LN, lymphoma * dyspnea, cough * Treatment * intrinsic tumours * bronchoscopy with laser or cryo * stent * Extrinsic tumours * chemo * radiation * stent * endobronchial radiation
26
Dysphagia and Radiation
* extrinsic compression from esophageal tumour, hypopahrynx, stomach, thymus, thyroid, meadistinal LN * Radiation: * useful * swallowing improved 80% * 2 weeks for efficacy * esophagitis AE
27
Urinary tract obstruction
* nephrostomy, ureteric stsents or TURP most appropriate * radiation alternative if procedure impossible or inappropriate
28
Limb edema and radiation
* venous obstruction, lymphatic obstruction, post radiation * radiation helpful for axillary, inguinal or pelvic lymphadenoapthy
29
Hydrocephalus
* Obstructive hydrocephalus from primary or secondary tumours * Posterior fossa or midbrain tumours obstructing aqueduct or 4th ventricle * leptomeningeal disease Treatment: * IV shunt * if not feasible, palliative radiation
30
Hemoptyis and radiation
* radiation effective 80% control * no survival advantage * pulmonary mets more difficult to treat * harder to ID site of hemorrhage * may require bronchosopcy to localize site
31
Hematuria and radiation
* must localize bleeding on cysto or CT for treatment planning * Causes of hematuria: * tumour bladder * cystitis * late complication of pelvic rad * tumour anywhere in GU tract * RT: * hemostasis in inoperable tumours * failure of conservative managemnt (TXA, irrigation, etc) * SE: diarrhea, nausea, vomiting
32
Uterine and vaginal bleeding : radiation
* uterine tumours * local infiltration of advanced bladder or rectal ca * Radiation helpful
33
GI Bleeding and radiation
* large bowel lesions can be radiated * stomach and small bowel difficult
34
Chest wall and skin lesions - Bleeding
* locoregional recurrence in breast can * skin nodules * primary skin cancers Treatment * radiation can control growth, bleeding and prevent fungation * skin nodules reponsive to RT
35
Fungating skin lesions -radiation
* Occurs with superficial tumours * most common is breast chest wall recurrence * metastatic LN in neck or groin Treatment * radiation best when skin is intact * can still treat once fungation has occured * antibiotics, analgesics, antibiotics, skin care
36
Kaposi's sarcoma
* AIDS * very radiosensitive - RT can lead to complete regression * presentation : * multiple purplish skin plaques * also in oral cavity and GI tract
37
Liver mets
* inoperable mets: stereotactic RT helpful * useful if: * good PS * normal bilirubin * not stomach or pancreas cancer * liver mets = terminal phase advanced cancer * liver has limited tolerance to radiation
38
Splenomegaly and radiation
* hematologic malignancies (leukemia, NHL, MDS) * splenectomy preferred management * radiation in advacned disease or poor PPS * consider if symptomatic from bulk or hypersplenism (thrombocytopenia and anemia) * may precipitate pancytopenia
39
Acute radiodermatitis : treatment
* Erythema, edema 1-2 weeks post RT * desquamation, ulcers * Treatment: * no prophlyaxis * wash with mild soaps, avoid deodorants, shaving * moisturizers * no benefit to steroids
40
Chronic radiodermatitis : treatment
* Vascular * dermal atrophy 4-6 months * dermal thinning 1 year * skin necrosis and ulcers Treatment: * emollients * prevention of trauma * radiation ulcers are treatment resistent * goal is to prevent infection and pain * hydrocolloids useful for ulcers
41
Radiation recall
* inflammatory reaction triggered by sytotoxic chemo in previously radiated areas (skin) * radiation could have been days or years prior * Presentation * well circumscribed erythema in previous rad field * gemcitabine, anthracyclines, taxanes * treatment * stop chemo * steroids, NSAIDS