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
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
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
4
Q
Radiation treatment planning
A
- Immobilization:
- face masks, etc
- Treatment volume dosing
- CT sim
- Dosimetric planning
- Verification
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
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
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
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
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
10
Q
Management of other radiation side effects
A
- Pneumonitis : steroids and antibiotics
- GI : nausea management
- Cystitis : analgesics, rule out infection, flomax, buscopan
11
Q
Radiotherapy and symptom control : general indications
A
- Pain
- Bone
- visceral
- Neuropathic
- Local pressure
- SCC
- Cranial nerve palsies
- Obstruction
- Bronchus
- Esophagus
- SVC
- Hydrocephalus
- limb swelling
- Bleeding
- hemoptysis
- hematuria
- vaginal bleeding
- rectal bleeding
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
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
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
15
Q
How does radiation acheive pain control?
A
- not clear
- tumour shrinkage may not occur
- osteoclast activation?
16
Q
Pain flare after radiation
A
- first few days
- 1-2 days duration
- dexamethasone
- opioids
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
-
multiple mets
-
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
