Oncology Flashcards
What two types of radiotherapy are used in the UK?
- Photons (External) (high energy x-rays)
■ Penetrate deep & spare overlying skin (produce secondary electrons & free radicals which cause DNA damage - Electrons
■ Deliver dose just below skin surface
Name two types of internal radiotherapy and describe them
Brachytherapy
■ Radiation sources placed within or close to tumour
Radioisotopes
■ Most commonly radioactive iodine to treat thyroid cancer
n.b. with radioisotopes have to stay in a lead-lined room for about 4 days until radiation they’re emitting is low enough to be safe to others
Describe two different methods of Brachytherapy
● Interstitial: material is put into the target (eg prostate)
● Intracavity: material is placed inside a body cavity near to the tumour (eg uterus/cervix, oesophagus
Why does radiotherapy work, i.e. why do cancer cells respond differently to normal cells ?
n.b. what can it sometimes cause?
Radiotherapy causes DNA damage to ALL cells
○ Normal cells can repair damage done by radiotherapy
○ Cancer cells already have faulty dna replication so can’t repair
Nb can cause secondary cancers caused by the
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What are the broad indications for radiotherapy? (4)
● Radical/Curative
○ often in combination with chemo (eg head and neck Ca)
● Adjuvant
○ Following surgery to reduce the risk of local recurrence (eg breast Ca)
● Palliative
○ To help symptom control (all cancer sites - especially bone for pain)
● Neo-adjuvant
○ Prior to surgery (eg rectal Ca)
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What is the expression/unit of the dose of radiation absorbed?
What is a series of small doses called?
● The number of fractions and the The absorbed dose of radiation is expressed as the unit “gray” (Gy)
● Radiotherapy (RT) is commonly delivered as a series of small doses called fractions rather than as a single dose
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List the 7 steps of a radiotherapy treatment pathway
- Consent
- Immobilisation - Must make sure you’re getting the same spot every time
- CT simulations - This is done by a clinical
oncologist to design the radiotherapy - Tattooing -Usually get three - one in the middle and two on either sides. This helps make sure the patient is not rotated
- Volume definition
- Radiotherapy
a. Given as outpatient on continuous weekdays - Follow up
Describe three measurements (volumes) involved in the volume definition before radiotherapy?
a. Gross tumour volume (GTV) = area of the tumour according to CT scan
b. Clinical target volume (CTV) = margins added for microscopic tumour spread
c. Planning target volume (PTV) = an extra margin made to allow for minor daily variations in patient and tumour position - try and be accurate within 2mm.
n.b. This is particularly the case with lung tumours that move up and down as the patient breaths.
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What does SACT stand for?
Systemic Anti-Cancer Treatment
Name 4 types of SACT
- Cytotoxic therapies
- Hormonal therapies
- Biological of targeted therapies
- Immunotherapy
Give three examples of cytotoxic therapy drugs
How do you normally calculate the dose required?
Which of these requires a different calculation for dosage?
Docetaxel, Cisplatin, Carboplatin
Calculate body surface area using the DUBOIS formula
Carboplatin is only one which do by renal function
n.b. ii. The most aggressive tumours (ie with higher cell replication) respond to chemo the best - eg SCLC
Cytotoxic therapies are normally given by IV, but how else can they be delivered? (3)
Can also be given regionally:
- Intravesical (into bladder)
- Intraperitoneal (eg for metastatic ovarian tumours)
- Intraarterial (if good blood supplies - eg liver mets)
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Describe 3 (broad objectives) types of hormonal therapy?
- Reduce production of hormone
i. In ‘sex-related’ tumours, try and suppress sex hormones
ii. In lymphatic malignancies, try to suppress corticosteroids - Inhibit hormone binding to receptor
i. Tamoxifen in all stages of breast cancer
ii.Cyproterone and bicalutamide used in prostate
cancer - Increasing hormones
i. Glucocorticoids in high concentration can cause apoptosis in some malignant lymphoid cells
ii. To induce negative feedback loops
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Give two types of Biological or targeted therapy. include an example drug name for each
a. Monoclonal antibodies
often end in ‘mab’, eg Herceptin, trastuzumab
b. Tyrosine kinase inhibitors
Often end in ‘ib’, Eg imatinib, sunitinib
Describe Immunotherapy (broad/brief summary)
Activation of the immune system against the cancer
n.b. All end in ‘mab’ (but not all things that end in mab are immunotherapy agents)
Eg anti-PD1 Pembrolizumab
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Give the definitions of the intentions of treatment for radiotherapy (often used incorrectly!)
- Radical / primary
- Adjuvant
- Neoadjuvant
- Palliative
○ Radical / primary = to cure (is sometimes used to mean ‘big’)
- Eg germ cell or hodgkin’s lymphoma
○ Adjuvant = after surgery or radiotherapy
○ Neoadjuvant = before surgery or radiotherapy
-Nb normally do adjuvant or neoadjuvant (rarely do both)
○ Palliative = symptom control
Give the definitions (in context of radiotherapy) of the following terms:
- Cycle
- Course
- Line
○ Cycle = repeating pattern of treatment & rest days (get side effects when not having treatment)
○ Course = complete pattern of cycles
○ Line = order of treatments (eg this is their 3rd line of therapy)
Give the definitions of WHO Performance status (context oncology) (0-5)
○ 0 = fully active, no change to normal
○ 1 = restricted in physically strenuous activity (but can do office / light house work)
○ 2 = unable to work, capable of all self care (up & about for >50% waking hours)
○ 3 = capable of only limited self care (in bed / chair for >50% of waking hours)
○ 4 = cannot carry out any self care, totally confined to bed / chair
○ 5 = dead
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Give 4 types of Oncological emergency
- Neutropenic Sepsis
- Metastatic Spinal Cord Compression
- Hypercalcaemia
- Superior Vena Cava Obstruction
What is Neutropenic Sepsis?
When does it typically occur?
○ Patients having cancer treatment whose neutrophil count is <0.5×10⁹/Litre
■ Who have either
● A temp >38degs
● OR other signs or symptoms consistent with neutropenic sepsis even if not febrile (eg hypotensive, tachycardic, other signs/symptoms of infection)
○ Typically occurs between 7-14 days post chemo (timing of chemo is key in Hx!)
List 6 things to ask in history of Neutrophenic Sepsis patient
- chemo drugs & timing, line & access, stents etc
- previous episodes
- localising symptoms- what’s the source?
- PMHx/other comorbidities
- Medications
■ Incl any recent paracetamol or ibuprofen - as this could mask a fever - Allergies
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What should you do in physical examination of Neutrophenic Sepsis patient? (5)
What should you NOT do?
1 Temp 2 circulatory status (ABC) 3 MEWS 4 Full systematic examination (cardiovascular, respiratory, abdominal) 5 focus on potential site of infection ■ remember lines & catheters ■ perianal area ■ Look in mouth - oral mucosa ■ Wound site
DO NOT do rectal or vaginal exam on someone who is neutropenic!
What investigations should you do if Neutrophenic Sepsis suspected? (Give the acronym. 6 letters)
What bloods should you do? (8)
○ Do BUFALO ■ Blood cultures ■ Urine output (measure) ■ Fluids ■ Antibiotics ■ Lactate ■ Oxygen
○ Bloods (ring down to get bloods done quickly)
1. FBC
2. LFTs
3. U&Es
4. CRP
5 Lactate (VBG)
6 glucose
7 Consider clotting
8 Blood culture - (PAIRED if have line in - 3 if have a line with double lumen - take from both lumens)
● x2 (aerobes, anaerobes)
● Line (all ports) & peripheral (or 2 peripheral sets if no line)
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Give 5 other types of analysis that can be done if Neutrophenic Sepsis suspected?
1.Swabs
■ If suspected site of infection, incl lines
2. Sputum culture
3. Urine analysis & culture
4. Stool analysis & culture (if diarrhoea)
5. CXR - if resp symptoms/signs
What percentage of fevers during neutropenia have no identifiable aetiology?
60% - 70% of fevers during neutropenia have no identifiable aetiology i.e. fever of unknown origin.
What is the main treatment option for neutrophenic Sepsis?
When should this be given and what do you need to check first?
What to do if not responding to treatment?
- Broad spectrum IV antibiotics (as per local guidelines)
- Given within 1 hour of admission to hospital in all suspected cases
- ALWAYS ASK ABOUT ALLERGIES
- Do cultures before give Abx!!
- If not improving after 48 hours, change to 2nd line broad spec
- If still not responding, consider fungal, viral or atypical cause
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What is another treatment for Neutrophenic Sepsis? (other than broad spec abx)
Can give colony stimulating factors (G-CSF) (filgrastim or lenograstim) which promote stem cell proliferation
■ Give if severe - not routinely given
What is a MASCC score, what is used for and what does it look at?
○ Assesses risk of complications during a febrile neutropenic episode
○ Looks at: burden of infection, comorbidities, BP, COPD, tumour type, haematological/ solid tumour, fluid status, age <60 yrs, in-patient vs outpatient
What red flag symptoms (general i.e. non cancer-specific) for back pain might indicate Metastatic Spinal Cord Compression (MSCC)? (4)
General: ■ Age <20 or >55 ■ Trauma ■ Weight loss ■ Pyrexia
What Cancer-Specific red flag symptoms for back pain might indicate MSCC? (3 broad)
Specific for cancer
1. Pain - MSSC may not have pain! - may have just tripped dt neuropathy
● Thoracic back pain, constant at night and rest
2.Pelvic symptoms
● Change in bowel or bladder function (nb often occurs late)
● loss of anal tone
● Saddle anaesthesia
- Neuromuscular
● Leg weakness (incl abnormal gait)
○ Can be unilateral or bilateral and often not complete
○ May be perceived changes (believe pt - you may not feel difference)
● Sensory loss
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What cancers commonly spread to bone (and thus increase risk of spinal cord compression)?
Most common(3) Less Common (2)
Most common 1. Gendered ● Prostate ● Breast 2. Smoking ● lung 3. Blood ● Lymphoma ● Myeloma
Less common
- Renal
- thyroid
What is the management for suspected MSCC? (4 steps)
- Lay flat
- Neurological exam (must do before request MRI)
● Including a PR (to assess perianal sensation & anal tone)
● Plantar reflex is the most useful part of the neuro exam in this instance
● They have UMN signs - 16mg dexamethasone (with PPI cover)
- Urgent MRI spine
● Within 24hrs
