Metastatic Bone Pain, Spinal Cord Compression and an Overview of Radiotherapy Flashcards
what is the presentation of bone metastases?
Pathological fracture Spinal cord compression Hypercalcaemia Symptoms of nerve root compression Swelling/deformity/loss of mobility Pain; especially if… -Progresses over time -Does not respond to simple -analgesia -Disturbs sleep -Associated with bony tenderness and or weight loss
what imaging would be used for diagnosing metastatic bone pain?
Plain film Bone scan MRI CT Biopsy under screening
what treatment is given for treating metastatic bone pain if radiotherapy doesn’t work?
Bisphosphonates Denosumab-reduce rate of progression Surgical fixation for pain Chemotherapy Vertebroplasty Radioactive isotopes
what is the most common type of cancer at the oesophagogastric junction?
adenocarcinoma (barrets is a precursor)
40yr old man present with firm non tender mass in scrotum and minimally high HCG. Diagnosis?
epididymitis (would be tender), hydrocele (would be soft), teratoma (high HCG) so answer is seminoma
Young man present with testicular mass what examination should be done?
Inguinal area examination,, supraclavicular examination, breast examination don’t need per rectal examination
what are the risk factors for cancer of the urinary bladder?
smoking, cyclophosphamide, aromatic amines
what are the risk factors for liver cancer?
hepatitis B, hepatitis C, cirrhosis
what are risk factors for prostate cancer?
ethnicity (black American, Caucasians, Asians have low risk
benign enlargement of the prostate arises in what zone of prostate?
peripheral zone
what is radiation?
energy carried by waves (photons) or a stream of particles
One of the main modalities to treat cancer, also chemotherapy and surgery
Only x-ray and gamma rays are used in radiotherapy
X-ray machines and CT scanners are diagnostic. Linear scan used in radiotherapy
what are the different types of radiotherapy
external beam
brachytherapy
internal
how is external beam radiotherapy delivered?
linear accelerator machine
what is brachytherapy?
keep the radioactive source very close to the organ with cancer (for cervical or prostate cancer)
what is internal radiotherapy?
administered orally or IV (oral I-131 for thyroid cancer / Ra-233 for prostate cancer)
what is the basic mechanism of radiation?
Interact with water and OH radicals produce which interact with DNA molecule and calling breaks in DNA and death
describe the importance of radiotherapy?
50% of cancer patients will need radiotherapy at some point
40% of cancer patients who are cured received radiotherapy
Effective in palliating bone pain from bone metastases
give examples of photons?
X-rays (megavoltage X-ray therapeutic, kilovoltage X-ray diagnostic) Gamma rays (radio isotopes)
give examples of particles used in radiotherapy?
Sub atomic particles (proton etc)
atomic (carbon ion)
what are the acute affects of radiotherapy?
during and upto 6 months after Temporary without much sequalae and dependent on site Fatigue Skin redness and itching Nausea, vomiting, diarrhoea Cystitis, proctitis Oesophagitis Odynophagia/dysphagia Cough SOB (pneumonitis) Hoarse voice Dysphagia Mucositis Skin pigmentation Hair loss
what are the late side effects of radiotherapy (after 6 months to life long)?
More important as tend to linger and lead to sequalae and Less common (5-10%)
Replacement of normal cells with fibrous tissue
Skin thinning and lacking elasticity
Bowel stricture, stenosis, decreased motility
Deranged organ function (depend on volume and dose)
Mucosa-dry mouth, telangiectasia- most common in pelvic radiotherapy (rectal bleeding and haematuria)
Soft tissue necrosis and mucosal ulceration
Hypopituitarism
Short term memory impairment
Secondary cancer
Children and growing adolescent: growth retardation, hypoplasia of organ irradiated, secondary cancer
describe the process of treatment planning for external beam radiotherapy?
CT scan or X-ray Contouring Computerised planning Checks-quality assurance Treatment delivery
describe curative delivery of treatment external beam radiotherapy?
60-70 gy in 6-7 weeks, 5 days a week. Depends on type of tumour and site, with or without surgery or chemotherapy
describe palliative treatment of external beam radiotherapy?
8 gy (unit of radiation) in one fraction (session). 20gy in 5 fraction over one week. 30 gy in 10 fractions over 2 weeks
what types of cancer is radiotherapy curative on its own?
Early stage Prostate Cervix Vocal cord Skin (non melanoma)
what types of cancer is radiotherapy curative when given before or after surgery?
Prostate Breast GYN H&N Sarcoma Lung Oesophagus Bowel Skin (non-melanoma)
what types of cancer is radiotherapy curative when given with chemotherapy?
Advance H&N lymphoma palliative pain control control bleeding spinal cord compression (cauda equina) reduce tumour mass so relieving mass effect
what are the aims of radiotherapy?
Curative on its own Curative before or after surgery Curative with chemotherapy Palliative care (extending life) Shrink tumour
describe normal calcium homeostasis?
Maintenance of healthy blood calcium levels include the kidneys, parathyroid glands, intestines and bones
2.2-2.6mmol/L
Serum calcium is bound to albumin and measurements should be adjusted for serum albumin
describe how cancer can lead to hypercalcaemia?
Significant bone lysis directly by the tumour-multiple myeloma
Paraneoplastic syndrome (most of the cancer). PTHr protein secretion
- Enhance osteoclast activation and bone resorption
- Increases renal tubular calcium reabsorption
what are the symptoms for a patient with hypercalcaemia?
Lethargy Dehydration Anorexia Nausea Polydipsia Constipation Renal impairment Polyuria Mood disturbance Cognitive dysfunction Confusion Coma Limb weakness Shortened QT interval Dysrhythmias Chronic: pancreatitis, gastric ulcer, kidney stones
what are the important examinations and investigations for hypercalcaemia?
General and abdominal examination Urine output Other cancer symptoms and signs Electrolytes, albumin, ALP T3 and T4 Medications ECG changes
what are the differentials for hypercalcaemia?
Infection Deranged kidney function/renal failure Brain metastases Spinal cord compression Depression Sub-acute or acute bowel obstruction Opioids related side effects
what are the potential causes of hypercalcaemia?
Lung-squamous cell and small cell Any advance squamous cell cancer (H&N, bladder, anal, vulva) Multiple myeloma Renal cell cancer-release of parathyroid hormones or other growth factors Advance breast cancer Primary hyperparathyroidism Sarcoidosis Vit D intoxication Thyrotoxicosis Medications
what is the management for hypercalcaemia?
Hydration – 2-4L of 0.9% saline over 24 hours (caution in elderly, cardiac history, obstructive uropathy, renal failure)
Mobilise
IV bisphosphanate
Glucocorticoid (inhibit 1,25 OH vitamin D production)
Manage malignancy
Resistant cases-consider calcitonin
Check medication lists-calcium and vitamin D supplement
Loop diuretics? -fluid overload
when should hypercalcaemia be treated?
Treat patient not calcium level
Adjusted calcium <3mmol/L and rising (often asymptomatic)- give fluids and bisphosphonates if persistent or symptomatic
Adjusted calcium 3-3.5mmol/L -fluids, bisphosphonates, glucocorticoids
Adjusted calcium >3.5mmol/L – risk of dysrrhymia and coma
End of life care-discuss and evaluate
describe the use of bisphosphonates in treating hypercalcaemia?
Inhibits osteoclasts
Pamidronate -30-90mg over 90 mins (starts working over 2-3 days and max effect over 1 week)
Zoledronic acid – 4mg over 15 mins, longer duration. Caution: renal function, flu like symptoms, hypocalcaemia, long use can cause bone (jaw) necrosis
what are the ECG changes in a patient with hypercalcaemia?
decreased QT interval
what are the most common secondary tumour locations?
Lung
Liver
BONE (3rd most common site of metastasis)
what are the most common primary tumours that metastasise to bone?
Prostate Breast Lung Kidney Myeloma
what are the common sites of bone metastasis?
Vertebrae Pelvis Ribs Femur Humerus Acrometastases- distal to elbow and knee are rare and usually due to renal and lung cancer as primary tumour)
describe the presentation of bone metastasis?
Asymptomatic
Pain (dependent on what structures are being affected.)
Pathologic fractures/spinal cord compression
if cortex affected increased risk of fracture.
If outside of cortex-risk of spinal cord compression
Hypercalcaemia-secretion of parathyroid hormone secreted from primary tumour or soft tissue metastasis. This is rare.
describe the mechanism of cancer causing bone fracture etc?
Bone undergoes constant remodelling maintaining osteoclastic (resorptive) and osteoblastic (Bone forming) activity
Tumour cell seeding through blood-bone marrow-cortex
Disrupts the balance between osteoclast and osteoblast activity
Osteoclast predominant-lytic metastases, greater chance of fracture than osteoblast predominant
Osteoblast predominant-disorganised ossification, still fractures
what are the radiological characteristics of bone metastasis in different cancers?
Mostly lytic metastasis
- Multiple myeloma
- Thyroid cancer
- Renal cell cancer
- Melanoma
Mostly sclerotic metastasis
- Prostate
- Breast
- Mucinous cancer of the bowel
Mixed sclerotic and lytic
- Lung cancer
- Bladder cancer
what are the important investigations for a patient with bone metastasis?
Bloods
- FBC
- Bone related ALP
- Kidney and liver function
- PSA
- Paraproteins
Urine
-Proteins (bence jones-multiple myeloma)
Imaging
- Plain x ray-more specific, less sensitive
- Bone scan-more sensitive, less specific
- Cross sectional imaging (CT, MRI)
what are the differentials for bone metastasis?
Primary bone tumour (benign or malignant) bone islands osteomyelitis healing fracture pagets disease endocrine and metabolic disease
describe the WHO ladder of pain management?
Ladder 1 = paracetamol `and anti-inflammatory
Ladder 2 = weak opioids, codeine, tramadol
Ladder 3 = stronger opioids; morphine, oxycodone, fentanyl
describe how bone pain can be managed?
Palliative radiotherapy
Bisphosphonates -zolidronic acid (IV every couple of weeks)
Orthopaedic intervention if fracture or at risk
what are the side effects of different treatments used for bone pain?
Paracetamol-hepatotoxic
Anti-inflammatory – renal function, gastritis
Opioids (titrate dose) – short acting then replace with long acting
Constipation, nausea, drowsiness, confusion
Bisphosphonates – nephrotoxic and jaw necrosis
define spinal cord compression/cauda equina?
Neurological symptoms and signs caused by mechanical pressure over the spinal cord (from epidural extension of metastasis in vertebra, from paravertebral region, from meningeal deposits).
Similar features occurring at vertebral level below L1 is cauda equina compression
what are the signs and symptoms of cord compression?
Pain 90% of patient
Worse lying down
If bone collapses pain worse on movement
Increases with Valsalva maneouver
If nerve root involved radicular pain
Tenderness
Muscle weakness 75% of patients (jelly legs, give way)
Sensory deficits-50-75%
Autonomic dysfunction 50-60% of patients
Symptoms and signs depend on timing, level of compression, pain and pre-existing condition
describe the anatomy of the spinal cord?
Medulla to conus medularis L1-L2
Cord projects 31 pairs of spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Conus meddularis-tapered structure at spinal cord end. At intervertebral disc between the first and second lumbar vertebrae. Consist of sacral spinal cord segments
Cauda equina – bundle of intradural nerve roots at end of the spinal cord
Filum terminale – fibrous extension of the cord. Non neural element that extends down the coccyx
describe the history of cauda equina?
Pain Functional status Mobility Difficulty in bowel and bladder numbness Comorbidities medications
what should you look for in examination in a patient with suspected cauda equina?
mobility and gait elicit tenderness power, tone and rigidity tendon reflexes including plantars light touch (sensory level) bladder fullness (urinary catheter?) anal tone and perianal sensation
describe the signs and symptoms of spinal cord UMN uniform condition?
pain-localised or radicular
motor-low power, rigidity
bladder-urge incontinence
reflexes-hyper
describe the signs and symptoms of cauda equina LMN assymetrical condtion?
localised or radicular pain
motor-flaccid paralyses
bladder-overflow incontinence
reflexes absent
what are the primary cancer sites causing metastatic spinal cord/cauda equina compression?
lung, prostate, breast, multiple myeloma, kidney, lymphoma, melanoma
what are the differentials for spinal cord compression/cauda equina?
osteoporotic fracture disc herniation brain metastases vascular lesion demyelination disorder injury primary tumour
what is the inital management for spinal cord compression/cauda equina?
immobilisation, steroids (dexamethasone 8mg BD with PPI), MRI, neurosurgery, radiotherapy, rehabilitation
if leukaemia and lymphoma-steroid and chemotherapy
what is the subsequent management for spinal cord compression/cauda equina?
taper off dexamethasone (risk of hyperglycaemia and gastric ulcer)
treat primary cancer
physiotherapy with gradual mobilisation
pain control
other specialty input (macmilln nurse, palliative care team, physiotherapist, occupational therapist, GP
what types of spinal cord compression have a good prognosis?
single lesion
respond to steroid
ambulatory/limited neurological deficit
radiation sensitive-multiple myeloma and small cell lung cancer
moderately sensitive-prostate and brest
early surgery and radiotherapy (within 24 hours)
what types of spinal cord compression have a poor prognosis?
multiple location extra spinal metastases non ambulatory/paraplegic radioresistant tumour (renal cell cancer, melanoma) cord compression with vertebral fracture
