Retinoblastoma Flashcards
what is retinoblastoma
- Retinoblastoma is a type of eye cancer that affects young children
- It is sight threatening but can also be life threatening if not treated- unlike rd which isn’t life threatning
- A tumour develops in the retina
how does retinoblastoma develop
In the very early stages of eye development, the eyes have cells called retinoblasts that grow very fast. Later, these stop growing and develop into mature retinal cells
Very rarely, the immature retinoblasts grow out of control and develop into a retinoblastoma
If untreated – this continues to grow and can fill the eye ball and spread around the body- metastates
This can lead to sight loss but can also be life threatening
Note: most retinoblastomas are diagnosed early and treatment preserves vision
who gets retinoblastoma
- typically affects children under the age of 5
Can be unilateral or bilateral
Can be sporadic or due to known genetic abnormality
Bilateral cases more likely to be genetic (McEvoy and Dyer, 2015)
what is the incidence of retinoblastoma
Incidence worldwide is approx. 1:16,000 live births (Dimaris et al, 2015)
Countries with higher birth rates and populations have the most cases
In the U.K. we see approximately 50 new cases per year (chect.org.uk)
mainly prevalent in Asian populations and low income countries
how are patients with retinoblastoma taken care of
multi disciplinary team manages these patients
MDT consists of oncologists, paediatricians, ophthalmologists, specialist nurses, orthoptists, clinical psychologists, play specialists, imagers etc…
MDT provides a unique care package specialised for each family and child
- Importance of orthoptist - Pre & post support for families and children, orthoptic examination, fundus imaging, OCT
what are the most common clinical features of retinoblastoma
Leukocoria - approx. 75%
Strabismus - approx. 25%
(Akhiwu et al, 2009 and Singh et al, 2007)
what are the less common clinical features of retinoblastoma
Sore, red or swollen eye
Change in iris colour
Deterioration of eye sight
No red reflex seen
Nystagmus
Note: Remember there are a lot of differential diagnoses a child may have so a full assessment is important prior to diagnosis
a whitish tinge in the pupil is referred to as…
Whitish tinge in pupil=leukoria
how is retinoblastoma diagnosed
Ophthalmoscopy +/- fundus imaging
Ultrasound of the eye
MRI/CT scans
Optical Coherence Tomography
Genetic tests – blood tests or saliva
how is opthalmoscopy used to diagnose retinoblastoma
=Dilated ophthalmoscopy is vital to ensure as much of retina is viewed as possible (in clinic or EUA)
IOP assessment is often warranted
Anterior segment assessment to check for iris neovascularisation
what is fundus imaging used for
Fundus imaging has become an important addition to ophthalmoscopy in the last 30 years
Fundus imaging has become an important part of the diagnostic testing
Retcam is a mainstay in Rb theatres and all patients are imaged to track course of disease and allow objective assessment from visit to visit
what are ct and MRI scans used for
Used more readily where extra-ocular or intra-cranial tumour extension is suspected
what are OCTS used for
Imaging technique that allows 3D imaging of retinal architecture (Sheth et al, 2013)
how is genetic testing used in the management of retinoblastoma
About 40% children diagnosed have a genetic mutation which often affects both eyes
The remaining 60% don’t have a known genetic mutation (these nearly always affect only one eye)
Important to obtain input from genetic counsellors- for concerns about effects on future children
There is a screening pathway for families with known RB
how is retinoblastoma managed
Management of Rb will depend on several factors such as their disease classification/stage and risk group
Treatment for retinoblastoma might include one or more of the following:
freezing therapy (cryotherapy) laser therapy chemotherapy radiotherapy surgery
how are the tumours classified
classed on a A-E grade
A= small tumours restricted sites
E= unsalvalagable
how is cryotherapy used in the treatment of retinoblastoma
Cryotherapy uses freezing to destroy cancer cells (Shields et al, 1989)
The doctor will use a small metal probe that is cooled in this treatment method (can be done multiple times)
Children will be under G.A.
It is mainly used for smaller tumours in restricted sites (mainly A)
how is laser therapy used in the treatment of retinblastoma
Two main types (laser photocoagulation and trans-pupillary thermal therapy (TTT)) – HEAT THERAPY (Soliman et al, 2018)
- Children require G.A for each method
Laser Photocoagulation
Laser beam aimed through the pupil and focused onto blood vessels that stop the blood supply to the tumour (good for small tumours)
Transpupillary thermal therapy (TTT)
Similar to above but not as hot, sometimes used in conjunction with chemotherapy in larger tumours
how is chemotherapy used in the treatment of retinoblastoma
The use of anti-cancer drugs to treat cancer
There are many different ways chemotherapy can be used in Rb
More often used if there is spread of cancer outside the eye
Use of chemotherapy must be very carefully considered in children, especially the very young who are developing
what is systemic chemotherapy
Systemic Chemotherapy
Chemotherapy that is given through the mouth or into a vein (IV)
what is intra-arterial chemotherapy
Intra-arterial chemotherapy – directly into virteous - (newer technique)
what is intra vitreal chemotherapy
Intra-arterial chemotherapy – directly into virteous - (newer technique)
Chemotherapy injected directly
Chemotherapy injected directly into ophthalmic artery (Yamane et al, 2004)
what are side effects of chemotherapy
Hair loss
Loss of appetite
Sickness
Diarrhoea
Increased chance of picking up infections (immunocompromised)
Extreme fatigue
Many more….
how is radiotherapy used in these patients
Radiotherapy uses high energy x-rays to attempt to kill the cancer/cancer cells
Radiotherapy is targeted directly to the cancer location after careful planning
It can be done in multiple sessions
It can be used as an adjunct to chemotherapy or on its own
Multiple types: external beam radiotherapy, intensity modulated radiation therapy, proton beam therapy
Must consider side effects prior to treatment
how is surgery used in these patients
Enucleation (eye removal) is usually a last resort
Removal of the eye and optic nerve (to reduce chance of any further spread)
Must consider both physical and psychological implications for the child
Orbital implant is usually used and nowadays, with technology, the implant can be made identical to the other eye
what is important in the orthoptic investigation
History
Important to ask about family history
Questions more likely to be directed to parents
Symptoms?
what symptoms are important to note
Symptoms?
- Leucocoria or strabismus – sudden or gradual?
- Sore, red or swollen eye?
- Changes in eye colour?
- Reduction in vision? Any amblyopia?
- Red reflex?
- Nystagmus?
what extra tests would be important to do
IOP assessment
Visual field?
Imaging – Fundus photos/OCT?
what tests should be included in the orthoptic investigation
VA
CT
OM
Binocular function
Measure angle of deviation
IOP assessment
Visual field?
Imaging – Fundus photos/OCT?
how should these patients be managed
Review and Observe
In line with U.K guidelines – Rb patients are reviewed frequently
Orthoptically ensure VA remains stable and administer amblyopia treatment if necessary
Continue imaging (if possible)
Management options
Amblyopia treatment (if required)
Refraction – to ensure correct Rx is worn
Support for child and family
what is retinblastoma
tumour of the eye
What imaging techniques could be useful for the detection of a retinoblastoma?
Oct, fundus photos
what is the most common sign of retinblastoma
Most common eye sign is leukocoria
bilateral cases of retinoblastoma are Moree likely to be ……….
genetic
