Page 10 - Clinical Connections - Autumn 2024

RVC RESEARCH STUDY VETERINARY SERVICES RVC.AC.UK
Equine
ADVANCES IN SARCOID TREATMENT

Andy Fiske-Jackson, Deputy Head of RVC Equine and Associate Professor in Equine Surgery
R VC Equine has long been at the Tumour specific electroporation
furthering
of
forefront
equine
Since the end of 2022 we have also been
oncology, with the use of novel
chemotherapeutic drugs and multi-modal able to offer TSE treatment. This modality
compared to others is especially useful for
treatment regimes. This includes a range of the treatment of large tumours and sarcoids
treatment modalities for sarcoids, tailored to situated over vital structures, such as joints,
the specific needs of individual patients. large blood vessels or the parotid region.
Modalities we use for treating sarcoids Surgical resection and topical cytotoxic
at RVC’s Equine Referral Hospital include creams carry a large risk of damage to
electrochemotherapy (ECT), tumour specific these vital structures.
electroporation (TSE) and thermofield
treatment.
We have been offering ECT to treat
sarcoids since 2017. RVC Equine was the
first veterinary centre in the UK to offer that
treatment option. This treatment involves
injecting carboplatin, followed by application
of a small electric current across the sarcoid.
The procedure can be combined with
other sarcoid treatments, such as laser Performing TSE Injecting bleomycin
excision. ECT is especially valuable for
sarcoids in areas where cytotoxic cream The cytotoxic drugs available for use in Initially we hoped only a single TSE
cannot be safely applied, such as around horses work by preventing cell division. treatment would be required but, as with
the eye, or where the cream could be However, the uptake of these drugs into ECT, repeat treatments appear to be more
rubbed onto unaffected areas. the cell is very limited due to the intact effective.
Three ECT treatments are usually membrane of the target cancer cell. Applying
required, all under a brief general an electric current to the cell causes pores Thermofield treatment
anaesthetic or standing sedation, if the to open in the cell membrane, allowing the Currently TSE and ECT are our most
treated area can be desensitised with nerve drug to enter the cell. utilised sarcoid treatments but we also offer
blocks. Larger sarcoids may require surgical Bleomycin, the drug we use with TSE, thermofield treatment. Application of heat
debulking beforehand. is increased in its concentration in the cell (hyperthermia) achieves a similar effect
ECT has been shown to be quick, by several hundred-fold or more following as ECT but also offers several additional
safe and efficacious but other treatment application of an electric current. This advantages. Heat not only increases uptake
modalities are more appropriate for certain process is called electroporation. This of drugs and potentiates their effects but
sarcoids. concept had already been adopted by ECT also activates the patient’s immune system
machines. and directly damages tumour cells by
We have enjoyed good success with suppressing new vessel growth and killing
treating small shallow sarcoids in horses cancer stem-like cells.
with ECT but static ECT can cause It also has analgesic properties,
unwanted thermal necrosis and destruction increasing patient comfort. In contrast
of normal tissue. TSE is an innovative to ECT, thermofield treatments can be
dynamic electroporation, designed to performed without general anaesthesia.
avoid such unwanted destruction of the
surrounding normal tissue by constantly The electrochemotherapy equipment
measuring the conductivity of the tissue and was funded by the RVC’s charity the
adjusting the pulse train accordingly. TSE Animal Care Trust (ACT). The tumour
also stimulates the host immune system to specific electroporation equipment was
attack the tumour or sarcoid. purchased by funds donated to the ACT
Like all machines and technologies, we by the Alice Noakes Memorial Charitable
are continuing to learn how to optimise the Trust. The thermofield equipment was
use of TSE. We have found the procedure purchased by funds donated to the ACT
does require a general anaesthetic unless by EBM Charitable Trust.
we can desensitise the area to perform the
treatment under sedation, such as on the
Performing ECT lower limb.
For equine referrals, please call: 01707
666297
Email:
equinehospital@rvc.ac.uk
10 Autumn 2024