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Contact Information:

Mrs Aniqa Tasnim
+44 (0)20 3108 4753
ctc.hot@ucl.ac.uk


Study Location:

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Be Part of Research - Trial Details - HoT – A phase III randomised trial to compare the rates of cancer returning in patients with low-risk differentiated thyroid cancer after a hemithyroidectomy and total thyroidectomy

HoT – A phase III randomised trial to compare the rates of cancer returning in patients with low-risk differentiated thyroid cancer after a hemithyroidectomy and total thyroidectomy

Medical Conditions

Low risk thyroid cancers


This information is provided directly by researchers, and we recognise that it isn't always easy to understand. We are working with researchers to improve the accessibility of this information. In some summaries, you may come across links to external websites. These websites will have more information to help you better understand the study.



Background and study aims
The rate of well-differentiated thyroid cancer (DTC) is increasing faster than any other tumour. The current standard treatment for low-risk DTC is surgical removal of the whole thyroid gland called total thyroidectomy (TT), followed by radioiodine treatment. More recently, surgeons have started performing hemithyroidectomy (HT) (removal of the cancerous half of the thyroid) as international guidelines changed and studies suggested patients may benefit from less extensive surgery, whilst maintaining excellent cure rates. HT patients may not require life-long hormone replacement therapy, calcium and vitamin D supplements, and radioiodine treatment. However, results from these studies are biased and conflicting. There is uncertainty surrounding the most appropriate surgery causing variations in practice between different teams and hospitals.

HoT is the first trial to directly compare TT versus HT in terms of the rate of cancer returning, impact on quality of life, surgery-related side-effects, need for thyroid hormone replacement therapy after surgery, health resources use and cost-effectiveness to the NHS.

Start dates may differ between countries and research sites. The research team are responsible for keeping the information up-to-date.  

The recruitment start and end dates are as follows:

13 Dec 2021 31 Jul 2025

There will be two groups of patients entering the trial with the same diagnoses and prognosis (i.e. risk of cancer returning):
- Group 1: Patients who have already had a hemithyroidectomy for thyroid problems and are then subsequently diagnosed with low-risk DTC will be randomly assigned (50:50 chance) to receive regular surveillance (follow-up only) OR have a second operation to remove the rest of their thyroid gland (two-stage total thyroidectomy).
- Group 2: Patients diagnosed with low-risk DTC but not undergone surgery, will be randomly assigned (50:50 chance) to have either the whole thyroid gland removed (single-stage total thyroidectomy) or only part of the gland removed (a hemi-thyroidectomy).
All thyroid surgeries performed on the trial will be as per the standard of care at the treating hospital.
All patients on the trial will be followed up regularly for up to 6½ years. Patients will attend clinic visits for standard checks on their progress and health before surgery, sometime between 2 and 4 weeks after surgery, 6 months after surgery, then once a year for 6 years. These checks include clinical examinations, blood tests to check thyroid gland function and neck ultrasound scans. All patients will have an ultrasound scan of their neck every year. In several hospitals this scan is already part of routine care. For all patients, there is one extra ultrasound scan of their neck 6 months after surgery.
For research purposes patients will also be asked to complete four questionnaires about their health and well-being and a questionnaire to check voice function. Selected patients may be able to complete the questionnaires at home, using a web-based application (‘app’) that will send text (SMS) message alerts to their mobile phone/tablet. They can then complete these questionnaires on their mobile phone/tablet, rather than completing paper questionnaires at the hospital during clinic appointments. Using this ‘app’ is another part of the HoT trial, and is being done in partnership with an American company called Navio who own the ‘app’. This ‘app’ allows electronic collection of information from trial patients allowing us to see if this approach is better and easier for patients than if they used paper questionnaires.
The first 30-50 patients recruited to the HoT study will be asked to use the ‘app’. After this, patients will be randomly allocated (50:50 chance) to complete the well-being questionnaires either using the ‘app’ OR using paper forms. Patients who do not wish to take part in this study that evaluates the ‘app’ can instead use the paper version of the questionnaires throughout the trial or can switch from the web-based app to the paper questionnaires at any time if they wish.
After the initial 6½ years of follow-up long term follow up data on recurrences and mortality will be collected electronically from national registries and databases (e.g. NCRAS) for an additional 13 ½ years.


Individuals aged 16 years or over with a diagnosis of low-risk differentiated thyroid cancer.

You can take part if:



You may not be able to take part if:


Group 1 (Hemithyroidectomy already performed prior to diagnosis):1. Tumour > 4cm2. Unifocal pT1a (< = 1cm) papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC) (unless pN1a as listed in inclusion criteria)3. Non-invasive encapsulated follicular variant of PTC4. Anaplastic, poorly differentiated or medullary thyroid carcinoma5. R2 resection6. Gross extrathyroidal extension 7. pT4 or macroscopic tumour invasion of loco-regional tissues or structures8. pN1a with > 5 foci or extranodal spread9. pN1b 10. M1 11. Aggressive PTC with any of the following features: - Widely invasive - Poorly differentiated - Anaplastic - predominance of Tall cell, Columnar cell, Hobnail, Diffuse sclerosing and other higher risk variants 12. FTC and oncocytic/Hürthle cell cancer with any of the following features: - Minimally invasive with extensive vascular invasion (now called encapsulated angioinvasive) (> 4 foci) - Widely invasive - Poorly differentiated - Anaplastic

Group 2 (Differentiated thyroid cancer on cytology or after core biopsy, who has not had prior thyroid surgery yet)1. M1


Below are the locations for where you can take part in the trial. Please note that not all sites may be open.

  • NHS Lothian
    Waverley Gate 2-4 Waterloo Place
    Edinburgh
    EH1 3EG
  • University College London Hospitals NHS Foundation Trust
    250 Euston Road
    London
    NW1 2PG
  • Cardiff & Vale University Lhb
    Woodland House Maes-y-coed Road
    Cardiff
    CF14 4HH
  • Ninewells Hospital
    Ninewells Avenue
    Dundee
    DD1 9SY
  • Aberdeen Royal Infirmary
    Foresterhill Road
    Aberdeen
    AB25 2ZN
  • The Royal Marsden NHS Foundation Trust
    Fulham Road
    London
    SW3 6JJ
  • Northwick Park Hospital
    Watford Road
    Harrow
    HA1 3UJ
  • University Hospitals Bristol and Weston NHS Foundation Trust
    Trust Headquarters Marlborough Street
    Bristol
    BS1 3NU
  • Nottingham City Hospital
    Hucknall Road
    Nottingham
    NG5 1PB
  • Queen Elizabeth Hospital
    Mindelsohn Way Edgbaston
    Birmingham
    B15 2GW
  • St George's Hospital
    Blackshaw Road Tooting
    London
    SW17 0QT
  • Luton and Dunstable University Hospital
    Lewsey Road
    Luton
    LU4 0DZ
  • Taunton Hospital
    Musgrove Park Hospital
    Taunton
    TA1 5DA
  • Addenbrookes
    Addenbrookes Hospital Hills Road
    Cambridge
    CB2 0QQ
  • Royal Berkshire Hospital
    Royal Berkshire Hospital London Road
    Reading
    RG1 5AN
  • Derriford Hospital
    Derriford Road Derriford
    Plymouth
    PL6 8DH
  • Northern General Hospital
    Northern General Hospital NHS Trust C Floor, Huntsmnan Building Herries Road
    Sheffield
    S5 7AU
  • Royal Derby Hospital
    Uttoxeter Road
    Derby
    DE22 3NE
  • Forth Valley Royal Hospital
    Stirling Road
    Larbert
    FK5 4WR
  • Leicester Royal Infirmary
    Infirmary Square
    Leicester
    LE1 5WW
  • Norfolk & Norwich University Hospital
    Colney Lane Colney
    Norwich
    NR4 7UY
  • Guy's & St Thomas Hospital
    Westminster Bridge Road
    London
    SE1 7EH
  • Ipswich Hospital
    Heath Road
    Ipswich
    IP4 5PD
  • Queen Alexandra Hospital
    Southwick Hill Road Cosham
    Portsmouth
    PO6 3LY
  • The Royal Liverpool University Hospital
    Prescot Street
    Liverpool
    L7 8XP
  • Gartnavel Royal Hospital
    1055 Great Western Road
    Glasgow
    G12 0XH
  • Medway NHS Foundation Trust
    Medway Maritime Hospital Windmill Road
    Gillingham
    ME7 5NY
  • Lister Hospital
    Chelsea Bridge Road
    London
    SW1W 8RH
  • Gstt @ Royal Devon and Exeter
    Royal Devon & Exeter Hospital Barrack Road
    Exeter
    EX2 5DW
  • Northampton General Hospital
    Cliftonville
    Northampton
    NN1 5BD

Patients will be treated as they would otherwise in routine care and receive the best treatment for their thyroid cancer whether they take part in this trial or not. By taking part in this trial, the patients will help us to understand more about treating patients, both in the UK and worldwide, with low-risk differentiated thyroid cancer and how best to treat them in the future. All patients taking part in the trial will have a neck ultrasound at their 6 month follow-up visit which may not always routinely be performed at all hospitals. Patients who have had a hemithyroidectomy before coming on to the trial and are then randomised to the surveillance arm will not need to have another surgery, avoiding the inconveniences of a second surgery along with the possible surgery-related complications. Patients who have a hemi-thyroidectomy as part of the trial may not need radioiodine ablation after (requires isolation in hospital) and may not need life-long thyroxine replacement therapy, which is likely to improve quality of life.
Both hemithyroidectomy and total-thyroidectomy procedures are performed routinely by surgeons as per standard of care and therefore do not pose any additional risks to patients beyond those associated with the surgeries. Both surgeries will be performed as per local site policy by qualified surgeons. A trial specific audit will be carried out on all recruiting hospitals to ensure both surgeries are being performed routinely there.
There is a small risk of the cancer recurring after both a hemithyroidectomy and a total thyroidectomy. Some studies have shown that the recurrence rate may be slightly higher in patients who have a hemithyroidectomy, however the difference was considered clinically small and overall survival was similar. Most recurrences happen within 3-5 years of initial treatment and whilst on the trial patients will be followed up annually for up to 6 and ½ years after the surgery with routine thyroglobulin measurements and neck ultrasound to check for signs of recurrence. Once trial follow-up visits end the patient will be followed up as per standard practice at their treating hospital. A risk assessment of the trial has been carried out and a site monitoring plan will be developed based on this to ensure the trial is being carried out according to the protocol and Good Clinical Practice.


The study is sponsored by University College London and funded by NIHR Evaluation, Trials and Studies Co-ordinating Centre (NETSCC); National Institute for Health Research (NIHR) (UK).




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Read full details for Trial ID: ISRCTN17004671

Or CPMS 48988

Last updated 10 November 2023

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