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Trial Details
Trial status:
In follow-up (non-recruiting)
Recruitment start date:
Cancer Research UK
Chief Investigator:
Dr Ujjal Mallick
Recruitment target:
EudraCT number:
Contact details:
Lay summary:
Multicentre randomised trial of high dose versus low dose radioiodine, with or without recombinant human thyroid stimulating hormone, for remnant ablation following surgery for differentiated thyroid cancer.
Design: HiLo was a randomised, phase III factorial randomised trial, stratified according to trial site, T stage and N stage. 
Patients were randomised to receive one of four treatment arms:
  • rhTSH followed by 1.1 GBq radioiodine ablation
  • rhTSH followed by 3.7 GBq radioiodine ablation
  • hormone withdrawal (no rhTSH) followed by 1.1 GBq radioiodine ablation
  • hormone withdrawal (no rhTSH) followed by 3.7 GBq radioiodine ablation

Key inclusion/exclusion criteria: Patients with histological confirmation of differentiated thyroid cancer, who had undergone a total thyroidectomy, with all known tumour resected were eligible for the trial. Patients with aggressive variants of thyroid carcinoma or those with severe co-morbid conditions were excluded.
Duration of recruitment: 438 patients were recruited between January 2007 and July 2010. Main results were published in 2012. The trial is in long term follow up.
The overall aim was to examine whether a low administered dose of radioiodine (1.1 GBq) had a similar remnant ablation success rate as a high dose (3.7 GBq), and to examine whether patients given rhTSH had a similar ablation success rate to those who discontinued thyroid hormone replacement
Trial protocols
Trial protocols must not be applied to patients treated outside trials. UCL CTC can only ensure that approved trial investigators are provided with amendments to protocols.
No protocols have been currently made available for download
Trial documents
No documents have been currently made available for download
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