Clinical trial NCT04391244: Investigating National Solutions for Personalised Iodine-131 Radiation Exposure
Official title: Investigating National Solutions for Personalised Iodine-131 Radiation Exposure - Measuring Absorbed Dose to Tumour and Organs at Risk Following Routine Iodine Ablation Therapy
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Differentiated Thyroid Cancer
Keywords: Radioiodine Therapy
Radiation Dose
Dosimetry
Lead sponsor: Royal Marsden NHS Foundation Trust
Sponsor class: OTHER
First posted: 2020-05-18
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with Differentiated Thyroid Cancer

Brief summary: This is a single-arm non-interventional prospective observational study to perform quantitative I-131 imaging and patient-specific dosimetry for patients undergoing radioiodine treatment.

Detailed description: The hypothesis underlying this study is that treatment outcome in molecular radiotherapy is dependent on the absorbed doses delivered rather than on the radioactivity administered. For up to 50 patients, post treatment dosimetry will be performed to establish the range of absorbed doses and associated uncertainties delivered to thyroid remnants, residual disease, and healthy organs from an ablative administration of I-131 radioiodine.

Imaging systems in participating centres will be characterised (system volume sensitivity, partial-volume effect and dead-time) and set up for quantitative imaging to allow for collation of data. Patients will be assigned to one of two dosimetry gamma camera scanning schedules. For scanning schedule 1 (Standard of Care) a single standard-of-care scan (SPECT/CT) will be acquired according to local protocol with regards to time post-radioiodine administration. A minimum of 20 patients will be assigned to scanning schedule 2 (Standard of Care + Additional Imaging), for which a standard-of-care scan and two to four additional SPECT scans will be acquired between 6 - 168 hours post-administration.

SPECT imaging datasets will be reconstructed with attenuation and scatter corrections to allow quantitative dosimetry calculations. Time integrated activity will be derived from analysis of the quantitative SPECT data and combined with relevant dose factors to obtain absorbed dose estimates for each target tissue. The subset of patients with additional imaging will be used to establish the pharmacokinetic properties of radioiodine in each tissue type (biological retention half-life) to enable determination of time integrated activity in patients with a single standard-of-care scan.

A minimum of 3 whole-body retention measurements will be performed per day during the patient's stay in hospital, approximately every 2-6 hours, according to local standard of care procedures. At each external measurement time point the quantified level of radioactivity in the whole body will be recorded.

Patients will be followed-up at their standard-of-care clinic visits to assess the success of treatment as well as for short to mid-term toxicity. Results from standard of care biochemical, radiological and haematological assessments (TSH, thyroglobulin, anti-thyroglobulin antibodies, ultrasound, serum creatinine, haemoglobin, white cell count, neutrophil count and platelet count) will be recorded to assess response to treatment. Statistical analysis of the relationship between the absorbed doses and outcome data will be performed.

Eligibility criteria: Inclusion Criteria:

* Written informed consent
* Histologically proven DTC (pT1b - pT3, any N, any M)
* Total thyroidectomy performed
* WHO PS 0-2 (autonomous, self-caring)

Exclusion Criteria:

* External radiotherapy in the last 6 weeks
* Systematic chemotherapy in the last 6 weeks
* Pregnancy or breast feeding

Primary outcomes:
measure: Range of absorbed doses and associated uncertainties delivered to thyroid remnants, residual disease, metastatic disease and healthy organs.
timeFrame: 9 months
Secondary outcomes:
measure: Proportion of patients with successful treatment.
timeFrame: 9 months
measure: Threshold absorbed dose to the thyroid remnant for treatment success.
timeFrame: 9 months
measure: Association of biomarkers with absorbed dose
timeFrame: 9 months
measure: Association of biomarkers with treatment success
timeFrame: 9 months
Other outcomes:
Locations:
city: Sutton
country: United Kingdom
facility: The Royal Marsden NHS Foundation Trust
state: Surrey
Study officials:
affiliation: Consultant Clinical Oncologist
name: Kate Newbold
role: STUDY_CHAIR
affiliation: Head of Radioisotope Physics
name: Glenn Flux
role: PRINCIPAL_INVESTIGATOR
References: