The EANM has issued guidelines on internal dosimetry for 131I treatment of neuroendocrine tumours. Guidelines for quantitative imaging of 131I have been provided by the Committee on Medical Internal Radiation Dose (MIRD) in pamphlet 24. Quantitative imaging is becoming more widely adopted and will in future be part of many multi-centre clinical studies in nuclear medicine. Image data acquisition and processing can only be standardised to a certain level due to local differences in logistics, available equipment and constraints in ethics approvals and regulations.
Multi-centre clinical studies involving a dosimetry component must be carefully planned and a consistent approach to quality assurance should be implemented to allow for the collation of results from the individual centres.
Dep settings for siemens step 7 trial#
A summary of the physics aspects of setting up a multi-centre clinical trial involving imaging-based dosimetry has been provided in. Multi-centre prospective clinical studies are ultimately necessary to resolve the controversies raised in the consensus paper by the ATA, EANM, SNMMI and ETA.Ĭlinical studies performed in a multi-centre setting enable a wider input into the trial design and data analysis. Previous studies that have investigated the relationship between the absorbed dose to the thyroid remnant and the treatment success rate have not been performed in a multi-centre setting, and treatment based on a dosimetry approach has, therefore, not been widely adopted. A number of studies have shown that a large range of absorbed doses is observed in patients when empirical activities are used. Several authors have hypothesised that the ablation success rate is dependent on the absorbed dose delivered to residual thyroid tissue rather than on the activity administered. concluded that it is not possible to determine from the literature whether ablation success rates are higher with higher administered activities. Furthermore, they recommend that major gaps in knowledge concerning the optimal use of radioiodine should be addressed by prospective studies.Ī review by Hackshaw et al. These ‘Martinique principles’ include the need to determine the optimal prescribed activity of radioiodine for adjuvant treatment and for patients at low risk. A consensus paper developed by experts from the American Thyroid Association (ATA), the European Association of Nuclear Medicine (EANM), the Society of Nuclear Medicine and Molecular Imaging (SNMMI) and the European Thyroid Association (ETA) has established several principles regarding treatment and has highlighted areas in need of investigation. Nevertheless, treatment regimens remain subject to controversy and administered activities can vary widely, in part due to a lack of evidence regarding potential risks from treatment. Radioiodine (NaI) has been used to treat thyroid cancer following partial or total thyroidectomy for nearly 80 years. This could potentially facilitate the extension of the imaging network for further dosimetry-based studies. Results presented here provide additional support for the proposal to use global calibration parameters for cameras of the same make and model. Furthermore, dead-time coefficients measured on two Siemens Intevo systems agreed well with previously published dead-time values. For volumes larger than 10 ml, the maximum observed difference between recovery coefficients was found to be ± 0.02. Recovery coefficients measured on three Siemens Intevo systems show good agreement. For a GE Discovery 670 (crystal thickness 5/8″) a system volume sensitivity of 92.2 cps/MBq was measured. System volume sensitivities of the Siemens Intevo systems (crystal thickness 3/8″) ranged from 62.1 to 73.5 cps/MBq. Five SPECT(/CT) systems at four European centres were characterised with respect to their system volume sensitivity, recovery coefficients and dead time.
Dep settings for siemens step 7 series#
This network will support a concurrent series of clinical studies to determine accurately absorbed doses for thyroid cancer patients treated with radioiodine. Material and methodsĪ European network of centres able to perform standardised quantitative imaging of radioiodine therapy of thyroid cancer patients was set-up within the EU consortium MEDIRAD.
Optimisation and standardisation of data acquisition and processing are necessary to ensure quantitative imaging and patient-specific dosimetry. Multi-centre clinical studies are required to ensure recruitment of sufficient patients to achieve the statistical significance required to address these issues. Differentiated thyroid cancer has been treated with radioiodine for almost 80 years, although controversial questions regarding radiation-related risks and the optimisation of treatment regimens remain unresolved.
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