Wadsley Jonathan, Gregory Rebecca, Flux Glenn, Newbold Kate, Du Yong, Moss Laura, Hall Andrew, Flanagan Louise, Brown Sarah R
1 Weston Park Hospital, Sheffield, UK.
2 Department of Physics, The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, UK.
Br J Radiol. 2017 May;90(1073):20160637. doi: 10.1259/bjr.20160637. Epub 2017 Mar 14.
Treatment options for patients with thyroid cancer that is no longer sensitive to iodine therapy are limited. Those treatments which currently exist are associated with significant toxicity. The SELIMETRY trial (EudraCT No 2015-002269-47) aims to investigate the role of the MEK inhibitor Selumetinib in resensitizing advanced iodine refractory differentiated thyroid cancer to radioiodine therapy. Patients deemed to have sufficient iodine uptake in previously iodine refractory lesions after 4 weeks of Selumetinib therapy will be given an empirical activity of 5.5 GBq I-131, and response to therapy will be assessed. The trial presents an opportunity to investigate the dosimetric aspects of radioiodine therapy for advanced thyroid cancer. Patients will undergo serial I-123 single-photon emission CT (SPECT)/CT scans following Selumetinib therapy to determine whether there has been a change in the degree of iodine uptake to justify further I-131 therapy, and to allow dosimetric calculations to predict absorbed dose to target lesions following therapy. Patients receiving I-131 therapy will undergo a further series of post-therapy SPECT/CT scans to allow dosimetric calculations. We describe the challenges in setting up a multicentre trial in a relatively underinvestigated field, describing the work that has been carried out to calibrate and validate measurements to ensure that standardized image data are collected at each site. We hope that this trial will lead to individualization and optimization of therapy for patients with advanced thyroid cancer and that the ground work carried out in setting up a network of centres capable of standardized molecular radiotherapy dosimetry will lead to further clinical trials in this field.
对于对碘治疗不再敏感的甲状腺癌患者，治疗选择有限。目前现有的那些治疗方法都伴有显著的毒性。SELIMETRY试验（欧洲临床试验注册号：2015-002269-47）旨在研究MEK抑制剂司美替尼在使晚期碘难治性分化型甲状腺癌对放射性碘治疗重新敏感方面的作用。在司美替尼治疗4周后，被认为在先前碘难治性病灶中有足够碘摄取的患者将接受5.5 GBq I-131的经验性活度治疗，并评估治疗反应。该试验提供了一个研究晚期甲状腺癌放射性碘治疗剂量学方面的机会。患者在接受司美替尼治疗后将接受系列I-123单光子发射计算机断层扫描（SPECT）/计算机断层扫描（CT），以确定碘摄取程度是否发生变化，从而证明进一步进行I-131治疗的合理性，并进行剂量学计算以预测治疗后靶病灶的吸收剂量。接受I-131治疗的患者将接受另一系列治疗后的SPECT/CT扫描，以便进行剂量学计算。我们描述了在一个相对研究不足的领域开展多中心试验所面临的挑战，介绍了为校准和验证测量所开展的工作，以确保在每个站点收集标准化的图像数据。我们希望这项试验将导致晚期甲状腺癌患者治疗的个体化和优化，并且建立一个能够进行标准化分子放射治疗剂量学的中心网络所开展的基础工作将促使该领域开展进一步的临床试验。
