Early prediction of treatment outcome for lenvatinib using 18F-FDG PET/CT in patients with unresectable or advanced thyroid carcinoma refractory to radioiodine treatment: a prospective, multicentre, non-randomised study

Satoshi Takeuchi; Kenji Hirata; Keiichi Magota; Shiro Watanabe; Rika Moku; Akihiko Shiiya; Jun Taguchi; Shin Ariga; Tomohiro Goda; Yoshihito Ohhara; Takurou Noguchi; Yasushi Shimizu; Ichiro Kinoshita; Rio Honma; Yasushi Tsuji; Akihiro Homma; Hirotoshi Dosaka-Akita

doi:10.1186/s13550-023-01019-9

Early prediction of treatment outcome for lenvatinib using ¹⁸F-FDG PET/CT in patients with unresectable or advanced thyroid carcinoma refractory to radioiodine treatment: a prospective, multicentre, non-randomised study

EJNMMI Res. 2023 Jul 17;13(1):69. doi: 10.1186/s13550-023-01019-9.

Authors

Satoshi Takeuchi¹, Kenji Hirata², Keiichi Magota³, Shiro Watanabe⁴, Rika Moku⁵, Akihiko Shiiya⁵, Jun Taguchi⁵, Shin Ariga⁵, Tomohiro Goda⁵, Yoshihito Ohhara⁵, Takurou Noguchi⁵, Yasushi Shimizu⁵, Ichiro Kinoshita⁵, Rio Honma⁶, Yasushi Tsuji⁶, Akihiro Homma⁷, Hirotoshi Dosaka-Akita⁵

Affiliations

¹ Department of Medical Oncology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan. stakeuch@med.hokudai.ac.jp.
² Department of Diagnostic Imaging, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
³ Division of Medical Imaging and Technology, Hokkaido University Hospital, Sapporo, Japan.
⁴ Department of Nuclear Medicine, Hokkaido University Hospital, Sapporo, Japan.
⁵ Department of Medical Oncology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
⁶ Department of Medical Oncology, Tonan Hospital, Sapporo, Japan.
⁷ Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.

Abstract

Background: Lenvatinib is widely used to treat unresectable and advanced thyroid carcinomas. We aimed to determine whether ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) performed 1 week after lenvatinib treatment initiation could predict treatment outcomes.

Results: This was a prospective, nonrandomised, multicentre study. Patients with pathologically confirmed differentiated thyroid carcinoma (DTC) and lesions refractory to radioiodine treatment were eligible for inclusion. Patients were treated with 24 mg lenvatinib as the initial dose and underwent PET/CT examination 1 week after treatment initiation. Contrast-enhanced CT was scheduled at least 4 weeks later as the gold standard for evaluation. The primary endpoint was to evaluate the discrimination power of maximum standardised uptake value (SUVmax) obtained by PET/CT compared to that obtained by contrast-enhanced CT. Evaluation was performed using the area under the receiver operating characteristic (ROC-AUC) curve. Twenty-one patients were included in this analysis. Receiver operating characteristic (ROC) curve analysis yielded an AUC of 0.714 for SUVmax after 1 week of lenvatinib treatment. The best cut-off value for the treatment response for SUVmax was 15.211. The sensitivity and specificity of this cut-off value were 0.583 and 0.857, respectively. The median progression-free survival was 26.3 months in patients with an under-cut-off value and 19.7 months in patients with an over-cut-off value (P = 0.078).

Conclusions: The therapeutic effects of lenvatinib were detected earlier than those of CT because of decreased FDG uptake on PET/CT. PET/CT examination 1 week after the initiation of lenvatinib treatment may predict treatment outcomes in patients with DTC.

Trial registration: This trial was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (number UMIN000022592) on 6 June, 2016.

Keywords: 18F-FDG PET/CT; Differentiated thyroid carcinoma; Early prediction; Lenvatinib; Treatment outcome.

Grants and funding

28-22/Pfizer Health Research Foundation