Role of [ 99m Tc]Tc-Galacto-RGD 2 SPECT/CT in identifying metastatic differentiated thyroid carcinoma after thyroidectomy and radioactive iodine therapy

• Published in: Nuclear medicine and biology 2020-09, Vol.88-89, p.34
• Main Authors: Xu, Qinfeng, Liu, Rencong, Wang, Jun, Huang, Yue, Li, Shaohua, Zhang, Lele, Wang, Feng
• Format: Article
• Language: English
• Subjects: Adenocarcinoma, Follicular - diagnostic imaging; Adenocarcinoma, Follicular - metabolism; Adenocarcinoma, Follicular - secondary; Adenocarcinoma, Follicular - therapy; Adult; Aged; Aged, 80 and over; Carcinoma, Papillary - diagnostic imaging; Carcinoma, Papillary - metabolism; Carcinoma, Papillary - secondary; Carcinoma, Papillary - therapy; Combined Modality Therapy; Female; Follow-Up Studies; Galactose - chemistry; Humans; Iodine Radioisotopes - chemistry; Iodine Radioisotopes - metabolism; Male; Middle Aged; Oligopeptides - chemistry; Organotechnetium Compounds - chemistry; Organotechnetium Compounds - metabolism; Prognosis; Radiopharmaceuticals - metabolism; Thyroid Neoplasms - diagnostic imaging; Thyroid Neoplasms - metabolism; Thyroid Neoplasms - pathology; Thyroid Neoplasms - therapy; Thyroidectomy - methods; Tomography, Emission-Computed, Single-Photon - methods; Tomography, X-Ray Computed - methods; Whole Body Imaging; Young Adult
• ISSN: 1872-9614
• DOI: 10.1016/j.nucmedbio.2020.06.006

Integrin αvβ3, a member of the arginine-glycine-aspartate (RGD)-binding subfamily, is associated with tumor angiogenesis and metastasis. The aim of study is to investigate the clinical role of [ Tc]Tc-Galacto-RGD SPECT/CT in high-risk differentiated thyroid carcinoma (DTC) after thyroidectomy and radioactive iodine (RAI) therapy. Thirty-six patients with high-risk DTC (20 males, 16 females; mean age: 59.9 ± 16.6 y) who underwent thyroidectomy and RAI therapy were consecutively enrolled in this study. All patients underwent [ Tc]Tc-Galacto-RGD SPECT/CT and diagnostic I whole-body scan 6 months after the last RAI treatment. A region of interest (ROI) was drawn and the ratio of tumor/non-target (T/NT) was calculated. Per-patient and per-lesion analysis was performed to evaluate the diagnostic efficacy. The final diagnosis was confirmed by histopathology and follow-up. Integrin αvβ3, CD31, and Ki-67 expression in the tumor were also analyzed for evaluation of angiogenesis and proliferation. Out of 36 patients, twenty-two had metastatic disease. By per-patient analysis, the area under the curve of [ Tc]Tc-Galacto-RGD SPECT/CT was marginally significantly higher than that of I whole-body scan and morphological imaging (P = 0.0034 and 0.0006). For per-lesion analysis, [ Tc]Tc-Galacto-RGD SPECT/CT identified 67 metastatic lymph nodes in 14 patients, 12 lung metastases in four patients, and 12 bone metastases in six patients; its sensitivity was significantly higher than that of I whole-body scan in detection of lymphatic (90.54% vs. 55.41%, P = 0.0124) and bone metastasis (92.31% vs. 30.77%, P = 0.046). The ratio of T/NT in metastatic lesions increased with the DTC upstaging. [ Tc]Tc-Galacto-RGD SPECT/CT has high sensitivity in the detection of metastasis in high-risk DTC and further contributes to evaluation of tumor angiogenesis and radio‑iodine refractory status.