Clinicopathologic risk factors of radioactive iodine therapy based on response assessment in patients with differentiated thyroid cancer: a multicenter retrospective cohort study

• Published in: European journal of nuclear medicine and molecular imaging 2020-03, Vol.47 (3), p.561-571
• Main Authors: Kwon, Seong Young, Lee, Sang-Woo, Kong, Eun Jung, Kim, Keunyoung, Kim, Byung Il, Kim, Jahae, Kim, Heeyoung, Park, Seol Hoon, Park, Jisun, Park, Hye Lim, Oh, So Won, Won, Kyoung Sook, Ryu, Young Hoon, Yoon, Joon-Kee, Lee, Soo Jin, Lee, Jong Jin, Chong, Ari, Jeong, Young Jin, Jeong, Ju Hye, Cho, Young Seok, Cho, Arthur, Cheon, Gi Jeong, Choi, Eun Kyoung, Hwang, Jae Pil, Bae, Sang Kyun
• Format: Article
• Language: English
• Subjects: Cancer; Cardiology; Classification; Cohort analysis; Criteria; Endocrinology; Evaluation; Humans; Imaging; Iodine; Iodine 131; Iodine Radioisotopes - therapeutic use; Medical imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Oncology; Original Article; Orthopedics; Patients; Predictions; Radiology; Regression analysis; Retrospective Studies; Risk analysis; Risk Factors; Therapy; Thyroglobulin; Thyroid cancer; Thyroid carcinoma; Thyroid Neoplasms - diagnostic imaging; Thyroid Neoplasms - radiotherapy; Thyroid Neoplasms - surgery; Thyroid-stimulating hormone; Thyroidectomy; Ultrasound
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-019-04634-8

Purpose We investigated whether predictive clinicopathologic factors can be affected by different response criteria and how the clinical usefulness of radioactive iodine (RAI) therapy should be evaluated considering variable factors in patients with differentiated thyroid carcinoma (DTC). Methods A total of 1563 patients with DTC who underwent first RAI therapy after total or near total thyroidectomy were retrospectively enrolled from 25 hospitals. Response to therapy was evaluated with two different protocols based on combination of biochemical and imaging studies: (1) serum thyroglobulin (Tg) and neck ultrasonography (US) and (2) serum Tg, neck US, and radioiodine scan. The responses to therapy were classified into excellent and non-excellent or acceptable and non-acceptable to minimize the effect of non-specific imaging findings. We investigated which factors were associated with response to therapy depending on the follow-up protocols as well as response classifications. Multivariate logistic regression analysis was performed to identify factors significantly predicting response to therapy. Results The proportion of patients in the excellent response group significantly decreased from 76.5 to 59.6% when radioiodine scan was added to the follow-up protocol ( P