{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T04:59:41Z","timestamp":1790744381707,"version":"4.1.0"},"reference-count":20,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T00:00:00Z","timestamp":1790294400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004951","name":"Atat\u00fcrk University","doi-asserted-by":"publisher","award":["TTU-2024-14581"],"award-info":[{"award-number":["TTU-2024-14581"]}],"id":[{"id":"10.13039\/501100004951","id-type":"DOI","asserted-by":"publisher"}]},{"award":["TTU-2024-14581"],"award-info":[{"award-number":["TTU-2024-14581"]}],"id":[{"id":"https:\/\/ror.org\/03je5c526","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background\/Objectives: Radioactive iodine (RAI) therapy is widely used after thyroidectomy for differentiated thyroid cancer, but early renal tubular changes may not be reflected by conventional renal function parameters. We prospectively evaluated urinary tubular biomarker changes across three administered RAI activities. Methods: We included 120 patients, with 40 in each activity group (1.11, 3.70, and 5.55 GBq). Blood was collected at baseline and day 7, and urine at baseline, day 1, and day 7. Urinary kidney injury molecule-1, netrin-1, cystatin C, and \u03b22-microglobulin were measured by enzyme-linked immunosorbent assay; conventional renal parameters were also assessed. Results: All four biomarkers increased significantly from baseline to Day 1 in all activity groups. Percentage increases were numerically greater at higher administered activities; however, baseline-adjusted mixed-effects analysis showed no significant activity-group effect or activity group \u00d7 time interaction. Absolute biomarker levels partially declined by Day 7 and remained numerically above baseline, whereas urinary creatinine-normalized biomarker ratios remained significantly elevated. Serum creatinine decreased and creatinine-based eGFR increased by Day 7, whereas urinary albumin, protein, and phosphate showed no consistent changes across the activity groups. Conclusions: The concordant early changes observed in urinary tubular biomarkers, without deterioration in conventional renal function parameters, support an early subclinical tubular response following RAI therapy. Although percentage increases were numerically greater at higher administered activities, baseline-adjusted mixed-effects analyses did not support an independent activity-related effect. Therefore, these findings should not be interpreted as evidence of clinically significant renal injury. Longer-term studies are needed to determine the persistence, reversibility, and clinical significance of these findings.<\/jats:p>","DOI":"10.3390\/diagnostics16193123","type":"journal-article","created":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T16:31:14Z","timestamp":1790353874000},"page":"3123","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Early Renal Effects After Radioactive Iodine Therapy in Differentiated Thyroid Cancer: A Prospective Observational Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-1402-7576","authenticated-orcid":false,"given":"Muhammed Enes","family":"Solako\u011flu","sequence":"first","affiliation":[{"name":"Department of Nuclear Medicine, Faculty of Medicine, Atat\u00fcrk University, 25240 Erzurum, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adem","family":"Maman","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Faculty of Medicine, Atat\u00fcrk University, 25240 Erzurum, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Esra","family":"Lalo\u011flu","sequence":"additional","affiliation":[{"name":"Department of Medical Biochemistry, Faculty of Medicine, Atat\u00fcrk University, 25240 Erzurum, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"841","DOI":"10.1177\/10507256251363120","article-title":"2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer","volume":"35","author":"Ringel","year":"2025","journal-title":"Thyroid"},{"key":"ref_2","first-page":"759","article-title":"Biodistribution and dosimetry of 131I in thyroidectomy patients using semiquantitative \u03b3-camera imaging","volume":"23","author":"Changlai","year":"2008","journal-title":"Cancer Biother. Radiopharm."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1445","DOI":"10.2967\/jnumed.108.052464","article-title":"131I effective half-life and dosimetry in thyroid cancer patients","volume":"49","author":"Remy","year":"2008","journal-title":"J. Nucl. Med."},{"key":"ref_4","first-page":"40","article-title":"Radioiodine-induced kidney damage and protective effect of amifostine: An experimental study","volume":"16","author":"Aktoz","year":"2012","journal-title":"Hippokratia"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1097\/MNM.0000000000000788","article-title":"Apoptosis and cell proliferation in short-term and long-term effects of radioiodine-131-induced kidney damage: An experimental and immunohistochemical study","volume":"39","author":"Yumusak","year":"2018","journal-title":"Nucl. Med. Commun."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1541","DOI":"10.1080\/09553002.2024.2400484","article-title":"Long-term biological effects after acute 131I-administration of two rat models (with and without thyroid)","volume":"100","author":"Souidi","year":"2024","journal-title":"Int. J. Radiat. Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1097\/00006231-199606000-00014","article-title":"Screening for microalbuminuria by RIA in 131I-treated thyroid cancer patients","volume":"17","author":"Bhatkar","year":"1996","journal-title":"Nucl. Med. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"619","DOI":"10.5603\/EP.a2022.0037","article-title":"Effects of high-activity radioactive iodine treatment on renal function in patients with differentiated thyroid carcinoma: Retrospective study","volume":"73","author":"Yin","year":"2022","journal-title":"Endokrynol. Pol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1316","DOI":"10.1093\/jalm\/jfab020","article-title":"AACC Guidance Document on Laboratory Investigation of Acute Kidney Injury","volume":"6","author":"Hoenig","year":"2021","journal-title":"J. Appl. Lab. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1097\/FTD.0000000000000589","article-title":"Biomarkers of drug-induced kidney toxicity","volume":"41","author":"Griffin","year":"2019","journal-title":"Ther. Drug Monit."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"S22","DOI":"10.3109\/1354750X.2011.587129","article-title":"Biomarkers of kidney injury","volume":"16","author":"Urbschat","year":"2011","journal-title":"Biomarkers"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"F552","DOI":"10.1152\/ajprenal.00285.2002","article-title":"Kidney injury molecule-1: A tissue and urinary biomarker for nephrotoxicant-induced renal injury","volume":"286","author":"Ichimura","year":"2004","journal-title":"Am. J. Physiol. Ren. Physiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"F729","DOI":"10.1152\/ajprenal.00085.2008","article-title":"Netrin-1: A potential universal biomarker for acute kidney injury","volume":"294","author":"Basnakian","year":"2008","journal-title":"Am. J. Physiol. Ren. Physiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1038\/nbt.1622","article-title":"Urinary clusterin, cystatin C, \u03b22-microglobulin and total protein as markers to detect drug-induced kidney injury","volume":"28","author":"Dieterle","year":"2010","journal-title":"Nat. Biotechnol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1089\/thy.2015.0020","article-title":"2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer","volume":"26","author":"Haugen","year":"2016","journal-title":"Thyroid"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1502","DOI":"10.1016\/j.ekir.2022.03.026","article-title":"Considerations in controlling for urine concentration for biomarkers of kidney disease progression after acute kidney injury","volume":"7","author":"Wen","year":"2022","journal-title":"Kidney Int. Rep."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"339","DOI":"10.4414\/smw.2009.12654","article-title":"Effects of thyroxine replacement on serum creatinine and cystatin C in patients with primary and central hypothyroidism","volume":"139","author":"Goede","year":"2009","journal-title":"Swiss Med. Wkly."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Berta, D.M., Teketelew, B.B., Cherie, N., Tamir, M., Abriham, Z.Y., Ayele Angelo, A., Tarekegne, A.M., Chane, E., Mulatie, Z., and Walle, M. (2025). Effect of radioactive iodine therapy on hematological parameters in patients with thyroid cancer: Systematic review and meta-analysis. Front. Endocrinol., 16.","DOI":"10.3389\/fendo.2025.1562851"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1193","DOI":"10.1507\/endocrj.EJ20-0242","article-title":"Short-term bone marrow suppression in differentiated thyroid cancer patients after radioactive iodine treatment","volume":"67","author":"Yi","year":"2020","journal-title":"Endocr. J."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Xin, C., Xie, J., Fan, H., Sun, X., and Shi, B. (2021). Association between serum cystatin C and thyroid diseases: A systematic review and meta-analysis. Front. Endocrinol., 12.","DOI":"10.3389\/fendo.2021.766516"}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/19\/3123\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T04:28:02Z","timestamp":1790742482000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/19\/3123"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,25]]},"references-count":20,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["diagnostics16193123"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16193123","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,25]]}}}