Predicting thyroid cancer ablation success: Pre-ablative 99mTc-Pertechnetate and post-ablative 131I scan comparison

• Published in: Médecine nucléaire : imagerie fonctionelle et métabolique 2024-11
• Main Authors: Mutevelizade, G., Parlak, Y., Bozdemir, B.C., Sezgin, C., Gumuser, G., Sayit, E.
• Format: Article
• Language: English
• Subjects: 131I scan; 99mTc-Pertechnetate; 99mTc-Pertechnétate; Ablation; Carcinome thyroïdien différencié; Differentiated thyroid carcinoma; Scan au 131I; Scintigraphie; Scintigraphy; Success; Succès
• ISSN: 0928-1258
• DOI: 10.1016/j.mednuc.2024.05.001

The purpose of this study was to evaluate the relationship between pre-ablative 99mTc-pertechnetate scintigraphy, and therapeutic iodine-131 (131I) whole-body scan (TxWBS), with ablation status and to investigate the possible predictive factors for successful ablation in differentiated thyroid carcinoma (DTC) patients. A total of 330 DTC patients underwent 99mTc-pertechnetate scintigraphy after thyroidectomy. Uptake values were determined using the region-of-interest technique. All patients had neck ultrasonography and TxWBS. Both scintigraphic scans were interpreted visually and qualitatively. The ablation status was evaluated with a diagnostic 131I whole-body scan. The success rate for residual thyroid ablation was 88.8%. The sensitivity, specificity, accuracy, PPV, and NPV of 99mTc-Pertechnetate scintigraphy were 82.4%, 87.5%, 82.7%, 99.2%, and 20.2%, respectively. Pre-ablative TG values and 99mTc uptake (%) were significantly lower in successfully ablated patients. The 99mTc uptake was determined as a significant predictive factor for ablation success (P=0.000). The optimal 99mTc uptake cut-off value of 0.75% was demonstrated for successful ablation. There were significant positive correlations between the visual and the calculated uptake (%) of residual tissues on both scintigraphic scans, Considering the number of remnant tissue foci, significant positive correlations were found between 99mTc-Pertechnetate scintigraphy, TxWBS, and USG. Pre-ablative 99mTc-Pertechnetate uptake (%) value of the remnant tissue can predict the ablation status in DTC patients. 99mTc-Pertechnetate scintigraphy, which is an easily applicable and accessible imaging method, has maintained its place in the postoperative and pre-ablative period in DTC patients over the years and has not lost any of its value. Cette étude visait à évaluer la relation entre la scintigraphie pré-ablative au 99mTc-pertechnétate et balayage corps entier à 131I thérapeutique (TxWBS) et à identifier les facteurs prédictifs de succès d’ablation chez les patients avec carcinome thyroïdien différencié (CTD). Au total, 330 patients atteints de CTD ont subi une scintigraphie post-thyroïdectomie au 99mTc-Pertechnetate, analysée par la technique ROI. Ils ont bénéficié d’une échographie et d’une TxWBS. L’efficacité de l’ablation a été vérifiée par scintigraphie à 131I. Le taux de réussite de l’ablation résiduelle de la thyroïde était de 88,8 %. La sensibilité, la spécificité, l’exactitude, la VPP et la VPN de