Correlation of technetium-99m MIBI and thallium-201 retention in solitary cold thyroid nodules with postoperative histopathology

Erdil T., Ozker K., Kabasakal L., Kanmaz B., Sonmezoglu K., Atasoy K., ...More

EUROPEAN JOURNAL OF NUCLEAR MEDICINE, vol.27, no.6, pp.713-720, 2000 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 27 Issue: 6
  • Publication Date: 2000
  • Doi Number: 10.1007/s002590050567
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.713-720
  • Istanbul University Affiliated: No


A comparative prospective study of technetium-99m methoxyisobutylisonitrile (MIBI) and thallium-201 with early (15 min) and delayed (90 min for MIBI, 3 h for Tl-201) imaging in the differentiation of thyroid lesions is presented, Forty patients with cold thyroid nodules visualised on Tc-99m-pertechnetate scan and with dyskaryotic or atypical epithelial cells verified by fine-needle aspiration biopsy underwent MIBI and Tl-201 scintigraphy at 3-day intervals. Subsequent thyroidectomies were carried out in all patients. Semiquantitative analysis was performed using a lesion to non-lesion ratio on early (ER) and delayed images (DR). Additionally, a retention index (RI) was calculated using the formula RI=(DR-ER) x 100/ER. The reproducibility of the method for the early and delayed measurements was tested by analysing intra- and inter-observer variability and repeatability coefficients. Histopathologically, the nodules were found to be well-differentiated thyroid cancer in 21 patients and benign in 19 patients. There was no significant difference in the ER between malignant and benign lesions for either Tl-201 or MIBI (P>0.05). However, for both agents significant differences were found between malignant and benign lesions with regard to DR (P<0.01 for Tl-201 and P<0.001 for MIBI) and RI (P<0.001 for both agents). Statistical comparison of the two agents showed no significant differences (P>0.05) except with regard to DR and RI in malignant nodules (P<0.05). A receiver operating characteristic analysis was performed to determine threshold levels for the differentiation of malignant from benign nodules. Following this analysis, ER, DR and RI levels of 1.03, 1.54 and 2 for MIBI and less than or equal to 1.42, 1.24 and 5 for Tl-201 were selected. Using these threshold levels, the sensitivity, specificity and accuracy of the study were 90.5%, 36.8% and 65% for ER MIBI, 61.9%, 94.7% and 77.5% for DR MIBI, 95.2%, 89.4% and 92.5% for RI MIBI, 85.7%, 47.3% and 67.5% for ER Tl-201 , 80.9%, 73.6% and 77.5% for DR Tl-201, and 90.5%, 4.7% and 92.5% for RI Tl-201. In conclusion, the DR for MIBI and Tl-201 is superior to the ER in detecting malignant nodules, and the RI for both MIBI and Tl-201 is more valuable than the DR in differentiating malignant from benign thyroid nodules.