Clinical application of 99Tcm-HL91 hypoxic imaging in differential diagnoses of malignancy from benign thyroid nodules

Objective Recent studies showed that99Tcm-4,9-diaza-3,3,10,10-tetramethyldodecan-2.11-dizone dioxime(HL91)might be of potential in characterizing hypoxic areas within malignant tumors.The aims of this study were to use99Tcm-HL91 in patients with thyroid nodules and also to explore its clinical utilities in differentiate benign and malignant thyroid nodules.Methods Fifry-eight patients with thyroid nodules.detected either by ultrasound or physical palpation.were enrolled.99Tcm-HL91 planar thyroid images were performed at early(10 min after iniection)and delay(4 h after injection)phases.The radioactivity ratio of tumor to non-tumor(T/N)was calculated and compared with the pathological results.The t test and χ2 test were used for data analysis.Results Of the 58 patients,21 were thyroid cancer and 37 were benign nodules.The sensitivity.specificity and accuracy of99Tcm-HL91 for thyroid cancer were 85.7%.94.6%and 91.4%respectively.Moreover.the sensitivity was positively correlated with the tumor size and was unrelated to the histological types(χ2=0.778,P＞0.05).A significant higher uptake of 99Tcm-HL91 in malignant nodule was noted than benign at delay phase(1.25±0.03 vs 0.91 ±0.12.t=3.885.P＜0.001).Conclusion 99Tcm-HL91 hypoxic imaging has potential in both detecting and differentiating malignancy from benign thyroid nodules,especially when delay phase was applied. Key words: Thyroid nodule;  Diagnosis,differential;  Radionuclide imaging;  HL91