Archives of Medical Science (Mar 2021)

Diagnostic and prognostic value of 99m Tc-Tektrotyd scintigraphy and 18 F-FDG PET/CT in a single-center cohort of neuroendocrine tumors

  • Jelena Saponjski,
  • Djuro Macut,
  • Nebojsa Petrovic,
  • Sanja Ognjanovic,
  • Bojana Popovic,
  • Zoran Bukumiric,
  • Dragana Sobić Saranović

DOI
https://doi.org/10.5114/aoms/130996
Journal volume & issue
Vol. 19, no. 6
pp. 1753 – 1759

Abstract

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Introduction The aim was to assess the diagnostic value of 99m Tc-Tektrotyd scintigraphy (TCT) and positron emission tomography/computed tomo­graphy using F-18 fluorodeoxyglucose ( 18 F-FDG PET/CT) in the detection and follow-up of neuroendocrine tumors (NETs), and their predictive value for disease progression. Material and methods In this retrospective cohort, TCT and 18 F-FDG PET/CT were performed in 90 patients (37 men, 53 women, mean age 52.7 ±15.1), with NET. Correlation of Ki67 and tumor grade versus Krenning score and SUV max was assessed, Kaplan-Meier analysis was used for progression-free survival (PFS), and Cox regression analysis was performed to identify the association between progression-related factors and PFS. Results Out of 90, true positive TCT was detected in 56 (62.2%) patients, true negative in 19 (21.1%), false positive in 4 (4.4%), false negative in 11 (12.2%), while 18 F-FDG PET/CT was true positive in 69 (76.7%) patients, true negative in 10 (11.1%), false positive in 5 (5.5%), false negative in 6 (6.7%). Mean 18 F-FDG PET/CT SUVmax was 6.8 ±6.2. Diagnostic sensitivity of TCT was 83.6%, specificity 82.6%, accuracy 83.3% vs. 18 F-FDG PET/CT sensitivity was 92.0%, specificity 66.7%, accuracy 87.8%. A significant correlation between Ki67 and SUV max was found in positive 18 F-FDG PET/CT findings, unlike the correlation between Ki67 and Krenning score. Median PFS was 25 months (95% CI: 18.2–31.8), in 18 F-FDG PET/CT positive patients 23 months (95% CI: 16.3–29.7) and 18 F-FDG PET/CT negative 26 months (p = 0.279). Progression-free survival predictors were SUV max and Krenning score. Conclusions In our study, TCT and 18 F-FDG PET/CT have high diagnostic accuracy in detection of NET. Higher Krenning score on TCT and SUV max in posi­tive 18 F-FDG PET/CT findings are predictors of disease progression. 99m Tc-Tektrotyd scintigraphy and 18 F-FDG PET/CT can be useful complementary tools in management of patients with NETs and in predicting patients’ outcome.

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