68Ga-DOTATATE PET/CT in recurrent medullary thyroid carcinoma: a lesion-by-lesion comparison with 111In-octreotide SPECT/CT and conventional imaging

• Published in: European journal of nuclear medicine and molecular imaging Vol. 44; no. 10; pp. 1695 - 1701
• Main Authors: Yamaga, Lilian Yuri Itaya, Cunha, Marcelo L., Campos Neto, Guilherme C., Garcia, Marcio R. T., Yang, Ji H., Camacho, Cleber P., Wagner, Jairo, Funari, Marcelo B. G.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2017
• Subjects: Cardiology; Imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Oncology; Original Article; Orthopedics; Radiology; In-octreotide; Positron emission tomography; Medullary thyroid carcinoma; Ga-DOTATATE
• ISSN: 1619-7070; 1619-7089
• DOI: 10.1007/s00259-017-3701-9

Purpose The aim of this study was to prospectively compare the detection rate of 68 Ga-DOTATATE PET-CT with 111 In-octreotide SPECT-CT and conventional imaging (CI) in medullary thyroid carcinoma (MTC) patients with increased calcitonin (Ctn) levels but negative CI after thyroidectomy. Methods Fifteen patients with raised Ctn levels and/or CI evidence of recurrence underwent 68 Ga-DOTATATE PET-CT, 111 In-octreotide SPECT-CT and CI. Histopathology, CI and biochemical/clinical/imaging follow-up were used as the reference standard. PET/CT, SPECT/CT and CI were compared in a lesion-based and organ-based analysis. Results PET/CT evidenced recurrence in 14 of 15 patients. There were 13 true positive (TP), 1 true negative (TN), 1 false positive (FP) and no false negative (FN) cases, resulting in a sensitivity and accuracy of 100% and 93%. SPECT/CT was positive in 6 of 15 cases. There were 6 TP, 2 TN, 7 FN and no FP cases, resulting in a sensitivity of 46% and accuracy of 53%. CI procedures detected tumor lesions in 14 of 15 patients. There were 13 TP, 1TN, 1 FP and no FN cases with a sensitivity of 100% and accuracy of 93%. A significantly higher number of lesions was detected by PET/CT (112 lesions, p  = 0.005) and CI (109 lesions, p  = 0.005) in comparison to SPECT/CT (16 lesions). There was no significant difference between PET/CT and CI for the total number of detected lesions ( p  = 0.734). PET/CT detected more lesions than SPECT/CT regardless of the organ. PET/CT detected more bone lesions but missed some neck nodal metastases evidenced by CI. The number of lesions per region demonstrated by PET/CT and CI were similar in the other sites. Conclusion 68 Ga-DOTATATE PET/CT is superior to 111 In-octreotide SPECT/CT for the detection of recurrent MTC demonstrating a significantly higher number of lesions. 68 Ga-DOTATATE PET/CT showed a superior detection rate compared to CI in demonstrating bone metastases.