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

• Published in: European journal of nuclear medicine and molecular imaging Vol. 44; no. 10; p. 1695
• 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: Germany 01-09-2017
• Subjects: Adult; Aged; Carcinoma, Neuroendocrine - drug therapy; Female; Humans; Male; Middle Aged; Octreotide - analogs & derivatives; Organometallic Compounds; Recurrence; Single Photon Emission Computed Tomography Computed Tomography - methods; Thyroid Neoplasms - drug therapy; Young Adult; 68Ga-DOTATATE; 111In-octreotide; Positron emission tomography; Medullary thyroid carcinoma
• ISSN: 1619-7089

The aim of this study was to prospectively compare the detection rate of
Ga-DOTATATE PET-CT with
In-octreotide SPECT-CT and conventional imaging (CI) in medullary thyroid carcinoma (MTC) patients with increased calcitonin (Ctn) levels but negative CI after thyroidectomy.
Fifteen patients with raised Ctn levels and/or CI evidence of recurrence underwent
Ga-DOTATATE PET-CT,
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.
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.
Ga-DOTATATE PET/CT is superior to
In-octreotide SPECT/CT for the detection of recurrent MTC demonstrating a significantly higher number of lesions.
Ga-DOTATATE PET/CT showed a superior detection rate compared to CI in demonstrating bone metastases.