RT Journal Article
SR Electronic
T1 High Level of Agreement Between Pretherapeutic <sup>124</sup>I PET and Intratherapeutic <sup>131</sup>I Imaging in Detecting Iodine-Positive Thyroid Cancer Metastases
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1339
OP 1342
DO 10.2967/jnumed.115.169649
VO 57
IS 9
A1 Marcus Ruhlmann
A1 Walter Jentzen
A1 Verena Ruhlmann
A1 Cinzia Pettinato
A1 Gloria Rossi
A1 Ina Binse
A1 Andreas Bockisch
A1 Sandra Rosenbaum-Krumme
YR 2016
UL http://jnm.snmjournals.org/content/57/9/1339.abstract
AB The aim of this retrospective study was to assess the level of agreement between PET and scintigraphy using diagnostic amounts of 124I and therapeutic amounts of 131I, respectively, in detecting iodine-positive metastases in patients with differentiated thyroid carcinoma. Methods: The study included patients who underwent PET/CT 24 and 120 h after administration of approximately 25 MBq of 124I and subsequently underwent imaging 5–10 d after administration of 1–10 GBq of 131I. For each patient, the intratherapeutic 131I imaging comprised a whole-body scintigraphy scan and a SPECT/CT scan of the neck to distinguish between metastatic and thyroid remnant tissues. Iodine uptake was rated as a metastatic focus if located outside the thyroid bed. Lesion- and patient-based analyses were performed. Results: The study included 137 patients with 227 metastases iodine-positive on both functional imaging modalities. In the lesion-based analysis, 124I PET and 131I imaging detected 98% (223/227) and 99% (225/227) of the iodine-positive metastases, respectively; the level of agreement between 124I PET and 131I imaging was 97% (221/227). Four metastases (3 lymph node and 1 bone) in 4 patients were 124I-negative but 131I-positive, and 2 lymph node metastases in 2 patients were 131I-negative but 124I-positive. In the patient-based analysis, 61 of the 137 patients presented with iodine-positive metastases. 124I PET and 131I imaging detected at least one iodine-positive metastasis in 97% (59/61) and 98% (60/61) of the patients, respectively. The level of agreement was 95% (58/61). Both imaging modalities concordantly identified 76 of 137 patients without pathologic iodine uptake. Conclusion: Because of the high level of agreement, pretherapeutic 124I PET/CT is an adequate methodology in the detection of iodine-positive metastases and can be used as a reliable tool for staging of thyroid cancer patients and individualized treatment planning.