RESUMO
The objective of this study was to evaluate the performance and utility of 99mTc HYNIC-TOC planar scintigraphy and SPECT/CT in the diagnosis, staging and management of gastroenteropancreatic neuroendocrine tumors [GPNETs]. 22 patients [median age, 46 years] with histologically proven gastroentero-pancreatic NETs underwent 99mTc HYNIC-TOC whole body scintigraphy and regional SPECT/CT as indicated. Scanning was performed after injection of 370-550 MBq [10-15 mCi] of 99mTc HYNIC-TOC intravenously. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as semi quantitatively [tumor to tumor to normal liver ratios on SPECT -CT images]. Results of SPECT/CT were compared with the results of conventional imaging. Histopathology results and follow-up somatostatin receptor scintigraphy with 99mTc HYNIC TOC or conventional imaging with biochemical markers were considered to be the reference standards. 99mTc HYNIC TOC showed sensitivity and specificity of 87.5% and 85.7%, respectively, for primary tumor and 100% and 86% for metastases. It was better than conventional imaging modalities for the detection of both primary tumor [P<0.001] and metastases [P<0.0001]. It changed the management strategy in 6 patients [31.8%] and supported management decisions in 8 patients [36.3%].99mTc HYNIC TOC SPECT/CT appears to be a highly sensitive and specific modality for the detection and staging of GPNETs. It is better than conventional imaging for the evaluation of GPNETs and can have a significant impact on patient management and planning further therapeutic options