Long-Acting Somatostatin Analog Therapy Differentially Alters68Ga-DOTATATE Uptake in Normal Tissues Compared with Primary Tumors and Metastatic Lesions

• DOI: 10.2967/jnumed.117.192203
• Publication Date: 2017-07-21T00:20:13Z
• Authors: Narjess Ayati; Sze Ting Lee; Rasoul Zakavi; Kunthi Pathmaraj; Louai Al-Qatawna; Aurora Poon; Andrew M. Scott
• Keywords: Radionuclide therapy

Synthetic somatostatin analogs have been posed as a potential source of error in receptor imaging through interference with tumor detection; however, experimental models and clinical studies shown complex mechanism the effect octreotide on tumors. The aim this study was to assess whether ⁶⁸Ga-DOTATATE uptake before treatment long-acting differs from that after treatment. <b>Methods:</b> Thirty patients (15 men; age [mean ± SD], 64.6 13.4 y) who had intermediately differentiated well-differentiated neuroendocrine tumors underwent PET/CT scanning receiving repeatable (Sandostatin LAR) were included study. SUV_max SUV_mean healthy target organs, residual primary tumor, up 5 lesions highest each organ compared <b>Results:</b> mean time interval between 2 9.6 7.2 mo, gap last Sandostatin LAR injection second 25.1 14.8 d. pretreatment both significantly higher thyroid, liver, spleen (<i>P</i> &lt; 0.05) than values measured administration LAR. No significant differences found among indices for or any metastatic bone, lung, lymph nodes &gt; 0.05). <b>Conclusion:</b> Long-acting diminished spleen, thyroid but did not compromise tracer lesions. These findings direct impact interpretation scans.