(99m)Tc-EDDA/HYNIC-TOC is a New Opportunity in Neuroendocrine Tumors of the Lung (and in other Malignant and Benign Pulmonary Diseases)

Neuroendocrine tumors (NETs) consist of a relatively rare spectrum of malignancies that can arise from neuroendocrine cells; lung NETs (L-NETs) represent about 25% of primary lung neoplasm and 10% of all carcinoid tumors. Diagnostic algorithm usually takes into consideration chest X-ray, contrast-enhanced CT and MRI. Nuclear medicine plays a crucial role in the detection and correct assessment of neoplastic functional status as it provides in vivo metabolic data related to the over-expression of Somatostatin Receptors (SSTRs) and also predicting response to peptide receptor radionuclide therapy (PRRT). (111)In-Pentreotide (Octreoscan(®)) is commercially available for imaging of neuroendocrine tumors, their metastases and the management of patients with NETs. More recently, (99m)Tc-EDDA/HYNIC-TOC(Tektrotyd(®)) was introduced into the market and its use has been approved for imaging of patients with L-NETs and other SSTR-positive tumors. (99m)Tc-EDDA/HYNIC-TOC could also represent a good alternative to (68)Ga-DOTA-peptides (DOTA-TOC, DOTA-NOC, DOTA-TATE) in hospitals or centers where PET/CT or (68)Ge/(68)Ga generators are not available. When compared to (111)In-Pentetreotide, Tektrotyd(®) showed slightly higher sensitivity, in the presence of higher imaging quality and lower radiation exposure for patients. Interesting perspectives depending on the kinetic analysis allowed by Tektrotyd(®) may be obtained in differential diagnosis of non-small cells lung cancer (NSCLC) versus small cells lung cancer (SCLC) and NETs. An interesting perspective could be also associated with a surgery radio-guided by Tektrotyd(®) in operable lung tumors, including either NETs and NSCLC.