Lung carcinoma is one of the most common neoplasms, both in men and women. Many methods are employed within diagnostics approaches in oncology, among them are radiological, endoscopic, cytological and isotopic ones. Synthetic proteins labelled with gallium (Ga67), indium (In111) or technetium (Tc99) binding with receptors localised on cells surface enable scintigraphic determination of intensive uptake sites. The aim of the study was to asses clinical usefulness of technetium99 labelled synthetic somatostatin analogue (depreotide) in the diagnosis of solitary pulmonary nodules. Thirty one patients (19 men and 12 women) with isolated peripheral pulmonary lesions in chest X-ray examination were included into the study. All patients received intravenous infusion of synthetic protein compound, trifluorodepreotide acetate labelled with technetium99, with radio activity of 555-740 MBq (mega Becquerel) [Neospect--Nycomed Amersham, UK]. Radiopharmaceutical uptake was determined by two-head gamma camera according SPECT method (single photon emission computed tomography) after 3-4 hours after an injection. Intensive radiopharmaceutical uptake by abnormal lesions was found in 22 patients (71%), however in 9 (29%) it was not found in the sites of radiological changes. Among 22 patients with intensive uptake, in 17 (77%) patients a diagnosis of carcinoma was confirmed and in 5 patients benign lesions were diagnosed. In the group of 5 patients without marker uptake single case of carcinoma was found and in 4 benign lesions. Four patients refused further invasive diagnostic procedures. The sensitivity of this method was 94% with a specificity of 44%. No serious adverse clinical reactions associated with 99Tc depreotide were observed.
Conclusions: 1. Technetium99 labelled synthetic somatostatin analogue [(depreotide) (NeoSpect)] is safe in pulmonological and oncological clinical diagnostics. 2. The use of this compound is a valuable scintigraphic, supplementary method to qualify patients for further invasive diagnosis of peripheral pulmonary solitary nodules.