Detection of suspected primary lung cancer by scintigraphy with indium-111-anti-carcinoembryonic antigen monoclonal antibodies (type F023C5)

Immunoscintigraphy with 111In-labeled anti-CEA-Mab (F023C5i) was carried out in 66 patients strongly suspected for a primary lung cancer and in 8 control patients suffering from different chest diseases. A sensitivity of 0.90, a specificity of 0.45 and an accuracy of 0.85 were calculated. False-negative results were mainly obtained in patients in whom the size of the lesion was below 2 cm and the tumor was centrally located. All patients affected by small-cell carcinoma were correctly identified. In 89% of the patients, a positive immunoscintiscan was associated with the presence of the antigen in the tumor. False-positive results were observed in control patients suffering from different chest diseases due to the nonspecific uptake of the tracer. The tumor definition was generally better after 120 hr than at an earlier time after injection due to the reduction of background activity. SPECT imaging defined the tumor better in each patient but did not reveal any tumor not seen on planar studies.

Estimation of glomerular filtration rate using chromium-51 ethylene diamine tetra-acetic acid and technetium-99m diethylene triamine penta-acetic acid.

Simultaneous measurements of the clearance rate of chromium-51 ethylene diamine tetra-acetic acid (51Cr-EDTA) and technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) were performed in 54 patients with a range of function between 9 and 176 ml/min. Using multiple blood samples the two clearance values correlated well (r = 0.97, SEE 8.6 ml/min) and DTPA clearance was higher by 2.9%. For each radiopharmaceutical the plasma clearance rates obtained using multiple blood samples were compared with those obtained with simplified methods, i.e., the 60-180 min two-sample method of Russell and the mono-exponential method with the Brochner-Mortensen correction. For both radiopharmaceuticals the clearance values correlated well with the Russell method (r = 0.99, SEE = 4.1 ml/min for EDTA; r = 0.99, SEE 4.9 ml/min for DTPA) and the mono-exponential method (r = 0.99, SEE 3.6 ml/min for EDTA; r = 0.99, SEE 3.9 ml/min for DTPA). The mean plasma clearance obtained using multiple blood samples did not differ significantly from that obtained with the Russell method, either in patients with a glomerular filtration rate (GFR) < 30 ml/min or in patients with GFR > or = 30 ml/min. The mean plasma clearance obtained using multiple blood samples differed significantly from that obtained with the mono-exponential method because of the great difference observed in patients with GFR > or = 30 ml/min. It is concluded that the Russell two-sample method after injection of 99mTc-DTPA is accurate enough for routine clinical use.