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Nuclear medicine is potentially of great value in assessing renal function. Due to the many simple methods which have been proposed and new developments in renal radiopharmaceuticals and computer software, quick, reliable and precise answers to questions from clinicians are possible. Depending on the needs and infrastructure of each clinic, and due to specific renal radiopharmaceuticals combined with the simplicity of radioactivity measurements, plasma clearance can be obtained from one or two plasma samples within 45 minutes with good accuracy. More widely used methods require the gamma camera, which gives the same functional results but, besides the global function, split renal function is obtainable. Today we have radiopharmaceuticals which are well validated. They measure functional parameters such as glomerular filtration rate (GFR) and the effective renal plasma flow (ERPF). Others can be used to give morphological information. The recently developed drugs can be labeled with Tc-99m, work-horse of the nuclear medicine physician. This radionuclide combines optimal physical properties (ideal gamma energy [140 keV]), no beta emission, short half life (6 h) and consequent low radiation dose to the patient) with low cost and permanent availability. Of the many agents cleared by GFR, two are mainly used in the clinic (chromium-51-EDTA and Tc-99m-DTPA). The first agent is very reliable due to its radiochemical and biological properties, but only the latter can be used when imaging is required. Two agents which are actively secreted by the renal tubules are available for the estimation of ERPF: radioiodinated ortho-iodohippurate (OIH) as radioactively labeled analog of the classic agent para-aminohippurate (PAH), and the new drug Tc-99m-mercaptoacetyltriglycine (MAG3).(ABSTRACT TRUNCATED AT 250 WORDS)

A new tumour marker, mucin-like carcinoma-associated antigen (MCA), was evaluated in 176 breast cancer patients classified either as free of tumour (NED, n = 141) or as having metastases (PD, n = 35). During the 5 year follow-up, 842 measurements of MCA and 363 measurements of CA 15-3 were done. MCA levels were significantly increased in the PD group (P = 0.0001) but not in the NED group. The sensitivities of the MCA and the CA 15-3 assays were 84% and 78% and the specificities were 81% and 78%, respectively. The negative predictive value of 97% for MCA was significantly higher (P = 0.0001) than the 88% for CA 15-3. Thus the MCA enzyme immunoassay is at least equivalent to the CA 15-3 test and is recommended in the assessment of metastatic spread or tumour recurrence in breast cancer patients.

A new tumor marker, mucin-like carcinoma-associated antigen (MCA), was evaluated in thirty-four patients with renal cell carcinomas and forty patients with carcinomas of the urinary collecting system. In the first group, specificity was 95%, sensitivity 65%, the predictive value for positive diagnosis was 94%, and for negative diagnosis 72%. In the second group specificity was 83%, sensitivity 71%, predictive value for positive diagnosis was 63%, and for negative diagnosis 88%. Receiver operating characteristic curves indicated that the maximum amount of information was greater in patients of the first group than the second (0.379 vs. 0.332 bits). In the light of these data, the MCA test can be recommended for assessing metastatic spread in patients particularly with renal cell carcinomas.