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A ten-year experience on 36 patients bearing macroprolactinomas (MP) and 86 others bearing microprolactinomas (mP) is reported in this study. Different therapeutical approaches were used: 1) trans-sphenoidal surgery in 24 patients with MP and in 25 with mP; 2) medical therapy with the oral form of bromocriptine (BRC) in all the 24 patients with MP previously subjected to surgery, in 48 patients with mP ab initio, and in 16 out of 25 patients with mP previously subjected to surgery; 3) medical therapy with the long-acting injectable forms of BRC in 12 MP- and 13 mP-bearing patients, and 4) conventional radiotherapy in 12 of the 24 patients with MP previously subjected to surgery. The follow-up, performed five years after surgery, showed that: a) all the 24 patients with MP but one had normal PRL levels during BRC administration, with a rebound of hyperprolactinemia in all cases after withdrawal; b) during the treatment BRC caused normalization of PRL in 15 of the 16 mP-bearing patients surgically treated and in all the 48 mP-bearing patients only treated with BRC; c) in 20 of the 25 patients the treatment with injectable retard BRC caused the normalization of plasma PRL and the shrinkage of the tumor mass in all the patients with MP but one, as revealed by seriate CT scans. In conclusion, the surgical treatment of prolactinomas was ineffective to normalize plasma PRL levels in most patients whereas BRC, in standard or in retard forms, was able to normalize plasma PRL levels, reduce the tumoral mass and preserve the pituitary residual tissue. BRC should be, therefore, used as first choice therapy both for MP and mP.

The authors have analysed the theoretical and clinical implications of a biological approach to radioimmu-noscintigraphy (RIS), a new diagnostic technique based on the in vivo reaction between radiolabelled monoclonal antibodies and tumor-associated antigens expressed by the neoplastic cells. The assumption is that, as in all radioisotopic procedures, the radioimmunoscintigraphic image is the expression of differences in concentration (and not in density) between adjacent tissues. This “biological premise” is analysed to demonstrate a possible role of RIS not only in diagnosis but also in prognosis and therapy. A comparison with other imaging procedures and with histopathology, considered as the “gold stand-ard” of the present-day morphological approach to diagnosis, is also discussed. Finally, biological premises, as well as the initial results and prospects regarding the use of high doses of radiolabelled monoclonal antibodies for therapeutic purposes are presented.

Fifteen patients with medullary carcinoma of the thyroid (MCT), who had persistently elevated levels of serum calcitonin (CT) and carcinoembryonic antigen (CEA) after total thyroidectomy, were studied in order to localize the sites of the recurrent disease. Routine diagnostic examinations, including ultrasonography (US) and computed axial tomography (CAT), were carried out in all the cases. Scintigraphy with radio-iodinated meta-iodobenzylguanidine ((131I)-MIBG) was performed in 13 cases; selective venous catheterization (SVC) to reveal a gradient of CT levels was performed in 12 cases. Ten patients underwent both (l31I)-MIBG scintigraphy and SVC. US and CAT revealed the sites of recurrent tumor in only 4 out of the total 15 patients. SVC in basal conditions showed the presence of small metastases in 2 cases, and after intravenous stimulus with pentagastrin in 4 others. The MIBG scan showed metastatic foci of sporadic MCT in 2 patients, residual medullary thyroid tissue in 4 others, and a pheochromocytoma in a previously undiagnosed patient with Sipple’s syndrome. More particularly, MIBG scan and SVC showed the localization of residual or metastatic tumor in 10 cases. In all 10 cases, results of the MIBG scan and SVC were confirmed as true positive by subsequent surgery and histopathologic examination. The conclusions of this study were twofold: (1) in the follow-up of MCT patients with persistently elevated CT and CEA levels, positive US and CAT findings make the MIBG scan useful, if positive, only to determine the nature of the lesion; (2) the association of the two approaches (MIBG scan and SVC) in patients with increased levels of CT and CEA but negative results of routine diagnostic examination can be useful to detect occult rnicrometastases, thus permitting an accurate clinicopathologic staging of the disease.

Twenty patients with known ovarian cancer have been investigated in this pilot study to verify the clinical usefulness of radioimaging using the B72.3 monoclonal antibody labelled with iodine-131. No adverse reactions occurred after intravenous injection of B72.3 MoAb. The radioimaging results were compared with those obtained with other diagnostic methods, including computed X-ray tomography and ultrasound. A sensitivity of 85% in the detection of primary ovarian cancers and collections of ascites, and of 84% in the detection of abdominal and extraperitoneal metastases has been demonstrated using this radioiodinated antibody in vivo. No false localization occurred. Immunohistochemical studies showed no cross-reactions between B72.3 MoAb and mesothelial cells, confirming the high specificity of binding between B72.3 MoAb and neoplastic cells in ascites. Negligible uptake of radiolabelled B72.3 MoAb has been demonstrated in the unaffected ovary. The major advantage of using this monoclonal antibody is related to the expression of a recognized antigen (called TAG 72) in mucinous, serous and in differentiated adenocarcinomas of the ovary.

Peptichemio, a peptide complex of m-[di-(2-chloroethyl)-amino]L-phenylalanine was submitted for clinical assessment in 120 patients, with hemoblastoses and solid tumours. A good antitumour effect was observed, especially in malignant lymphomas and some types of solid tumours. The tolerability was good on the whole.