Serum and Cerebrospinal Fluid Human Chorionic Gonadotropin (hCG) and alpha-fetoprotein (AFP) in Intracranial Germ Cell Tumors

We report a retrospective study on serum and cerebrospinal fluid (CSF) alpha-fetoprotein (AFP) and β-human chorionic gonadotropin (βhCG) determination in a series of 30 patients bearing intracranial germ cell tumors. At diagnosis five patients had high serum and CSF AFP levels. No patient had positive serum AFP and negative CSF AFP or vice versa. Twelve of 30 patients had serum βhCG levels above 5 mIU/mL, eight had high βhCG only in CSF, and ten were completely negative. During treatment and follow-up both markers were accurate indicators of the response to therapy, decreasing rapidly and often becoming normal already after the first phase of treatment. We conclude that these two markers, and mostly βhCG, may be useful in the diagnosis and monitoring of the response to therapy of patients with intracranial germ cell tumors.

Neuron-specific enolase evaluation in patients with neuroblastoma

Neuron-specific enolase (NSE) may be of interest for the prognostic evaluation and follow-up surveillance in patients with neuroblastoma. We evaluated NSE levels in 80 patients with neuroblastoma. The marker correlated with stage (in stage 1 patients, the median NSE level was 9.9 ng/ml, in stage 2, 45.1 ng/ml, in stage 3, 49 ng/ml, in stage 4, 93.9 ng/ml, in stage 4S, 53.4 ng/ml) and with survival. In patients with a favorable or a poor outcome, the difference in basal NSE serum levels was statistically significant (p = 0.0001). Serial measurements revealed that there was a good correlation between NSE levels and disease course. We concluded that NSE is a good marker for neuroblastoma and its quantitative determination in serum is valuable in the management of these patients to confirm the diagnosis, monitor the effect of treatment and detect recurrent disease.

The breast cancer cell line MCF7 as a model of 99mTc-SestaMIBI, 99mTc-tetrofosmin and 99mTc-Medronate incorporation

Hexakis-2-methoxyisobutylisonitrile (SestaMIBI) and 1,2-bis[bis(2-ethoxyethyl)phosphino]ethane (tetrofosmin) are 99mtechnetium compounds widely used in oncologic imaging. We investigated the uptake and release of SestaMIBI and tetrofosmin together with 99mTc-medronate in the MCF7 breast carcinoma cell line. All the tracers showed similar uptake kinetics, with a rapid increase in the first 30 minutes and a slower trend up to 120 minutes. Cell-associated activity was the same for SestaMIBI and tetrofosmin (4% of administered activity) and considerably lower for medronate (0.8%). For all tracers, almost all the accumulated activity was released within 1 hour. Furthermore, to verify an association between cell proliferation and tracer uptake, we performed growth-curve uptake experiments. Tetrofosmin uptake was lower in the logarithmic phase and higher in the plateau phase, whilst SestaMIBI showed the opposite trend. The differences between the tracers could be due to a relationship between proliferation and SestaMIBI uptake, or even to the influence of medium pH on membrane potential.

Breast cancer seeking agents: basic approach

The knowledge of biochemical and physiological mechanisms involved in tissue localization is important so as to understand the information given by diagnostic nuclear medicine imaging, and eventually to design new radiopharmaceuticals. The cellular mechanisms which permit a high cancer uptake involve the perfusion and metabolism around the tumour tissue, the interference with normal function, the altered perfusion and/or metabolism within the tumour. All these phenomena can contribute to a high concentration of particular radiotracers in cancer and can create a favourable tumour/background ratio uptake sufficient for cancer imaging. Those molecules might be also powerful tools for reaching an advanced understanding of neoplastic and even "normal" cell biology. During these last years, some radiotracer specifically designed for different applications proved to be promising radiopharmaceuticals for breast cancer imaging. This is the case of monoclonal antibodies (Mabs) developed in the past against membrane cancer antigens. Other tracers, originally proposed for the study of vascular perfusion (cardiovascular tracers), have also revealed a capacity to be taken up by cancer cells. The radiopharmaceuticals mostly used as tumour seeking agents today (Radiothallium, Sestamibi, Tetrophosmin) were generated with other applications in mind. In this paper we review the mechanisms of uptake of the most relevant agents currently proposed for breast cancer imaging, including 18F-fluorodeoxyglucose (FDG). The radiotracers will be examined on the basis of the available scientific evidence regarding their cellular uptake and release. Moreover, we report our preliminary studies on the cellular uptake and release of these and other compounds recently introduced in clinical trials.