Somatostatin receptors in meningiomas: Diagnostic and therapeutic value

Objective. We discuss the diagnostic and therapeutic usefulness of the presence of somatostatin receptors (SR) in meningiomas. Development. The SR are membrane receptors, may be saturated, have great affinity and pharmacological specificity for somatostatin (SS) and its analogues. SR have been found in 100% of the meningiomas studied. The presence of a large number of Sr in different tumours permits gammagraphic detection in vivo by marking SS analogues with 1-231-DTPA and subsequent visualization using a gamma camera. This study may help to differentiate between meningiomias and other tumour lines. Experiments using different SS analogues have shown different degrees of affinity of these SS analogues for the different receptors. In various animal models a potent inhibitor effect on tumour growth has been seen following SS and its analogues. Unlike in hypophyseal adenomas and endocrine gastro-entero-pancreatic tumours, neither SS nor its analogues have shown any direct inhibitory action on the growth of maningioma cell cultures. Quite the opposite occurs. A small but significant stimulation of growth was seen in the presence of SS. Conclusions. We consider the detection of SR by isotopic marking of SS analogues is useful in the differential diagnosis of meningiomas. The therapeutic usefulness of the analogues of SS for treatment of meningiomas remains controversial. Further study of the different types of receptors and analogues is necessary.