The
somatostatin analogue [111In-
DTPA-d-Phe1]-
octreotide (111In-octreotide) allows scintigraphic visualization of
somatostatin receptor-expressing tissue. While it is well known that a large variety of tissues express
somatostatin receptors and
111In-octreotide scintigraphy has a clearly defined role in various neuroendocrine diseases, the clinical value of
111In-octreotide scintigraphy in brain tumours is still under clinical investigation. In 124 patients with 141 brain lesions (63
meningiomas, 24
pituitary adenomas, 10
gliomas WHO class I and II, 12
gliomas WHO class III and IV, 11
neurinomas and 2
neurofibromas, 7
metastases and 12 other varieties: three non-Hodgkin
B-cell lymphomas, two epidermoids, one
abscess, one
angioleiomyoma, one
chordoma, one haemangiopericytoma, one
osteosarcoma, one
plasmacytoma and one pseudocyst),
111In-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 110-220 MBq
111In-octreotide. Planar images of the head in four views with a 128x128 matrix and single-photon emission tomographic images (64x64 matrix) were acquired, and lesions were graded according to qualitative tracer uptake. Fifty-nine of the 63
meningiomas showed moderate to intense tracer uptake. Nine of 24
pituitary adenomas were visible; the remaining 15 did not show any tracer uptake. None of the class I and II
gliomas with an intact blood-brain barrier were detected whereas 11/12 class III and IV
gliomas showed
111In-octreotide uptake. None of the
neurinomas or
neurofibromas were positive. Five of seven
metastases were classified as positive, as were the
osteosarcoma, two of three non-Hodgkin
B-cell lymphomas, one
abscess, one
angioleiomyoma, one
chordoma and one haemangiopericytoma. The other varieties (one non-Hodgkin
B-cell lymphoma, two epidermoids, one
plasmacytoma and one pseudocyst) did not show
111In-octreotide uptake. The results demonstrate that a large variety of intracranial lesions express
somatostatin receptors and therefore can be visualized by [111In-
DTPA-d-Phe1]-
octreotide scintigraphy. This technique can be valuable in the differentiation between
meningiomas and
pituitary adenomas, based on qualitative tracer uptake. [111In-
DTPA-d-Phe1]-
octreotide scintigraphy allows differentiation between
meningiomas and
neurinomas or
neurofibromas and therefore provides complementary information to computed tomography or magnetic resonance imaging. Furthermore, this technique allows differentiation between
scar tissue and recurrent
meningiomas postoperatively and can help in non-invasive tumour differentiation of multiple intracranial lesions, which can be of value in defining the most adequate therapeutic strategy.