[Detection of the cutaneous melanomas, their metastasis and relapses by scintigraphies with 99MTC-HMPAO]

A pilot study was carried out in the Nuclear Medicine Department of the National Institute of Oncology and Radiobiology to learn the diagnostic efficacy of the 99mTc-HMPAO scintigraphy in the detection of cutaneous melanoma, distant and local metastases, in patients with a confirmed histological diagnosis. The planar and/or SPECT scintigraphy was performed in 17 patients and revealed 90% sensitivity for the detection of the disease. We calculated the tumor/background index in all the images obtained and found a value greater than 1 in every case. Thus, we can affirm that the 99mTc-HMPAO accumulation in tumors was higher than the background in all cases. We recommend that this procedure be considered in the follow up of these patients as a new diagnostic method which is very useful in the determination of the patient stage and prognostic evaluation.

Lack of perfusion enhancement after administration of nicotinamide and carbogen in patients with glioblastoma: a 99mTc-HMPAO SPECT study

BACKGROUND

Nicotinamide (NAM) and carbogen both have been shown to enhance the radiation effect in rodent tumour models and are currently being tested in clinical trials. These agents have demonstrated to act against hypoxia and one of their underlying mechanisms could be an increase of tumour blood perfusion.

PURPOSE

To analyse the effect of both agents on normal brain perfusion and tumour perfusion in patients with glioblastoma.

MATERIALS AND METHODS

Nineteen patients with glioblastoma were studied with 99mtechnetium-hexamethylpropyleneamine oxime single photon emission computed tomography (99mTc-HMPAO SPECT) before and after administration of carbogen and/or NAM. Another six patients were studied with the same procedure but without any flow modulator and were used as controls.

RESULTS

Although the variations between patients were large, no significant enhancement in mean tumour and normal brain perfusion could be demonstrated with NAM or carbogen compared to the control patients. Also no consistent changes in the mean perfusion ratio between tumour and surrounding normal brain were found, suggesting an absence of a selective perfusion effect.

CONCLUSIONS

No significant influence of carbogen and/or NAM on tumour perfusion and normal brain perfusion could be detected with SPECT in patients with glioblastoma.

Brain blood flow in anxiety disorders. OCD, panic disorder with agoraphobia, and post-traumatic stress disorder on 99mTcHMPAO single photon emission tomography (SPET)

BACKGROUND

We compared regional cerebral blood flow (rCBF) in three groups of patients with DSM-III-R anxiety disorders.

METHOD

Fifteen patients with obsessive -compulsive disorder (OCD), 15 with panic disorder with agoraphobia (PA), and 16 with post-traumatic stress disorder (PTSD) and a similar group of healthy controls were assessed on brain-dedicated high-resolution SPET.

RESULTS

MANOVA revealed significant rCBF differences between diagnostic groups (F = 4.4; d.f. = 3, 57; P = 0.007) and between cerebral regions (F = 6.4; d.f. = 1, 57; P = 0.01) in OCD and PTSD compared with PA and healthy controls, limited to bilateral superior frontal cortices and right caudate nuclei. Whole brain blood flow correlated positively with anxiety (r = 0.24, n = 46, P = 0.05). Beck depression scores correlated significantly negatively with left caudate rCBF (r = -0.24, n = 46, P = 0.05) and right caudate rCBF (r = -0.31, n = 46, P = 0.02). PTSD syndrome severity correlated significantly negatively with the left caudate (r = -0.49, n = 16, P = 0.03) and with right caudate rCBF (r = -0.7, n = 16, P = 0.001).

CONCLUSIONS

Functional rCBF differences in anxiety disorders could relate to repetitive, intrusive, distressing mental activity, prominent in both OCD and PTSD.

Caudate regional cerebral blood flow in obsessive-compulsive disorder, panic disorder and healthy controls on single photon emission computerised tomography

We compared regional cerebral blood flow (rCBF) in 15 patients with DSM IIIR obsessive-compulsive disorder (OCD), 15 patients with DSM IIIR panic disorder and 15 healthy controls matched for age, sex and hand preference, using uptake of technetium-99m-D,L-hexamethyl-propylene amine oxime (99mTc HMPAO), on single photon emission computerised tomography (SPECT). Caudate rCBF was significantly reduced in OCD patients compared to healthy subjects and panic disorder patients. When four patients were excluded from each group, right caudate rCBF remained significantly lower in OCD patients than in panic disorder patients or healthy subjects. The data suggest functional involvement of the right caudate nucleus is present in OCD.

Schizophrenic auditory hallucinations are associated with increased regional cerebral blood flow during verbal memory activation in a study using single photon emission computed tomography

Single photon emission tomography with split-dose technetium-99m-d, l-hexamethyl-propylene amine oxime was used to measure regional cerebral blood flow (rCBF) during a memory-activation paradigm in a group of 18 medicated DSM-III-R schizophrenic patients. The relationship between clinical features of schizophrenia and rCBF patterns was examined. Increased blood flow to the left basal ganglia was revealed during activation in patients reporting hallucinations in the previous month, a finding that was not influenced by medication dose or other confounding variables. This result adds to previous functional imaging studies that have related basal ganglia abnormalities to hallucinatory phenomena and suggests that left basal ganglia hyperactivity may be relevant to an internal monitoring deficit responsible for the appearance of those symptoms in schizophrenia.

Regional cerebral blood flow (rCBF) in schizophrenia during verbal memory activation: a 99mTc-HMPAO single photon emission tomography (SPET) study

Regional cerebral blood flow (rCBF) was investigated in a group of medicated DSM-III-R schizophrenic patients and age, sex and handedness matched normal volunteers using a split-dose 99mTc-HMPAO Single Photon Emission Tomography (SPET) protocol. Measures were taken during the performance of a verbal memory task aimed at activating the left medial temporal lobe, a region repeatedly suggested to be structurally abnormal in schizophrenia. In normal subjects, the performance of the task was associated with significant rCBF increases in the left medial temporal, left inferior frontal and anterior cingulate cortices, and right cerebellum. Despite their significantly poorer performance on the memory task, the degree of medial temporal activation measured in the schizophrenic patients was not significantly different from that found in the control group. This finding suggests that memory deficits in schizophrenia do not necessarily imply failure to activate the left medial temporal lobe as assessed by 99mTc-HMPAO SPET.