Search

Unruptured brain arteriovenous malformations (AVM) have a heterogeneous clinical presentation, mainly related to the presence of intracerebral hemorrhage. We report the diagnosis of AVM in a patient with Parkinson's disease (PD), who undergone positron emission tomography/magnetic resonance imaging (PET/MRI) molecular brain imaging with fluorine-18-dihydroxyphenylalanine (F-18-DOPA). This case suggests that AVM may be occasionally recognized in molecular imaging studies using positron-emitting amino acids. Magnetic resonance imaging with susceptibility-weighted imaging (SWI) sequences and 3D time of flight (TOF) reconstruction may contribute to manage patients with AVM.

The diagnostic use of radiolabeled octreotide has shown that somatostatin receptor scintigraphy can be successfully used in various neoplasms with a strictly neuroendocrine derivation, because of a good correlation between in vitro receptor expression and in vivo uptake. Moreover, 111In-Octreotide uptake has been demonstrated in various pathologies owing to the receptorial expression on cell elements such as lymphocytes, fibroblasts and endothelium. Although main diagnostic role is in neuroendocrine tumours, octreotide can be also used to obtain an immunological imaging in other fields. The presence of type 2 receptors on activated lymphocytes has stimulated the use of somatostatin in both the treatment and diagnosis of disease activity in patients with Graves' ophthalmopathy. Somatostatin analogs have been successfully used for the treatment and imaging of various tumours of thymic origin. Our research group has evaluated the possible clinical role of octreotide scintigraphy in paediatric patients with thymic hyperplasia after chemotherapy for lymphoma. Even if not routinely applicable, these approaches offer interesting diagnostic, prognostic and therapeutic prospects

Freezing of gait (FOG) generally occurs as a late manifestation of Parkinson's Disease (PD). FOG, however, can present in isolation, constituting the so-called "Primary Progressive Freezing Gait"(PPFG). Myocardial (123)Metaiodiobenzylguanidine (MIBG) enables the assessment of postganglionic sympathetic cardiac nerve terminals. MIBG uptake reflects sympathetic system integrity, and reduced myocardial uptake of the tracer has been observed in nearly all patients with PD. We investigated MIBG uptake in 7 patients with PPFG, 14 patients with mild PD, and 6 patients with advanced PD and FOG (PD-FOG), and 18 control subjects. Our study shows that myocardial MIBG uptake was normal in all patients with PPFG (H/M ratio: mean+/-SD, 1.85+/-0.11 early; 1.71+/-0.15 delayed) and in the controls (H/M ratio: mean+/-SD, 1.94+/-0.18 early; 2.02+/-0.19 delayed) whereas it was markedly decreased in the patients with mild and advanced PD (H/M ratio: mean+/-SD, PD: 1.17+/-0.02 early; 1.16+/-0.02 delayed; PD-FOG: 1.22+/-0.10 early; 1.08+/-0.06 delayed). Our findings demonstrate that cardiac sympathetic denervation did not occur in patients with PPFG, confirming that PPFG and PD are distinct diseases.

The skeleton is one of the preferential sites for metastases of solid tumors, and metastatic disease is the most common malignancy of the bone. Diagnosis and evaluation of skeletal metastases require more frequently a combined approach of different diagnostic methods. Between the currently available imaging modalities, a major role is devoted to two radionuclide functional techniques namely scintigraphy and positron emission tomography (PET) imaging. Both these techniques require the use of different radiopharmaceuticals. The aim of this paper is to review the most important radiocompounds that can be successfully used to detect and/or characterize bone metastases.

Somastostatin (SS) scintigraphy (SRS) is an effective diagnostic tool for neuroendocrine tumours (NET). High diagnostic accuracy is based on the high affinity binding between SS and its receptors (sstr) expressed both in NET and in some non neoplastic cells. Different SS analogues have been proposed in clinical practice because of the short half-life of the native peptide. Among all synthetic compounds Pentetreotide labelled with In-111 is the most widely used for imaging because of high affinity for sstr 2 and 5. New tracers, showing a different and/or wider affinity, are now available and radio- labelling has been obtained both with gamma and positron emitters. The broader spectrum of interaction with sstr gives a better chance to detect, over NET, other pathological conditions, as chronic inflammation, because of the sstr expression on inflammatory cells, including activated lymphocytes, epithelioid and monocytes.

The somatostatin receptor scintigraphy (SRS), using octreotide radiolabelled with 111In (octreoscan, OCTs), is a consolidated diagnostic procedure in patients with neuroendocrine tumors. A higher accuracy has been demonstrated with single photon emission computed tomography-CT, while a further improvement has been obtained with positron emission tomography (PET)-CT, using somatostatin analogues radiolabeled with 68Ga, significantly increasing the number of detected lesions. Although the well-known presence of an OCTs uptake in many benign diseases, when in an active phase, the application of SRS in these patients did not find any clinical relevance yet. In this paper we discuss two fields of endocrinological interest where SRS could play a clinical role. In patients with Graves exophtalmos, the capability to differentiate between active and non-active disease can be helpful in define prognosis and therapeutic strategies. In patients with endocrine paraneoplastic syndromes (PNS), SRS can help in finding the underlying neoplasm, contributing to its characterization as premise to a therapeutic choice. The possible role of a surgery guided by OCTs is also explained and suggested. The incremental value of PET-CT with Ga-68 peptides is hypothesized to reduce the number of unknown neoplastic lesions frequently present in patients with PNS.

Background and Objectives We report our initial experience with a relatively new technique, the so-called “dynamic sentinel node biopsy”, in patients with penile cancer. Methods From January 2001 to February 2003, 17 consecutive patients with bilateral, clinically node negative penile cancer were enrolled. Dynamic sentinel node biopsy was followed by local excision of the primary lesion or penile amputation during the same session. Standard inguinal node dissection was performed 4 weeks after the first operation in all the patients. Results Pre-operative lymphoscintigraphy revealed no sentinel nodes in 1, unilateral sentinel nodes in 5, and bilateral in 11 patients. Metastases were noted in 5 out of 16 patients (31.25%), bilaterally in 3 of them. Among the five patients with sentinel node metastasis, this was the only tumor positive lymph node in one patient. In all cases with negative dynamic sentinel node biopsy, no metastatic nodes were found at the following inguinal node dissection. Therefore, the technique showed a 100% negative predictive value and an 88% sensitivity. Conclusions We believe that dynamic sentinel node biopsy is a minimally invasive procedure that can be easily performed. The goal is to offer the possibility of less extensive surgery for selected low risk patients. J. Surg. Oncol. 2006;93: 181–185. © 2006 Wiley-Liss, Inc.

The term 'fever of unknown origin' includes a wide range of conditions that often remain undiagnosed. The possibility of an infection must be promptly diagnosed in order to begin appropriate therapy. Imaging with radiopharmaceuticals, computed tomography, magnetic resonance imaging and ultrasound are the most commonly applied techniques, usually performed in addition to blood tests, biopsies or tissue cultures when required. The lack of comparative studies investigating the accuracy of each radiopharmaceutical for the study of fever of unknown origin was the incentive to perform a meta-analysis of peer articles published between 1981 and 2004 (33 papers) describing the use of nuclear medicine imaging for this purpose. Furthermore, infection of subcutaneous devices, brain abscesses and endocarditis must be considered amongst the causes of fevers of unknown origin. Reviews of 23, 10 and 10 papers, respectively (from 1976 to 2005), were performed on these specific topics. The results may be a useful guide for the choice of the optimal radiopharmaceutical(s) and diagnostic strategy to be applied in each clinical condition and for different aims.

We have performed pituitary scintigraphy with 111In-pentreotide (OCT), a somatostatin analogue, and with metoxybenzamide (IBZM) by 123I-IBZM in two patients affected by mixed growth hormone/prolactin-secreting pituitary tumors. Short-term growth hormone (GH) inhibition by a single injection of OCT (100 micrograms s.c.), and short-term prolactin (PRL) inhibition by oral administration of 2.5 mg of bromocriptine (BCR), were also performed in both patients. The first patient, a 26 year old man, showed intense tumor uptake of 123I-IBZM scintigraphy, whereas 111In-OCT scintigraphy showed moderate tumor uptake. Five hours after the BCR inhibition test, a fall of 83% in PRL plasma levels (from 8,336 micrograms/L to 1,417 micrograms/L), and of 91.6% in GH plasma levels (from 39.5 micrograms/L to 3.3 micrograms/L) were observed. OCT inhibition test suppressed GH plasma levels from 36 micrograms/L to 3.5 micrograms/L. The patient was submitted to treatment with BCR and OCT. A dramatic shrinkage of the tumor was seen after six months of therapy. The lesion disappeared one year after the start of therapy. The second patient, a 64 year old man, showed intense uptake at 111In-OCT scintigraphy, while 123I-IBZM uptake was not observed. A test dose of BCR resulted in an acute fall of PRL (from 145 micrograms/L to 118 micrograms/L), but not of GH. A test dose of OCT decreased the GH plasma level from 61 micrograms/L to 4.5 micrograms/L. The patient was submitted to treatment with BCR and OCT that resulted in a computed tomography and magnetic resonance imaging decrease of 45% of tumor volume one year after the start of therapy. Our results suggest that both suppression tests with OCT and BCR, and scintigraphic studies in vivo with 123I-IBZM and 111In-OCT can be predictive for the effectiveness of therapies with dopamine agonists and/or SS-analogs in patients with mixed PRL/GH-secreting pituitary tumors. Further studies are required to evaluate the role of suppressive tests in selecting patients for appropriate clinical treatments.

The neuroendocrine tumors (NET) of the gastro-entero-pancreatic area (GEP) represent a heterogeneous group of malignancies from the histologic, clinico-laboratoristic (functioning and non-functioning variants), and therapeutic point of view. It is an issue becoming more frequent for the diagnostic imager, being radiologist as well as nuclear physician. Imaging (together with biopsy) plays a key role in the diagnostic assessment and staging (including grading and prognostic definition), in evaluating response to treatment, and in follow-up of GEP-NET. Multislice computed tomography (MSCT), octreoscan and PET-CT are the most widely diffuse and accurate imaging modalities employed in this setting. Other methods, such as Magnetic Resonance and Endoscopic Ultrasound, may also play a significant role.