D. Rubini

18 F-FDG PET/CT contribution to diagnosis and treatment response of rhino-orbital-cerebral mucormycosis

OBJECTIVE Mucormycosis is an infection caused by mycetes mucorales, emerged as a life-threatening infection associated with severe morbidity and high mortality. Conventional imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) are usually performed to assess mucormycosis extension, but they may present insufficiencies in their performance. CASE PRESENTATION We present the case of a 13 years old patient with diagnosis of rhino-orbital-cerebral mucormycosis (RCM) who performed head MRI and [(18)F]2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) both for the infection spread assessment and for the early evaluation of response to systemic amphotericin-B treatment. CONCLUSION This case suggests that (18)F-FDG PET/CT could be considered as a valuable tool for the initial staging of RCM when compared with MRI and should be performed as soon as possible after the first clinical suspicion of this disease. In addition (18)F-FDG PET/CT may also be useful for the assessment of response to treatment.

I-131 MIBG scintigraphy of neuroectodermal tumors: comparison between I-131 MIBG and In-111 DTPA octreotide

An account is given of the results observed with 1-131 MIBG scintigraphy in four patients (1 bladder pheochromocytoma, 3 neuroblastomas) chosen on account of their particular clinical and diagnostic interest from a series of 41 apudoma patients examined by means of this technique. In the first patient, the unusual site of the tumor in the posterior wall of the bladder meant that its detection by 1-131 MIBG was only possible after catheterizatlon of the bladder. In the second patient, uptake in the metastasis was only evident after removal of the primary tumor. In the third patient, the scintiscan revealed several metastases (some in bone) not detected by CT. In the fourth patient (congenital neuroblastoma), enhanced uptake accompanied the appearance of high plasma catecholamlne and urinary vanillylhandelic acid values, suggesting a functional switch from a nonsecret- Ing to a secreting form. A supplementary ln-111 DTPAOctreotide (OCT) scintiscan of this patient demonstrated the presence of somatostatln receptors on the neuroblasts. Thus, this examination would seem particularly useful for the differentiation of nonsecretlng neuroblastomas. Its employment in assessment of the therapeutic capacity of OCT itself is also suggested.

Correlation between bone imaging and the clinical picture in two unsuspected cases of progressive diaphyseal dysplasia (Engelmann's disease).

Progressive diaphyseal dysplasia was incidentally discovered in two patients referred for Tc-99m MDP bone scintigraphy (one for intense sciatica, the other for the detection of breast cancer metastases). Tracer accumulation in the diaphyses of the lower limbs and the base of the skull was accompanied by bone thickening and patency of the medullary cavity, as demonstrated by radiography, MRI, and bone marrow scanning. Comparison of the clinical pictures with the results of instrumental examinations showed that these were cases of sporadic progressive diaphyseal dysplasia of slight and average gravity, respectively. The differentiation of Ribbings disease is explained and reference also is made to a finding not mentioned in the literature, namely frontal bone resorption lacunules in one patient.

18F-FDG PET/CT in suspected recurrences of epithelial malignant pleural mesothelioma in asbestos-fibers-exposed patients (comparison to standard diagnostic follow-up)

This retrospective study evaluated the role of 18-fluorine-labeled 2-deoxy-2-fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with previous occupational or environmental exposure to asbestos, with histopathological diagnosis of epithelial malignant pleural mesothelioma and suspected recurrences, comparing the data from 18F-FDG PET/CT and computed tomography with contrast enhancement (CECT). 18F-FDG PET/CT has greater sensitivity than CECT in identifying local extent, lymph nodes, and metastasis. 18F-FDG PET/CT whole-body explorations are useful to monitor the follow-up and evaluate the metabolic response to chemo- and radiotherapy, modifying the scheduled treatment plan.

124Iodine: A Longer-Life Positron Emitter Isotope—New Opportunities in Molecular Imaging

124Iodine (124I) with its 4.2 d half-life is particularly attractive for in vivo detection and quantification of longer-term biological and physiological processes; the long half-life of 124I is especially suited for prolonged time in vivo studies of high molecular weight compounds uptake. Numerous small molecules and larger compounds like proteins and antibodies have been successfully labeled with 124I. Advances in radionuclide production allow the effective availability of sufficient quantities of 124I on small biomedical cyclotrons for molecular imaging purposes. Radioiodination chemistry with 124I relies on well-established radioiodine labeling methods, which consists mainly in nucleophilic and electrophilic substitution reactions. The physical characteristics of 124I permit taking advantages of the higher PET image quality. The availability of new molecules that may be targeted with 124I represents one of the more interesting reasons for the attention in nuclear medicine. We aim to discuss all iodine radioisotopes application focusing on 124I, which seems to be the most promising for its half-life, radiation emissions, and stability, allowing several applications in oncological and nononcological fields.

Prospective analysis of 18F-FDG PET/CT predictive value in patients with low rectal cancer treated with neoadjuvant chemoradiotherapy and conservative surgery.

This study prospectively assessed 18F-FDG PET/CT in predicting the response of locally advanced low rectal cancer (LRC) to neoadjuvant chemoradiation (nCRT). Methods. 56 patients treated with chemoradiation underwent two 18F-FDG PET/CT scans (baseline and 5-6 weeks post-nCRT). 18F-FDG uptake (SUVmax and SUVmean) and differences between baseline (SUV1) and post-nCRT (SUV2) scans (ΔSUV and RI%) were evaluated. Results were related to the Mandards TRG and (y)pTNM. Results. 18F-FDG PET/CT sensitivity, specificity, accuracy, PPV and NPV resulted in 88.6%, 66.7%, 83.92%, 90.7%, and 61.5%. SUV2 resulted in better than SUV1 to predict nCRT response by TRG, with no significant statistical difference between the SUVmax2 and SUVmean2 AUC (0.737 versus 0.736; P = 0.928). The same applies to the (y)pTNM (0.798 versus 0.782; P = 0.192). In relation to the TRG, RI values had a higher AUC than ΔSUV, with no significant difference between RImax and RImean (0.672 versus 0.695; P = 0.292). The same applied to the (y)pTNM (0.742 versus 0.741; P = 0.940). In both cases ΔSUV does not appear to be a good predictive tool. Logistic regression confirmed the better predictive role of SUVmax2 for the (y)pTNM (odds ratio = 1.58) and SUVmean2 for the TRG (odds ratio = 1.87). Conclusions. 18F-FDG PET/CT can evaluate response to nCRT in LRC, even if more studies are required to define the most significant parameter for predicting pathologic tumor changes.

La carcinosi peritoneale da carcinoma ovarico: utilità della 18F-FDG-PET/TC e del biomarker CA125

The purpose of this study was to evaluate the contribution of 18F-FDG-PET/CT in highlighting the peritoneal involvement in patients with ovarian cancer, also in relation to the biomarker CA125. We retrospectively analyzed 64 female patients with histological diagnosis of ovarian cancer who underwent 18F-FDG-PET/CT and CA125 measurement. Sensitivity and specificity of 18F-FDG-PET/CT were both 90.63% (95% CI: 80-100%). Sensitivity and specificity of CA125 were 93.33% (95% CI: 80-100%) and 33.33% (95% CI: 25-64%), respectively. In patients with peritoneal carcinomatosis from ovarian cancer, it is recommended to perform 18F-FDG-PET/CT, in particular when elevated CA125 levels are detected.

Acute pulmonary embolism: comparison and integration of perfusion lung scintigraphy with multislice spiral CT

Purpose.This study compared and integrated the data from perfusion lung scintigraphy and multislice computed tomography (CT) for the emergency diagnosis of acute pulmonary embolism in nuclear medicine and radiology departments operating around the clock.Materials and methods.One hundred and seven patients with a clinical and laboratory suspicion of acute pulmonary embolism who had already undergone chest radiography were divided into four groups according to the time interval between onset of clinical suspicion and performance of the two diagnostic examinations (0–24 h, 24–48 h, 0–48 h, 2–7 days). Cohens test for the analysis of statistical concordance was used.Results.Perfusion lung scintigraphy and multislice CT were positive in 29/107 (27.1%) and negative in 78/107 (72.89%). Positive concordance (PC) was found in 22 cases and negative concordance (NC) in 71 cases: 0–24 h: PC in 12, NC in 32 cases; 24–48 h: PC in 3, NC in 15 cases; 0–48 h: PC in 15, NC in 47 cases; 2–7 days: PC in 7, NC in 24 cases.Conclusions.Perfusion lung scintigraphy and multislice CT demonstrated elevated concordance if performed within 7 days of the onset of suspicion of acute pulmonary embolism. Concordance was higher if the examinations were completed within 24–48 h. In suspected acute pulmonary embolism, it is mandatory to reach a correct diagnosis within few hours – 48 at the most.

Chiluria notturna: ruolo della diagnostica per immagini

Lymphoscintigraphy is a first-line imaging technique for the assessment of abnormal lymphatic drainage in chyluria. It can provide information about the site of origin of chyluria, and may be helpful in selecting patients for surgery and assessing treatment efficacy. We report the case of a 59-year-old male with chyluria correctly diagnosed with lymphoscintigraphy.

[The PET/CT with 18F-fluorocholine in the diagnosis of gliomatosis cerebri type 2].

In a patient with cerebral gliomatosis type II MRI revealed a large area of altered signal in the temporal region, parietal and occipital lobes associated with a single nodule with perilesional contrast enhancement, which showed increased uptake on PET/CT with 18F-FCH, characterizing heterogeneous cellularity of the tumor.