Coupling motor evoked potentials and BRAIN [18F]FDG-pet in amyotrophic lateral sclerosis: Preliminary findings on disease severity.

BACKGROUND: The diagnosis of amyotrophic lateral sclerosis (ALS) is primarily clinical, supported by the electromyographic examination to reveal signs of lower motor neuron damage. Identifying reliable markers of upper motor neuron (UMN) involvement is challenging. On this regard, the role of transcranial magnetic stimulation-induced motor-evoked potentials (TMS-MEPs), and its relationship with UMN burden, is still under investigation. OBJECTIVE: To evaluate the ability of TMS-MEPs in delineating the neurophysiological UMN damage, and to determine the relationship between TMS-MEPs and [18F]FDG-PET measures of neural dysfunction. METHODS: We retrospectively selected 13 ALS patients who underwent, during the diagnostic process, the TMS-MEPs and [18F]FDG-PET scans. Demographic and clinical data were collected. For the MEP evaluation, we considered normal MEP, absent MEP, or significantly increased central-motor-conduction-time. For [18F]FDG-PET, we conducted voxel-wise analyses, both at single-subject and group levels, exploring hypometabolism and hypermetabolism patterns in comparison with a large dataset of healthy controls (HC). RESULTS: Based on TMS-MEPs, we identified 4/13 patients with normal MEP in all limbs (GROUP-NO), while 9/13 had an abnormal MEP in at least one limb (GROUP-AB). Despite the [18F]FDG-PET single-subject analysis revealed heterogenous expression of regional hypo- and hyper-metabolism patterns in the patients, the group-level analysis revealed a common hypometabolism, involving the precentral gyrus and the supplementary motor area, the paracentral lobule and the anterior cingulate cortex in the GROUP-AB. Moreover, exclusively for the GROUP-AB compared with HC, a relative hypermetabolism was observed in the right cerebellum, right inferior and middle temporal gyrus. The GROUP-NO showed no specific cluster of hypo- and hyper-metabolism compared to HC. CONCLUSION: This study showed altered brain metabolism only in the ALS group with abnormal MEPs, suggesting an association between the two biomarkers in defining the UMN damage.

Role of Flex-Dose Delivery Program in Patients Affected by HCC: Advantages in Management of Tare in Our Experience.

Background: Introduced in the latest BCLC 2022, endovascular trans-arterial radioembolization (TARE) has an important role in the treatment of unresectable hepatocellular carcinoma (HCC) as a "bridge" or "downstaging" of disease. The evolution of TARE technology allows a more flexible and personalized target treatment, based on the anatomy and vascular characteristics of each HCC. The flex-dose delivery program is part of this perspective, which allows us to adjust the dose and its radio-embolizing power in relation to the size and type of cancer and to split the therapeutic dose of Y90 in different injections (split-bolus). Methods: From January 2020 to January 2022, we enrolled 19 patients affected by unresectable HCC and candidates for TARE treatment. Thirteen patients completed the treatment following the flex-dose delivery program. Response to treatment was assessed using the mRECIST criteria with CT performed 6 and 9 months after treatment. Two patients did not complete the radiological follow-up and were not included in this retrospective study. The final cohort of this study counts eleven patients. Results: According to mRECIST criteria, six months of follow-up were reported: five cases of complete response (CR, 45.4% of cases), four cases of partial response (PR, 36.4%), and two cases of progression disease (PD, 18.2%). Nine months follow-up reported five cases of complete response (CR, 45.4%), two cases of partial response (PR, 18.2%), and four cases of progression disease (PD, 36.4%). No intra and post-operative complications were described. The average absorbed doses to the hepatic lesion and to the healthy liver tissue were 319 Gy (range 133-447 Gy) and 9.5 Gy (range 2-19 Gy), respectively. Conclusions: The flex-dose delivery program represents a therapeutic protocol capable of "saving" portions of healthy liver parenchyma by designing a "custom-made" treatment for the patient.

Impact of patient's habitus on image quality and quantitative metrics in 18F-FDG PET/CT images.

PURPOSE: To study how the quantitative parameters of 18F-FDG PET imaging change with the emission scan duration (ESD) and the body-mass-index (BMI) in phantom and patients on a time-of-flight (TOF)-PET/CT system. METHODS: The image-quality phantom with (b-NEMA-IQ, BMI = 29.2 kg/m2) and without (NEMA-IEC, BMI = 21.4 kg/m2) a 'belt' of water-bags was filled with 18F-FDG activities to obtain nominal standardized uptake values (SUV) of 19, 8 and 5. Patients with BMI ≤ 25 kg/m2 (L-BMI) and BMI > 25 kg/m2 (H-BMI) were enrolled in this study. Phantom and patients underwent list-mode PET acquisition at 120 s/bed-position. Images reconstructed with clinical protocol and different ESD (120, 90, 75, 60, 45, 30 s) were analysed for comparison of maximum SUV (SUVmax), maximum standardized uptake value lean-body-mass corrected (SULmax) and noise. RESULTS: 79 oncologic patients (45 L-BMI, 44 H-BMI) were analysed. From 90 s to 30 s, an increasing variation of SUVmax and SULmax with respect to the reference 120 s time was observed, from 18% to 60% and from 16% to 37% for phantom and patients, respectively. SUVmax values were significantly higher (+50%) in b-NEMA-IQ than NEMA-IQ phantom and in H-BMI (+33%) than L-BMI patients. No significant difference was found in SULmax for the two BMI categories in both phantom and patients. CV values decreased when increasing ESD, being higher in H-BMI patients (0.13-0.25) and b-NEMA-IQ phantom (0.15-0.28) than in L-BMI patients (0.11-0.21) and NEMA-IQ phantom (0.11-0.20). CONCLUSIONS: Reduction of ESD may severely impact on the variations of SUVmax and SULmax in 18F-FDG PET/CT imaging. This study confirms recommendations of using SUL for lesion uptake quantification, being unaffected by BMI variation.

Clinical relevance of single-subject brain metabolism patterns in amyotrophic lateral sclerosis mutation carriers.

BACKGROUND AND OBJECTIVES: The ALS diagnosis requires an integrative approach, combining the clinical examination and supporting tests. Nevertheless, in several cases, the diagnosis proves to be suboptimal, and for this reason, new diagnostic methods and novel biomarkers are catching on. The 18F-fluorodeoxyglucose (18F-FDG)-PET could be a helpful method, but it still requires additional research for sensitivity and specificity. We performed an 18F-FDG-PET single-subject analysis in a sample of familial ALS patients carrying different gene mutations, investigating the genotype-phenotype correlations and exploring metabolism correlations with clinical and neuropsychological data. METHODS: We included ten ALS patients with pathogenic gene mutation who underwent a complete clinical and neuropsychological evaluation and an 18F-FDG-PET scan at baseline. Patients were recruited between 2018 and 2022 at the ALS Tertiary Centre in Novara, Italy. Patients were selected based on the presence of ALS gene mutation (C9orf72, SOD1, TBK1, and KIF5A). Following a validated voxel-based Statistical Parametric Mapping (SPM) procedure, we obtained hypometabolism maps at single-subject level. We extracted regional hypometabolism from the SPM maps, grouping significant hypometabolism regions into three meta-ROIs (motor, prefrontal association and limbic). Then, the corresponding 18F-FDG-PET regional hypometabolism was correlated with clinical and neuropsychological features. RESULTS: Classifying the patients with C9orf72-ALS based on the rate of disease progression from symptoms onset to the time of scan, we observed two different patterns of brain hypometabolism: an extensive motor and prefrontal hypometabolism in patients classified as fast progressors, and a more limited brain hypometabolism in patients grouped as slow progressors. Patients with SOD1-ALS showed a hypometabolic pattern involving the motor cortex and prefrontal association regions, with a minor involvement of the limbic regions. The patient with TBK1-ALS showed an extended hypometabolism, in limbic systems, along with typical motor involvement, while the hypometabolism in the patient with KIF5A-ALS involved almost exclusively the motor regions, supporting the predominantly motor impairment linked to this gene mutation. Additionally, we observed strong correlations between the hypometabolism in the motor, prefrontal association and limbic meta-ROI and the specific neuropsychological performances. CONCLUSIONS: To our knowledge, this is the first study investigating brain hypometabolism at the single-subject level in genetic ALS patients carrying different mutations. Our results show high heterogeneity in the hypometabolism maps and some commonalities in groups sharing the same mutation. Specifically, in patients with C9orf72-ALS the brain hypometabolism was larger in patients classified as fast progressors than slow progressors. In addition, in the whole group, the brain metabolism showed specific correlations with clinical and neuropsychological impairment, confirming the ability of 18F-FDG-PET in revealing pattern of neuronal dysfunction, aiding the diagnostic workup in genetic ALS patients.

18F-FDG PET/CT as predictive and prognostic factor in esophageal cancer treated with combined modality treatment.

PURPOSE: [18F] fluorodeoxyglucose positron emission tomography/computed tomography ([18F] FDG-PET/CT) is used for diagnosis, staging, response assessment and prognosis prediction in different tumors, but its role in esophageal cancer is still debated. The aim of this study was to evaluate the role of semiquantitative baseline PET parameters as possible prognostic and predictive factors in a series of esophageal carcinomas treated with combined modalities. METHODS: 43 patients with esophageal carcinoma were treated with chemoradiotherapy (CRT) followed by surgery in 20 cases and underwent pre-treatment 18F-FDG-PET/CT. Semiquantitative PET parameters were evaluated including Standardized Uptake Value (SUVmax e SUVmean), Metabolic Tumor Volume (MTV) and Total Lesion Glycolysis (TLG) with isocontour of 41 and 50%. Further variables analyzed were gender, primary tumor site, histological type, use of surgery, achievement of a radical resection and the type of chemotherapy regimen. The correlation of all variables with treatment response, loco-regional control (LR), Overall survival (OS) and Disease-Free Survival (DFS) was evaluated. RESULTS: SUVmax, SUVmean50 and SUVmean41 were significantly higher in node-positive cases and in squamous cell carcinomas. With respect to prognostic factors, MTV was found to be correlated with OS: patients with MTV41 < 11.32 cm3 and MTV50 < 8.07 cm3 (both p values = 0.04) showed better 3-year OS rates (33 vs. 20%). Further factors predicting a better prognosis were the use of surgery and radical resection (R0) (both p values < 0.01). CONCLUSIONS: Pre-treatment MTV values were significant prognostic factors for OS, together with the use of surgery and R0 resection in esophageal cancers treated with multimodal therapies.

Sarcopenia Diagnosis: Reliability of the Ultrasound Assessment of the Tibialis Anterior Muscle as an Alternative Evaluation Tool.

Sarcopenia is a skeletal muscle disorder characterized by reduced muscle mass, strength, and performance. Muscle ultrasound can be helpful in assessing muscle mass, quality, and architecture, and thus possibly useful for diagnosing or screening sarcopenia. The objective of this study was to evaluate the reliability of ultrasound assessment of tibialis anterior muscle in sarcopenia diagnosis. We included subjects undergoing total or partial hip replacement, comparing measures with a healthy control group. We measured the following parameters: tibialis anterior muscle thickness, echogenicity, architecture, stiffness, skeletal muscle index (SMI), hand grip strength, and sarcopenia related quality of life evaluated through the SarQoL questionnaire. We included 33 participants with a mean age of 54.97 ± 23.91 years. In the study group we found reduced tibialis anterior muscle thickness compared to the healthy control group (19.49 ± 4.92 vs. 28.94 ± 3.63 mm, p < 0.05) with significant correlation with SarQoL values (r = 0.80, p < 0.05), dynamometer hand strength (r = 0.72, p < 0.05) and SMI (r = 0.76, p < 0.05). Moreover, we found reduced stiffness (32.21 ± 12.31 vs. 27.07 ± 8.04 Kpa, p < 0.05). AUC measures of ROC curves were 0.89 predicting reduced muscle strength, and 0.97 predicting reduced SMI for tibialis anterior muscle thickness, while they were 0.73 and 0.85, respectively, for muscle stiffness. Our findings showed that ultrasound assessment of tibialis anterior muscle might be considered a reliable measurement tool to evaluate sarcopenia.

Role of radiotherapy to bulky sites of advanced Hodgkin lymphoma treated with ABVD: final results of FIL HD0801 trial.

The role of consolidation radiotherapy (RT) for bulky lesions is controversial in patients with advanced-stage Hodgkin lymphoma who achieve complete metabolic response (CMR) after doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD)-based chemotherapy. We present the final results of the Fondazione Italiana Linfomi HD0801 trial, which investigated the potential benefit of RT in that setting. In this phase 3 randomized study, patients with a bulky lesion at baseline (a mass with largest diameter ≥5 cm) who have CMR after 2 and 6 ABVD cycles were randomly assigned 1:1 to RT vs observation (OBS) with a primary endpoint of event-free survival (EFS) at 2 years. The sample size was calculated estimating an EFS improvement for RT of 20% (from 60% to 80%). The secondary end point was progression-free survival (PFS). One hundred sixteen patients met the inclusion criteria and were randomly assigned to RT or OBS. Intention-to-treat (ITT) analysis showed a 2-year EFS of 87.8% vs 85.8% for RT vs OBS (hazard ratio [HR], 1.5; 95% confidence interval [CI], 0.6-3.5; P = .34). At 2 years, ITT-PFS was 91.3% vs 85.8% (HR, 1.2; 95% CI, 0.5-3; P = .7). Patients in CMR randomly assigned to OBS had a good outcome, and the primary end point of a 20% benefit in EFS for RT was not met. However, the sample size was underpowered to detect a benefit of 10% or less, keeping open the question of a potential, more limited role of RT in this setting. This trial was registered at www.clinicaltrials.gov as #NCT00784537.

Heterogeneity of bone metastases as an important prognostic factor in patients affected by oestrogen receptor-positive breast cancer. The role of combined [18F]Fluoroestradiol PET/CT and [18F]Fluorodeoxyglucose PET/CT.

PURPOSE: To assess the prognostic role of different inter and intralesional expression (heterogeneity) of oestrogen receptor (ER) in bone metastases, as identified by the combined use of [18F]FES PET/CT and [18F]FDG PET/CT in patients with oestrogen receptor-positive (ER+) metastatic breast cancer (BC). METHODS: We analysed patients with a new diagnosis of bone metastases who were candidates for first-line systemic endocrine therapy. Before starting therapy, patients underwent baseline [18F]FES PET/CT and [18]FDG PET/CT. Semi-quantitative evaluation of whole-body bone metabolic burden (WB-B-MB) was performed on [18F]FES and [18F]FDG PET/CT in order to evaluate disease extent, tumour metabolism and ER heterogeneity. We used time-to-event analyses (Kaplan-Meier and Cox proportional-hazards methods) to estimate progression-free (PFS) and overall survival (OS), in order to assess the independent prognostic value of [18F]FES PET/CT and [18F]FDG PET/CT, alone and in combination. RESULTS: According to our criteria, we enrolled 49 patients. Over a median follow-up of 44.7 months, 35 patients suffered disease progression (71.4 %) and 15 died of disease (30.6 %). When the risk of disease progression was calculated by means of the Cox model, only [18F]FDG WB-B-MB was independently and directly associated to PFS (p = 0.02). On analysing the association between all prognostic parameters and survival, the Cox model showed that the only parameter associated with OS was the WB-B-MB FES/FDG ratio (p = 0.01). CONCLUSION: The combined use of [18F]FES-PET/CT and [18F]FDG-PET/CT can identify ER heterogeneity in BC bone metastases. This heterogeneity is significantly associated with survival. Moreover, the extension of the FDG-avid component correlates with the risk of disease progression.

The role of activity, scan duration and patient's body mass index in the optimization of FDG imaging protocols on a TOF-PET/CT scanner.

BACKGROUND: Time-of-flight (TOF) PET technology determines a reduction in the noise and improves the reconstructed image quality in low count acquisitions, such as in overweight patients, allowing a reduction of administered activity and/or imaging time. However, international guidelines and recommendations on the 18F-fluoro-2-deoxyglucose (FDG) activity administration scheme are old or only partially account for TOF technology and advanced reconstruction modalities. The aim of this study was to optimize FDG whole-body studies on a TOF-PET/CT scanner by using a multivariate approach to quantify how physical figures of merit related to image quality change with acquisition/reconstruction/patient-dependent parameters in a phantom experiment. METHODS: The NEMA-IQ phantom was used to evaluate contrast recovery coefficient (CRC), background variability (BV) and contrast-to-noise ratio (CNR) as a function of changing emission scan duration (ESD), activity concentration (AC), target internal diameter (ID), target-background activity ratio (TBR) and body mass index (BMI). The phantom was filled with an average concentration of 5.3 kBq/ml of FDG solution and the spheres with TBR of 21.2, 8.8 and 5.0 in 3 different sessions. Images were acquired at varying background activity concentration from 5.1 to 1.3 kBq/ml, and images were reconstructed for ESD of 30-151 s per bed position with and without point spread function (PSF) correction. The parameters were all considered in a single analysis using multiple linear regression methods. RESULTS: As expected, CRC depended only on sphere ID and on PSF application, while BV depended on sphere ID, ESD, AC and BMI of the phantom, in order of decreasing relevance. Noteworthy, ESD and AC resulted as the most significant predictors of CNR variability with a similar relevance, followed by the BMI of the patient and TBR of the lesion. CONCLUSIONS: AC and ESD proved to be effective tools in modulating CNR. ESD could be increased rather than AC to improve image quality in overweight/obese patients to fulfil ALARA principles.

Role of positron emission tomography in the assessment of disease burden and risk of relapse in patients affected by giant cell arteritis.

Giant cell arteritis (GCA) is characterized by two subsets: cranial GCA and large-vessel GCA (LV-GCA); positron emission tomography (PET) is an essential tool in the diagnosis of LV-GCA. In this study, we aimed to investigate its potential prognostic value in the stratification of relapse risk. We retrospectively revised all the clinical records of patients who received a diagnosis of GCA at an immuno-rheumatology clinic of a University Hospital along 6 years and who underwent to a PET-CT examination at diagnosis. Clinical, laboratory, and imaging data were collected. Relapses were recorded. The study population included 19 patients (10 females, 52.6%; median age 74.0 [65.5-76.0] years), 12 with typical cranial GCA (63%) and 7 (37%) with LV-GCA. Based on PET findings, a diagnosis of aortitis was made in 15/19 patients, including 8/12 patients with a classical cranial GCA (58%). Along a median follow-up of 15 months [4.5-26.5], 4 relapses were observed. All relapsers were male; indeed, the difference in gender distribution was the only variable reaching statistical difference between relapsers and non-relapsers. Specifically, aortitis was not more frequent among relapsers. Our study confirms PET as a valid tool in the identification of LV-GCA with no cranial involvement. We failed to demonstrate a role for PET in the prognostic stratification of GCA, while male gender is suggested as a potential risk factor for GCA relapse.Key Points• A significant proportion of patients with GCA presents with non-cranial disease, the identification of which requires imaging studies, among which PET is particularly useful.• Aortitis might be detected also in patients with the classical, cranial GCA type but does not seem to have prognostic implications, at least in terms of relapse risk.• Male gender is suggested as a risk factor for relapse in GCA.

Performance evaluation of a new time of flight PET/CT scanner: Results of a multicenter study.

PURPOSE: The aim of this multicenter study was to evaluate the performance of the upgraded version of the Ingenuity TF PET/CT scanner, according to the NEMA NU-2 2012 standards. METHODS: Spatial resolution, sensitivity, count rate response, scatter fraction, image quality and accuracy were evaluated on three Ingenuity TF scanners installed in Italian hospitals. Furthermore, energy and timing resolution were measured. A detailed image quality phantom analysis was performed to evaluate the effect of different clinical reconstruction parameters, including the application of PSF correction. RESULTS: Results show an average spatial resolution of 4.7 mm and an average absolute system sensitivity of 7.9 cps/kBq. The average maximum NECR was 119.83 kcps at 20.67 kBq/ml, while the maximum true event rate was 322.62 kcps at the concentration of 24.51 kBq/ml. The average maximum bias below NECR peak was 12.58%. All the results of NEMA tests were in agreement with the values declared by the manufacturer. The estimated average energy and timing resolution were 10.83% and 536.2 ps, respectively. Image quality phantom analysis obtained with different reconstruction settings showed that PSF correction was the parameter that affected mainly on contrast recovery coefficient, while the iteration number and amplitude of Gaussian filter had no significant effect. Of relevance, the application of PSF correction never led to recovery coefficient values higher than 100% and to Gibbs or edge artifacts. CONCLUSIONS: The new Ingenuity TF model shows physical performance similar to other scanners of the latest generation for all standard NEMA NU2-2012 measurements.

A case of late-onset OCD developing PLS and FTD.

We describe a 64-year-old woman, suffering from late-onset obsessive-compulsive disorder (OCD) from the age of 57, who developed dysarthria and dysphagia, spastic diplegic, and proximal muscles weakness. Needle electromyography showed no active denervation. Neuropsychological evaluation showed intact cognitive functioning. We diagnosed upper motor neuron disease (MND), with no known genetic correlates. Brain magnetic resonance (MRI) detected bilateral hippocampal atrophy with sclerosis of right hippocampus. 18F-FDG positron emission tomography (PET) showed moderate right temporal cortex thinning. Six months later, motor and behavioral symptoms worsened. Neuropsychological examination revealed long-term memory deficit and executive dysfunction. MRI and PET evidenced severe worsening of atrophy in temporal and frontal lobes. Four years later a definitive diagnosis of primary lateral sclerosis (PLS) and FTD was made. To our knowledge, this is the first report of PLS and FTD with OCD at onset.

Comparison of retrospective PET and MRI-DWI (PET/MRI-DWI) image fusion with PET/CT and MRI-DWI in detection of cervical and endometrial cancer lymph node metastases.

OBJECTIVES: The aim of this study was to compare the accuracy of retrospective image fusion of PET/MRI-DWI with that of PET/CT and MRI-DWI alone in detecting metastatic lymph nodes in patients with cervical and endometrial carcinoma. MATERIALS AND METHODS: Twenty-seven patients with endometrial (n = 14) and cervical (n = 13) cancer who had undergone preoperative MRI-DWI and PET/CT for staging were retrospectively evaluated. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PET/CT, MRI-DWI, and PET/MRI-DWI image fusion were calculated on a per-patient basis and on a per-node basis. Histopathological and follow-up imaging results were used as the gold standard. RESULTS: On a per-patient basis PET/MRI-DWI had the same sensitivity (87.5 %), specificity (84.2 %), diagnostic accuracy (85.1 %), PPV (70 %), and NPV (94.1 %) as PET-CT, but on a per-node basis PET/MRI-DWI showed better sensitivity (89 vs 70.2 %), specificity (91.6 vs 90.5 %), diagnostic accuracy (91.2 vs 87 %), PPV (68.7 vs 60.4 %), and NPV (97.6 vs 93.6 %) than PET-CT. Comparison of the areas under the ROC curves for the detection of metastatic lymph nodes demonstrated a non-significant difference (p = 0.055) between PET/CT and fused PET/MRI-DWI. CONCLUSION: PET/MRI-DWI may be a valuable technique for N-staging patients with endometrial and cervical cancer, but more studies are needed to investigate its potential clinical utility.

Interim Positron Emission Tomography Response-Adapted Therapy in Advanced-Stage Hodgkin Lymphoma: Final Results of the Phase II Part of the HD0801 Study.

PURPOSE: The clinical impact of positron emission tomography (PET) evaluation performed early during first-line therapy in patients with advanced-stage Hodgkin lymphoma, in terms of providing a rationale to shift patients who respond poorly onto a more intensive regimen (PET response-adapted therapy), remains to be confirmed. PATIENTS AND METHODS: The phase II part of the multicenter HD0801 study involved 519 patients with advanced-stage de novo Hodgkin lymphoma who received an initial treatment with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and who underwent an early ifosfamide-containing salvage treatment followed by stem-cell transplantation if they showed a positive PET evaluation after two cycles of chemotherapy (PET2). The primary end point was 2-year progression-free survival calculated for both PET2-negative patients (who completed a full six cycles of ABVD treatment) and PET2-positive patients. Overall survival was a secondary end point. RESULTS: In all, 103 of the 512 evaluable patients were PET2 positive. Among them, 81 received the scheduled salvage regimen with transplantation, 15 remained on ABVD (physician's decision, mostly because of minimally positive PET2), five received an alternative treatment, and two were excluded because of diagnostic error. On intention-to-treat analysis, the 2-year progression-free survival was 76% for PET2-positive patients (regardless of the salvage treatment they received) and 81% for PET2-negative patients. CONCLUSION: Patients with advanced-stage Hodgkin lymphoma for whom treatment was at high risk of failing appear to benefit from early treatment intensification with autologous transplantation, as indicated by the possibility of successful salvage treatment in more than 70% of PET2-positive patients through obtaining the same 2-year progression-free survival as the PET2-negative subgroup.

Combined multimodal co-registration of PET/CT and MRI images increases diagnostic accuracy in squamous cell carcinoma staging.

OBJECTIVES: The purpose of our study was to assess the diagnostic value of multi-modal imaging through co-registration of short tau inversion recovery (STIR) and diffusion-weighted imaging (DWI) MRI with (18)FDG-PET/CT in T and N staging of head and neck tumours. MATERIALS AND METHODS: 25 patients with head and neck squamous cell carcinoma who had undergone MRI and PET/CT before treatment were retrospectively evaluated. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PET/CT, MRI and their combined use were assessed in T and N staging. Histopathology and follow-up imaging results were used as the gold standard. RESULTS: In assessing trans-compartmental extensions, PET-MRI showed 93 % sensitivity, 88 % specificity, 94 % PPV, and 88 % NPV, as compared to the 94 and 53 % sensitivity, 75 and 75 % specificity, 89 and 82 % PPV, and 86 and 43 % demonstrated by MRI and PET, respectively. In the identification of pathological lymph nodes, PET-MRI showed 92 % sensitivity, 89 % specificity, 96 % PPV, and 89 % NPV, whereas PET/CT displayed 72 % sensitivity, 89 % specificity, 95 % PPV and 53 % NPV. The corresponding figures for DWI and STIR sequences were 84 and 100 % sensitivity, 67 and 56 % specificity, 88 and 86 % PPV, and 60 and 100 % NPV, respectively. CONCLUSIONS: Multi-modal imaging assessment of co-registered MRI and PET/CT images provides more accurate results for trans-compartmental extensions in T and N staging than the individual techniques alone.

Staging of Primary Abdominal Lymphomas: Comparison of Whole-Body MRI with Diffusion-Weighted Imaging and (18)F-FDG-PET/CT.

Background. The purpose of this study was to compare the accuracy of whole-body MRI with diffusion-weighted sequences (WB-DW-MRI) with that of (18)F-FDG-PET/CT in the staging of patients with primary gastrointestinal lymphoma. Methods. This retrospective study involved 17 untreated patients with primary abdominal gastrointestinal lymphoma. All patients underwent (18)F-FDG-PET/CT and WB-DW-MRI. Histopathology findings or at least 6 months of clinical and radiological follow-up was the gold standard. The Musshoff-modified Ann Arbor system was used for staging, and diagnostic accuracy was evaluated on a per-node basis. Results. WB-DW-MRI exhibited 100% sensitivity, 96.3% specificity, and 96.1% and 100% positive and negative predictive values (PPV and NPV), respectively. The sensitivity, specificity, and PPV and NPV of PET/CT were 95.9%, 100%, and 100% and 96.4%, respectively. There were no statistically significant differences between the two techniques (p = 0.05). The weighted kappa agreement statistics with a 95% confidence interval were 0.97 (0.95-0.99) between the two MRI readers and 0.87 (0.82-0.92) between the two methods. Conclusions. WB-DW-MRI appears to have a comparable diagnostic value to (18)F-FDG-PET/CT in staging patients with gastrointestinal lymphoma.

Single thymic gland metastasis from resected non-small-cell lung cancer.

Primary thymic tumors are rare, but secondary ones are exceptionally uncommon. We report the case of a single metastasis within the thymic gland from a lung adenocarcinoma that had been completely resected 3 years before. There was high diagnostic doubt because the thymic lesion was not associated with the recurrence of the paraneoplastic syndrome or the increased CEA levels described at the moment of the treatment of the primary tumor. The lesion was diagnosed and treated at the same time by transcervical thymectomy. At the one-year follow-up, the patient is alive and disease-free.