Metastatic pancreatic and lung cancer patient in complete remission following immunotherapy: A case report and review of literature

BACKGROUND

Metastatic pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with dispiriting survival data. Immunotherapy is a promising approach to many cancer types, but achieves poor outcomes in advanced PDAC due to its immunosuppressive tumor microenvironment. We describe a case of metastatic PDAC effectively treated with pembrolizumab.

CASE SUMMARY

We report the case of a 67-year-old woman with unresectable locally advanced PDAC, treated with gemcitabine plus nab-paclitaxel followed by radiotherapy plus capecitabine. At nine months, pancreatic tumor progression was observed at the level of the hepatic hilum with the appearance of a new pulmonary nodule suggestive of a second primary, confirmed by left lung biopsy. Systemic immunotherapy was then initiated with pembrolizumab, an immune checkpoint inhibitor targeting programmed cell death protein-1 that covers the two tumor types. The patient showed a complete metabolic response that was maintained throughout the treatment. The patient continues to be disease-free at 5.6 years since the start of immunotherapy.

CONCLUSION

These results suggest that the administration of pembrolizumab after chemoradiotherapy has a beneficial effect in patients with metastatic PDAC. To our knowledge, this is the first reported case of a patient with metastatic PDAC and metastatic lung cancer showing such a long-lasting complete response after pembrolizumab treatment without curative surgery. Further studies are required to determine biomarkers that identify PDAC patients most likely to benefit from this immunotherapy.

Recommendations for the management of yttrium-90 radioembolization in the treatment of patients with colorectal cancer liver metastases: a multidisciplinary review

PURPOSE

Strategies for the treatment of liver metastases from colon cancer (lmCRC) are constantly evolving. Radioembolization with yttrium 90 (Y-90 TARE) has made significant advancements in treating liver tumors and is now considered a potential option allowing for future resection. This study reviewed the scientific evidence and developed recommendations for using Y-90 TARE as a treatment strategy for patients with unresectable lmCRC.

METHODS

A multidisciplinary scientific committee, consisting of experts in medical oncology, hepatobiliary surgery, radiology, and nuclear medicine, all with extensive experience in treating patients with ImCRC with Y-90 TARE, led this project. The committee established the criteria for conducting a comprehensive literature review on Y-90 TARE in the treatment of lmCRC. The data extraction process involved addressing initial preliminary inquiries, which were consolidated into a final set of questions.

RESULTS

This review offers recommendations for treating patients with lmCRC using Y-90 TARE, addressing four areas covering ten common questions: 1) General issues (multidisciplinary tumor committee, indications for treatment, contraindications); 2) Previous process (predictive biomarkers for patient selection, preintervention tests, published evidence); 3) Procedure (standard procedure); and 4) Post-intervention follow-up (potential toxicity and its management, parameters for evaluation, quality of life).

CONCLUSIONS

Based on the insights of the multidisciplinary committee, this document offers a comprehensive overview of the technical aspects involved in the management of Y-90 TARE. It synthesizes recommendations for applying Y-90 TARE across various phases of the treatment process.

How to estimate body composition in Huntington's disease. A cross-sectional, observational study using multiple frequencies bioimpedance

INTRODUCTION

Huntington´s disease (HD) is a rare neurodegenerative disorder. Reliable information about nutritional status, especially body composition from individuals with HD is critical for clinical care and research. The ease of application and portability of multiple frequencies bioelectrical impedance analysis (mfBIA) make it an attractive tool for measuring body composition, but its accuracy in HD is unknown.

AIM

To evaluate the accuracy of mfBIA vs. Dual X-ray absorptiometry (DEXA) in HD.

PATIENTS AND METHODS

Cross-sectional, observational, and single-center study. HD severity was measured using motor subscale of the unified Huntington´s disease rating scale (m-UHDRS) and the total functional capacity (TFC). Body composition was measured in terms of fat-free mass (FFM), fat mass (FM), fat-free mass index (FFMI), and fat mass index (FMI). Using Bland-Altman plots, we analyzed reliability between DEXA and mfBIA using the Intraclass Correlation Coefficient with 95% confidence intervals (CI) and bias estimates for all.

RESULTS

We included 16 patients with HD, 7 men, and 9 women, median age of 58.5 (32;68) years, TFC: 10 (3;13), and m-UHDRS: 31 (7;85). The reliability between mfBIA and DEXA were high for FFMI in men: 0.88 (95% CI 0.17-0.98), and women: 0.90 (95% CI 0.61- 0.98); for FMI, men: 0.97 (95% CI 0.83-0.99), and women: 0.91 (95% CI 0.68-0.98). Compared to DEXA, mfBIA slightly overestimated FFM, FM, FMI and FFMI in men and underestimated FFMI in women.

CONCLUSIONS

mfBIA is an easy-to-use, safe, non-invasive, accurate method for measuring body composition and nutritional status in patients with mild-moderate HD.

[18F]DCFPyL PET/CT versus [18F]fluoromethylcholine PET/CT in Biochemical Recurrence of Prostate Cancer (PYTHON): a prospective, open label, cross-over, comparative study

PURPOSE

Primary objective was to compare the per-patient detection rates (DR) of [18F]DCFPyL versus [18F]fluoromethylcholine positron emission tomography/computed tomography (PET/CT), in patients with first prostate cancer (PCa) biochemical recurrence (BCR). Secondary endpoints included safety and impact on patient management (PM).

METHODS

This was a prospective, open label, cross-over, comparative study with randomized treatment administration of [18F]DCFPyL (investigational medicinal product) or [18F]fluoromethylcholine (comparator). Men with rising prostate-specific antigen (PSA) after initial curative therapy were enrolled. [18F]DCFPyL and [18F]fluoromethylcholine PET/CTs were performed within a maximum time interval of 12 days. DR was defined as the percentage of positive PET/CT scans identified by 3 central imaging readers. PM was assessed by comparing the proposed pre-PET/CT treatment with the local treatment", defined after considering both PET/CTs.

RESULTS

A total of 205 patients with first BCR after radical prostatectomy (73%; median PSA = 0.46 ng/ml [CI 0.16;27.0]) or radiation therapy (27%; median PSA = 4.23 ng/ml [CI 1.4;98.6]) underwent [18F]DCFPyL- and/or [18F]fluoromethylcholine -PET/CTs, between July and December 2020, at 22 European sites. 201 patients completed the study. The per-patient DR was significantly higher for [18F]DCFPyL- compared to [18F]fluoromethylcholine -PET/CTs (58% (117/201 patients) vs. 40% (81/201 patients), p < 0.0001). DR increased with higher PSA values for both tracers (PSA ≤ 0.5 ng/ml: 26/74 (35%) vs. 22/74 (30%); PSA 0.5 to ≤ 1.0 ng/ml: 17/31 (55%) vs. 10/31 (32%); PSA 1.01 to < 2.0 ng/ml: 13/19 (68%) vs. 6/19 (32%);PSA > 2.0: 50/57 (88%) vs. 39/57 (68%) for [18F]DCFPyL- and [18F]fluoromethylcholine -PET/CT, respectively). [18F]DCFPyL PET/CT had an impact on PM in 44% (90/204) of patients versus 29% (58/202) for [18F]fluoromethylcholine. Overall, no drug-related nor serious adverse events were observed.

CONCLUSIONS

The primary endpoint of this study was achieved, confirming a significantly higher detection rate for [18F]DCFPyL compared to [18F]fluoromethylcholine, in men with first BCR of PCa, across a wide PSA range. [18F]DCFPyL was safe and well tolerated.

Impact of routine preoperative 18 FDG PET/CT on the surgical management of primary colorectal cancer

OBJECTIVES

Determine the usefulness of [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸ FDG-PET/CT) in the preoperative setting of colorectal cancer (CRC), assessing its impact on changes in management strategy.

METHODS

Retrospective study of CRC patients who underwent preoperative ¹⁸ FDG-PET/CT and CT staging scans in a single referral center. The agreement between ¹⁸ FDG-PET/CT, contrast-enhanced CT, and colonoscopy for the surgical location was compared using the κ coefficient. Maximum standardized uptake (SUV_max ) value was obtained. Univariate and multivariate analyses were conducted.

RESULTS

One hundred ninety-five patients were included. ¹⁸ FDG-PET/CT improved tumor localization in 84.6% (165/195) of cases (κ value 0.798, p < 0.001), thus correcting endoscopic errors 69.7% (30/43) of the time. In patients with incomplete colonoscopies, ¹⁸ FDG-PET/CT detected synchronous tumors in 2.5% (5/195) patients, overlooked by CT staging scans. Based on extracolonic ¹⁸ FDG-uptake, the second primary malignancy was diagnosed in 7(3.6%,7/195) patients and total accuracy for lymph node and distant metastasis was 66.1% and 98.4%, respectively. The treatment plan was altered in 30 (15.4%, 30/196) patients. There was a significant association between the SUV_max and tumor size (odds ratio [OR] 4.254, p = 0.003) and the depth of tumor invasion (OR 1.696, p = 0.026).

CONCLUSIONS

Based on its ability to aid in preoperative evaluation and definitively alter surgical treatment planning, ¹⁸ FDG-PET/CT should be further evaluated in primary CRC.

How Adsorbed Oxygen Atoms Inhibit Hydrogen Dissociation on Tungsten Surfaces

Hydrogen molecules dissociate on clean W(110) surfaces. This reaction is progressively inhibited as the tungsten surface is precovered with oxygen. We use density functional theory and ab initio molecular dynamics to rationalize, at the atomic scale, the influence of the adsorbed O atoms on the H₂ dissociation process. The reaction probability is calculated for kinetic energies below 300 meV and different O nominal coverages. We show that the adsorbed O atoms act as repulsive centers that modulate the dynamics of the impinging H₂ molecules by closing dissociation pathways. In agreement with existing experimental information, H₂ dissociation is absent for an O coverage of half a monolayer. The results show that the influence of O adsorbates on the dissociation dynamics on W(110) goes much beyond the blocking of possible H adsorption sites. Adsorbed O atoms create a sort of chemical shield at the surface that prevents further approach and dissociation of the H₂ molecules.

A systematic literature review of the economic evidence for transarterial radioembolization for the treatment of hepatocellular carcinoma

e16159

Background: Evidence synthesis can be used to demonstrate the economic value of medical technologies. Transarterial radioembolization (TARE) is a clinically effective therapy for hepatocellular carcinoma (HCC); however, a synthesis of the comparative economic outcomes is lacking. This study systematically reviewed and summarized the available economic evaluations of TARE for the treatment of HCC. Methods: A systematic review of economic evaluations of TARE for HCC treatment following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. English and Spanish publications were identified from PubMed, Embase, Cochrane, MEDES, health technology assessment agencies, and scientific congress databases published through May 2021. Results: Among 423 records screened, 20 economic evaluations (two cost-effectiveness analyses (CEAs), eight cost-utility analyses (CUAs), one cost-minimization analysis, six cost analyses, and three budget impact analyses) met the pre-defined criteria for inclusion. Included studies were evaluated from a payer perspective (n = 20) and included both payer and societal perspectives (n = 2). Thirteen studies were published from a European perspective, six from the United States, and one from the Canadian perspective. Included studies evaluated early (n = 4) vs. intermediate and advanced HCC (n = 15). TheraSphere and Sir-Spheres were the most evaluated TARE therapies compared to transarterial chemoembolization (TACE) (n = 12) alone or TACE/sorafenib agents (n = 10). The time horizon in the included studies varied: TARE vs. sorafenib (5-years and lifetime) and TARE vs. TACE (5-years). Variability in health outcomes was observed with greater health benefits reported for TARE vs. TACE for intermediate (n = 1) and advanced-stage patients (n = 2) and TARE vs. sorafenib for intermediate (n = 1) and advanced-stage patients (n = 6). All CEAs compared the costs and survival benefits of TARE vs. TACE/Transarterial embolization (TAE)/sorafenib/tyrosine-kinase inhibitor. Of the 20 studies, TARE was associated with lower treatment costs in ten studies. From the payer perspective, TARE costs varied widely in the Barcelona Clinic Liver Cancer (BCLC) staging system and ranged from $1,770 (BCLC-A) to $66,800 (BCLC-C). The life-years gained (LYG) ranged from 1.1 years (TARE vs. sorafenib/lenvatinib) to 3.1 years (TARE vs. TACE/TAE/drug-eluting bead-TACE). The incremental cost-utility ratio (ICUR) for TARE vs. sorafenib ranged from $38,352/QALY to $71,386 (dominant) and one CUA of TARE vs. TACE and showed an ICUR of $22,181/QALY. Conclusions: Economic evaluations of TARE for HCC treatment are heterogeneous. Overall, TARE is a cost-effective short- and long-term treatment for HCC, driven by increased LYG compared to other HCC therapies.

Biomarkers associated with survival and favourable outcome of radioembolization with yttrium-90 glass microspheres for colon cancer liver metastases: Single centre experience

OBJECTIVE

To determine the therapeutic effectiveness and safety of transarterial radioembolization (TARE) with Yttrium-90 in patients with colorectal cancer (CRC) liver metastases and to evaluate the prognostic value of different biomarkers.

MATERIAL AND METHODS

This prospective longitudinal study enrolled consecutive patients with CRC liver metastases treated with TARE between November 2015 and june 2020. The therapeutic response at three and six months (RECIST1.1 criteria) and the relationship of biomarkers with therapeutic response, by calculating objective tumor response rates (ORR) and disease control (DCR), and overall survival (OS) and progression-free (PFS).

RESULTS

Thirty TAREs were performed in 23 patients (mean age, 61.61 ± 9.13 years; 56.5% male). At three months, the objective response rate (ORR) was 16.7% and the disease control rate (DCR) 53.3%. At six months, the disease progressed in 80%. The ORR and DCR were significantly associated with age at diagnosis (P = 0.047), previous bevacizumab treatment (P = 0.008), pre-TARE haemoglobin (P = 0.008), NLR (P = 0.040), pre-TARE albumin (P = 0.012), pre-TARE ALT (P = 0.023) and tumour-absorbed dose > 115 Gy (P = 0.033). Median overall survival (OS) was 12 months (95% CI, 4.75-19.25 months) and median progression-free survival (PFS) 3 months (95% CI, 2.41-3.59). OS was significantly associated with primary tumour resection (P = 0.019), KRAS mutation (HR: 5.15; P = 0.024), pre-TARE haemoglobin (HR: 0.50; p = 0.009), pre-TARE NLR (HR: 1.65; P = 0.005) and PLR (HR: 1.01; P = 0.042).

CONCLUSION

TARE prognosis and therapeutic response were predicted by different biomarkers, ranging from biochemical parameters to tumour dosimetrics.

Biomarkers associated with survival and favourable outcome of radioembolization with yttrium-90 glass microspheres for colon cancer liver metastases: Single centre experience

OBJETIVE

To determine the therapeutic effectiveness and safety of transarterial radioembolization (TARE) with Yttrium-90 in patients with colorectal cancer (CRC) liver metastases and to evaluate the prognostic value of different biomarkers.

MATERIAL AND METHODS

This prospective longitudinal study enrolled consecutive patients with CRC liver metastases treated with TARE between November 2015 and june 2020. The therapeutic response at three and six months (RECIST1.1 criteria) and the relationship of biomarkers with therapeutic response, by calculating objective tumor response rates (ORR) and disease control (DCR), and overall survival (OS) and progression-free (PFS).

RESULTS

Thirty TAREs were performed in 23 patients (mean age, 61,61±9,13 years; 56,5% male). At three months, the objective response rate (ORR) was 16,7% and the disease control rate (DCR) 53,3%. At six months, the disease progressed in 80%. The ORR and DCR were significantly associated with age at diagnosis (P=.047), previous bevacizumab treatment (P=.008), pre-TARE haemoglobin (P=.008), NLR (P=.040), pre-TARE albumin (P=.012), pre-TARE ALT (P=.023) and tumour-absorbed dose>115Gy (P=.033). Median overall survival (OS) was 12 months (95% CI, 4.75-19.25 months) and median progression-free survival (PFS) 3 months (95% CI, 2.41-3.59). OS was significantly associated with primary tumour resection (P=.019), KRAS mutation (HR: 5.15; P=.024), pre-TARE haemoglobin (HR: .50; p=.009), pre-TARE NLR (HR: 1.65; P=.005) and PLR (HR: 1.01; P=.042).

CONCLUSION

TARE prognosis and therapeutic response were predicted by different biomarkers, ranging from biochemical parameters to tumour dosimetrics.

Systematic review on wearable lower-limb exoskeletons for gait training in neuromuscular impairments

Gait disorders can reduce the quality of life for people with neuromuscular impairments. Therefore, walking recovery is one of the main priorities for counteracting sedentary lifestyle, reducing secondary health conditions and restoring legged mobility. At present, wearable powered lower-limb exoskeletons are emerging as a revolutionary technology for robotic gait rehabilitation. This systematic review provides a comprehensive overview on wearable lower-limb exoskeletons for people with neuromuscular impairments, addressing the following three questions: (1) what is the current technological status of wearable lower-limb exoskeletons for gait rehabilitation?, (2) what is the methodology used in the clinical validations of wearable lower-limb exoskeletons?, and (3) what are the benefits and current evidence on clinical efficacy of wearable lower-limb exoskeletons? We analyzed 87 clinical studies focusing on both device technology (e.g., actuators, sensors, structure) and clinical aspects (e.g., training protocol, outcome measures, patient impairments), and make available the database with all the compiled information. The results of the literature survey reveal that wearable exoskeletons have potential for a number of applications including early rehabilitation, promoting physical exercise, and carrying out daily living activities both at home and the community. Likewise, wearable exoskeletons may improve mobility and independence in non-ambulatory people, and may reduce secondary health conditions related to sedentariness, with all the advantages that this entails. However, the use of this technology is still limited by heavy and bulky devices, which require supervision and the use of walking aids. In addition, evidence supporting their benefits is still limited to short-intervention trials with few participants and diversity among their clinical protocols. Wearable lower-limb exoskeletons for gait rehabilitation are still in their early stages of development and randomized control trials are needed to demonstrate their clinical efficacy.

Description of Influenza B in seasonal epidemic in Cantabria during the beginning of the pandemia due to SARS-CoV-2

Introduction. Co-circulation of the two Influenza B lineages hinders forecast of strain to include in trivalent vaccine. Autonomous Communities such as Cantabria continue without supplying tetravalent vaccine. The aim of this study was to analyse epidemiological characteristics of influenza type B in Cantabria (2019-2020 season) as well as to establish the predominant lineage and its relation to the recommended vaccine. Methods. Retrospective study whereby flu diagnosis and lineage analysis were determined by RT-PCR. Results. All samples belonged to the Victoria lineage. Most prevalent viral co-infection was due to SARS-CoV-2. The population affected by influenza B was mainly paediatric and non-vaccinated patients more frequently required hospital admittance. Conclusions. Influenza type B has a higher incidence in the paediatric population and type A affects more the adult population. Only 28.8% of patients with Influenza B that presented with some underlying condition or risk factor were vaccinated. This shows the need to increase coverage with tetravalent vaccines in order to reduce the burden of disease associated with the Influenza B virus.

Evaluation of an exercise-enabling control interface for powered wheelchair users: a feasibility study with Duchenne muscular dystrophy

Background

Powered wheelchairs are an essential technology to support mobility, yet their use is associated with a high level of sedentarism that can have negative health effects for their users. People with Duchenne muscular dystrophy (DMD) start using a powered wheelchair in their early teens due to the loss of strength in their legs and arms. There is evidence that low-intensity exercise can help preserve the functional abilities of people with DMD, but options for exercise when sitting in a powered wheelchair are limited.

Methods

In this paper, we present the design and the feasibility study of a new version of the MOVit device that allows powered-wheelchair users to exercise while driving the chair. Instead of using a joystick to drive the wheelchair, users move their arms through a cyclical motion using two powered, mobile arm supports that provide controller inputs to the chair. The feasibility study was carried out with a group of five individuals with DMD and five unimpaired individuals. Participants performed a series of driving tasks in a wheelchair simulator and on a real driving course with a standard joystick and with the MOVit 2.0 device.

Results

We found that driving speed and accuracy were significantly lowered for both groups when driving with MOVit compared to the joystick, but the decreases were small (speed was 0.26 m/s less and maximum path error was 0.1 m greater). Driving with MOVit produced a significant increase in heart rate (7.5 bpm) compared to the joystick condition. Individuals with DMD reported a high level of satisfaction with their performance and comfort in using MOVit.

Conclusions

These results show for the first time that individuals with DMD can easily transition to driving a powered wheelchair using cyclical arm motions, achieving a reasonable driving performance with a short period of training. Driving in this way elicits cardiopulmonary exercise at an intensity found previously to produce health-related benefits in DMD.

When Classical Trajectories Get to Quantum Accuracy: The Scattering of H2 on Pd(111)

When elementary reactive processes occur at such low energies that only a few states of reactants and/or products are available, quantum effects strongly manifest and the standard description of the dynamics within the classical framework fails. We show here, for H₂ scattering on Pd(111), that by pseudoquantizing in the spirit of Bohr the relevant final actions of the system, along with adequately treating the diffraction-mediated trapping of the incoming wave, classical simulations achieve an unprecedented agreement with state-of-the-art quantum dynamics calculations.

Usefulness of 18F-fluorocoline PET/CT in prostate cancer patients with biochemical recurrence: Influence of PSA kinetics and hormone therapy

PURPOSE

To evaluate the capacity of 18f-fluorocholine positron emission tomography/computed tomography (FCH PET/CT) to detect biochemical recurrence of prostate cancer and to determine the correlation with PSA kinetics and influence of antiandrogen hormone therapy.

PATIENTS AND METHODS

Observational and retrospective study, which included patients with prostate cancer and criteria for biochemical recurrence and/or resistance to castration, according to the European Association of Urology. FCH PET/CT results were classified as positive or negative, using as gold standard the pathology report, findings of other imaging test, and/or clinical follow-up results. The correlation between FCH PET/CT and PSA kinetics (PSA at the time of exploration [PSA-trigger], doubling time [PSAdt] and velocity [PSAva]) was studied and the influence of hormone therapy was analysed.

RESULTS

The study included 203 patients. The FCH PET/CT detection rate was 43.3%. The group of patients with FCH PET/CT positive showed more aggressive PSA kinetics (PSAdt: 7.5 months and PSAva 8.37±14.8ng/ml/a) than the FCH PET/CT negative group (PSAdt: 14.5±7.6 months and PSAva: 1.8±3.7ng/ml/a). The detection rate of FCH PET/CT in the subgroup with castration resistance was 89.1%, significantly higher than in the group with radical treatment at 29.9%, p<.001.

CONCLUSIONS

FCH PET/CT is useful to detect biochemical recurrence of prostate cancer, especially in patients who receive hormone therapy or more aggressive PSA kinetics.

Impact of amyloid-PET in daily clinical management of patients with cognitive impairment fulfilling appropriate use criteria

To evaluate the use of amyloid-positron emission tomography (PET) in routine clinical practice, in a selected population with cognitive impairment that meets appropriate use criteria (AUC).A multicenter, observational, prospective case-series study of 211patients from 2 level-3 hospitals who fulfilled clinical AUC for amyloid-PET scan in a naturalistic setting. Certainty degree was evaluated using a 5-point Likert scale: 0 (very low probability); 1 (low probability); 2 (intermediate probability); 3 (high probability); and 4 (practically sure), before and after amyloid PET. The treatment plan was considered as cognition-specific or noncognition-specific.Amyloid-PET was positive in 118 patients (55.9%) and negative in 93 patients (44.1%). Diagnostic prescan confidence according amyloid-PET results showed that in both, negative and positive-PET subgroup, the most frequent category was intermediate probability (45.7% and 55.1%, respectively). After the amyloid-PET, the diagnostic confidence showed a very different distribution, that was, in the negative-PET group the most frequent categories are very unlikely (70.7%) and unlikely (29.3%), while in the positive-PET group were very probable (57.6%) and practically sure (39%). Only in 14/211 patients (6.6%) the result of the amyloid-PET did not influence the diagnostic confidence, while in 194 patients (93.4%), the diagnostic confidence improved significantly after amyloid-PET results. The therapeutic intention was modified in 93 patients (44.1%). Specific treatment for Alzheimer disease was started, before amyloid-PET, in 80 patients (37.9%).This naturalistic study provides evidence that the implementation of amyloid-PET is associated with a significant improvement in diagnostic confidence and has a high impact on the therapeutic management of patients with mild cognitive impairment fulfilled clinical AUC.

Diagnosis of metastasis in castration-resistant prostate cancer patients: decision algorithm in imaging tests

INTRODUCTION

In castration-resistant prostate cancer (CRPC), early detection of metastases is essential for the selection of treatment, and prevention of bone complications. However detecting incipient metastases remains a challenge as the conventional radiological tests (bone scintigraphy or computerised tomography) lack sufficient sensitivity. Diagnostic imaging techniques are currently available that have greater sensitivity and specificity, but are little used due to shortfalls in the recommendations.

OBJECTIVE

To create an algorithm that indicates the most suitable diagnostic imaging techniques for the different M0 CRPC patient profiles based on the scientific evidence.

EVIDENCE ACQUISITION

Meetings were held with eight experts in Urology, Pathological Anatomy, Radiodiagnostics and Nuclear Medicine organised by the Andalusian Association of Urology, in which the recommendations and scientific evidence on each of the diagnostic imaging techniques were reviewed.

SUMMARY OF THE EVIDENCE

We present the current recommendations for the detection of metastasis in M0 CRPC patients, the patients that would benefit from early detection, and summarise the evidence to support the use of each of the new techniques.

CONCLUSIONS

Techniques such as ¹⁸F-Choline PET/CT or DWWB MRI and probably open MRI have been demonstrated to have good sensitivity and specificity for patients with low PSA (<10ng/ml). Their inclusion in routine clinical practice will help improve the early detection of metastasis in CRPC patients.

Using CT Data to Improve the Quantitative Analysis of 18F-FBB PET Neuroimages

¹⁸F-FBB PET is a neuroimaging modality that is been increasingly used to assess brain amyloid deposits in potential patients with Alzheimer's disease (AD). In this work, we analyze the usefulness of these data to distinguish between AD and non-AD patients. A dataset with ¹⁸F-FBB PET brain images from 94 subjects diagnosed with AD and other disorders was evaluated by means of multiple analyses based on t-test, ANOVA, Fisher Discriminant Analysis and Support Vector Machine (SVM) classification. In addition, we propose to calculate amyloid standardized uptake values (SUVs) using only gray-matter voxels, which can be estimated using Computed Tomography (CT) images. This approach allows assessing potential brain amyloid deposits along with the gray matter loss and takes advantage of the structural information provided by most of the scanners used for PET examination, which allow simultaneous PET and CT data acquisition. The results obtained in this work suggest that SUVs calculated according to the proposed method allow AD and non-AD subjects to be more accurately differentiated than using SUVs calculated with standard approaches.

Food protein-induced enterocolitis syndrome by fish: Not necessarily a restricted diet

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity usually due to cow's milk or soy. Recent researches show that fish is 1 of the most important triggers of FPIES in the Mediterranean countries. Due to the risk of multiple-food FPIES, avoiding foods in the same category or that often occur together may be reasonable. The aim of this study was to evaluate the evolution and follow-up of FPIES related to fish over a period of 20 years. We describe the clinical features of our population, discuss different approaches to oral food challenges, and analyze the possibility of introducing the culprit fish or other nonrelated fish to avoid unnecessary restricted diets.

Role of PET-CT with 18F-fluorocholine in biochemical recurrence after treatment of prostate cancer with curative intent

OBJECTIVES

To analyse the ability of the PET-CT with ¹⁸F-fluorocholine (¹⁸F-FCH) to detect disease on biochemical recurrence after treatment with curative intent. To determine the clinical variables that would be able to optimise the test's diagnostic yield.

MATERIAL AND METHODS

A retrospective study of PET-CTs with ¹⁸F-fluorocholine performed on 61 patients with prostate cancer who had undergone treatment with curative intent and met the criteria for biochemical recurrence. The results of the PET-CT were categorised into positive or negative and were validated using pre-established criteria. The relationship between the result of the PET-CT and the initial PSA nadir, PSA trigger, rising PSA velocity (PSAva) and PSA doubling time (PSAdt). The relationship between the metastatic sites on the PET-CT and the remaining variables was analysed.

RESULTS

There was a 34.4% detection rate of the disease. The initial PSA, PSA nadir, PSA trigger and PSAva showed statistically significant differences according to the result of the PET-CT. The best discriminatory cut-off point between a positive or negative PET-CT for PSA trigger and PSAva was 3.5ng/ml and 0.25ng/ml/month respectively. The PSAdt was significantly lower in patients with remote disease compared to patients with localised disease (5.1 vs 16.8 months, P=.01). The probability that the PET-CT would detect remote disease vs localised disease was 3.2 times higher if the PSAdt was under 6 months (80% vs 20%, OR: 3.2, P=.02). In the multivariate analysis, only the initial PSA and not having undergone radical prostatectomy were demonstrated as independent predictive factors of a positive PET-CT result.

CONCLUSIONS

The PET-CT with ¹⁸F-FCH can detect disease in a high percentage of patients with biochemical recurrence and provides information on its anatomical location. PSA kinetics and the patient's previous treatment are key variables in increasing the test's diagnostic.

Clinical utility of (18)F-fluorocholine positron-emission tomography/computed tomography (PET/CT) in biochemical relapse of prostate cancer after radical treatment: results of a multicentre study

OBJECTIVE

To evaluate (18)F-fluorocholine positron-emission tomography (PET)/computed tomography (CT) in restaging patients with a history of prostate adenocarcinoma who have biochemical relapse after early radical treatment, and to correlate the technique's disease detection rate with a set of variables and clinical and pathological parameters.

PATIENTS AND METHODS

This was a retrospective multicentre study that included 374 patients referred for choline-PET/CT who had biochemical relapse. In all, 233 patients who met the following inclusion criteria were analysed: diagnosis of prostate cancer; early radical treatment; biochemical relapse; main clinical and pathological variables; and clinical, pathological and imaging data needed to validate the results. Criteria used to validate the PET/CT: findings from other imaging techniques, clinical follow-up, treatment response and histological analysis. Different statistical tests were used depending on the distribution of the data to correlate the results of the choline-PET/CT with qualitative [T stage, N stage, early radical prostatectomy (RP) vs other treatments, hormone therapy concomitant to choline-PET/CT] and quantitative [age, Gleason score, prostate-specific antigen (PSA) levels at diagnosis, PSA nadir, PSA level on the day of the choline-PET/CT (Trigger PSA) and PSA doubling time (PSADT)] variables. We analysed whether there were independent predictive factors associated with positive PET/CT results.

RESULTS

Choline-PET/CT was positive in 111 of 233 patients (detection rate 47.6%) and negative in 122 (52.4%). Disease locations: prostate or prostate bed in 26 patients (23.4%); regional and/or distant lymph nodes in 52 (46.8%); and metastatic bone disease in 33 (29.7%). Positive findings were validated by: results from other imaging techniques in 35 patients (15.0%); at least 6 months of clinical follow-up in 136 (58.4%); treatment response in 24 (10.3%); histological analysis of lesions in 17 (7.3%); and follow-up plus imaging results in 21 (9.0%). The statistical analysis of qualitative variables, corresponding to patients' clinical characteristics, and the positive/negative final PET/CT results revealed that only whether or not early treatment with RP was done was statistically significant (P < 0.001), with the number of positive results higher in patients who did not undergo a RP. Among the quantitative variables, Gleason score, Trigger PSA and PSADT clearly differentiated the two patient groups (positive and negative choline-PET/CT: P = 0.010, P = 0.001 and P = 0.025, respectively). A Gleason score of <5 or ≥ 8 clearly differentiated positive from negative PET. Trigger PSA: mean of 8 ng/mL for positive PET/CT vs 2.8 ng/mL for negative PET/CT; PSADT: mean of 8 months for positive vs 12.6 months for negative. The optimal threshold values were: 3 ng/mL for Trigger PSA level and 6 months for PSADT (Youden index/receiver operating characteristic curve). Analysing these two variables together showed that PSADT was more conclusive in patients with lower Trigger PSA levels. Analysing variables by location showed that only PSADT was able to differentiate between those with disease confined to the prostate compared with the other two locations (lymph nodes and bone), with shorter PSADT in these two, which was statistically significant (P < 0.002). In the patient group with a PSA level of <1.5 ng/mL, 30.8% had the disease, 7% of whom had metastatic bone disease. In the multivariate logistic regression, the risks factors that were clearly independent for those with positive PET/CT were: PSA level of >3 ng/mL, no early RP, and Gleason score of ≥ 8.

CONCLUSION

Our results support the usefulness of (18)F-fluorocholine PET/CT in biochemical relapse of prostate cancer after radical treatment, with an overall disease detection rate close to 50%, and it can be recommended as first-line treatment. As mentioned above, besides Trigger PSA levels, there are other clinical and pathological variables that need to be considered so as to screen patients properly and thus minimise the number of nodular lesions and increase the diagnostic accuracy of the examination.

The role of positron emission tomography/computed tomography imaging with radiolabeled choline analogues in prostate cancer

INTRODUCTION

prostate cancer is the most frequent solid malignant tumor in Western Countries. Positron emission tomography/x-ray computed tomography imaging with radiolabeled choline analogues is a useful tool for restaging prostate cancer in patients with rising prostate-specific antigen after radical treatment (in whom conventional imaging techniques have important limitations) as well as in the initial assessment of a selected group of prostate cancer patients. For this reason a literature review is necessary in order to evaluate the usefulness of this imaging test for the diagnosis and treatment of prostate cancer.

EVIDENCE ACQUISITION

a MEDLINE (PubMed way) literature search was performed using the search parameters: «Prostate cancer» and «Choline-PET/CT». Other search terms were «Biochemical failure» and/or «Staging» and/or «PSA kinetics». English and Spanish papers were selected; original articles, reviews, systematic reviews and clinical guidelines were included.

CONCLUSIONS

according to available data, radiolabeled choline analogues plays an important role in the management of prostate cancer, especially in biochemical relapse because technique accuracy is properly correlated with prostate-specific antigen values and kinetics. Although is an emerging diagnostic technique useful in treatment planning of prostate cancer, final recommendations have not been submitted.

Ability of FDG-PET/CT in the detection of gallbladder cancer

PURPOSE

To assess the value of FDG-PET/CT in the evaluation of gallbladder carcinomas (GBC).

METHODS

A prospective cohort of patients with suspicion of or confirmed GBC was studied with FDG-PET/CT. Diagnostic accuracy parameters were calculated in comparison with pathology and/or the clinical course of patients. Clinical impact of PET/CT imaging was estimated.

RESULTS

Forty-nine patients were enrolled (34 malignant tumors, 15 benign lesions; 37 staging, 12 restaging). Overall diagnostic accuracy was 95.9% for the diagnosis of the primary lesion, 85.7% for lymph node involvement and 95.9% for metastatic disease. Mean SUVmax in malignant gallbladder lesions was 7.92 ± 6.25 Analysis of ROC curves showed a SUVmax cut-off value of 3.62 for malignancy (S: 78.1%; Sp: 88.2%). Diagnostic accuracy in the restaging group reached 100%. FDG-PET/CT changed the management of 22.4% of the population.

COMMENTS

Diagnosis of malignancy or benignity of suspicious gallbladder lesions is accurately made with FDG PET/CT, allowing a precise staging of GBC due to its ability to identify unsuspected metastatic disease. SUVmax has a complementary role in addition to visual analysis.

[Differential association between the regional metabolism of the prefrontal cortex and limbic structures, and the time of abstinence in substance dependent individuals]

Despite the existence of numerous neuroimaging studies demonstrating significant brain functional alterations in substance users, only a few studies have tried to analyze the association between the duration of abstinence and brain metabolism within substance users. The aim of this study was to examine the association between resting-state regional brain metabolism (measured with 18F-fluordeoxyglucose Positron Emission Tomography (FDGPET) and duration of drug abstinence in a sample of 49 abstinent polysubstance users. PET images were pre-processed and analyzed using SPM5 and SPSS 15. After image pre-processing, the level of glucose uptake in a pre-established set of regions of interest was extracted and bivariate correlations between this and the duration of abstinence of the participants were conducted. Results showed a negative correlation between duration of abstinence and the amygdale and the hippocampus bilaterally and a positive correlation between duration of abstinence and the left inferior frontal operculum. The associations found suggest different involvement of these structures in maintaining abstinence and emphasize the need to work on stress regulation, craving and behaviour control even after significant periods of abstinence.

Surgical adhesive may cause false positives in integrated positron emission tomography and computed tomography after lung cancer resection

Surgical adhesives are frequently used after pulmonary resection to prevent or reduce pulmonary air leakages, since leakages may cause complications delaying the removal of chest drainage tubes and prolonging in-hospital stay. In this paper, we present 2 patients who underwent curative-intent pulmonary resection for non-small-cell lung carcinoma, in which the biological adhesive BioGlue(®) was used. Follow-up fluoro-2-deoxy-D-glucose positron emission tomography/computed tomographic (FDG-PET/CT) imaging revealed hypermetabolic pulmonary nodular lesions. Subsequent surgical exploration showed that the lesions were foreign body reactions to the bioadhesive. To our knowledge, this is the first study to examine false-positive follow-up FDG-PET/CT scans caused by the use of BioGlue(®) in pulmonary resection procedures.

Neptunium multipoles and resonant x-ray Bragg diffraction by neptunium dioxide (NpO2)

The low-temperature ordered state of neptunium dioxide (NpO(2)) remains enigmatic. After decades of experimental and theoretical efforts, long-range order of a time-odd (magnetic) high-order atomic multipole moment is now generally considered to be the fundamental order parameter, the most likely candidate being a magnetic triakontadipole (rank 5). To date, however, direct experimental observation of the primary order parameter remains outstanding. In the light of new experimental findings, we re-examine the effect of crystal symmetry on the atomic multipoles and the resulting x-ray resonant scattering signature. Our simulations use the crystallographic point group ̅3m (D(3d)), because corresponding magnetic groups ̅3m', ̅3'm', and ̅3'm are shown by us to be at odds with a wealth of experimental results. In addition to the previously observed (secondary) quadrupole order, we derive expressions for higher-order multipoles that might be observed in future experiments. In particular, magnetic octupole moments are predicted to contribute to Np M(2,3) and L(2,3) resonant scattering via E2–E2 events. The Lorentzian-squared lineshape observed at the M(4) resonance is shown to be the result of the anisotropy of the 3p(3/2) core levels. Quantitative comparison of our calculations to the measured data yields a core–hole width Γ = 2.60(7) eV and a core-state exchange energy [absolute value]ε(1/2)[absolute value] = 0.76(2) eV.

[Positron tomography with 18F-fluorodeoxyglucose in the preoperative evaluation of gall bladder lesions suspicious of malignancy. Diagnostic utility and clinical impact]

BACKGROUND

Gallbladder carcinoma is a neoplasm having a poor prognosis in which the role of the positron emission tomography with (18)F-fluordeoxyglucose as a diagnostic tool, although of possible usefulness, has not been well-defined.

METHODS/DESIGN

It is a prospective cohort of patients with radiologically malignant suspicious gallbladder lesions. A staging diagnostic presurgical FDG-PET study was carried out in each patient using both dedicated PET and multimodality PET-CT scanners. Diagnostic accuracy parameters were calculated from the results of PET imaging and were correlated with the condition and/or the clinical course of the patients. The clinical impact of its implementation in the diagnosis of gallbladder carcinoma was also analyzed.

RESULTS

A total of 42 patients were recruited (22 malignant lesions, 20 benign). Overall diagnostic accuracy was 83.33% for the diagnosis of the primary lesion, 88.89% for the evaluation of lymph node involvement and 85.1% for the evaluation of metastatic disease. Mean SUVmax in malignant gallbladder lesions was 6.14±2.89. ROC curve showed a cut-off value of 3.65 in the SUVmax for malignancy. Accuracy of PET studies alone (n=21) was slightly lower than that of the PET/CT (n=21). FDG-PET changed the management of 14.8% of the population due to the identification of unsuspected metastatic disease.

COMMENTS

FDG-PET accurately diagnoses malignancy or benignity of suspicious gallbladder lesions, with the addition of its capacity to identify unsuspected metastatic disease. PET-CT improves the diagnostic accuracy of the procedure, due to the metabolic-structural complementarity of their information. The SUVmax has a complementary value added to the visual analysis.

The value of metabolic imaging to predict tumour response after chemoradiation in locally advanced rectal cancer

Background

We aim to investigate the possibility of using 18F-positron emission tomography/computer tomography (PET-CT) to predict the histopathologic response in locally advanced rectal cancer (LARC) treated with preoperative chemoradiation (CRT).

Methods

The study included 50 patients with LARC treated with preoperative CRT. All patients were evaluated by PET-CT before and after CRT, and results were compared to histopathologic response quantified by tumour regression grade (patients with TRG 1-2 being defined as responders and patients with grade 3-5 as non-responders). Furthermore, the predictive value of metabolic imaging for pathologic complete response (ypCR) was investigated.

Results

Responders and non-responders showed statistically significant differences according to Mandard's criteria for maximum standardized uptake value (SUV_max) before and after CRT with a specificity of 76,6% and a positive predictive value of 66,7%. Furthermore, SUV_max values after CRT were able to differentiate patients with ypCR with a sensitivity of 63% and a specificity of 74,4% (positive predictive value 41,2% and negative predictive value 87,9%); This rather low sensitivity and specificity determined that PET-CT was only able to distinguish 7 cases of ypCR from a total of 11 patients.

Conclusions

We conclude that 18-F PET-CT performed five to seven weeks after the end of CRT can visualise functional tumour response in LARC. In contrast, metabolic imaging with 18-F PET-CT is not able to predict patients with ypCR accurately.

Real-time three-dimensional transesophageal echocardiographic imaging of cor triatriatum and persistent left superior vena cava

The authors describe the case of a 54-year-old woman with the association of two rare congenital cardiac anomalies: cor triatriatum and persistent left superior vena cava with the special characteristic of direct drainage to the right atrium. Real-time three-dimensional transesophageal echocardiography offered a comprehensive anatomic and functional evaluation of these infrequent entities.

Diagnostic accuracy of 201Thallium-SPECT and 18F-FDG-PET in the clinical assessment of glioma recurrence

PURPOSE

Reliable differential diagnosis between tumour recurrence and treatment-induced lesions is required to take advantage of new therapeutic approaches to recurrent gliomas. Structural imaging methods offer a high sensitivity but a low specificity, which might be improved by neurofunctional imaging. This study aimed to test the hypothesis that incorporation of 18-fluoro-deoxy-glucose positron emission tomography (FDG-PET) increases the accuracy of this differential diagnosis obtained with 201Tl chloride-single-photon emission computed tomography (201Tl-SPECT).

MATERIALS AND METHODS

Seventy-six patients (mean age 47.72 +/- 16.19 years) under suspicion of glioma recurrence, 42% with low-grade and 58% with high-grade lesions, were studied by (201)Tl-SPECT and FDG-PET, reporting results under blinded conditions using visual analysis. Tumour was confirmed by histological confirmation (23 patients) or clinical and structural neuroimaging follow-up (mean of 2.6 years).

RESULTS

This population had a high disease prevalence (72%). Globally, highest sensitivity was obtained using 201Tl-SPECT assessed with MRI (96%) and highest specificity using FDG-PET + MRI (95%). FDG-PET appeared slightly better for confirming tumour recurrence, whereas 201Tl-SPECT was superior for ruling out possible recurrence (disease present in 38% of FDG-PET negative explorations). In the high-grade subgroup, there were no false-positive examinations (specificity: 100%), but sensitivity differed among techniques (201Tl-SPECT : 94%; 201Tl-SPECT + MRI: 97%; FDG-PET + MRI: 83%). In the low-grade subgroup, 201Tl-SPECT + MRI showed highest sensitivity (95%) and lowest posttest negative probability (9%); FDG-PET + MRI offered highest specificity (92%) with a posttest negative probability of 35%.

CONCLUSIONS

FDG-PET does not clearly improve the diagnostic accuracy of (201)Tl-SPECT, which appears to be a more appropriate examination for the diagnosis of possible brain tumour recurrence, especially for ruling it out.

Fluorine-18 fluorodeoxyglucose PET in the preoperative staging of colorectal cancer

INTRODUCTION

In patients with colorectal cancer (CC), preoperative evaluation and staging should focus on techniques that might alter the preoperative or intraoperative surgical plan. Conventional imaging methods (CT, MRI) have low accuracy for identifying the depth of tumour infiltration and have limited ability to detect regional lymph node involvement. The aim of this study was to evaluate the utility of FDG-PET in the initial staging of patients with CC in comparison with conventional staging methods and to determine its impact on therapeutic management.

METHODS

One hundred and four patients with a diagnosis of CC (53 males and 51 females; mean age 66.76+/-12.36 years), selected prospectively, were studied for staging using a standard procedure (CT) and FDG-PET. When possible, the reference method was histology.

RESULTS

In 14 patients, surgery was contraindicated by FDG-PET owing to the extent of disease (only 6/14 suspected by CT). FDG-PET revealed four synchronous tumours. For N staging, both procedures showed a relatively high specificity but a low diagnostic accuracy (PET 56%, CT 60%) and sensitivity (PET 21%, CT 25%). For M assessment, diagnostic accuracy was 92% for FDG-PET and 87% for CT. FDG-PET results led to modification of the therapy approach in 50% of patients with unresectable disease. FDG-PET findings were important, revealing unknown disease in 19.2%, changing the staging in 13.46% and modifying the scope of surgery in 11.54% (with a change in the therapeutic approach in 17.85% of those patients with rectal cancer).

CONCLUSION

Compared with conventional techniques, FDG-PET appears to be useful in pre-surgical staging of CC, revealing unsuspected disease and impacting on the treatment approach.

Tomografía de emisión de positrones con fluordesoxiglucosa-F18 en el seguimiento del cáncer de endometrio

OBJECTIVE

To assess the utility of FDG-PET in the follow-up of patients treated for endometrial cancer and with suspicion of recurrence according to conventional imaging methods (CT, MRI) and/or elevation of serum tumour markers.

MATERIALS AND METHODS

Between April 2002 and December 2005, eleven patients underwent 17 FDG-PET studies (six with 2 studies); mean age was 63.4 yrs (range, 52-69 yrs) and time since diagnosis ranged from 11 months to 12 yrs (mean of 56 months). Initially, seven patients were in stage I, three in stage III and one in stage IV (FIGO classification). Histologically, they corresponded to 8 endometrioid carcinomas and 3 non endometrioid carcinomas.

RESULTS

FDG-PET showed infradiaphragmatic uptake in 3 patients and disseminated disease in 7 cases. FDG-PET showed no uptake in one patient. CT (n = 7) or MRI (n = 7) detected infradiaphragmatic lesions in 5 patients and visceral lesions in 2. In 11 patients, tumour markers were elevated (CA125, n = 9; CA19.9, n = 2; CA15.3, n = 2). In 7 patients, FDG-PET modified the information yielded by conventional imaging techniques and in 4 patients, the FDG-PET contributed no additional information. In 2 patients, histologic confirmation of the lesions was obtained and in 9 patients, there were clinical follow-up (from 3 to 20 months, mean of 8.7 months) and imaging studies.

CONCLUSIONS

FDG-PET is superior to CT and MRI for detecting recurrences in the follow-up of patients with endometrial cancer.

Application of modern imaging methods in diagnosis of gallbladder cancer

The poor prognosis of gallbladder cancer (GBC) is related to its dissemination capacity and usually late diagnosis due to its non-specific clinical appearance. Recent improvements in hepatobiliary surgery have underlined the importance of an early specific diagnosis, which requires a multidisciplinary approach and, when possible, specialized equipment. The first step in an early diagnosis is to identify patients in the appropriate epidemiological setting (e.g., incidental finding, chronic cholecystitis) for the correct interpretation of test results. It is desirable to enhance the sensitivity of the initial ultrasound (US) examination by use of the appropriate technology in skilled specialist hands. When GBC is suggested by US findings, FDG-PET can be considered complementary to establish the benign/malignant nature of the lesion and to obtain a primary staging study. If GBC is confirmed, thin slice spiral CT can contribute valuable information on local spread. In this regard, recent hybrid PET-CT systems provide structural and functional information simultaneously and may offer early and accurate T, N, and M staging with an improved specificity.

Positron-emission tomography with fluorine-18-fluoro-2-deoxy-D-glucose for gallbladder cancer diagnosis

BACKGROUND

Recent advances in hepatobiliary surgery have underscored the need for presurgical diagnosis of gallbladder cancer. Frequently, clinical presentation, biochemical analysis, and structural ultrasound or computed axial tomography images do not enable definitive differentiation of cholecystitis or cholethiasis from gallbladder cancer. The aim of this study was to evaluate the role of fludeoxy glucose-positron-emission tomography (FDG-PET) in establishing the benign or malignant nature of gallbladder lesions.

METHODS

A case series of 16 patients with clinical symptoms suggestive of biliary colic or chronic cholecystitis and with inconclusive ultrasound and/or computed axial tomography findings for presence of gallbladder cancer were studied by FDG-PET.

RESULTS

FDG-PET showed a sensitivity of 0.80, a specificity of 0.82, and positive and negative predictive values of 0.67 and 0.90, respectively. There was 1 false- negative result in 1 patient with mucinous adenocarcinoma and 2 false-positive results in 1 patient with tuberculoid granulomatous reaction and 1 patient with polypoid lesion with adenomyomatosis.

CONCLUSIONS

FDG-PET may be of utility to establish the diagnosis of gallbladder cancer in patients with nonspecific clinical and imaging findings.

201Tl-SPECT in low-grade gliomas: diagnostic accuracy in differential diagnosis between tumour recurrence and radionecrosis

PURPOSE

The aim of this work was to describe the usefulness of a simple (201)Tl single-photon emission computed tomography (SPECT) technique in the differential diagnosis between tumour recurrence and radionecrosis during the follow-up of patients treated for low-grade gliomas.

METHODS

The study population comprised 84 patients treated for low-grade gliomas who showed suspicion of tumour recurrence during their follow-up. All patients were examined by neuro-anatomical imaging procedures (CT, MRI) and (201)Tl-SPECT. (201)Tl-SPECT images were assessed by visual analysis based only on the information on the prescription form and by estimation of the uptake index (ratio of mean counts in the lesion to those in the contralateral mirror area). Examiners were blinded to the results of other tests.

RESULTS

Under these conditions, the neuro-anatomical procedures yielded 26.2% inconclusive reports, with a global diagnostic accuracy of 0.61, a sensitivity of 0.63 and a specificity of 0.59. The global diagnostic accuracy for (201)Tl-SPECT was 0.83, with a sensitivity of 0.88 and a specificity of 0.76. Diagnostic pitfalls were observed in regions with physiological (201)Tl uptake, i.e. the posterior cranial fossa, diencephalon, lateral ventricles and cavernous and longitudinal venous sinuses. An uptake index cut-off value of 1.25 showed a sensitivity of 0.90 and specificity of 0.80 for detection of tumour activity.

CONCLUSION

(201)Tl-SPECT has adequate diagnostic accuracy to be part of routine algorithms in the follow-up of patients with low-grade glioma suspected of tumour recurrence, as an alternative to neuro-anatomical procedures and not solely as a complementary test.

Utility of fluorine-18-fluorodeoxyglucose positron emission tomography in differentiated thyroid carcinoma with negative radioiodine scans and elevated serum thyroglobulin levels

BACKGROUND

This study aimed to determine the role of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in the follow-up of patients who underwent total thyroidectomy and iodine-131 ((131)I) ablation therapy for differentiated thyroid cancer and presented increased thyroglobulin levels with negative (131)I and thallium-201 ((201)Tl) scans.

METHODS

Two patients with follicular carcinoma and eight with papillary tumors underwent total thyroidectomy and (131)I therapy until the (131)I scan was negative. (131)I and (201)Tl scans were performed with negative results in all cases, while serum thyroglobulin measurements were all positive with negative thyroglobulin autoantibodies. One week after the (131)I scans, all the patients underwent FDG-PET whole-body scans.

RESULTS

The FDG-PET scan detected in 4 patients, a single focal increase of FDG uptake in one lymph node metastasis (subsequently confirmed histologically); in 1 patient, multiple pathological focal uptakes in brain, neck, and chest; and in 1 patient, two mild focal uptakes in the mediastinum, close to the tracheal branch. In 2 other patients, pathological FDG uptakes in cervical spine and mediastinum were not confirmed by other imaging techniques, and in the 2 remaining patients the scan results were inconclusive. The sensitivity of FDG-PET whole-body scan for detecting metastatic thyroid cancer was 60%.

CONCLUSIONS

This study indicates that the FDG-PET whole-body scan is a useful tool in the follow-up of patients with differentiated thyroid cancer, negative (131)I and (201)Tl scans and elevated serum thyroglobulin levels. The FDG-PET scan detects metastatic disease in 60% of patients with differentiated thyroid cancer, enabling surgical therapy to be performed on accessible lesions.

False positive thallium-201 SPECT imaging in brain abscess

Three cases of intracranial 201Tl uptake, reported as positive tumour activity in patients with a final diagnosis of abscess, are described. 201Tl has been proposed as a useful oncotropic radiotracer in the diagnosis of brain tumour activity. These cases suggest a note of caution in the interpretation of 201Tl brain images in the differential diagnosis of an intracranial expanding mass.

An alternative to the reference method for testing the radiochemical purity of 99Tcm-tetrofosmin

The recommended method for controlling the radiochemical purity (RCP) of 99Tcm-labelled tetrofosmin is thin-layer chromatography (TLC) with silica gel as the stationary phase and acetone:dichloromethane (35:65, v/v) as the mobile phase. However, this test is time-consuming and uses a toxic substance. We propose an alternative method to control RCP, based on a solid-phase extraction method (SPE) using a Sep Pak C18 cartridge. We used both methods to analyse 35 samples and to determine the percentages of colloid, radiopharmaceutical and free 99Tcm-pertechnetate. Normal labelling processes were modified to obtain a wide range of values. The range of RCP values obtained was 63.4-96.5% (median = 93.8%) by the standard TLC method and 70.1-96.4% (median = 94.1%) by the SPE method. A significant difference was observed only for the percentage of free 99Tcm-pertechnetate (P < 0.05). The agreement between the two methods, using 90% RCP as the limit, gave a kappa index = +1 (P < 0.001), indicating total agreement between them. The proposed method is useful to control RCP because it yields results that are in good agreement with those of the standard method, and because it is safer and less time-consuming.