Introduction Dynamic contrast-enhanced CT (DCE-CT) and positron emission tomography/CT (PET/CT) have a high reported accuracy for the diagnosis of malignancy in solitary pulmonary nodules (SPNs). The aim of this study was to compare the accuracy and cost-effectiveness of these. Methods In this prospective multicentre trial, 380 participants with an SPN (8–30 mm) and no recent history of malignancy underwent DCE-CT and PET/CT. All patients underwent either biopsy with histological diagnosis or completed CT follow-up. Primary outcome measures were sensitivity, specificity and overall diagnostic accuracy for PET/CT and DCE-CT. Costs and cost-effectiveness were estimated from a healthcare provider perspective using a decision-model. Results 312 participants (47% female, 68.1±9.0 years) completed the study, with 61% rate of malignancy at 2 years. The sensitivity, specificity, positive predictive value and negative predictive values for DCE-CT were 95.3% (95% CI 91.3 to 97.5), 29.8% (95% CI 22.3 to 38.4), 68.2% (95% CI 62.4% to 73.5%) and 80.0% (95% CI 66.2 to 89.1), respectively, and for PET/CT were 79.1% (95% CI 72.7 to 84.2), 81.8% (95% CI 74.0 to 87.7), 87.3% (95% CI 81.5 to 91.5) and 71.2% (95% CI 63.2 to 78.1). The area under the receiver operator characteristic curve (AUROC) for DCE-CT and PET/CT was 0.62 (95% CI 0.58 to 0.67) and 0.80 (95% CI 0.76 to 0.85), respectively (p<0.001). Combined results significantly increased diagnostic accuracy over PET/CT alone (AUROC=0.90 (95% CI 0.86 to 0.93), p<0.001). DCE-CT was preferred when the willingness to pay per incremental cost per correctly treated malignancy was below £9000. Above £15 500 a combined approach was preferred. Conclusions PET/CT has a superior diagnostic accuracy to DCE-CT for the diagnosis of SPNs. Combining both techniques improves the diagnostic accuracy over either test alone and could be cost-effective. Trial registration number NCT02013063

BACKGROUND:Current pathways recommend positron emission tomography-computerised tomography for the characterisation of solitary pulmonary nodules. Dynamic contrast-enhanced computerised tomography may be a more cost-effective approach. OBJECTIVES:To determine the diagnostic performances of dynamic contrast-enhanced computerised tomography and positron emission tomography-computerised tomography in the NHS for solitary pulmonary nodules. Systematic reviews and a health economic evaluation contributed to the decision-analytic modelling to assess the likely costs and health outcomes resulting from incorporation of dynamic contrast-enhanced computerised tomography into management strategies. DESIGN:Multicentre comparative accuracy trial. SETTING:Secondary or tertiary outpatient settings at 16 hospitals in the UK. PARTICIPANTS:Participants with solitary pulmonary nodules of ≥ 8 mm and of ≤ 30 mm in size with no malignancy in the previous 2 years were included. INTERVENTIONS:Baseline positron emission tomography-computerised tomography and dynamic contrast-enhanced computer tomography with 2 years' follow-up. MAIN OUTCOME MEASURES:Primary outcome measures were sensitivity, specificity and diagnostic accuracy for positron emission tomography-computerised tomography and dynamic contrast-enhanced computerised tomography. Incremental cost-effectiveness ratios compared management strategies that used dynamic contrast-enhanced computerised tomography with management strategies that did not use dynamic contrast-enhanced computerised tomography. RESULTS:A total of 380 patients were recruited (median age 69 years). Of 312 patients with matched dynamic contrast-enhanced computer tomography and positron emission tomography-computerised tomography examinations, 191 (61%) were cancer patients. The sensitivity, specificity and diagnostic accuracy for positron emission tomography-computerised tomography and dynamic contrast-enhanced computer tomography were 72.8% (95% confidence interval 66.1% to 78.6%), 81.8% (95% confidence interval 74.0% to 87.7%), 76.3% (95% confidence interval 71.3% to 80.7%) and 95.3% (95% confidence interval 91.3% to 97.5%), 29.8% (95% confidence interval 22.3% to 38.4%) and 69.9% (95% confidence interval 64.6% to 74.7%), respectively. Exploratory modelling showed that maximum standardised uptake values had the best diagnostic accuracy, with an area under the curve of 0.87, which increased to 0.90 if combined with dynamic contrast-enhanced computerised tomography peak enhancement. The economic analysis showed that, over 24 months, dynamic contrast-enhanced computerised tomography was less costly (£3305, 95% confidence interval £2952 to £3746) than positron emission tomography-computerised tomography (£4013, 95% confidence interval £3673 to £4498) or a strategy combining the two tests (£4058, 95% confidence interval £3702 to £4547). Positron emission tomography-computerised tomography led to more patients with malignant nodules being correctly managed, 0.44 on average (95% confidence interval 0.39 to 0.49), compared with 0.40 (95% confidence interval 0.35 to 0.45); using both tests further increased this (0.47, 95% confidence interval 0.42 to 0.51). LIMITATIONS:The high prevalence of malignancy in nodules observed in this trial, compared with that observed in nodules identified within screening programmes, limits the generalisation of the current results to nodules identified by screening. CONCLUSIONS:Findings from this research indicate that positron emission tomography-computerised tomography is more accurate than dynamic contrast-enhanced computerised tomography for the characterisation of solitary pulmonary nodules. A combination of maximum standardised uptake value and peak enhancement had the highest accuracy with a small increase in costs. Findings from this research also indicate that a combined positron emission tomography-dynamic contrast-enhanced computerised tomography approach with a slightly higher willingness to pay to avoid missing small cancers or to avoid a 'watch and wait' policy may be an approach to consider. FUTURE WORK:Integration of the dynamic contrast-enhanced component into the positron emission tomography-computerised tomography examination and the feasibility of dynamic contrast-enhanced computerised tomography at lung screening for the characterisation of solitary pulmonary nodules should be explored, together with a lower radiation dose protocol. STUDY REGISTRATION:This study is registered as PROSPERO CRD42018112215 and CRD42019124299, and the trial is registered as ISRCTN30784948 and ClinicalTrials.gov NCT02013063. FUNDING:This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 17. See the NIHR Journals Library website for further project information.

Abstract Introduction: Recent published (British Society of Gastroenterology) guidelines strongly recommended investigating unexplained chronic loose stools with SeHCAT scans when available rather than empirical treatment. SeHCAT scan was introduced at our trust in 2015. We aimed to audit this locally. Methods All SeHCAT scans that were done at our trust trust from Jan 2015 to March 2020 were included. Patient demographics along with risk factors and duration of symptoms were documented as well as the referred speciality. Results 55 patients were identified. Average age at time of diagnosis was 50y (18-70y). M:F was 1:3.2 . Most scans were requested by the oncology team as part of the “pelvic radiotherapy late effects service” (n = 25), followed by the gastroenterology team (n = 22) and general surgery team (n = 8). The mean duration of symptoms was 4 years. 73% of the scans showed evidence of bile acid malabsorption (BAM) (n = 40) with bile retention <15%, with the majority of them (n = 30) having severe BAM (retention <5%). 60% of the patients had at least one lower GI endoscopy as part of their workup. The majority of patients were found to have type 3 BAM (n = 37). 60% of patients had symptom improvement on either diet alone or with bile-acid sequestrants (n = 23) and were discharged. Conclusion: SeHCAT scan is a useful test to investigate unexplained chronic diarrhoea. It is important to identify patients at risk of developing bile acid malabsorption. It is currently underutilized by our trust, which might be because of funding issues and awareness among clinicians.

Purpose Early and accurate localization of lesions in patients with biochemical recurrence (BCR) of prostate cancer may guide salvage therapy decisions. The present study, 18F-Fluciclovine PET/CT in biochemicAL reCurrence Of Prostate caNcer (FALCON; NCT02578940), aimed to evaluate the effect of 18F-fluciclovine on management of men with BCR of prostate cancer. Methods and Materials Men with a first episode of BCR after curative-intent primary therapy were enrolled at 6 UK sites. Patients underwent 18F-fluciclovine positron emission tomography/computed tomography (PET/CT) according to standardized procedures. Clinicians documented management plans before and after scanning, recording changes to treatment modality as major and changes within a modality as other. The primary outcome measure was record of a revised management plan postscan. Secondary endpoints were evaluation of optimal prostate specific antigen (PSA) threshold for detection, salvage treatment outcome assessment based on 18F-fluciclovine-involvement, and safety. Results 18F-Fluciclovine was well tolerated in the 104 scanned patients (median PSA=0.79 ng/mL). Lesions were detected in 58 out of 104 (56%) patients. Detection was broadly proportional to PSA level; ≤1 ng/mL, 1 out of 3 of scans were positive, and 93% scans were positive at PSA >2.0 ng/mL. Sixty-six (64%) patients had a postscan management change (80% after a positive result). Major changes (43 out of 66; 65%) were salvage or systemic therapy to watchful waiting (16 out of 66; 24%); salvage therapy to systemic therapy (16 out of 66; 24%); and alternative changes to treatment modality (11 out of 66, 17%). The remaining 23 out of 66 (35%) management changes were modifications of the prescan plan: most (22 out of 66; 33%) were adjustments to planned brachytherapy/radiation therapy to include a 18F-fluciclovine-guided boost. Where 18F-fluciclovine guided salvage therapy, the PSA response rate was higher than when 18F-fluciclovine was not involved (15 out of 17 [88%] vs 28 out of 39 [72%]). Conclusions 18F-Fluciclovine PET/CT located recurrence in the majority of men with BCR, frequently resulting in major management plan changes. Incorporating 18F-fluciclovine PET/CT into treatment planning may optimize targeting of recurrence sites and avoid futile salvage therapy.

Objective The aim of this study was to investigate the accuracy of locating parathyroid adenomas using dual-Isotope subtraction single-photon emission computed tomography-computed tomography (SPECT-CT) in comparison with clinical follow-up and pathology findings from surgery. Patients and methods A retrospective cohort study of dual-isotope subtraction SPECT-CT was carried out on 224 consecutive patients who were diagnosed with primary hyperparathyroidism. All the patients were injected with 20MBq of iodine-123-iodide, followed 20 min later by 900MBq of technetium-99m-sestamibi. Planar neck and chest views and SPECT-CT images were acquired 15 min after administration, followed by an additional planar image set at 2 h to view washout; all images were dual energy. In all, 115 out of 224 of the patients imaged underwent parathyroid surgery. The imaging results were compared with pathology findings when available and, in those who did not undergo surgery, and in some complex cases, with clinical measures after a 2-year clinical follow-up period. Findings Out of the 224 patients, 135 patients had complete pathology and/or clinical follow-up data and were included in the analysis. The sensitivity of the subtraction SPECT-CT findings was measured to be 95%, with a specificity of 89% for the detection and localization of parathyroid adenomas. The positive predictive value was found to be 97% and the negative predictive value was found to be 83%. The accuracy of the technique was 94% in detecting parathyroid adenoma and 92% in accurate localization. Conclusion Dual-isotope subtraction SPECT-CT imaging has a very high sensitivity and specificity in detecting and locating a parathyroid adenoma, showing that it is a very reliable preoperative imaging technique in primary hyperparathyroidism. Copyright (c) 2017 Wolters Kluwer Health, Inc. All rights reserved.

Purpose: To assess the sensitivity and specificity of 99mTc-Sestamibi/123I-Iodide dual isotope subtraction SPECT-CT in identifying and localising parathyroid adenomas in patients with primary hyperparathyroidism.

Background:: Positron emission tomography computerized tomography (PET-CT) is useful in radiotherapy planning for lung cancer. However, its role in malignant pleural mesothelioma (MPM) is unknown. Objectives:: This exploratory study investigated the possible role for PET-CT in radiotherapy planning for MPM. Patients and Methods:: Patients receiving radiotherapy for the treatment of pain in MPM, had fluorodeoxyglucose (FDG) PET-CT scanning in addition to their standard CT scan. PET-CT images were then fused with CT planning images, termed Planning-PET-CT. Target volume delineation was undertaken first using CT and subsequently incorporated Planning-PET-CT. Planning treatment volume (PTV), conformity index (CI), mean distance to conformity (MDC), center of gravity distance (CGD) and standard uptake values (SUV) were examined. Results:: Sixteen patients were recruited into the study. PET-CT upstaged nine patients. No association between SUV max and either survival or pain response was seen. Volumes contoured using Planning-PET-CT differed markedly from those outlined using CT alone as shown by the following parameters: CI = 0.3 (0.24 - 0.38). MDC = 21.47 (16.73 - 33.70) and CGD = 16.40 (11.80 - 33.87). The median percentage of over contouring was 44.00% (34.33 - 72.50) with 46.67% under contoured (34.00 - 55.00). Conclusions:: PET-CT alters the position of the PTV in MPM and upstaged a proportion of patients. Further work to elucidate the role of Planning-PET-CT in target volume definition is justified.

18-fluorine fluorodeoxyglucose (18F-FDG) positron emission tomography–computed tomography (PET–CT) has an established role for the characterization of solitary pulmonary nodules (SPN). Visual assessment of nodule morphology, together with maximum standardized uptake value (SUVmax), is used to estimate likelihood of malignancy. We correlated SUVmax value with pathology of SPN and assessed diagnostic accuracy in differentiating malignant from benign nodule, using 2.5 as threshold SUVmax.

Objectives Paraneoplastic syndromes (PNS) are remote manifestations of malignancy unrelated to tumour invasion or metastases. They pose a diagnostic challenge because of diverse presentations. F-18-Fluorodeoxyglucose (F-18-FDG) PET-CT is an emerging technique for the detection of malignancy; however, there is a paucity of data with regard to its role in the evaluation of PNS and its relation to pretest clinical risk.Methods A retrospective review of the database at the West of Scotland PET centre from 2007 to 2010 was conducted. Data extracted included demographics, clinical and pathological diagnosis, presence of classical syndromes, cross-sectional imaging, PET-CT imaging and management changes. A clinical scoring system was constructed to evaluate the pretest likelihood of having PNS, and the impact of a subsequent positive PET-CT scan was evaluated.Results A total of 68 consecutive patients with a median age (range) of 58 (23-82) years, of whom 44 (65%) were female, were included. Symptoms were neurological in 55 (81%), musculoskeletal in five (7%), endocrine in three (4%) and constitutional in five (7%) patients. Forty-three (620/o) patients had a classical paraneoplastic syndrome and 34 (50%) had positive biomarkers. Eighteen (26%) patients had a positive PET-CT result. PET-CT was concordant with the clinical scoring in 49 (72%) patients; it upgraded the score in eight (12%) patients, and downgraded the score in 11 (16%) patients. Eight (12%) patients had confirmed malignancy. PET-CT was estimated to have 100% sensitivity, 82% specificity, 42% positive predictive value and 100% negative predictive value.Conclusion PET-CT is a highly sensitive and specific imaging technique in the evaluation of PNS and adds confidence to clinical likelihood. Nucl Med Commun 33:872-880 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

541 Objectives The interpretation of Tc-99m MDP planar bone scintigraphy can be limited by its low sensitivity in lytic metastases and the lack of anatomical details. SPECT-CT allows accurate localisation of functional changes as well as better visualisation of destructive lesions and soft tissue infiltration. Our aim was to review the impact of SPECT/CT bone scan in the assessment of bone metastases in breast cancer. Methods 449 women with breast cancer (mean age 63 years, range 28-98) who had bone scans for assessment of bone metastases in our center during 2008 were retrospectively reviewed. Patients had planar bone scan first and in case of inconclusive lesions SPECT/CT was proceeded for better localisation and characterisation. Scan results were compared with follow up clinical records; further imaging results and pathological staging information. Results 368/449 cases (82%) had planar imaging alone, which gave conclusive results in 346/449 cases (77%). Remaining 103/449 cases (23%) had inconclusive planar scans: proceeding to SPECT-CT in 81/449 cases (18%) or suggesting further radiology correlation in 21/449 cases (5%). With the addition of SPECT/CT the overall inconclusive results of the group decreased to 26/449 cases (6%). SPECT/CT demonstrated true positive bone metastases in 16/81 patients including lytic diseases and critical spinal canal invasion. Hot spots were localised to benign bone/joint diseases in 53 patients. There were 5 inconclusive results, 5 false positives and 2 false negatives in the SPECT/CT group. The sensitivity, specificity and accuracy for SPECT/CT group (n=81) was 89%, 91% and 90%; for the whole group (n=449) was 94%, 97% and 91%. Conclusions SPECT/CT improves the diagnostic accuracy of bone scan and reduces the requirement for further imaging in the assessment of bone metastases in breast cancer

Background and aim: Radio-labelled Aprotinin has been shown to bind with amyloid fibrils in vitro as well as in vivo. The aim was to test the usefulness of Tc-99m-Aprotinin imaging in systemic amyloidosis. Methods: Thirty-five cases who had Tc-99m-Aprotinin scans for the assessment of systemic amyloidosis were reviewed retrospectively. Eighteen had biopsy-proven amyloidosis and 17 were controls (amyloidosis was excluded by negative biopsies and non-invasive tests). Five of 18 patients with amyloidosis had final diagnosis of cardiac amyloid. Results: Physiological uptake of Tc-99m-Aprotinin was noted in the urinary tract (kidneys and bladder) and in the liver of all patients and controls; and non-specific uptake of Tc-99m-Aprotinin was visualised in the spleen and oro-facial structures in the majority of both groups. Myocardial Tc-99m-Aprotinin uptake was noted in all five patients with final diagnosis of cardiac amyloidosis and in none of the 30 subjects who did not have cardiac amyloid. The median heart to background uptake ratio was 2.0 in cardiac amyloid patients and 1.1 in subjects without cardiac amyloid (P = 0.0004). Single Photon Emission Tomography (SPECT) studies of the thorax confirmed that the site of uptake lay within the myocardium. In the amyloidosis group, site-specific Tc-99m-Aprotinin uptake was also identified in the subcutaneous tissue of the legs and in a breast nodule shown to be positive for amyloidosis on biopsy. Conclusions: Tc-99m-Aprotinin imaging may be a useful non-invasive method for the assessment of the presence and extent of extra-abdominal amyloid, particularly cardiac amyloidosis. It has little role in diagnosis of amyloidosis involving the oro-facial and abdominal structures.