A comparative analysis: international variation in PET-CT service provision in oncology-an International Cancer Benchmarking Partnership study.

OBJECTIVE: To explore differences in position emission tomography-computed tomography (PET-CT) service provision internationally to further understand the impact variation may have upon cancer services. To identify areas of further exploration for researchers and policymakers to optimize PET-CT services and improve the quality of cancer services. DESIGN: Comparative analysis using data based on pre-defined PET-CT service metrics from PET-CT stakeholders across seven countries. This was further informed via document analysis of clinical indication guidance and expert consensus through round-table discussions of relevant PET-CT stakeholders. Descriptive comparative analyses were produced on use, capacity and indication guidance for PET-CT services between jurisdictions. SETTING: PET-CT services across 21 jurisdictions in seven countries (Australia, Denmark, Canada, Ireland, New Zealand, Norway and the UK). PARTICIPANTS: None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): None. RESULTS: PET-CT service provision has grown over the period 2006-2017, but scale of increase in capacity and demand is variable. Clinical indication guidance varied across countries, particularly for small-cell lung cancer staging and the specific acknowledgement of gastric cancer within oesophagogastric cancers. There is limited and inconsistent data capture, coding, accessibility and availability of PET-CT activity across countries studied. CONCLUSIONS: Variation in PET-CT scanner quantity, acquisition over time and guidance upon use exists internationally. There is a lack of routinely captured and accessible PET-CT data across the International Cancer Benchmarking Partnership countries due to inconsistent data definitions, data linkage issues, uncertain coverage of data and lack of specific coding. This is a barrier in improving the quality of PET-CT services globally. There needs to be greater, richer data capture of diagnostic and staging tools to facilitate learning of best practice and optimize cancer services.

Treatment of classical Hodgkin lymphoma in young adults aged 18-30 years with a modified paediatric Hodgkin lymphoma protocol. Results of a multicentre phase II clinical trial (CRUK/08/012).

This phase II trial was designed to determine the safety and efficacy of a modified paediatric risk-stratified protocol in young adults (18-30 years) with classical Hodgkin Lymphoma. The primary end-point was neurotoxicity rate. The incidence of grade 3 neurotoxicity was 11% (80% CI, 5-19%); a true rate of neuropathy of >15% cannot be excluded. Neuropathy and associated deterioration in quality of life was largely reversible. The overall response rate was 100% with 40% complete remission (CR) rate. Twelve months disease-free survival (DFS) was 91%. We demonstrate that a risk-stratified paediatric combined modality treatment approach can be delivered to young adults without significant irreversible neuropathy.

PET-CT Surveillance versus Neck Dissection in Advanced Head and Neck Cancer.

BACKGROUND: The role of image-guided surveillance as compared with planned neck dissection in the treatment of patients with squamous-cell carcinoma of the head and neck who have advanced nodal disease (stage N2 or N3) and who have received chemoradiotherapy for primary treatment is a matter of debate. METHODS: In this prospective, randomized, controlled trial, we assessed the noninferiority of positron-emission tomography-computed tomography (PET-CT)-guided surveillance (performed 12 weeks after the end of chemoradiotherapy, with neck dissection performed only if PET-CT showed an incomplete or equivocal response) to planned neck dissection in patients with stage N2 or N3 disease. The primary end point was overall survival. RESULTS: From 2007 through 2012, we recruited 564 patients (282 patients in the planned-surgery group and 282 patients in the surveillance group) from 37 centers in the United Kingdom. Among these patients, 17% had nodal stage N2a disease and 61% had stage N2b disease. A total of 84% of the patients had oropharyngeal cancer, and 75% had tumor specimens that stained positive for the p16 protein, an indicator that human papillomavirus had a role in the causation of the cancer. The median follow-up was 36 months. PET-CT-guided surveillance resulted in fewer neck dissections than did planned dissection surgery (54 vs. 221); rates of surgical complications were similar in the two groups (42% and 38%, respectively). The 2-year overall survival rate was 84.9% (95% confidence interval [CI], 80.7 to 89.1) in the surveillance group and 81.5% (95% CI, 76.9 to 86.3) in the planned-surgery group. The hazard ratio for death slightly favored PET-CT-guided surveillance and indicated noninferiority (upper boundary of the 95% CI for the hazard ratio, <1.50; P=0.004). There was no significant difference between the groups with respect to p16 expression. Quality of life was similar in the two groups. PET-CT-guided surveillance, as compared with neck dissection, resulted in savings of £1,492 (approximately $2,190 in U.S. dollars) per person over the duration of the trial. CONCLUSIONS: Survival was similar among patients who underwent PET-CT-guided surveillance and those who underwent planned neck dissection, but surveillance resulted in considerably fewer operations and it was more cost-effective. (Funded by the National Institute for Health Research Health Technology Assessment Programme and Cancer Research UK; PET-NECK Current Controlled Trials number, ISRCTN13735240.).

Management of advanced nodal disease in patients treated with primary chemoradiotherapy.

PURPOSE OF REVIEW: The management of advanced nodal disease in patients treated with chemoradiotherapy has been a controversial topic for many years. New data have recently been reported, including the results of a multicentre randomized trial making this review timely. RECENT FINDINGS: The PET-NECK trial showed that PET-computer tomography (CT) surveillance is as effective as planned neck dissection in terms of overall survival, but results in much fewer neck dissections, less complications and is more cost effective. Cost-effectiveness data from a single centre study demonstrated that strategies that include PET-CT were more effective than CT-alone-guided strategies. SUMMARY: There is now level 1 evidence to support image-guided surveillance strategies as the standard of care for advanced nodal disease in patients treated with primary chemoradiotherapy.

Bevacizumab and Combination Chemotherapy in rectal cancer Until Surgery (BACCHUS): a phase II, multicentre, open-label, randomised study of neoadjuvant chemotherapy alone in patients with high-risk cancer of the rectum.

BACKGROUND: In locally advanced rectal cancer (LARC) preoperative chemoradiation (CRT) is the standard of care, but the risk of local recurrence is low with good quality total mesorectal excision (TME), although many still develop metastatic disease. Current challenges in treating rectal cancer include the development of effective organ-preserving approaches and the prevention of subsequent metastatic disease. Neoadjuvant systemic chemotherapy (NACT) alone may reduce local and systemic recurrences, and may be more effective than postoperative treatments which often have poor compliance. Investigation of intensified NACT is warranted to improve outcomes for patients with LARC. The objective is to evaluate feasibility and efficacy of a four-drug regimen containing bevacizumab prior to surgical resection. METHODS/DESIGN: This is a multi-centre, randomized phase II trial. Eligible patients must have histologically confirmed LARC with distal part of the tumour 4-12 cm from anal verge, no metastases, and poor prognostic features on pelvic MRI. Sixty patients will be randomly assigned in a 1:1 ratio to receive folinic acid + flurourcil + oxaliplatin (FOLFOX) + bevacizumab (BVZ) or FOLFOX + irinotecan (FOLFOXIRI) + BVZ, given in 2 weekly cycles for up to 6 cycles prior to TME. Patients stop treatment if they fail to respond after 3 cycles (defined as ≥ 30 % decrease in Standardised Uptake Value (SUV) compared to baseline PET/CT). The primary endpoint is pathological complete response rate. Secondary endpoints include objective response rate, MRI tumour regression grade, involved circumferential resection margin rate, T and N stage downstaging, progression-free survival, disease-free survival, overall survival, local control, 1-year colostomy rate, acute toxicity, compliance to chemotherapy. DISCUSSION: In LARC, a neoadjuvant chemotherapy regimen - if feasible, effective and tolerable would be suitable for testing as the novel arm against the current standards of short course preoperative radiotherapy (SCPRT) and/or fluorouracil (5FU)-based CRT in a future randomised phase III trial. TRIAL REGISTRATION: Clinical trial identifier BACCHUS: NCT01650428.

Eligibility for 177Lu-PSMA Therapy Depends on the Choice of Companion Diagnostic Tracer: A Comparison of 68Ga-PSMA-11 and 99mTc-MIP-1404 in Metastatic Castration-Resistant Prostate Cancer.

177Lu-prostate-specific membrane antigen-617 (177Lu-PSMA-617) is an effective therapy for metastatic castration-resistant prostate cancer (mCRPC), with evidence of improved survival over standard care. The VISION trial inclusion criteria required a metastatic lesion-to-liver ratio of greater than 1 on 68Ga-PSMA-11 PET scans. We aimed to determine whether an equivalent ratio is suitable for a SPECT tracer, 99mTc-MIP-1404, and to compare lesion and lesion-to-normal-organ ratios between the 2 radiotracers. Methods: Two cohorts of patients with mCRPC matched for age, prostate-specific antigen level, and total Gleason score, with either 99mTc-MIP-1404 SPECT/CT (n = 25) or 68Ga-PSMA-11 PET/CT (n = 25) scans, were included for analysis. Up to 3 lesions in each site (prostate/prostate bed, lymph nodes, bone and soft-tissue metastases) as well as normal liver, parotid gland, spleen, and mediastinal blood-pool SUVmax were measured. Results: 99mTc-MIP-1404 SPECT lesion SUVmax was not significantly different from 68Ga-PSMA-11 PET (median, 18.2 vs. 17.3; P = 0.93). However, 99mTc-MIP-1404 liver SUVmax was higher (median, 8.5 vs. 5.8; P = 0.002) and lesion-to-liver ratios were lower (median, 2.7 vs. 3.5; P = 0.009). There was no significant difference in parotid gland or splenic SUVmax or lesion-to-parotid gland ratios between the 2 tracers although there was a small difference in lesion-to-spleen ratios (P = 0.034). Conclusion: There are differences in biodistribution and, in particular, liver activity, between 68Ga-PSMA-11 and 99mTc-MIP-1404. Therefore, if 99mTc-MIP-1404 is used to assess eligibility for 177Lu-PSMA-617 therapy, a lower adjusted lesion-to-liver ratio should be used.

PET-CT for Staging and Detection of Recurrence of Head and Neck Cancer.

FDG PET-CT is one the main investigations for squamous cell (Sq) head and neck (H&N) cancer patients. FDG PET-CT has a key role for the staging of patients with T4 cancer of the hypopharynx and nasopharynx and patients with N3 nodal disease. It is effective in detecting recurrent disease accurately. In addition, it has an emerging role in the surveillance of Sq H&N cancer survivors. In patients with advanced neck nodal disease treated with chemoradiotherapy, there is compelling evidence that patients with no FDG uptake in the neck 12 weeks following completion of treatment do not require neck dissection. There is considerable interest in using FDG PET-CT for develop more effective clinical pathways for the surveillance of Sq H&N cancer. Currently, the detection rate of recurrence in patients who attend regular clinical follow-up is poor, less than 1% in asymptomatic patients. FDG PET-CT may enable survivors to be stratified into groups based on the likelihood of having recurrent disease. Optimal surveillance pathways can be developed, reserving most intense imaging regimes and most frequent follow-up for survivors at high risk of recurrence. FDG PET CT is sometimes considered for patients with non Sq H&N cancer. If used in this context, a baseline FDG PET-CT should be done to ensure that the tumour is avid. Most H&N malignant tumours are avid. However, salivary gland cancers, and tumours with muco-epidermoid, adenoid cystic and clear cell histology show paucity of FDG avidity, especially when they recur. In addition, peri-neural invasion cannot be detected reliably with FDG PET-CT.

The COVID-19 pandemic: impact on NHS England PET-CT services and lessons learnt.

PURPOSE: The purpose of the study was to examine the impact of the first wave of COVID-19 on National Health Service (NHS) 18F-fluorodeoxyglucose positron emission tomography computed tomography (FDG PET-CT) scanning activity across England. METHODS: Monthly FDG PET-CT scanning activity was collected from 41/48 NHS England provider sites. Data from 31/41 sites were stratified by nononcology/oncology, cancer type, with lung cancer and lymphoma split into specific indications, turn-around times and delays due to radiotracer. RESULTS: In April and May 2020, a 32 and 31% decrease in activity was observed, a larger decrease for noncancer compared with cancer FDG PET-CT. In June 2020, activity started to recover with 6% fewer scans recorded compared with June 2019. Of the six most common indications, lung and oesophageal cancer had the largest decrease in activity and slowest recovery. Lymphoma and melanoma showed the smallest decrease and fastest recovery. Lung cancer scans for initial diagnosis/staging saw the largest fall and slowest recovery compared with scans for known lung cancer. There was no percentage increase in overall turn-around time compared with the same months in 2019, and no increase in turn-around time of more than 7 working days due to FDG supply during April and May 2020 compared with the 3 previous months. CONCLUSIONS: There is no correlation between FDG PET-CT activity (fall and recovery) in England and the ability to provide the service by NHS England. It most likely reflects a combination of changes in health-seeking behaviour, NHS health policy and a decrease in the use of investigations that carry a high risk of COVID-19 transmission.

An overview of nuclear medicine research in the UK and the landscape for clinical adoption.

BACKGROUND AND OBJECTIVES: Nuclear medicine contributes greatly to the clinical management of patients and experimental medicine. This report aims to (1) outline the current landscape of nuclear medicine research in the UK, including current facilities and recent or ongoing clinical studies and (2) provide information about the available pathways for clinical adoption and NHS funding (commissioning) of radiopharmaceuticals. METHODS: Evidence was obtained through database searches for UK-based nuclear medicine clinical studies and by conducting a questionnaire-based survey of UK radiopharmaceutical production facilities. A recent history of clinical commissioning, either through recommendations from the National Institute for Health and Care Excellence (NICE) or through NHS specialised services commissioning, was compiled from publicly available documents and policies. RESULTS: The collected data highlighted the UK's active nuclear medicine research community and recent investment in new facilities and upgrades. All commissioning routes favour radiopharmaceuticals that have marketing authorisation and since 2017 there has been a requirement to demonstrate both clinical and cost-effectiveness. Whilst radiopharmaceuticals for molecular radiotherapy are well suited to these commissioning pathways, diagnostic radiotracers have not historically been assessed in this manner. CONCLUSIONS: We hope that by collating this information we will provide stimulus for future discussion and consensus statements around this topic.

Radionuclide calibrator intercomparison study of clinical PET centres in England to a single traceable 68Ge syringe source.

OBJECTIVES: The aim of this study was to characterize national variation in radionuclide calibrator activity response to a single National Institute of Standards and Technology (NIST) traceable reference Ge source used as a surrogate for F at clinical PET centres in England using National Physical Laboratory approved techniques. METHODS: Readings from 20 instruments at 13 centres using local F and Ge factor settings were recorded with the source located in vial and syringe positions. Ten repeat measurements were conducted to investigate repeatability using % coefficient of variability (COV). Comparison ratios to investigate accuracy were made between calibrator responses and decay-corrected NISTref reference activity for syringe and vial position measurements. RESULTS: The maximum %COV was 0.79%, while 90, 95 and 80% of calibrators conformed to 5% accuracy for F syringe, Ge syringe and Ge vial position readings, respectively. We revealed a trend towards reduced bias in measurements using Veenstra devices for F and using Capintec devices for Ge factor settings. CONCLUSIONS: This study demonstrated good repeatability in local device measurements. In total, 70% of English calibrators tested and 88% of all measurements performed achieved 5% accuracy. While statistically significant bias was exhibited between different vendor equipment dependent upon radioisotope selected, our study recommends regular traceability checks for optimum instrument performance conducted within National Metrology Institutes guidelines.

Positron emission tomography PET/CT harmonisation study of different clinical PET/CT scanners using commercially available software.

OBJECTIVES: Harmonisation is the process whereby standardised uptake values from different scanners can be made comparable. This PET/CT pilot study aimed to evaluate the effectiveness of harmonisation of a modern scanner with image reconstruction incorporating resolution recovery (RR) with another vendor older scanner operated in two-dimensional (2D) mode, and for both against a European standard (EARL). The vendor-proprietary software EQ•PET was used, which achieves harmonisation with a Gaussian smoothing. A substudy investigated effect of RR on harmonisation. METHODS: Phantom studies on each scanner were performed to optimise the smoothing parameters required to achieve successful harmonisation. 80 patients were retrospectively selected; half were imaged on each scanner. As proof of principle, a cohort of 10 patients was selected from the modern scanner subjects to study the effects of RR on harmonisation. RESULTS: Before harmonisation, the modern scanner without RR adhered to EARL specification. Using the phantom data, filters were derived for optimal harmonisation between scanners and with and without RR as applicable, to the EARL standard. The 80-patient cohort did not reveal any statistically significant differences. In the 10-patient cohort SUVmax for RR > no RR irrespective of harmonisation but differences lacked statistical significance (one-way ANOVA F(3.36) = 0.37, p = 0.78). Bland-Altman analysis showed that harmonisation reduced the SUVmax ratio between RR and no RR to 1.07 (95% CI 0.96-1.18) with no outliers. CONCLUSIONS: EQ•PET successfully enabled harmonisation between modern and older scanners and against the EARL standard. Harmonisation reduces SUVmax and dependence on the use of RR in the modern scanner. ADVANCES IN KNOWLEDGE: EQ•PET is feasible to harmonise different PET/CT scanners and reduces the effect of RR on SUVmax.

Prognostic value of 18FDG PET/CT volumetric parameters in the survival prediction of patients with pancreatic cancer.

PURPOSE: To investigate the value of 18 FDG PET/CT volumetric parameters in the prediction of overall survival (OS) in patients with pancreatic cancer and also, assess their independence relative to well-established clinico-pathological variables. METHODS: We conducted a retrospective analysis of patients with a confirmed diagnosis of pancreatic cancer who underwent 18 FDG PET/CT. The tumour maximum standardised uptake value (SUVmax) in addition to SUVmean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated. The prognostic value of 18 FDG PET/CT and clinico-pathological parameters for OS were assessed using univariate and multivariable analyses. RESULTS: A sum of 89 patients were analysed in this study. Median survival for patients categorised as having high TLG (≥55) and low TLG (<55) was 18 vs 5 months (p < 0.001). Similarly, the respective high vs low SUVmean, MTV and SUVmax were 18 vs 6 months (p = 0.001), 16 vs 6 months (p = 0.002) and 18 vs 6 months (p = 0.001). Univariate analysis showed SUVmax, SUVmean, MTV, TLG, tumour size, tumour differentiation and presence of distant metastasis as prognostic factors for OS. On multivariable analysis, TLG (HR 2.0, 95% CI 1.26-3.18, p = 0.004) and the presence of distant metastasis (HR 3.37, 95% CI 1.97-5.77, p < 0.001) emerged as independent prognostic factors. Subgroup analysis identified TLG as the only significant PET metric after adjusting for the presence of distant metastasis. CONCLUSIONS: 18 FDG PET/CT is a useful tool in the preoperative evaluation of patients with pancreatic cancer. Tumour TLG offer an independent prognostic value in both potentially operable and metastatic disease settings.

Pharmacogenomics in the UK National Health Service: opportunities and challenges.

Despite increasing interest in pharmacogenomics, and the potential benefits to improve patient care, implementation into clinical practice has not been widespread. Recently, there has been a drive to implement genomic medicine into the UK National Health Service (NHS), largely spurred on by the success of the 100,000 Genomes Project. The UK Pharmacogenetics and Stratified Medicine Network, NHS England and Genomics England invited experts from academia, the healthcare sector, industry and patient representatives to come together to discuss the opportunities and challenges of implementing pharmacogenomics into the NHS. This report highlights the discussions of the workshop to provide an overview of the issues that need to be considered to enable pharmacogenomic medicine to become mainstream within the NHS.

Effect of PET Image Reconstruction Techniques on Unexpected Aorta Uptake

Objectives: To determine if unexpected aorta uptake seen in some patients is influenced by popular modern reconstruction algorithms using semi-quantitative and qualitative analysis. Methods: Twenty-five consecutive patients without suspected vascular disease were selected for 18F-FDG positron emission tomography/ computed tomography (PET/CT) scanning and images of the aorta were created using iterative reconstruction (IT), IT + time of flight (TOF), IT + TOF + point spread function correction (referred collectively as UHD) with and without metal artefact reduction (MAR) algorithms. An experienced radiologist created aorta and blood pool (BP) regions of interests then copied these to all reconstructions for accurate positioning before recording target aorta standardized-uptake-values (SUVmax) and background BP SUVmean. Furthermore, target-to-background ratio (TBRmax) was defined by aorta SUVmax-to-BP SUVmean ratio for more analysis. Results: For aorta SUVmax with IT, IT + TOF, UHD, UHD + MAR reconstructions the mean ± standard deviation recorded were 2.15±0.43, 2.25±0.51, 2.25±0.45 and 2.09±0.4, respectively. Values for BP SUVmean were 1.61±0.31, 1.58±0.28, 1.58±0.28 and 1.47±0.25, respectively. Likewise, for TBRmax these were 1.35±0.19, 1.43±0.21, 1.43±0.19, 1.43±0.18, respectively. ANOVA analysis revealed no significant differences for aorta SUVmax (F(0.86) p=0.46), BP SUVmean (F(1.22) p=0.31) or TBRmax (F(0.99) p=0.4). However, the qualitative visual analysis revealed significant differences between IT + TOF with UHD (p=0.02) or UHD + MAR (p=0.02). Conclusion: Reconstruction algorithm effect on aorta SUVmax or BP SUVmean or TBRmax was not statistically significant. However, qualitative visual analysis showed significant differences between IT + TOF as compared with UHD or UHD + MAR reconstructions. Harmonization of techniques with a larger patient cohort is recommended in future clinical trials.

UK guidelines on 18F-fluciclovine PET/CT in prostate cancer imaging.

The purpose of these guidelines is to assist specialists in Nuclear Medicine and Radionuclide Radiology in recommending, performing, interpreting and reporting F-fluciclovine PET/computed tomography. It should be recognised that adherence to the guidance in this document will not assure an accurate diagnosis or a successful outcome. These guidelines will assist individual departments in the formulation of their own local protocols. The guidelines apply to studies on adults. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources and the needs of the patient in order to deliver effective and safe medical care.

[(64)Cu]diacetyl-bis(N(4)-methyl-thiosemicarbazone) - a radiotracer for tumor hypoxia.

Positron emission tomography scanning using the radiotracer-labeled copper (II)-diacetyl-bis(N(4)-methylthiosemicarbazone) has been proposed as a noninvasive method for evaluating tumor hypoxia. Tumor hypoxia results in a more aggressive tumor phenotype together with resistance to both radiotherapy and chemotherapy. A noninvasive technique for evaluation of tumor hypoxia is not currently available. Validation of this technique would provide clinicians with a tool for determining the most appropriate cancer therapy, prognostic information, and subvolume delineation for the radiotherapy dose escalation to the radioresistant hypoxic regions within a tumor. This review article describes the background to the development of this tracer, its proposed retention mechanism, biodistribution dosimetry and the preclinical and clinical studies to date. It outlines the potential use of this radiotracer for imaging in the field of oncology.

Role of PET/PET CT in the staging and restaging of thoracic oesophageal cancer and gastro-oesophageal cancer: a literature review.

BACKGROUND: Current evidence for the use of FDG PET/PET-CT in staging thoracic oesophageal and GOJ cancer is reviewed. METHODS: PubMed, Medline, Embase (1988-November 2006) and the Cochrane database identified studies in which FDG PET and PET CT were used for the assessment of thoracic and GOJ cancer. RESULTS: Conventional assessment remains the mainstay for evaluating the primary site. EUS is used for assessing the primary site, but when EUS is incomplete or not tolerated FDG PET CT is invaluable. The major of advantage of FDG PET CT lies in the ability to detect metastatic disease beyond the celiac axis. There is growing evidence to show that FDG PET CT is useful for assessment of treatment response. FDG PET CT will also detect other occult primary cancers. CONCLUSIONS: The contribution of FDG PET CT to the investigation of patients with primary thoracic oesophageal and GOJ cancer has resulted in improved staging, so providing the ability to optimise treatment.

The effects of N-butylscopolamine on bowel uptake: an 18F-FDG PET study.

PURPOSE: To determine the effect of N-butylscopolamine (buscopan) on intestinal uptake of 18F-FDG. METHODS: Seventy-two oncology patients were prospectively studied and 36 patients received 20 mg of N-butylscopolamine intravenously. All patients were imaged with a Siemens PET scanner. After a 4-h fast, patients were injected with FDG and then scanned 1 h post-injection. Two experienced observers interpreted all studies independently. Scans were scored visually, grading 18F-FDG bowel uptake (0-3) and the influence of bowel uptake to a lack of confidence in scan reporting (0-3). For semi-quantitative comparison, the ratio of radiotracer uptake in the bowel to mean liver (B/L) was obtained. RESULTS: All results were in favour of N-butylscopolamine. For the qualitative data, a Mann-Whitney test was used. Results for contribution of bowel uptake to lack of confidence in reporting scores, showed P=0.0001 for observer 1, and P=0.002 for observer 2; for degree of uptake in bowel scores, observer 1 results gave a value of P=0.0001 and observer 2 P=0.001. For agreement of uptake scores, Kappa index showed 'moderate' agreement between observers for the control group and 'fair' agreement for the N-butylscopolamine group. For contribution of bowel uptake to lack of confidence scores, there was 'very good' agreement for the control group and 'fair' agreement for the N-butylscopolamine group. The semi-quantitative effect of N-butylscopolamine on bowel-to-liver ratio was determined using an unrelated t-test that produced significance at the level of P<0.001. CONCLUSION: This study showed that administration of N-butylscopolamine can reduce artefacts in the bowel during 18F-FDG PET, and can potentially improve accuracy of 18F-FDG PET reporting.

Correction to: The Edinburgh Consensus: preparing for the advent of disease-modifying therapies for Alzheimer's disease.

Since the publication of this article [1], it has come to the attention of the authors that information for one of the authors was not included in the competing interests section. Craig Richie has declared potential competing interests with the following companies; Janssen, Eisai, Pfizer, Eli Lilly, Roche Diagnostics, Boeringher Ingleheim, Novartis, AC Immune, Ixico, Aridhia, Amgen, Berry Consultants, Lundbeck, Sanofi, Quintiles (IQVIA) and Takeda. The full competing interests section for this article can be found below.