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.

Randomized double-blind placebo-controlled trial of perhexiline in heart failure with preserved ejection fraction syndrome

Recently heart failure with preserved ejection fraction (HFpEF) has emerged as a huge epidemic. Increasing evidence shows the role of energy deficiency in the pathophysiology of HFpEF. In the current study, we hypothesize that the use of metabolic modulator perhexiline would correct myocardial energy deficiency and improve exercise capacity and diastolic abnormalities in patients with this syndrome.

Optimized response prediction in esophagogastric junction adenocarcinomas (EGJAc) with combination of molecular biomarkers and FDG-PET

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Background: Predictive biomarkers (BMs) for EGJAc would optimise treatment selection and avoid ineffective therapy. Metabolic response (MR) defined as >35% decrease in tumour FDG Standardized Uptake Value (SUV) between day 0 & 14 after starting chemotherapy has a high negative predictive value (95%) for response, but limited positive predictive value (50%). Combining molecular BMs with FDG-PET may optimise response prediction. We used global gene expression profiling (GEP) to identify molecular BMs that when combined with FDG-PET would improve predictive accuracy.

Methods: 28 patients with locally advanced or metastatic EGJAc received platinum based chemotherapy (PBC). FDG PET CT scans were at day 0 and day 14 and GEP (Affymetrix ST1.0 Exon Genechips) on day 0 tumour biopsies. A tissue microarray comprising an independent set of 154 OGJAc who underwent surgery +/− neoadjuvant PBC was used with immunohistochemistry (IHC) for qualification of GEP results. Radiological response was assessed after 3/ 4 cycles of PBC by RECISTv1.1.

Results: We identified a gene expression signature (86 genes) that separated FDG PET MR patients(>35% fall SUV day 0 to14) into those that do and do not go on to have a RECIST response. In cross validation, this signature correctly predicted response in 28/28. Pathway analysis on GEP data identified potential novel mechanisms of response, including the Leptin pathway. Leptin mRNA was higher in FDG metabolic responders who did not have a RECIST response compared to those that did. In the independent set, high Leptin protein by IHC was strongly associated with lack of histopathologic response to neoadjuvant PBC (n=64, p=0.002). High Leptin expression also had a therapy independent prognostic effect with longer survival in the absence of histopathologic response or with no neoadjuvant PBC and in low Leptin patients poor survival was mitigated to a certain extent by neoadjuvant PBC (n=154, Kaplan-Mieier, log rank p=0.041 & Cox MVA p=0.040).

Conclusions: Molecular biomarkers (Leptin in particular) combine with FDG PET to optimise response prediction in EGJAc. Further investigation of this combined molecular and imaging approach is warranted.